A variety of bite-raising appliances are involved in contemporary orthodontic treatment depending on an individual’s malocclusion and the objectives of treatment. The appliances can affect the dentoskeletal and neuromuscular system over the short and long terms. Most of the bite-raising appliances do not change the immediate muscle response at rest, but temporarily decreases the activity during maximum clenching. The activity returns to the previous state after a period of treatment in long-term observation. The purpose of this article is to compare similarities and contrast differences between various types of orthodontic bite-raising appliances, both in the short and long term. Factors affecting the masticatory muscle responses included vertical dimension, number of occlusal contacts, jaw relocation, material, and wearing duration. Moreover, suggestions for further studies are also discussed.

The aim of this article is to evaluate the effect of drinking green tea on antimicrobial activity and wound healing after the surgical removal of an impacted mandibular third molar. The study was carried out as a randomized
controlled clinical trial. Twenty patients with impacted mandibular third molars were randomly divided into two equal groups (drinking green tea or drinking water) after lower third molar removal. The same conditions were applied to all the patients, including the interrupted sutures were given by 4-0 silk in both groups. The outcome variables were soft tissue healing and number of colony-forming units per milliliter. There were 3 males and 17 females, in the age range of between 19-31 years. The mean of soft tissue healing index was higher for the green tea group at all times but did not show statistical significance. The mean of microbial loads was lower in the green tea group on a postoperative day 7 (10-5 CFU/mL in concentration). The present study found that drinking green tea can decrease the bacterial count in the suture and may improve wound healing after the surgical removal of lower third molars.

The objective of this study was to establish the cephalometric norms of skeletal and dental for Thai children between 7-10 years of age by means of various lateral cephalometric analyses of soft tissue. The materials of 84
children (44 boys, 40 girls) with an average age of 9.97±0.78 years. The subjects were selected on the basis of (1) Presence of first molars and central incisors, (2) No congenital missing teeth and no premature loss of teeth, (3)
Angle’s Class I molar relationship, normal overbite and overjet, (4) Good dental alignment or having crowding or spacing not exceed 3 mm, (5) No previous history of orthodontic treatment. Results of this study showed that cephalometric standard means of Thai children are differ from previous studies, that were done in Thai adults or foreign children. The standard means from this study can be clinically applied to the diagnosis, treatment planning and treatment in young Thai orthodontic patients.

This study aimed to compare the cyclic fatigue resistance of four single-file Nickel-Titanium systems in both single curvature and double curvature canals. Fifty samples (N=50) of One Curve, Hyflex EDM, WaveOne Gold Primary, and Reciproc Blue R25 instruments were tested. Simulated canals made of stainless steel with a single (60° angle of curvature and 5 mm radius of curvature) or double curvature (coronal curve, 60° angle of curvature and 5 mm radius of curvature; and apical curve, 70° angle of curvature and 2 mm radius of curvature) were used for testing. Each file specimen was tested until fracture occurred and time of failure recorded. The fracture surface was examined using a scanning electron microscope to investigate types of fracture. The data were statistically analyzed using Kruskal Wallis Post hoc Dunn tests with 95 % confidence level. Results showed that Hyflex EDM had statistically highest fatigue resistance in single curvature canal. One Curve had statistically lowest fatigue resistance in double curvature canal.

This study aimed to determine the prevalence of Enterococcus faecalis in root canal-treated teeth requiring retreatment and investigate its relationship with clinical parameters and the capacity for biofilm formation. Clinical
samples (N=41) from previously root canal-filled teeth that required retreatment were collected using paper points for culture and polymerase chain reaction assay to detect Enterococcus faecalis. Clinical and radiographical
examinations were performed to assess signs and symptoms, periapical lesions, quality of previous root filling and coronal restorations. Data were analyzed with Fisher’s Exact test. The prevalence of Enterococcus faecalis was 9.8 %
and 75.6 % by culture and polymerase chain reaction techniques, respectively. No significant association was observed between clinical parameters and Enterococcus faecalis in root canals (p>0.05), but Enterococcus faecalis was significantly associated with periapical lesion in cases that did not heal (n=19, p=0.035). In addition, clinical isolates of Enterococcus faecalis showed different levels of biofilm formation as examined by crystal violet staining. In conclusion, Enterococcus faecalis was frequently detected in root canal-filled teeth that required retreatment and they showed various levels of biofilm forming capacity.

The purpose of this study was to compare the accuracy of digital and conventional impression techniques for multiple implants in edentulous areas at different impression levels: the implant and abutment levels. An
edentulous mandibular model with five dental implants was fabricated to serve as a reference model (three anterior straight and two posterior angulated implants). Forty impressions were made at the implant and abutment levels using digital and conventional techniques (four cast groups, n = 10 each). Digital impressions were taken with an intraoral scanner. The custom open-tray splinted-impression coping technique was used for the conventional impression. All reference models and working casts were digitized to STL files using a high-resolution laboratory scanner, and the 3D-distances and angulations were measured using PolyWork software for assessing displacement from references. Two-way repeated-measures ANOVA was used to examine the differences between levels of impression and impression techniques and their interactions (α=.05). The Bonferroni post-hoc test and Wilcoxon-sign rank test were used to test differences in accuracy and precision between digital and conventional techniques (α=.05), and the results showed that significant differences were found between the level of impression, impression techniques, and their mutual interaction. For 3D-distance displacement, the implant level-digital impression showed lower trueness values than conventional impression overall (P<0.001). For angulation displacement, there was a significant difference in the conventional-implant level impression group (P=0.003). Overall, no differences were found between the reference model and the two techniques at the abutment level impressions (P=0.508, 1.000). In conclusion, impression techniques and levels of impression affected the transfer accuracy. The abutment level impression with the open-tray conventional technique was more accurate than the digital technique, while the digital technique demonstrated superior outcome in angulation transfer for angulated implants at implant-level impressions. However, the total distance and angulation displacement with both techniques were clinically acceptable.

A variety of commercial children’s toothbrushes are commercially available with different physical properties. The aim of this study was to evaluate the physical properties of commercial children’s toothbrushes, toothbrush wear, bristle-tip wear, and effect of brushing on primary enamel surfaces using a V8 cross-brushing machine, in vitro. Primary enamel specimens (2x2 mm2) were mounted in acrylic blocks (n=42) and randomly assigned to 6 groups:
CUdent (7mm), CUdent (8mm), Berman®, Colgate®, Fluocaril®, and Kodomo®. The specimens were mounted and brushed in a V8 cross-brushing machine for 100,000 strokes. Following brushing, the toothbrush-heads were measured to calculate the wear index and the bristle-tips were evaluated based on the Thai Industrial Standards (TIS). The specimens were measured for surface roughness and average mean depth using a profilometer. This study revealed that the wear index before brushing was 0.035–0.038 with no significant differences between groups. However, the wear index after brushing was 0.088–0.245 with significant difference between groups (p<0.001) and the post-hoc analysis revealed that the Fluocaril® and CUdent (8mm) groups had significantly higher index scores than the others. The percentage of acceptable bristle-tip before and after brushing was 90.67–94.67 and 78.2 –96.00, respectively. The surface roughness and average mean depth before brushing were 9.054–10.563 and 0.021–0.028 nm, respectively, and after brushing was 9.638–10.792 and 0.032–0.058 nm, respectively. No significant differences between groups were found before and after brushing. These findings indicate that the commercial children’s toothbrushes had similar physical properties. Furthermore, Fluocaril® and CUdent (8mm) groups were the most worn after brushing. All toothbrushes tested passed the TIS for acceptable bristle-tip before and after brushing. In addition, no significant abrasion of the primary enamel surfaces was found after brushing with the tested toothbrushes.

The study aimed to find an optimal concentrations of novel herbal mouthwashes which do not cause cytotoxicity to human gingival fibroblast-like cells (HGFs), according to ISO 10993-5, and to compare their cytotoxic effect to
CUdent Stevia Fluoride™ mouthwash on HGFs. Three herbal extracts, ginseng (G), peppermint (P), and licorice (L), were dissolved in 25% v/v diluted CUdent Stevia Fluoride™ mouthwash to find the maximum dissolution. An optimal concentration of each herbal extract was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The determined concentration was used to formulate the ginseng mouthwash solutions into two groups, ginseng-peppermint (GP) and ginseng-licorice (GL). Each group was tested once again by MTT assay to compare its cytotoxicity. One-sample t-test was used to analyze the determination of the cytotoxicity and one-way ANOVA to compare the cytotoxic effect between each group. The maximum dissolution of ginseng, peppermint, and licorice extract in CUdent Stevia Fluoride™ mouthwash was 5, 5, and 0.5 mg/mL respectively with no statistically significant cytotoxic effect (%viability ≥70%, p>0.05). When the novel mouthwashes were prepared, there was no statistically significant cytotoxic effect in any formulation (%viability ≥70%, p>0.05). Therefore, the cytotoxic effects on HGFs of every formulation were compared with CUdent Stevia Fluoride™ mouthwash, and they showed less cytotoxic effect (p<0.05). It can be concluded that the optimum concentration of ginseng, peppermint, and licorice extract is 0.5, 0.5, and 0.05 mg/mL. All formulas of ginseng mouthwashes in this study; pure ginseng solution (Gsol), ginseng-peppermint (GP), and ginseng-licorice (GL) showed less cytotoxic effect than the CUdent Stevia Fluoride™ mouthwash.

