The aim of this in vitro study was to compare the centering ability of 2 single file systems; One Shape and Reciproc after root canal preparation in 34 acrylic resin simulated severely curved canals. These two instruments use different motions, One Shape uses continuous rotation while Reciproc uses reciprocating motion. Indian ink and methylene blue dye were used to stain the canals before and after root canal preparation. Photographs were taken by dental operating microscope and the pictures superimposed using Adobe Photoshop CS2.0. Canal transportation was defined as the distance (in millimeters) from the pre- to the post-instrumented canal wall measured on both the outer and inner curve of the simulated canal. Measurement of the distances was done in a perpendicular plane to the resin block’s long axis at 10 positions with 1 millimeter increment. Statistical analysis was performed using T-test and Mann-Whitney U test at the 95 % confidence interval. Results found no statistically significant difference in the mean centering ratio at any level (p=0.998). In conclusion, the centering ability of One Shape and Reciproc were not different.

The purpose of this study was to examine the associations among admissions criteria and academic
performance of “Newtract” dental students at Thammasat University. This study consisted of a retrospective analysis
of 242 students who enrolled in Thammasat dental program between 1996 and 2010. Data about admissions criteria
and academic records of the students were obtained from the Office of the Registrar. Multiple regression analyses
were used to identify the best combination of predictors in the regression equation. As two groups of admissions
criteria were used during the time period of the study, the regression analyses were then divided into two groups,
Group 1: including eight predictors, i.e., predental GPAX, scores on six subjects & manual dexterity; and Group 2:
including four predictors, i.e., predental GPAX and scores on three parts of the Scholastic Assessment Test (SAT).
Three academic performance categories were considered: GPA for each academic year, overall GPAX and preclinical
performance in restorative dentistry, endodontology, and prosthodontics courses. Predental GPAX
correlated positively with GPA in each level of the dental curriculum, and overall GPAX in both groups (p<0.05). In
Group 1, the best model for predicting academic performance is the model with four predictors, i.e., predental
GPAX, scores on biology, physics and English, these four predictors accounted for 31 % (R2=0.31) of variance in the
predicted values for second year GPA. In Group 2, the best model for predicting second year GPA (R2=0.33) and
dental GPAX (R2=0.32) is the model with one predictor, i.e., predental GPAX. Other models show significant correlation
between other admissions criteria and academic performance, they accounted for 7-26 % of variance in predicted
values for the academic outcomes. Overall, the findings suggest that there is a positive relationship between predental
GPAX and scores of some subject tests with academic performance, however, the predictive ability is weak.

The objective of this study is to compare knowledge attitude and practice of hand hygiene including alcohol
hand rub use among dentist groups who had different number of years in current practice by gathering the data
from 149 returned questionnaires. In each category, the average scores were compared among 3 groups of dentistswho had been in practice for 0-10 years, 11-20 years and 21-30 years. The results were found that no statistical
significant differences in the average total scores among groups in knowledge attitude and practice category (p<0.05).
However, the 21-30-year group had significantly lower average score than the 11-20-year group in hand hygiene
practice category (p<0.05) and the 0-10 year group had significantly lower average score than other groups in alcohol
hand rub attitude category (p<0.05). In summary, number of years in practice has no significant effect on average
total scores among groups in knowledge attitude and practice category. However, dentist who has been working
for longer time tends to achieve less score in hand hygiene practice while dentist who has been working for shorter
time tends to achieve less score in alcohol hand rub attitude.

The objective of this study is to establish the sex determination tool using canines in Thais. The samples
in this study were 266 Thai people, including 140 females and 126 males with age 20.05±1.47 years old. The
mesiodistal width of four canines and the upper and lower tip-to-tip intercanine width were measured. The differences
of all distances between sex were determined by the independent samples t-test with 0.05 significant level. Simple
and multiple logistic regression analyses were used to establish the sex determination equations for single and
multiple variables, respectively. Statistically significant differences between sex were found in all measurements.
Moreover, the sex determination equation with one variable for each measurement was statistically significant.
However, when all measurements were investigated together, only lower left canine and upper intercanine widthwere included in the sex determination equation with 25.1 % R2, and the odd ratio were 4.912 and 1.280 for lower
left canine and upper intercanine width, respectively. Moreover, the accuracy of novel equation is 68.18 %. In
conclusion, canine can be another tool to determine sex together with other factors.

The aim of this in vitro study was to investigate the effect of remineralization and time on the color and
microhardness change of bleached teeth using 10 % carbamide peroxide (CP) and 40 % hydrogen peroxide (HP).
Seventy-two 6x6x2 mm3 enamel slabs were prepared from human premolars. The specimens’ color and Vickers’
microhardness were recorded at baseline (T0). The specimens were divided into six groups: twelve specimens per
group. Two groups were treated with 10 % CP with or without casein phosphopeptides and amorphous calcium
phosphate (CPP-ACP) (10 % CP and 10 % CP/CPP-ACP, respectively), two groups were treated with 40 % HP with or
without CPP-ACP (40 % HP and 40 % HP/CPP-ACP, respectively), one group received no bleaching (CON) and
another group received only CPP-ACP treatment without bleaching, (CON/CPP-ACP). The CPP-ACP groups were
treated with CPP-ACP twice daily for five minutes for seven days after completing their respective protocol. The
color change and Vickers’ microhardness were recorded at three time points after treatment; one day (T1), two
weeks (T2), and one month (T3). After one month, the tooth color changed (ΔE) in all groups at every time point;
however, significant ΔE was found only at T3 for the 10 % CP and the CON/CPP-ACP groups (p<0.05). Microhardness
tended to decrease from the baseline (T0) value at each time point. There were significant differences between
time points in microhardness (ΔVHN) in the 40 % HP, CON, and CON/CPP-ACP groups. A relationship between ΔE
and ΔVHN was found in the 10 % CP and 10 % CP/CPP-ACP groups. In summary, tooth whiteness decreased in the
10 % CP group from T1 to T3. CPP-ACP can prevent color relapse in the 10 % CP/CPP-ACP and CON/CPP-ACP groups.
Microhardness improved in the 10 % CP/CPP-ACP group compared with the 10 % CP group at T3. Both tooth whiteness
and microhardness were stable for at least one month when CPP-ACP was used as an intervention in the 10 % CP/
CPP-ACP group.

The aim of this study was to evaluate the frequency of root canal separation on radiographs of mandibular
molars taken for determining endodontic treatment working length using a 20o mesial (M) or distal (D) shift jig compared
with a perpendicular (0o) angle. Radiographs of 42 human mandibular molars were taken at a horizontal angle of
0o, 20o M shift, or 20o D shift to the tooth. The radiographs were evaluated by two examiners. Seventy-one percent
and 73 % of the 20o M shift radiographs were deemed acceptable (separated roots) by the first and second examiner,
respectively. In contrast, 54 % and 64 % of the 20o D shift radiographs were acceptable to the first and second
examiner, respectively. The strength of agreement from both examiners was at a high level of 0.804-0.904. The
percentage of acceptable M and D shift radiographs for each examiner were similar (P>0.05) and significantly higher
compared with the 0o x-ray beam angle (P<0.05). Radiographs taken using either the 20o M or D shift jigs are more
likely to have distinct mandibular molar root canal separation when determining the working length for root canal
treatment compared with 0o images. The advantage of these jigs is the precise determination of the shifted
radiograph angle.

The proposes of this study were to compare the effective on promoting oral health care for bedridden
elderly people between applying motivational interviewing (MI) and conventional dental health education (CDE).
This study was a quantitative part of a mix method based on an explanatory sequential design. Sixty-two elders
and family caregivers in Krabi Province were randomly assigned to an intervention or a control group. In the 3
months’ follow up, 28 and 26 participants remained in the intervention and control group, respectively. At baseline,
there were no significant differences between the intervention and control groups on levels of plaque index, oral
health behavior care for elders as well as general characteristics of elders and caregivers except elder’s diet types,
number of permanent teeth, caregivers’ education and age (p<0.05). At 3 months’ follow-up, the proportion of
appropriate oral health care for the elders in the intervention group was significantly different from the control group (p<0.05) such as toothbrushing with fluoride toothpaste, rinsing with mouthrinse, frequency on oral hygiene
care, oral hygiene and oral status-check after oral hygiene care. Furthermore, level of positive attitudes towards oral
health care was increased at 3 months’ follow-up in an intervention-group. There were no significant differences
of level of plaque index between groups, but dental plaque index of each group decreased comparing with their
baselines.