Dens evaginatus (DE) is a dental developmental anomaly with reports of variability in the frequency of the trait between racial groups and familial occurrences. This study aims to investigate characteristics of dens evaginatus
and associated genomic variants. DNA samples of four patients with dens evaginatus and their fathers and mothers were taken and whole exome sequencing was performed. For radiographic analysis, ten teeth with dens evaginatus from six patients were examined and received CBCT. Depending on the clinical diagnosis of pulpal and periapical status, all teeth received either prophylaxis treatment or endodontic treatment. Participants were categorized as the exposed pulp group or the non-exposed pulp group. 3D images were evaluated with one volume viewer. Factors including main pulp canal extension, dens evaginatus-located cusp steepness, size, shape, location and pulp extension of dens evaginatus cusp were tested for association with clinical pulpal exposure using Pearson’s chi-square or Fisher’s Exact Test. From the results, genes of genetic interest to 18 genes were narrowed down but a definite pathogenic variant was not identified in all the participants. From the CBCT investigation, there was a significantly higher chance of pulpal exposure in a tooth with dens evaginatus with a ratio of less than 0.45 and degree of buccal cusp inclination of less than 33°. Size, shape and location of dens evaginatus cusp are not statistically related to pulpal exposure. In conclusion, factors influencing clinical pulpal exposure in a tooth with DE were main pulp canal extension and dens evaginatus-located cusp steepness (p<0.05).

This research aimed to compare the amount of voids in different resin cements and different film thicknesses in endodontically treated tooth restored with fiber reinforced prefabricated post. The research studied the voids
in different types of resin cements, which include Maxcem Elite (Kerr, USA), Rely X Unicem (3M ESPE, USA) and Superbond C&B (Sun Medical, Japan) at 200 and 400 micrometer film thicknesses. After the sample were complete
polymerization, cut with the diamond disc, cleaned by ultrasonic and examined under scanning electron microscope at 350X magnification. Maxcem Elite, RelyX Unicem, and Superbond C&B resin cement had significant difference in the amount of void formation (p< 0.05). The resin cement with the most amount of void was Maxcem Elite, followed by RelyX Unicem, and Superbond C&B respectively. Maxcem Elite and RelyX Unicem had large amount of small size voids. Superbond C&B usually had large, interconnected voids. However there was no significant difference in the amount of voids under different film thicknesses of the resin cements. Different types of resin cements had different amount of void formation significant difference; the amount of voids in different film thicknesses of the resin cements was no significant difference; After the sample were complete polymerization. Unfilled resin, total
etch resin cement had less amount of void formation, yet the voids had multiple lobules and were interconnected. Self-etch and self-adhesive resin cements with fillers had smaller voids with greater distance in between.

Medication-Related Osteonecrosis of the Jaw (MRONJ) is an adverse reaction found in patients prescribed with antiresorptive and antiangiogenic drugs. Even though the incidence is low but the symptoms are relatively severe and could affect the patients’ quality of life. Oral infection and invasive dental treatments are among the risk factors of MRONJ. Careful risk assessment and treatment planning are required considering the category of the disease (cancer versus non-cancer) and the timing of treatment (before versus after starting antiresorptive and antiangiogenic drugs). The other risk factors to be considered are type, dose and duration of medication, type of dental treatment, smoking status, systemic diseases and genetic factor. As the number of patients receiving antiresorptive and antiangiogenic drugs is increasing, this review aims to describe the dental management for patients at risk of MRONJ in order to provide some guidelines for dentists who work with this group of patients. Patient education, primary prevention and multidisciplinary approach from both dentist and physician involved are necessary to provide good care of the patient taking these drugs and reduce the risk of this severe complication

Denture stomatitis is a chronic inflammatory condition on denture-bearing mucosa which affects 15-70 % of patients wearing dentures, particularly in elderly people. It is considered as a multifactorial disease precipitated by several predisposing and etiologic factors. Candida infection, poor denture hygiene, ill-fitting denture, along with denture trauma and continual wearing denture are recognized as the local risk factors. Various treatment protocols were proposed including oral hygiene instruction, use of antiseptic/disinfectant agents, antifungal therapy, and prosthesis adjustment. Due to variation of treatment modalities and lack of the definite treatment guideline, this article reviewed the treatment protocols of denture stomatitis based on the existing clinical studies. To provide the appropriate management of this bothersome condition, details of each treatment and its treatment outcome focusing on the resolution of inflammation and the reduction of microorganisms were summarized.

These case reports present the treatment of infants with complete cleft lip and cleft palate using extraoral appliances including lip strap, alar hook, and Nasoform. The first infant was a unilateral complete cleft lip and cleft palate patient. The second infant was a bilateral complete cleft lip and cleft palate patient. Both families did not need an obturator, therefore feeding techniques were used to deal with the problems of cleft palate. The shape of lip and nose was moulded using extraoral appliances from the first week after birth until the day of surgery at age 4 months. Approximately 1-2 weeks after the surgical repair of cleft lip and nasal deformity, the previously used Nasoform was adjusted to fit with the nose for using as a postoperative maintaining device. When the existing used Nasoform was too small, the new one was chose and adjusted for continued use. The outcome occurred in both infants showed that the use of extraoral appliances together with feeding techniques could be an alternative treatment for the patients with unilateral and bilateral complete cleft lip and cleft palate.

The aim of this study was to evaluate void formation by micro-computed tomography in two-surface Class II cavities restored using four different placement methods with three bulk-fill resin composites. Standardized Class II cavities were prepared in forty intact human maxillary first premolar teeth. The teeth were randomly divided into four groups and restored using (n=10): 1) one bulk placement with a hand instrument; 2) two-bulk placement with a hand instrument; 3) one bulk placement with an injectable dispenser; 4) one bulk placement with an injectable dispenser and a sonic-activated handpiece. Percentage of void formation in the entire restoration was evaluated. One way ANOVA and Games-Howell post hoc analyses were performed with a significance level of 0.05. One bulk placement with a hand instrument (Group 1) and two-bulk placement with a hand instrument (Group 2) had a significantly higher percentage of void formation than a one-bulk placement with an injectable dispenser (Group 3) and one-bulk placement with an injectable dispenser and sonic-activated handpiece (Group 4). There was no significant difference in the percentage of void formation between the hand instrument placement groups (Groups 1 and 2) and also between the injectable dispenser groups (Groups 3 and 4). In conclusion, different placement methods affected void formation in two-surface Class II cavity restored with bulk-fill resin composite. Placement with a hand instrument had a significantly higher void formation than placement with an injectable dispenser.

The objective of this study was to evaluate the effects of 2.5%, 5%, and 10% by weight silane-treated nanoalumina and alumina reinforcement on the flexural strength of heat-polymerized acrylic resins. Seventy rectangular (65x10x3 mm3) (ISO standard 1567) heat-polymerized acrylic resins were fabricated and divided into seven groups according to the size and weight % of aluminum oxide reinforcement (n=10). The control group was an intact heat-polymerized acrylic resin group. The six experimental groups were reinforced with 2.5%, 5%, and 10% by weight silane-treated nano-aluminum oxide (20 nm) and aluminum oxide particles (50-70 µm). The specimens were tested for flexural strength using a three-point bending test. Independent t-test, One-way ANOVA and Tukey Honestly Significant  Difference (HSD) were used for statistical analysis. The flexural strength of 10% by weight of silane-treated nano-alumina and silane-treated alumina reinforced groups (Groups NA3, A3) (111.36, 110.45 MPa) significantly increased compared to the control group (Group C) (99.25 MPa) (p<0.05), even though the flexural strength of 2.5% and 5% by weight of silane-treated nano-alumina and silane-treated alumina reinforced groups (Groups NA1, NA2, A1, A2) (101.00, 105.34, 99.27, 104.42 MPa) did not increase significantly compared to the control (p>0.05). Group NA3 showed the highest flexural strength compared to the control (p<0.05). Changing the percentage by weight of silane-treated aluminum oxide reinforcement affected the flexural strength of heat polymerized acrylic resins. The flexural strength increased when 10% by weight of silane-treated nano-alumina and alumina fillers were added. Both silaned-treated micro-sized and silaned-treated nano-sized alumina can be used to reinforce the flexural strength of heat-polymerized acrylic resins due to resembling the effect of increase in flexural strength.