Deep cervical lesion is one of the bacterial tracts that can cause pulpal infection. Although, most
endodontically treated posterior teeth are susceptible to fracture due to marginal ridge loss, it is doubtful about
the effect of deep cervical loss to fracture resistance and the proper restoration for these teeth. This study
investigated the effect of wedge-shaped cervical tooth loss and/or endodontic access and resin composite restoration
on the fracture resistance and fracture pattern of maxillary premolars. Sixty-five intact extracted upper premolars
were divided into 5 groups (n=13) with different amounts of tooth structure loss: 1) Intact tooth (IT), 2) Cervical
lesion (CL), 3) Endodontic access (EA), 4) Cervical lesion and Endodontic access (CLEA), and 5) Cervical lesion,
Endodontic access, and Resin composite restoration (CLEAR). Each specimen was vertically loaded on its occlusal
surface using a universal testing machine until fracture occurred. Fracture resistance was analyzed using One-way
analysis of variance, followed by the Tukey HSD test (α=.05). The fracture patterns were determined by visual
inspection. The EA and CLEA group presented significantly lower fracture resistance than the IT groups. The fracture
resistance of The CLEAR group was not significantly different from that of the IT group. Most teeth in the IT, CL and
CLEAR group fractured above cemento-dentinal junction (CEJ) but in the EA and CLEA groups, fracture under CEJ
were prevalent. In conclusion, endodontic access significantly reduced the fracture resistance of maxillary premolars,
especially when combined with a cervical lesion. Resin composite restoration increased the fracture resistance to
approximately that of the intact tooth.

The aim of this study was to compare the effectiveness of different oral health education (OHE) programs
in late elementary school students in Bangkok. One hundred and fifty-four students were divided into 3 groups:
Group 1 was instructed OHE by school health teacher, Group 2 was instructed OHE by school health teacher in
combination with peer modeling activities, Group 3 served as a control group which did not receive any interventions.The teacher used OHE instructor guide which comprised of dental caries, gingivitis, and tooth cleaning technique.
Peer models served as a model and motivated other students to brush their teeth during the lunch break. Knowledge
scores and plaque scores were assessed in all students before OHE program and 3 months afterward. The knowledge
was evaluated by multiple choice questions while plaque level was detected by erythrosine dye and measured
with soft debris index. The results indicated that post-test knowledge scores increased statistically significant in both
OHE groups (p<0.001) when compared with pre-test knowledge scores and the control group (p<0.001). However,
there is no statistically significant difference between both OHE groups. Plaque scores decreased statistically significant
only in peer group when compared with baseline (p<0.001). The results suggested that OHE by school health
teacher was not enough in term of changing tooth brushing behavior when using plaque scores as an indicator. The
participation of peer models in OHE program increased the effectiveness of OHE in school.

The objective of this study was to evaluate the mechanical, biological and aesthetic performance of
ceramic veneers after 5 to 7 years of service. The ceramic veneer restorations were clinically examined using a
modified criteria of the United States Public Health Service (USPHS) and World Dental Federation (FDI). Clinical
evaluation was performed by two clinicians during maintenance appointments between September 2016 and August 2017. Intra-examiner and inter-examiner reliability was evaluated by calculating the intraclass correlation coefficient and by inter-examiner calibration. The results were analysed by the Kaplan-Meier survival estimation method and log-rank test at a 95 % confidence level. One hundred and sixty-three veneers [a mean clinical service of 68.1±0.66 months] were examined. Overall survival rate of the veneer restorations was 97.5 % with 2.5 % (four veneers)
presenting clinically unacceptable problems, such as fracture and debonding. Caries were not detected in any teeth.
Radiographic examination found the development of a periapical lesion in one patient after veneer placement.
Veneer placement in premolars showed a higher failure rate than other dental regions. Most patients were
comfortable with their restorations and satisfied with the aesthetic results. Ceramic veneers demonstrated a high
survival rate with most failure cases resulting from fracture and debonding.