The aim of this study is to investigate surface roughness and gloss of nanocomposite materials before and after several periods of tooth brushing simulation. Ten tested specimens of nano-filled resin composite (Filtek Z350 XT®), nano-hybrid resin composite (Premise®, Ceram.X SphereTEC one universal®) and giomer (Beautifil II®) were prepared. All specimens were polished with a set of aluminum oxide abrasive disk (Sof-Lex®). Baseline surface roughness (Ra) was obtained using contact type profilometer and baseline surface gloss (GU) was obtained using micro-gloss meter. All specimens were brushed for 10,000, 20,000 and 40,000 cycles with tooth brushing machine. The surface roughness and gloss were measured after each brushing period and two specimens of each material were selected to be surface analyzed by scanning electron microscope. The obtained data were analyzed by two way repeated measures ANOVA and Tukey HSD test with the level of significance at p=0.05. The results revealed that after the brushing, all materials were significantly increased in surface roughness and significantly decreased in gloss. Average change in surface roughness and gloss of nano-filled resin composite (Filtek Z350 XT®) were the lowest and of giomer (Beautifil II®) were the highest. There was significant negative correlation between surface roughness and gloss. It can be concluded that for all tested nanocomposites, there was a significant increasing in surface roughness and decreasing in gloss after tooth brushing simulation. The surface roughness affected the gloss of the materials.

The purpose of this study was to evaluate outcomes of three-dimensional analysis of virtual surgical planning for two-jaw orthognathic surgery. A retrospective study of 13 patients (four males, nine females) was conducted. Cone beam computed tomography images were imported into a Dolphin program, virtual surgical planning was performed and used to fabricate surgical splints. Postoperatively, the planned and actual position were generated as a three-dimensional skeletal model using a Dolphin program. Then, ten bone positions were created and 30 values were measured to compare the predicted outcomes and actual outcomes at six months after surgery. The mean age of the 13 patients was 29 years old. The mean difference of the total of the ten bone positions in the anteroposterior direction was 1.76 ± 2.83 mm, in the vertical direction was 2.12 ± 1.47 mm, and in the medio-lateral direction was 0.91 ± 0.76 mm. There was a significant difference between the antero-posterior position at the A-point (P = 0.006) and the planned position. In conclusion, the utilization of virtual surgical planning by the Dolphin program was a reliable method for two-jaw orthognathic surgery, and the antero-posterior position at the A-point of the maxilla was still a sensible position.

The aim of this study was to evaluate and compare reliability and validity of spectrophotometer and intraoral scanners for human tooth color measurement. Subjects were right maxillary central incisors of 50 volunteers. The tooth was cleaned by pumice, rinsed with water spray and distilled water and moist dried with gauze. Color measurement was consecutively performed at cervical, middle and incisal areas by VITA Easyshade® V spectrophotometer, TRIOS 3shape intraoral scanner and CEREC Omnicam intraoral scanner. The color was recorded as VITA 3D-MASTER color system. Data was analyzed using Randolph kappa for reliability and chi’s square for validity. The result shown that the reliability of VITA Easyshade® V spectrophotometer and TRIOS 3Shape intraoral scanner was in the good strength of agreement (between 0.61-0.80) and CEREC Omnicam intraoral scanner was in the moderate strength (between 0.41-0.60). The validity of TRIOS 3Shape intraoral scanner was 28.2 % and of CEREC Omnicam intraoral scanner was 27.7 % when compared to VITA Easyshade® V spectrophotometer. There was no significantly different in validity between CEREC Omnicam intraoral scanner and TRIOS 3Shape intraoral scanner (p = 0.210). It can be concluded that the reliability of VITA Easyshade® V spectrophotometer and TRIOS 3 shape intraoral scanner was in the good range and CEREC Omicam intraoral scanner was in the moderate range. The validity of both intraoral scanners was not significantly different but significant less than VITA Easyshade® V spectrophotometer.

This cross-sectional study aimed to describe the relationship between caregiver oral health literacy and dental caries status of pre-school children in Kongkrailas District, Sukhothai Province by using oral health literacy questionnaires which modified from combining 2 Thai version assessment test.The self-administered questionnaires measure 3 aspects, which were functional, communicative and critical oral health literacy, and children’s dental caries status assessment part which examined by a dentist. The multi-stage random sampling of 364 child/caregiver dyads were recruited from child development centers and kindergartens. All data was collected during August 2019 to October 2019 and were analyzed by using descriptive statistics, percentage and analytical statistics. The results showed a positive correlation was found between caregiver’s oral health literacy scores and children’s dental caries status. Oral health literacy scores varied from 6 to 41 so the oral health literacy score of 37 was used as a cut-off point to classify the caregiver’s oral health literacy as adequate (73 %) and inadequate (27 %).The social factors of caregiver that associated to oral health literacy were gender, level of education and the number of oral health information received channels.The present results indicated that caregiver’s oral health literacy is important to their children’s dental caries status and social factors of caregivers also associate to their oral health literacy. In order to improve caregiver’s oral health literacy, dental personnels should improve their oral health communication which must be suitable to caregiver’s oral health literacy level and also sensitive to caregiver’s cultural and social background.

This study investigated the shear bond strength (SBS) of polymer-infiltrated ceramic network (PICN) to resin cement by application of different restorative primers which are commonly available in dental clinic. Fifty square-shaped PICN specimens were prepared and treated with 5% hydrofluoric acid. Then, the specimens were randomly divided into five groups with different surface treatments as follows: non-chemical surface treatment as control group (C), surface treatment with Monobond N (MN), Alloy Primer (AP), Super-Bond Universal Ceramic Primer (SB), and ClearfilTM Ceramic Primer Plus (CF). The specimens were then bonded to cylindrical resin composite block with PanaviaTM V5. The SBS test was performed with universal testing machine. Data were recorded and statistically analyzed by One-way ANOVA and Tamhane’s T2. The mode of failure was also evaluated under a stereomicroscope at 35x. The results showed that the mean SBS values of MN, CF, and SB groups were significantly higher than that of the C group (p<0.05), but not significantly different to each other (p>0.05). In contrast, AP group provided the lowest SBS value among all the groups (p<0.05). The modes of failure of MN, CF, and SB groups were much preferable than that of C and AP groups. Thus, selection of restorative primers prior to cementation should be thoroughly considered due to the positive and negative effect on the SBS value of the PICN restorative material.

The aim of this study was to compare the clinical and radiographic success rates of a light-cured resin-modified calcium silicate, 2% chlorhexidine gluconate and calcium hydroxide in indirect pulp treatment of lower primary molars with deep caries lesion. Forty-six children, aged 3-8 years old, with 90 lower primary molars with deep carious lesions were included in this randomized clinical control trial. From radiographic examination, all the teeth had caries involved to inner one-third of dentin. The teeth were randomly divided into 3 groups: (1) a light-cured resin-modified calcium silicate (TheraCal LC®, Bisco, Inc., USA) (n=30), (2) 2% chlorhexidine gluconate (n=30) and (3) control: calcium hydroxide (Dycal®, Dentsply, USA) (n=30). Selective caries removals were performed. All the teeth were applied with different materials according to the group and restored with stainless steel crown. After 6-11 and 12-32 months, clinical and radiographic examination were performed. At 6-11 months recall, the success rates were 84 %, 88.89 % and 86.67 % for groups 1, 2 and 3 respectively. At 12-32 months, the success rates were 72.73 %, 84 % and 86.2% for groups 1, 2 and 3 respectively. No statistically significant difference between the groups was observed at 6-11 and 12-32 months (p>0.05). Indirect pulp treatment of deep carious primary teeth with a light cured resin-modified calcium silicate, 2% chlorhexidine gluconate or calcium hydroxide showed no difference in successful treatment outcomes after 6-11 and 12-32 months.

The purpose of this study was to evaluate the effect of silanization and thermocycling on the microshear bond strength (µSBS) of a silane-containing universal adhesive (Scotchbond Universal adhe-sive; 3M ESPE) (SU), and a 3 step etch and rinse adhesive system (Adper™ Scotchbond™ Multi-Purpose Adhesive; 3M ESPE) (SM). Seventy-two thermocycling-aged resin composite specimens were prepared and divided into four groups based on silane application. Group 1: no silane application before SM adhesive (SMN), Group 2: silane application before SM adhesive (SMS), Group 3: no silane application before SU (SUN), and Group 4: silane application before SU adhesive (SUS). Each group was randomly divided into two equal subgroups: 24 h in water storage (n=9) or 5,000-cycle thermocycling (n=9) before µSBS evaluation. The µSBS values were analyzed using Three-way ANOVA and Tukey’s post hoc test (p=0.05) and the fracture modes of the fracture interface were evaluated. Threeway ANOVA indicated that thermocycling and silanization significantly affected µSBS (p<0.05), while the adhesive system did not affect µSBS(p>0.05). In the 24 h water storage subgroups, the SMS group had a significantly higher µSBS compared with that of the other groups. In contrast, in the thermocycled subgroups, there was no significant difference in µSBS between groups. In conclusion, after a 5,000-cycle thermocycling, the repair bond strengths of a silane-containing universal adhesive and a conventional etch-and-rinse adhesive were comparable.

Intraoral devices used to evaluate tooth contour while making tooth alteration for removable partial denture components are lacking. Thus, the new intra-oral surveyor has been developed with the aid of 3D printing technology. The aim of this study was to compare the survey lines obtained from the newly developed intra-oral surveyor with a conventional surveyor. Ten graduate prosthodontic students were instructed to use the newly developed intra-oral surveyor to draw survey lines (Sn) on assigned abutment teeth following a previously determined surveying path. Each student had to survey 4 different models which were mounted in a phantom head in pair, using a blue pencil-lead. Subsequently, each model was removed from the phantom head and was surveyed by a prosthodontist using a conventional surveyor (Ney) in the same surveying path, using a red pencil-lead to create reference survey lines (Sr). A total of 40 models with doubled survey lines (Sn and Sr) were scanned by a 3D model scanner, after which a series of 2D pictures of each studied tooth surface were captured. Each picture was examined for (1) the overlapping amount of Sn and Sr lines and (2) the vertical distances between reference points on an occlusal edge and Sn and Sr lines on each studied surface, using Image J software. Intraclass correlation coefficient for the vertical distances was estimated to assess an accuracy and an agreement measurement of the two survey lines. Complete overlapping of Sn and Sr lines was found in 93 percent of studied tooth surfaces (354 out of 380 surfaces). Agreement between Sn and Sr lines was excellent, with the intraclass correlation coefficient equaled to 0.997. Within the limitations of this study, it can be concluded that the newly developed intra-oral surveyor was highly accurate and provided similar survey lines when compared with a conventional surveyor.

In vitro transcribed (IVT) nucleoside-modified messenger ribonucleic acid (mRNA) has emerged as a novel platform in regenerative medicine. Given the potential of a mRNA platform to encode any protein of interest and produce it directly in vivo, mRNA encoding growth factor could be a promising alternative to recombinant protein in promoting periodontal tissue and bone regeneration. Bone morphogenetic protein-2 (BMP-2) is one of most extensively studied growth factors due to its osteogenic potential. To date, an in vivo study of mRNA encoding BMP-2 therapy in the field of periodontology is scarce. In addition, a proper mRNA delivery system has yet to be identified. Therefore, this study aimed to examine the effect of N1-methylpseudouridine-modified mRNA encoding BMP-2 (m1Ψ-BMP-2 mRNA) with different delivery systems on the level of BMP-2 protein and inflammatory response at local tissue upon intragingival injection. Twelve Sprague-Dawley rats were randomly assigned into four groups injected with m1Ψ-BMP-2 mRNA in Dulbecco’s phosphate-buffered saline (dPBS), sucrose citrate buffer, Lipofectamine® 2000, or dPBS alone without mRNA as a control at palatal gingiva. Gingival tissues were collected at 24 hours for analysis of BMP-2 protein and pro-inflammatory cytokines (interleukin-1β, interleukin-6, and tumor necrosis factor-α) using enzyme-linked immunosorbent assay. The highest BMP-2 protein expression in gingival tissue was observed in a rat injected with m1Ψ-BMP-2 mRNA in Lipofectamine® 2000. The amount of interleukin-1β in all the groups was less than 100 pg/mg of protein, while interleukin-6 and tumor necrosis factor-α were undetected. The findings from this in vivo study demonstrated that intragingival injection of m1Ψ-BMP-2 mRNA in Lipofectamine® 2000 resulted in increased BMP-2 production with minimal local immune responses. Our preliminary data suggested that intragingival injection of m1Ψ-BMP-2 mRNA was able to promote BMP-2 protein expression in gingival tissues. Nucleoside-modified mRNA could be a potential therapeutics platform for periodontal regeneration; however, further studies are required.

The challenge in dental curriculum brings a stressful learning environment. To be competent in patient treatment, adequate practicing time is required. The COVID-19 pandemic control strategies including city lockdown
may impact the mental health status of dental students. Therefore, this cross-sectional study was performed to survey the prevalence and the impact of COVID-19 pandemic on stress and burnout of undergraduate dental students (UG). The UG studying at the Faculty of Dentistry, Chulalongkorn University (FDCU) in the academic year 2020 were invited to participate. The self-reported questionnaire was distributed online during 23rd June – 05th July 2021. The stress and burnout level was measured using a specific Thai language questionnaire. Demographic data, personality type, and the level of COVID-19 impaction on the UG’s mental health were also collected. Descriptive statistics and ordinal logistic regression were used to investigate the associated factors of stress and burnout with a significance at p-value<0.05. The number of respondents was 180 (30 % response rate), 122 (67.8 %) were female, mean age 21.7 years. The participants who had job stress, began to burnout, and burnout were 66 (36.7 %), 39 (21.7 %), and 36 (20 %), respectively. The attitude during their study was the greatest odds of association with stress and burnout, while the personality type and exercise frequency were also associated factors. The worry of unable to complete the clinical requirements due to COVID-19 lockdown had the highest impact on the 4th and 5th year UG. In conclusions, around 80 % of UG of FDCU had stress and 40 % was classified as burnout. Several associated factors of stress and burnout were identified. The consequences of COVID-19 outbreak impacted the stress level. These results suggest an urgent need to support the UG to improve their mental well-being and quality of life.

This study compared back- and forward-scattered doses from nine contemporary dental materials from the noble alloy group (gold alloy type I, gold alloy type IV, palladium alloy); the titanium group (commercially pure titanium (grade 4), titanium alloy (milling), titanium alloy (laser sintering); and the ceramic group (3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP), lithium disilicate, feldspathic porcelain). A linear accelerator (LINAC) with a single exposure dose of 200 cGy and 6 MV of photon energy was used to irradiate nine dental materials. Five specimens of each dental material were prepared, and each specimen was sandwiched with Optically Stimulated Luminescence (OSL) dosimeters above and below for back- and forward-scattered dose measurement, respectively. All specimens were irradiated two times. Percentage dose enhancement and attenuation were calculated from the exposure dose and compared among nine dental materials by using the one-way ANOVA and Bonferroni test with a p-value below 0.01. The gold alloy type I showed the highest backscattered dose (37.41 %) followed by gold alloy type IV (33.35 %), palladium alloy (24.20 %), zirconia (16.44 %), commercially pure titanium (grade 4) (10.30 %), titanium alloy (milling) (10.03 %), titanium alloy (laser sintering) (9.84 %), lithium disilicate (2.53 %) and feldspathic porcelain (1.58 %). Feldspathic porcelain was observed for the lowest dose attenuation while palladium alloy was noted for the highest dose attenuation. The higher atomic number and density of materials, the more backscattered dose enhancement and the less of forward-scattered dose were found. Gold alloy type I and zirconia showed the most backscattered dose among the noble alloy and ceramic group, respectively.

The objectives of this research were: 1) to study the efficacy of different light-curing protocols on microhardness and degree of conversion of two high viscosity bulk-fill resin composites (Filtek™ One Bulk Fill and Tetric® N Ceram Bulk Fill) and a conventional resin composite (Filtek™ Z350XT), and 2) to evaluate the correlation between two variables. Ninety-six resin composite specimens (size 2x4 mm and 4 mm height) were fabricated in vitro from class II cavity in extracted human molar. For each composite material, specimens (n=32) were divided into 4 groups (n=8) according to light-curing protocols (group A: occlusal 20 s, group B: occlusal 40 s, group C: occlusal 10s + buccal 10s and lingual 10s and group D: occlusal 20 s + buccal 10s and lingual 10s). Degree of conversion of each specimen was evaluated using the Raman spectroscopy technique in two depths (0 mm and 4 mm depth). Microhardness was evaluated using the Knoop microhardness tester at three depths (0 mm, 2 mm, and 4 mm depth). Data were analyzed using three-way ANOVA, one-way ANOVA, Games-Howell post-hoc test and Pearson’s correlation at a confidential level of 95%. Light-curing protocols and depths affected mean degree of conversion values and mean microhardness values of all materials significantly (p<0.05). At 4 mm depth, when both of the bulk-fill resin composites were cured by the group A protocol, mean degree of conversion values and mean microhardness values were significantly lower than the other curing protocols (p<0.05). Similar results were found when curing of conventional resin composite at 2 mm depth. Only group D of Filtek™ One Bulk Fill showed acceptable depth of cure. Microhardness ratios and degree of conversion ratio were correlated (p<0.001) in all materials. In conclusion, an appropriate light-curing protocol depends on the type of product being used. An additional curing time from the manufacturer’s recommendations may be advised since it can lead to higher degree of conversion and microhardness of materials.