Cleaning a root canal is important for successful endodontic treatment. Currently, several irrigants have
been suggested for primary teeth. The objective of this study was to evaluate the cleaning ability of various root
canal irrigants in primary teeth. Forty-four primary anterior teeth with periapical lesion were selected and divided into
four groups using different root canal irrigants: 1 % sodium hypochlorite; 2 % chlorhexidine liquid; 2 % chlorhexidine
gel and normal saline. The roots were prepared for SEM analysis. Four areas of each one third were examined and
scored. The data were analyzed using Kruskal Wallis H and Friedman test. Result showed that the best cleaning
was found in the coronal third and the worst in the apical third (P<0.01). Cleaning result of chlorhexidine gel did
not significantly differ from that of sodium hypochlorite. In addition, the cleaning ability of chlorhexidine gel was
better than that of chlorhexidine liquid in all root thirds. No significant difference was observed between chlorhexidine
liquid and normal saline in any root thirds. It was concluded that the least effective cleaning ability of all irrigants
were found in the apical third, chlorhexidine gel showed better cleaning than chlorhexidine liquid and normal
saline, but did not differ from sodium hypochlorite.

Objectives of supportive periodontal therapy are to maintain healthy periodontium and prevent periodontal disease progression by regular recall appointments. Clinical parameters recorded during visits can identify current periodontal status and, moreover, can predict disease progression in the future. It is useful for treatment planning especially in risk sites which are possible to have further loss of clinical attachment. This review article gathers information regarding the importance and predictability in disease progression of three clinical parameters including bleeding on probing, suppuration, and probing pocket depth during supportive periodontal therapy. Each clinical parameter can predict disease progression in different levels. To date, no clinical parameter can forecast the attachment loss accurately.

Sialadenoma papilliferum (SP) is a rare benign salivary gland tumor. Mostly, it occurs in association with minor salivary glands, especially at the posterior palate. The typical clinical features of this tumor are asymptomatic, slow growing, broad-based papillary projections of the oral mucosa. Here, we report a case of SP at the posterior palate of a 57-year-old woman. After incisional biopsy, complete excision of the tumor was performed. Histopathological examination showed parakeratinized stratified squamous epithelium which exhibits exophytic papillary projections along with underlying fibrocollagenous vascular connective tissue containing ductal structures lined by inner columnar cells and outer cuboidal cells. Based on these findings, the final diagnosis of SP was given. No recurrence was observed at 12 months follow-up. Reviews of previous case reports, clinical and histopathological differential diagnosis are discussed.

Artificial eruption (AE) is an orthodontic procedure aiming at assisting an impacted tooth to erupt and to align with adjacent teeth for functional and/or esthetic purposes. AE of multiple or poor prognosis impacted teeth is challenging and needs an interdisciplinary approach. The objective of this case report is to present the AE procedures and outcomes of two cases with complicated impacted dentition. The first patient had 3 high impacted maxillary anterior teeth of which self-eruption occurred after space in the dental arch was gained. The second patient had a tooth impacted in a poor prognosis position. The tooth was eventually brought into the arch after a series of attachment reposition and force direction design. All rescued teeth were well aligned with their adjacent teeth. Periodontal status was as healthy as their counterparts on the other side of the arch.

Topical corticosteroid is the first-line drug for treating immune-mediated oral lesions, 0.1 % being the most effective concentration. However, conventional topical Triamcinolone acetonide (TA) applications are poorly retained on the oral mucosa. Hydroxypropyl methylcellulose (HPMC) polymer patches are used as buccal mucosa drug delivery systems, as they enhance a drug’s ability to adhere to the oral mucosa and reduce the frequency and amount of drug application. The objective of this study was to prepare a new HPMC-based buccal muco-adhesive polymer patch for the delivery of 0.1 % TA. The solubility, water absorption, muco-adhesion and in vitro drug release study using high-performance liquid chromatography (HPLC) were compared with a commercial product. The results revealed that the 3 % and 2 % HPMC patches had significantly lower dissolution rates, a favorable property, compared with that of the commercial product (p<0.05). The 3 % HPMC group demonstrated the highest dissolution time. Every concentration of the newly developed muco-adhesive polymer patches had higher water absorption than that of the commercial patches at 1 and 5 min. In addition, the 3 % and 2 % HPMC patches demonstrated significantly higher water absorption compared with the commercial patches at 10 and 30 min. There was no significant difference in muco-adhesion between the developed patches with commercial product. All HPMC groups did not show significantly higher drug release compared with the commercial product group at every time point. 3 % HPMC group had the highest drug release. The 3 % HPMC group had significantly higher drug release than 1 % HPMC at 2, 4 and 6 h. We demonstrated the potential of a buccal muco-adhesive polymer patch as an alternative treatment for oral ulcerations. The buccal mucosa patches had a higher dissolution time compared with the commercial product. The 3 % HPMC had lower dissolving and higher drug release at 2 to 10 h. The newly developed muco-adhesive polymer patches had improved properties pertaining to drug application. Further study is needed to improve some of the properties of the oral patches and to implement a clinical study.