This study compared some physical properties of White Portland cement with bismuth oxide dissolved in a distilled water (control), 1% chitosan solution, 6% calcium chloride solution and chitosan-calcium chloride mixture solution. A compressive strength, setting time, water solubility and acid erosion were tested at first and 21st day. The data was analyzed using one-way ANOVA. The control group showed the lowest compressive strength at both first and 21st day and also the longest initial and final setting time. The chitosan-calcium chloride mixture solution group achieved the highest compressive strength at first day, the fastest initial and final setting time, the least water soluble at 21st day, and the least acid erosion. The 6% calcium chloride solution group showed the highest compressive strength at 21st day and the least water soluble at first day. However, the 6% calcium chloride solution group had the greatest acid erosion property. The 1% chitosan solution group and the combination group resulted in the highest water soluble at first day. In addition, the control and 6% calcium chloride solution groups also showed the highest water soluble at 21st day. Adding either or both chitosan and calcium chloride affected the  compressive strength, setting time, water solubility and acid erosion. The addition of these 2 substances may improve the physical properties of the Portland cement.

This study aims to evaluate the effects of the addition of bioactive glasses (45S5, S53P4) and zinc oxide fillers on the mechanical, physical, and antibacterial properties of resin composite. Resin composites incorporated with various fillers (15wt% 45S5, 15wt% S53P4, and 1wt% ZnO) were produced. The mechanical properties (flexural strength, flexural modulus, and fracture toughness), physical properties (water sorption, and water solubility), depth of cure, and antibacterial property of these experimental composites were compared with a SiO2 composite and a commercial Systemp onlay. Both 15wt% bioactive glass sample groups showed significantly lower flexural strength, flexural modulus, and fracture toughness than the 1wt% ZnO and SiO2 groups. The incorporated 45S5 bioactive glass composite had the highest water sorption. The Systemp onlay displayed the highest water solubility, while the S53P4 bioactive glass group indicated a negative solubility. The depth of cure was deepest in the Systemp onlay and the shallowest in the ZnO composite. All experimental composites did not demonstrate antibacterial effects against Streptococcus mutans. The addition of 15wt% bioactive glasses negatively impacted the mechanical properties, physical properties, and depth of cure of resin composite. None of the filler materials enhanced the antibacterial properties of resin composites.

The purpose of this study was to compare the remineralizing ability of resin-modified glass ionomer cement(RMGIC) and resin-modified calcium silicate cement (RMCSC). Twenty-four permanent molars were cut at the middlethird of the occlusal surface and prepared to obtain class I cavity. The class I cavity was divided into three areas forthe microhardness test; control area, demineralized area and remineralized area. Nail varnish was coated externally,surrounding the tooth surface and 1/3 of the cavity for the control area. The specimens were subjected to a pH-cyclingmodel, and nail varnish coated another 1/3 of the cavity for the demineralized area. All the specimens were dividedinto two groups (n=12): RMGIC group and RMCSC group. Each cavity was filled with tested material according to thegroup. All specimens were immersed in deionized water at 37°C for 30 days. All specimens were embedded in acrylic resin and cut mesiodistally into halves. Knoop microhardness test was performed on each tested area at 20, 40, 60,100, 150 and 200 μm from restoration margin. Three indentations were made for each level, 100 μm apart. The difference of average knoop microhardness value on each area was calculated. The pair t-test was used to compare the depth of remineralization of each material. The independent t-test was used to compare the remineralization effect between two materials. The significant level was set at p<.05. The result showed that the depth of remineralization between two materials was not different. The change in microhardness value after remineralization of the RMCSC group was lower than the RMGIC group. From the results of this study, RMGIC seems to be more effective in remineralization than RMCSC.

The purpose of this study was to evaluate the effect of a desensitizing toothpaste, containing calcium sodium phosphosilicate, on the microtensile bond strength of adhesive systems treated with dentine. Fifty-two human third molars were embedded into acrylic resin, and cut to expose a flat dentin surface. The specimens were randomly divided into two groups, 1) no brushing, and 2) brushing with Sensodyne Repair & Protect (GSK, London,
UK) for 10,000 cycles with a V-8 cross brushing machine (Sabri Dental Enterprise, Inc., USA). Subsequently, both groups were divided into three groups for resin composite build-up using different adhesive agents: OptiBond FL® (Kerr, Orange, CA, USA), Clearfil SE Bond® (Kuraray Medical Inc, Japan), and Single Bond Universal® (3M ESPE, USA). All samples were subsequently sectioned to obtain microtensile test specimen, after which the sectioned sticks in the same tooth were divided into two subgroups: 1) microtensile bond strength test, and 2) thermocycling for 10,000 cycles, followed by microtensile bond strength test. Two-way ANOVA revealed that the μTBS values of each adhesive system was not significantly affected by brushing with desensitizing toothpaste containing calcium sodium phosphosilicate. After brushing with desensitizing toothpaste containing calcium sodium phosphosilicate, OptiBond FL® had the highest μTBS value. Clearfil SE bond® showed no significantly different immediate μTBS value compared to Single Bond Universal®, but showed a significantly higher μTBS value than Single Bond Universal® after 10,000-cycle thermocycling. In addition, 10,000-cycle thermocycling significantly decreased the μTBS value of Single Bond Universal® after brushing. In conclusion, desensitizing toothpaste containing calcium sodium phosphosilicate had no effect on OptiBond FL® or Clearfil SE bond®, either for immediate μTBS or after 10,000-cycle thermocycling. Meanwhile, Single Bond universal® adhesive showed decreased μTBS after 10,000-cycle thermocycling.

The aims of this study were to evaluate patients’ understanding of postoperative self-care instructions and to compare patients’ understanding of the instructions given by undergraduate (UG) with those given by postgraduate (PG) dental students. This was a cross-sectional descriptive study. Self-administered questionnaires were given to patients aged >15 years-old who could read and understand Thai language, after they received postoperative selfcare instructions. Sixteen items evaluating their understanding of postoperative self-care were used. Participants received one point for each correct answer. The IBM SPSS Statistics software was used for descriptive and inferential statistical analysis. Two hundred and four patients participated in this study (124 and 80 received instructions from UG and PG dental students, respectively). There were no patients in the low level of understanding (score 0–6); while 76.6 % and 87.5 % of the patients receiving instructions from UG and PG, respectively, were at the good level of understanding (score 12–16). The mean±SD of understanding scores were 12.74±1.74 and 13.16±1.44 in patients receiving instructions from UG and PG, respectively, which was not significantly different when comparing between both groups with the t-test (t=1.803, p=0.07). In conclusion, most of the patients receiving instructions from dental students understood postoperative self-care well. There was no difference in the understanding score between the patients receiving instructions from UG or PG dental students.

Studying in postgraduate dental program may cause students excessive and prolonged stress and may result in burnout or emotional exhaustion. The exhausted postgraduate dental students (PG) may feel dispirited
or depressed and cannot fulfil their studies. However, the level of stress and burnout in Thai PG has never been reported. Therefore, this study was performed to investigate the level and associated factors of stress and burnout of PG. The self-reported questionnaire created on google platform was sent to PG who were studying in the Faculty of Dentistry, Chulalongkorn University (FDCU) during January - October 2019. Descriptive study, Chi-square test,and multiple logistic regression were used for statistical analysis. One hundred and sixty-six questionnaires were returned from total 243 PG (68 % response rate). The average age of respondents was 29 years, 74 % were females, 24.7 % reported moderate and severe stress and burnout. The level of stress was not significantly different when comparing between men and women, also clinical-based course and research-based course. Work hour per week and workload did not affect the stress and burnout level. PG who had good and very good relationship with their colleagues and hobbies had significantly less stress and burnout (P=0.033 and 0.042, respectively). PG who graduated their Doctor of Dental Surgery degree from other universities, not FDCU and who had no monthly salary granted tended to possess stress and burnout 2.6 and 4.0 times, respectively. In conclusion, one-fourth of PG were in moderate to severe stress and burnout. Factors associated with stress and burnout were salary, relationship with colleagues, hobbies, and the graduated universities.

The aim of this study was to compare the effect of polishing and glazing procedure on surface roughness of hybrid resin-ceramic CAD/CAM materials before and after tooth brushing simulation. 40 tested specimens (n = 20 per material) were prepared of CAD/CAM blocks from Polymer infiltrated ceramic network or PICN (Vita Enamic) and resin nanoceramics (CeraSmart). All specimens were randomly divided into 4 groups (10 specimens each). Group 1 (VM) and 3 (CM): Vita Enamic and CeraSmart were polished with hybrid resin-ceramic polishing kit. Group 2 (VG) and 4 (CG): Vita Enamic and CeraSmart were glazed with light-cured glazing materials. All specimens were polished with silicon carbide paper 600, 800 and 1200 grits. Group VM and CM then were polished with hybrid resin-ceramic polishing kit (Poly-ceramic, Meisinger, USA) and Group VG and CG were glazed with light-cured glazing material (Vita Enamic glaze and Optiglaze, respectively). After that, all specimens were brushed 20,000 cycles with tooth brushing machine (v8-cross brushing machine, Sabri Dental enterprise, Inc. Illinois, USA). The average surface roughness (Ra) was obtained from contact type profilometer after surface polishing with SiC paper (Ra1), after surface treatment (Ra2) and after 20,000 cycles of brushing simulation (Ra3). Data were analyzed using two-way repeated measures ANOVA and Tukey HSD test with the level of significance at p<0.05. The mean Ra1 of all groups showed no significant difference. After surface treatment, the mean Ra2 of polished groups were not significantly different, whereas glazed groups were significantly different. The mean Ra2 of CG was the highest. After 20,000 brushing cycles, the mean Ra3 of all groups increased in the order CG, VM and VG, CM, respectively. From the result of this study, the polishing and glazing procedures were effective similarly when the surface roughness were measured immediately. After tooth brushing simulation, for Vita Enamic, both polishing and glazing procedures were not different. However, polishing of CeraSmart yields superior effectiveness compared to glazing procedure with light-cured glazing materials

The aim of this study was to compare the frictional resistance in posterior units, which are influenced by canine angulation, with different wire sizes. Stainless steel (SS) arch wires, 0.016” x 0.016” and 0.016” x 0.022”, were ligated to posterior units consisting of different numbers of posterior 0.018-inch slot bracket and tube. The test assembly was fixed to a universal testing machine with 50-N load cell. To simulate the situation that a canine was distalized and tipped when using sliding mechanics, the wires were angled (0°, 5°, 10°, 15°) at the distance 12.5 mm from the mesial wing of premolar bracket and drawn through the units at a cross-head speed of 10 mm/min over 2 mm at room temperature. The maximum frictional resistance was measured. Frictional resistance in a posterior unit increased with the increasing angulation and wire size. Among the different angulations, wire sizes, and posterior unit combinations, a 15° angle 0.016” x 0.022” SS wire in a one-bracket + one-tube unit had the greatest frictional resistance. Frictional resistance in the 15° and 10° angle groups were significantly greater when compared to the 0° and 5° angle groups for nearly all bracket-wire combinations. The 0.016” x 0.022” SS wires demonstrated significantly greater frictional resistance than 0.016” x 0.016” SS wires in a one bracket + one tube unit with all wire angles. Frictional resistance of the posterior unit increased when the wire angle and the wire size increased. These results implied that increased canine angulation during the canine retraction phase increases frictional resistance of the posterior unit clinically.

The purpose of this study was to evaluate the effect of vitamin C containing sodium ascorbate prepared solution on the dentin bond strength of a resin composite to a non-vital bleached tooth and on the fracture resistance of a restored non-vital bleached tooth. Sixty (30 pairs, left and right) extracted sound human maxillary premolar teeth were collected from 30 patients. All the teeth were endodontically treated and each pair was randomly assigned into microtensile bond strength and fracture resistance tests. The teeth of each test were divided into three groups which were 1) non-bleached tooth, 2) bleached with 35% hydrogen peroxide and immediately restored with resin composite, and 3) bleached with 35% hydrogen peroxide, followed by an application of 10% vitamin C prepared solution and immediately restored with a resin composite. Samples of the microtensile bond strength test were cut to obtain stick-shaped specimens and tested with a universal testing machine. Samples of the fracture resistance test were embedded in acrylic resin with a simulated periodontal ligament before being subjected to an axial compression test with the universal testing machine. Results showed that the bleached tooth followed by 10% vitamin C solution application group had the highest microtensile bond strength while the bleached group had the significant lowest bond strength. The non-bleached group showed the highest fracture strength, and the bleached group had the significantly least strength. There was no significant difference between the non-bleached group and vitamin C solution application group in both microtensile bond strength and fracture strength tests. The most failuremode for all groups was adhesive failure in the microtensile bond strength test and was favorable failure in the fracture resistance test. The microtensile bond strength was positively correlated to the fracture resistance. In conclusion, the use of 10 % vitamin C containing sodium ascorbate prepared solution could reverse the microtensile bond strength and fracture strength of a non–vital bleached tooth.

The objective of this study was to compare the effectiveness of regenerative endodontic irrigation procedures using ethylenediaminetetraacetic acid (EDTA) to those using normal saline as final flush agents for disinfecting noninstrumented large root canals. Sterilized root samples (0.8-mm-wide apical foramen) (n=53) were prepared from extracted human mandibular premolars and 2 samples were used as sterile controls. Fifty-one samples were infected with Enterococcus faecalis for 21 days and randomly assigned into 3 groups (n=17 per group) with the following irrigation procedures, respectively: no irrigation (initial), irrigation with 1.5% NaOCl and a final flush with normal saline (N-NS), and irrigation with 1.5% NaOCl and a final flush with 17% EDTA (N-EDTA). Subsequently, the root canal walls were shaved and processed for microbial analysis, while 2 samples from each group were split and processed for observation using scanning electron microscopy. The number of remaining bacteria (CFUs) were determined and analyzed using one-way ANOVA. All irrigation procedures significantly reduced bacterial numbers when compared with the initial group (P<0.001). The N-EDTA group (5.43 CFUs/mL) had significantly fewer bacteria than the other groups (P<0.001), with approximately 373-fold lower than the N-NS (2.02x103 CFUs/mL) group and 1.3x105-fold lower than the initial group (7.13x105 CFUs/mL). Using a non-instrumented large root canal model, a final flush using EDTA after 1.5% NaOCl irrigation was more effective for root canal disinfection than using normal saline. Therefore, to improve the effectiveness of root canal disinfection in regenerative endodontic procedures, EDTA should be chosen for a final flush agent.

This study aimed to compare the efficacy of zinc phosphate cement (ZP), zinc polycarboxylate cement (ZPC), conventional glass ionomer cement (GI), resin modified glass ionomer cement-powder/liquid (RMGI-PL), resin modified glass ionomer cement-paste/paste (RMGI-PP), and polyacid-modified composite resin (PMCR) on inhibition of enamel demineralization at the area adjacent to cemented band. This in vitro study was conducted on 70 human upper premolars. The distal surfaces of the crown were smooth polished and painted with nail varnish, except a 1 x 2 mm2 window on middle of distal surface. Seventy teeth were divided into 7 groups; (1) ZP (Zinc Cement Improved®), (2) ZPC (Hy-Bond Polycarboxylate Cement®), (3) GI (HyBond Glasionomer CX®), (4) RMGI-PL (GC Fuji Ortho LC®), (5) RMGI-PP (GC Fuji Ortho Band Paste Pak®), (6) PMCR (Ultra Band-Lok®) and (7) control group. All specimens were thermocycled for 24 hours, and pH cycled for 21 days. The teeth were then debanded, and decemented. The percentage of fluorescence loss (ΔF), maximum percentage of fluorescence loss (ΔFmax), lesion area (Area) and lesion volume (ΔQ) were measured by quantitative light-induced fluorescence-digital. The Kruskal-Wallis showed statistically significant differences for ΔF, ΔFmax, Area and ΔQ among group (p<0.001). the pairwise comparisons showed that there were no significant difference between the groups of Control:PMCR, ZP:ZPC, ZP:GI, ZP:RMGI-PL, ZP:RMGI-PP, ZPC:GI, ZPC:RMGI-PL, ZPC:RMGI-PP, GI:RMGI-PL, GI:RMGI-PP, RMGI-PL:RMGI-PP and RMGI-PL:PMCR in the mean ΔF, ΔFmax, Area and ΔQ, but the groups of Control:ZP, Control:ZPC, Control:GI, Control:RMGI-PL, Control:RMGI-PP, PMCR: ZP, PMCR:ZPC, PMCR:GI and PMCR:RMGI-PP are statistically significant differences. This study demonstrated that the use of ZP, ZPC, GI and RMGI-PP inhibit demineralization of enamel adjacent to cemented bands. Demineralization occurred in RMGI-PL, PMCR and control group, however, the demineralization of RMGI-PL group was less than control group and no difference between PMCR and control group.

The aim of this study was to determine the appropriate sagittal maxillary position in Thai adults for orthognathic surgery. The study included males and females with completed orthodontic treatment, normal profile, dental and skeletal Class I. Two linear and four angular parameters of lateral cephalometry were measured to obtain maxillary position and upper incisor to Nasion perpendicular (UI-Nperp) distance. The digital cephalometric analyses were performed using Dolphin Imaging Software. Seventy-five patients met the inclusion criteria with a mean age of 23.79 ± 4.74 years. The means of UI-Nperp were 7.3 ± 4.6 mm for males and 8.4 ± 3.6 mm for females. No significant difference was observed in the UI-Nperp distance between the extraction and non-extraction groups. In conclusion, the UI-Nperp distance could be a useful tool for determining proper sagittal maxillary position when performing Le Fort I osteotomy in orthognathic surgery.