Objectives: The aim of the study was to evaluate the influence of four resin composites on voids in small and large Class II cavities. Furthermore, the thickness of the first increment of the restorations was studied. Methods: Eighty artificial lower second premolars were divided into two preparation designs with 40 standardized Class II cavities in each, and then restored with four resin composites (three bulk-fill types: SonicFill 2, Filtek Bulk Fill (capsule), Filtek Bulk Fill (syringe) and a conventional nanohybrid resin composite: Premise). Restorations were sectioned for microscopic evaluation and a Kruskal-Wallis analysis was performed to evaluate the number of voids and percent void area. The thickness of the first increment was measured and analyzed. Results: There were significant differences in the number of voids and percent void area among the 4 groups in small cavities. SonicFill 2 and Filtek Bulk Fill (capsule) placed with the injection technique showing reduced voids. In contrast, no significant differences were detected among the 4 groups in large cavities. Most of the first increment thicknesses of the restorations in both cavity preparations were thicker than recommended. Conclusions: Voids were reduced when the injectable resin composites were applied in small Class II cavity preparations, and the best results were achieved using SonicFill 2.

Objective To investigate the effect of ferrous sulphate (FeSO4) as a chemical activator to hydrogen peroxide tooth bleaching gels on color change and treatment time. Methods One hundred and twenty extracted human upper premolars, hue A or B, were selected. One enamel-dentin specimen was prepared from each tooth. The specimens were divided into twelve groups (n=10), based on bleaching product, FeSO4 and treatment time. Three in-office bleaching products were used in this study: Opalescence® BoostTM, PolaOffice® and ZOOM!® WhitespeedTM. Each product was used per its specific protocol: 1: untreated control (C), 2: FeSO4 added, using the product’s specified treatment time (Fe100 %), 3: FeSO4 added, using approximately 75 % of the specified time (Fe75 %), 4: FeSO4 added, using approximately 50 % of the specified time (Fe50 %). The color was measured before and immediately after bleaching, using a VITA Easyshade® V spectrophotometer based on the CIE-L*a*b* color system. Data between experimental groups of each product were analyzed using one-way ANOVA and Tukey’s or Tamhane’s test (p=0.05). Results Color parameter (ΔL, Δa, Δb and ΔE) evaluation indicated no differences between the C, Fe100 % and Fe75 % of each product. Compared with the C group, only Δb of the ZOOM!® WhitespeedTM Fe50 % group was significantly different (p=0.001). No differences were found between the Opalescence® BoostTM and PolaOffice® C and Fe50 % groups with each material. Conclusion Adding FeSO4 was effective in reducing the treatment time of Opalescence® BoostTM, PolaOffice® and ZOOM!® WhitespeedTM by at least 25 %.

The aims of this study were to develop an age estimation equation in Thai population using segmented pulp/tooth area ratio (sPTR) and to test the reliability of that equation. The sample consisted of 400 digital periapical images of right maxillary central incisors derived from 163 men and 237 women aged between 10.03 and 81.61 years (mean=32.38 years). sPTR measurement modified from the Cameriere’s method was performed in the 400 samples. Subsequently, statistical analysis was performed in order to generate a regression model for age estimation. Then, another 103 samples were tested for the accuracy of the regression model. The difference between the chronological age and the estimated age was statistically calculated. The correlation coefficient was statistically significant, with r=-0.86 (p<0.05). The power regression model for the Thai sample yielded the following equation: Age=0.790×sPTR(-2.059). The coefficient of determination (R2) was 0.82. The mean difference value between the estimated and the chronological ages was -0.80. The mean absolute error (MAE) was 4.26 years. The standard error of prediction (SEP) was 5.70 years. In conclusion, the sPTR on the maxillary central incisor we firstly proposed in this study can be useful for age estimation in Thais.