This clinical study aimed to determine the differences in lipstick stains between ceramic veneers and natural teeth. Types of lipsticks affecting lipstick stains on ceramic veneers and natural teeth were also investigated. A total of 30 patients were divided into two groups: ceramic-veneer group and natural-teeth group, with 15 patients in each group. Seven lipstick types: Gloss & Balm, Gloss & Sheer, Cream, Liquid matte, Matte & Frost, Satin, and Matte were applied on patients’ lips. There were two methods to evaluate lipstick stain in this study: (a) visual method, and (b) instrumental method. Six labial surfaces of the maxillary anterior teeth were evaluated for the frequency of lipstick staining with each type of lipstick. Thus, 90 maxillary anterior teeth were examined per group. Data were analyzed using one-way repeated measures ANOVA (α = 0.05). One-way repeated measures ANOVA revealed that types of lipsticks had a statistically significant effect on lipstick stains (P < 0.001). Gloss & Balm lipstick left the highest frequency of lipstick staining in both groups. Matte lipstick had the lowest frequency of lipstick staining. However, there was no statistically significant difference between the two substrate groups concerning the lipstick staining (P = 0.083). In conclusion, based on our findings, types of lipsticks affected lipstick stains in both groups. Regarding substrates, there was no statistically significant difference between the two groups.

The objective of this study was to evaluate the translucency, degree of conversion and microhardness of three high viscosity bulk-fill resin composites (Tetric® N-Ceram Bulk Fill, Filtek™ One Bulk Fill and SonicFill™2) in comparison to conventional resin composite (Filtek™ Z350XT) as the control group. The correlations between three variables were analyzed. Five cylindrical specimens (7 mm diameter and 4 mm height) were fabricated for each material (n=5). The high viscosity bulk-fill resin composites were polymerized at 4 mm thickness and the conventional resin composite was polymerized at each 2 mm thickness followed the manufacturer’s recommendations. Translucency was evaluated by translucency parameter. Degree of conversion was determined using Fourier transform infrared spectroscopy and microhardness was measured by a Knoop microhardness tester. Data were analyzed using one-way ANOVA, Tukey HSD test and Pearson’s correlation at confidential level of 95 %. Translucency, degree of conversion and microhardness were significantly different among the groups (p<0.05). Tetric® N-Ceram Bulk Fill exhibited the highest translucency (2.69 ± 0.51) and significantly highest degree of conversion (65.13 ± 3.97 %) compared to other high viscosity bulk-fill resin composites but not significantly different from the control group (57.62 ± 2.54 %). SonicFill™2 exhibited significantly lowest translucency (1.11 ± 0.11) compared to other high viscosity bulk-fill resin composites but not significantly different from the control group (0.92 ± 0.17) and lowest degree of conversion (47.54 ± 5.14 %). Only Tetric® N-Ceram Bulk Fill showed acceptable depth of cure (bottom-to-top microhardness ratio>0.8) at 4 mm. Translucency, degree of conversion and microhardness of three high viscosity bulk-fill resin composites were correlated (p<0.05). From the results of this study, more opaque high viscosity bulk-fill resin composites demonstrated lower degree of conversion at 4 mm depth. Tetric® N-Ceram Bulk Fill was the only bulk-fill resin composite which had acceptable depth of cure at 4 mm.

Esthetic dental treatment can improve the appearance of a patient. However, esthetic perception of smile discrepancies is different among evaluators. The purpose of this study was to compare esthetic perception
between dentists and laypersons by difference of asymmetrical width and length of maxillary central and lateral incisors under 5 and 15 seconds evaluation time. Photos of women were digitally altered by Adobe Photoshop® program to create images with symmetrical and asymmetrical tooth width or length in 0.5 mm increments. Final images were randomly presented on a computer screen using an equal ratio to the actual tooth. Thirty-six dentists and 36 laypersons were asked to rate the attractiveness of those smiles on a numerical rating scale within 5 and 15 seconds of evaluation time. Mann-Whitney U and Wilcoxon Signed-Rank tests demonstrated that there was no statistically significant difference between two different evaluation times. Dentists could detect 0.5 mm narrowing of the central incisor and 1.0 mm of lateral incisor. 1.0 mm and 1.5 mm narrowing of central and lateral incisors were required for laypersons. Both groups could distinguish all levels of asymmetrical length in the central incisor. Laypersons were more tolerant than dentists with the asymmetrical length in the lateral incisor. Overall, dentists were esthetically more critical than laypersons. Both asymmetrical width and length affected smile attractiveness. Asymmetrical length was easily recognized and should be of concern.

This study was an in vitro pH-cycling model that aimed to study and compare the effect of grape seed extract (GSE) and CPP-ACP on the microhardness of artificial root caries. Sixty sound human premolars extracted for orthodontics treatment were sectioned at the cervical portion of the root and embedded in resin. Nail varnish was coated on the root dentin surfaces except on a window of 4 mm. x 4 mm. Knoop hardness indentations were tested for baseline (KHNb) and sixty specimens with KHNb between 60-70 were included. All specimens were stored in a demineralization solution for 96 hours to induce artificial root caries lesions and measured initial Knoop microhardness (KHNi). Sixty specimens were randomly divided into four groups randomly (n=15 per group) including: the deionized water group (control group), the GSE group, the GSE + CPP-ACP group and the CPP-ACP group. The demineralized specimens were pH-cycled, six cycles per day for eight days, then a final microhardness test (KHNf) was performed. The means of the four indentations of KHNb, KHNi and KHNf from each specimen were analyzed. The means of differences in microhardness values between KHNf and KHNi (ΔKHN) among groups were analyzed using one-way ANOVA, followed by the Games-Howell post-hoc test at a significance level of 0.05. The results of this study indicated that all test groups had a significantly higher ΔKHN than the control group at (p<0.01). Both the GSE group and the GSE + CPP-ACP group showed a significantly higher ΔKHN compared to the CPP-ACP group at (p<0.01). The GSE group and the GSE + CPP-ACP group showed no statistically significant difference of ΔKHN (p<0.01). It was concluded that the GSE and the GSE+CPP-ACP increased microhardness values more than the CPP-ACP. All three interventions increased microhardness compared to the control group.

The aim of this study was to determine the cytotoxicity of Melaleuca cajuputi Powell and Cymbopogon citratus essential oil formulated in alcohol-free mouthwash on oral fibroblast cell; human gingival fibroblast cell. In
vitro study, human gingival fibroblast cells were plated in 96-well plates with 2.5 x104 cell/well and cultured in DMEM (no phenol red) containing 10% FBS and antibiotics. Mouthwashes were divided into 5 groups; alcohol-free mouthwash with basic ingredients, alcohol-free mouthwash with essential oil from Cymbopogon citratus 4 μl/ml, alcohol-free mouthwash with essential oil from Melaleuca cajuputi Powell 8 μl/ml, alcohol-free mouthwash supplemented with 4 μl/ml Cymbopogon citratus and 8 μl/ml Melaleuca cajuputi Powell mix essential oils and 0.12% chlorhexidine mouthwash. The concentration of all groups was prepared by two-folds dilution in 96-well plate; the positive control cultured in 0.12% chlorhexidine mouthwash and the negative control cultured in DMEM (no phenol red). Plates were incubated for 24 hours in incubator at 37 °C, 5% CO2, 100% humidity and determined the cytotoxicity by MTT assay and LDH assay. Cell viability was measured by optical density and ELISA Reader machine was use to read the result. One-way ANOVA analysis follow by multiple comparison at 95 % confidence of interval to compare non-cytotoxic concentration of 5 groups. MTT assay showed that the maximum non-cytotoxic concentration of 5 groups was at 1:8, 1:16, 1:32, 1:32 and 1:128, respectively and statistically significant differences (p<0.05). LDH assay showed the maximum non-cytotoxic concentration was at 1:8, 1:16, 1:32, 1:32 and 1:256, respectively and statistically significant differences (p<0.05). In conclusion, the alcohol-free mouthwash with basic ingredients was least cytotoxicity to human gingival fibroblast cell. The alcohol-free mouthwash supplemented with 4 μl/ml Cymbopogon citratus was less cytotoxicity than alcohol-free mouthwash with essential oil from Melaleuca cajuputi Powell 8 μl/ml. The alcohol-free mouthwash supplemented with both mix essential oils and alcohol-free mouthwash with essential oil from Melaleuca cajuputi Powell was non-cytotoxicity at the same concentration. 0.12% chlorhexidine mouthwash was the most cytotoxicity.

This study was conducted to observe and evaluate the difference in static and dynamic loadings between two mini-implant systems; one system is designed and manufactured as Chulalongkorn’s mini-implant products
(RetenDent), the other is Korean mini-implant products (MS denture® system, OSSTEM). This in vitro study was designed to use compressive loadings as a masticatory force. This compressive force was angulated to the implant at 30o from its vertical axis according to ISO 14801 guidelines Ten specimens from each group were subjected to static load tests. Subsequently, five cyclic loadings were calculated from static compressive strength These loads include 320N,275N, 230N, 185N, and 140N. Three specimens were randomly selected and tested at each loading condition, a total of 15 specimens for each mini-implant system. The number of survived cycles and fatigue limit were measured and analyzed. The Independent T- test was utilized to obtain the statistical differences of the static compressive strength, while descriptive statistics was utilized to compare the difference of dynamic loading between two mini-implant systems. The average static compressive strengths of RetenDent and OSSTEM mini-implants were 462.969 + 16.73N and 403.407 + 25.55N, respectively. Overall, RetenDent demonstrated a higher number of survived cycles except at 320N loading condition compared to OSSTEM. The fatigue limit of RetenDent and OSSTEM mini-implants was defined at 185N and 140N, respectively. RetenDent demonstrated a statistically higher static compressive strength. Both of the mini-implant systems had higher compressive strength than mean masticatory force in the anterior and premolar regions and RetenDent also has a higher dynamic compressive strength than the maximum bite force for a complete denture.

This study aimed to evaluate treatment acceptance, adverse effects and caries-arresting effects of silver diamine fluoride (38% SDF) in preschool children aged 3-6 years who restrict on access to dental service. An oral
examination of 75 kindergarten children from four public schools in Muang district, Chiang Mai province who had at one tooth with active dentine caries in upper anterior primary teeth. According to methodology, SDF was applied directly to only the affected tooth surfaces in two applications at six-month intervals. The children’s acceptance and adverse effects were evaluated one day after each procedure. The parental acceptance was assessed two weeks after the procedure. The caries-arresting effects was assessed at six-month to calculate the caries arresting rate and caries reduction. Most children and their parents showed positive results from using SDF therapy. The children’s acceptance of black discoloration after the first and second SDF applications were 78.7 % and 52.0 %. The parents’ acceptance of black discoloration after the first and second SDF applications were 77.3 % and 65.3 %. There were adverse effects such as gingival pain and irritation (n=17), tooth pain (n=5), and nausea and vomiting (n=8). At the six-month follow-up, caries arrest rate was 91.4 % and caries reduction was 27.7 %. In conclusion, most children and parents who restrict on access to dental service responded well to SDF therapy. SDF has a positive effect on cariesarresting effect. However, prior to treatment, parents and children should be provided with detailed information about the treatment process, pros and cons, in order to decide to receive treatment.

The aim of this study was to compare reliability and validity in color measurement of spectrophotometer and intraoral scanners. Three sets of brand-new VITA classical and VITA 3D master shade guides were cleaned with
ultrasonic cleaner and three similar color of each shade guide were put in gum shade guide. The color of middle shade guide was measured at middle third area in the black box for simulating intraoral environment. Experimental groups were divided to 3 groups of color measurement devices which were VITA Easyshade® V spectrophotometer, TRIOS 3shape intraoral scanner and CEREC Omnicam intraoral scanner. Color calibration of each device was done every nine times of measurement and the data was recorded. Data were analyzed using Randolph kappa for reliability and chi’s square for validity. The reliability of VITA Easyshade® V spectrophotometer and CEREC Omnicam intraoral scanner were in the very good strength of agreement (between 0.8-1) and of TRIOS 3Shape intraoral scanner was in the good strength of agreement (between 0.61-0.8). The validity of VITA Easyshade® V spectrophotometer was 85.4 % when measured VITA Classical shade guides and 82.8 % when measured VITA 3D Master, TRIOS 3Shape intraoral scanner was 37.5 % when measured VITA Classical and 44.8 % when measured VITA 3D Master and CEREC Omnicam intraoral scanner was 62.5 % when measured VITA Classical and 48.4 % when measured VITA 3D Master. Chi’s square (McNemar correlation) test showed significantly difference of validity between VITA Easyshade® V spectrophotometer and TRIOS 3Shape intraoral scanner (P value=0.001) and CEREC Omnicam intraoral (P value=0.036). It can be concluded that reliability in color measurement of VITA Easyshade® V spectrophotometer and CEREC Omnicam intraoral scanner was very good while TRIOS 3Shape intraoral scanner was good. Validity of both of intraoral scanners was significantly lower and different from spectrophotometer whereas validity of CEREC Omnicam intraoral scanner and TRIOS 3shape intraoral scanner was no significantly different.

The aim of this in vitro study was to investigate the effect of arginine containing fluoride toothpaste on demineralization and remineralization of artificial root dentin caries and to assess the appropriate concentration of
arginine in fluoride toothpaste. Fifty root segments below cementoenamel junction of extracted human third molars were collected. Artificial caries lesions were created with the size of 3×4 mm by immersion in demineralizing solution for 96 hours at 37°C. All samples were randomly divided into 5 groups (n=10): (1) 1450 ppm sodium fluoride toothpaste (Colgate-Palmolive Company, USA) with 2% arginine (Sigma-Aldrich, USA), (2) 1450 ppm sodium fluoride toothpaste with 4% arginine, (3) 1450 ppm sodium fluoride toothpaste with 8% arginine, (4) 1450 ppm sodium fluoride toothpaste only, and (5) deionized water (control). The samples of each group were immersed in either of the solutions for 7 daysunder pH cycling model. The surface microhardness was measured with Knoop microhardness test (FUTURE-TECH, Japan) at baseline, after artificial caries formation, and after immersion in each designated solution. The percentages of surface microhardness recovery were calculated and statistically analyzed using One-way ANOVA and Tukey’s test at a significance level of 0.05. All experimental groups showed statistical similarity in the percentages of surface microhardness recovery, which were significantly higher than that of the control group (p<0.05). Within the limitations of this study, we concluded that the toothpaste containing sodium fluoride both with and without arginine equally prevented demineralization and promoted remineralization of artificial root carious lesions. The different concentrations of arginine (2%, 4%, and 8%) had no significant effect on the remineralization.

The aims of this study were to evaluate caries relapse rates of children who received comprehensive dental treatment under general anesthesia (DGA) at one and three years of follow-up and to investigate factors associating with the relapse rate. This retrospective study obtained data from dental records of pediatric patients under 18 years of age who underwent comprehensive DGA by postgraduate students at the Department of Pediatric Dentistry, Chulalongkorn University between 2007-2016. Frequencies and means were used for data description. Chi-square and logistic regression analysis were used to determine caries relapse predictors at a statistically significant level of 0.05. A total of 220 patients were recruited into the study. During one-year and three-year follow-up periods, 184 (83.6 %) and 196 (89.1 %) children had at least one recall visit, with caries relapse rates of 42 % and 61 %, respectively. According to multivariate analysis, there was no significant relationship between caries relapse one year after treatment and any factor. In three-year follow-up period, caries relapse rate was associated with patients with primary dentition, lack of oral hygiene instruction in any recall visit and having average recall frequency more than once a year. In conclusion, in a one- and three-year follow-up period, caries relapse rates in children who undergone comprehensive DGA were relatively high. Not having oral hygiene instruction in every recall visit was an important factor associated with caries relapse within three years following comprehensive DGA.

The purpose of this study was to compare microleakage and shear bond strength on the restoration with two-step self-etch adhesive and resin composite after applying desensitizing agents. 90 extracted, intact human premolars were divided into 3 groups (control, glutaraldehyde and oxalate group) in each experiment. For the microleakage test (n=13), class V cavities (4 mm in length, 2 mm in width and 2 mm in depth) were prepared on the buccal surface of each tooth, beveled at occlusal margin, applied desensitizing agent according to the testing group, restored with two-step self-etch adhesive and resin composite, thermocycled for 5,000 cycles, immersed in1% methylene blue solution and evaluated the microleakage. For the shear bond strength test (n=17), buccal dentin was used, the surface was polished, then treated according to the testing group, restored with adhesive and resin composite, thermocycled, tested using a universal testing machine and analyzed the mode of failure in each fractured sample under a stereomicroscope at x40 magnification. The results showed that there was no statistically significant difference among 3 groups in microleakage test at the occlusal margin. In the meantime, microleakage at the gingival margin of both desensitized groups were higher than the control group with significant level and microleakage at both margins in each group were statistically different. In addition, for shear bond strength, oxalate group exhibited significantly lower value than both control and glutaraldehyde groups and mode of failure of all groups mostly were the adhesive failure. It could be concluded that applying desensitizing agents before the restoration with two-step self-etch and resin composite affects the microleakage and bond strength of restorative materials.