The aim of this study was to assess whether a reference manual toothbrush alone and in conjunction with variable width of floss would have different efficacy in plaque removal or result in different amounts of reduction of gingival inflammation. The randomized, controlled, double blind examiner, two-period crossover study examined floss efficacy in 34 healthy subjects following use of a standardized manual toothbrush alone and in combination with four floss products (Oral B® Essential floss, Oral B® Satin floss, Sparkle® expanded floss, Paldent® expanded floss). The gingival index score (Löe and Silness) and Rustogi Modified Navy plaque index score were examined. The results presented that mean gingival index score reductions (baseline minus endpoint) were as follows: 0.4628, 0.5005, 0.3818, and 0.3923 for the toothbrush in combination with Oral B® Essential floss, Oral B® Satin floss, Sparkle® expanded floss, and Paldent® expanded floss, respectively. Mean plaque reductions in floss contact areas were as follows: 0.3475, 0.3096, 0.3159, and 0.198 for toothbrush in combination with Oral B® Essential floss, Oral B® Satin floss, Sparkle® expanded floss, and Paldent® expanded floss, respectively. No statistically significant differences were found between any pairs of floss. All four floss treatments showed greater (p<0.05) plaque removal and reduction in gingival inflammation than toothbrush alone. In conclusion, all four floss products in combination with a manual toothbrush removed plaque significantly better than the toothbrush alone. Among floss types, there were no significant treatment differences.

This study aimed to survey and evaluate knowledge and practice of Dental Safety among Thai Dentists in public hospitals. Eight hundred and fifty-five dentists representing 855 public hospitals were asked to complete the online-survey questionnaire enclosed with details of the study along with the consent letter. The questionnaire regarding Dental Safety Goals and Guidelines (DSGG) classified into 5 categories- Safe Communication, Safe Dental Treatment, Safe Infection Control, Safe Record and Risk Management. Response options were graded on a 4-point-Likert scale ranging from 0 to 3. The non-respondents received a reminder email after the second week. The data was analyzed by descriptive statistics using Statistical Package for Social Science (SPSS, version 22.0). Two hundred and twenty-seven dentists returned the DSGG questionnaire. A response rate of 26.5 % was achieved. Participants were in hospitals in every region of Thailand. Approximately 57 % of them were DSGG-survey-participants in the last two years. The results indicating the highest DSGG compliance is Patient Medical History taking (score=2.90±0.22) and the lowest DSGG compliance is Respiratory Hygiene (score=1.58±1.13). The overall responses indicated that most dentists had good practice in regards to DSGG.

The aim of this study was to compare the maximum static frictional resistance of the various orthodonticligation methods. The 0.019”x0.025” straight stainless steel main archwires were ligated on 0.022”x0.028” slot maxillary right central incisor standard stainless steel brackets. The samples were divided into six groups according to ligation methods (10 samples per group): stainless steel ligation (Group 1); and five elastomeric ligations which were conventional ligation (Group 2); one pair of wing ligation (Group 3); two pairs of wing ligation (Group 4); cross-wing ligation (Group 5); and figure of eight ligation (Group 6). Then, all samples were tested using a Universal Testing Machine. The main archwires were pulled vertically and the maximum static frictional resistance was calculated. In order to compare the mean maximum static frictional resistance among the groups, One-Way ANOVA and Dunnett’s T3 multiple comparison test were used. Most ligation methods had different maximum static frictional resistance (p<0.05). The least mean maximum static frictional resistance was in the stainless steel ligation group (37.12±15.15 g), and was not significantly different from that in the cross-wing elastomeric ligation group (44.10±7.50 g). The greatest static frictional resistance was in the figure of eight elastomeric ligation group (226.64±37.94 g).

Periodontal disease is one of the major health problem impacted the quality of human life and associated with systemic diseases. A number of antiplaque agents and antibiotics have been used as an adjunctive treatment for periodontal therapy. However, the use of these agents might increase bacterial resistance and unwanted side effects. Herbs are important sources of new drug development. Some herbs have been used for century in traditional medicine. This literature will provide the research information about Thai medicinal plants that have potential to be the candidates for development of anti-plaque and anti-periodontal agents in the future.

The maintenance of mandibular position is an important part of the treatment process in the hemimandibulectomy patient. It corrects the mandibular position into the normal and helps patient function the jaw. This case report presents the usage of an oral appliance modified from the upper occlusal splint, which the palatal and labial flanges were added for guidance in a 31-year-old female patient who was treated for myxoid chondrosarcoma by the right hemimandibulectomy. After the surgery, the patient had her mandible deviated 10 millimeters to the right in the habitual occlusion. By wearing the oral appliance at night time for 6 months, she could constantly bite in the intercuspal position without mandibular manipulation. The patient reported that her mastication was improved. In conclusion, the intraoral appliance modified from the occlusal splint is profitable in maintaining the mandibular position of the hemimandibulectomy patient.

There are various patterns of longitudinal tooth fractures. Patients often present with pain or sensitivity.Radiographic evaluation cannot detect initial crack, it may difficult to locate the caused tooth. The location, direction and extension of cracks and fractures have an effect on the choice of treatment. Cracks and fractures are the pathways for bacterial penetration, which could lead to inflammation and disease of pulp tissue. In this report, clinical examinations, diagnosis and treatments of longitudinal tooth fracture are reviewed and discussed.

The aims of this study were to determine the effect of different surface treatment methods and provisional materials on the shear bond strength of orthodontic brackets. One hundred and sixty samples were randomly divided into 4 material groups (n=40); A: acrylic resin (Unifast™ Trad), B: bis-acryl (Protemp™ 4), C: polycarbonate crown (3M ESPE), D: denture teeth (Cosmo™ HXL). In groups A and B, 5×5×2 millimeter box-form cavities were prepared on cured resin blocks and these cavities were filled with provisional materials. After polymerization, the materials’ surfaces were polished and stored in distilled water for 7 days. In group C and group D, samples were embedded in a self-curing epoxy resin within polyvinyl chloride pipes in which the labial surfaces of C and D were above the self-curing epoxy resin and stored in distilled water for 7 days. Samples of each group were randomly divided into 4 subgroups of the following surface treatments (n=10); 1: Control, 2: 600-grit sandpaper, 3: Assure™ Plus, and 4: Sandblast. Lower incisors brackets (Gemini™, 3M) were attached with Transbond™ XT adhesive. All samples were stored in distilled water for 24 hours. A thermocycling procedure was conducted for 500 cycles between 5 °C and 55 °C. Samples were stored in distilled water for 24 hours. The shear bond strength was measured with a universal testing machine. The mode of failure was examined under a stereo microscope.
The results of the surface treatment groups showed that the mean shear bond strength of sandblasting groups was significantly higher than all other surface treatment groups of all materials, except for sandblasting on the bis-acryl group (B4) (p<0.05). Other surface treatment methods on all materials showed no statistically significantly difference except in the polycarbonate crown with Assure™ Plus (C3), which presented the lowest mean shear bond strength (p<0.05). The mean shear bond strengths of custom type materials (group A and B) were significantly higher than the prefabricated type material (group C and D) (p<0.05).
Both types of materials and surface treatment methods influenced the shear bond strength of the brackets bonded to the provisional materials. The sandblasting technique enhanced the shear bond strength effectively in all materials except for bis-acryl that originally expressed high shear bond strength even without surface treatment. The surface treatment that uses the sandblasting technique and using bis-acryl composite which exhibited higher shear bond strength to other materials and surface treatment may offer a good option in clinical practice.

This study purposed to assess the average of the facial alveolar bone thickness at the facial root surface of the maxillary anterior teeth, along with its relationship to the root position by using cone-beam computed tomography (CBCT) in a group of Thai population. Seventy CBCT scans (420 teeth) were randomly selected from the CBCT database at School of Dental Medicine, Rangsit University. The exclusion criteria were the subjects with extensive dental caries, fixed coronal restoration, severe root resorption, and destructive periodontal disease in maxillary anterior region. After recruitment, 406 teeth were used to measure facial alveolar bone thickness and sagittal root position (SRP). The data of the facial alveolar bone thickness was collected in cross-sectional dimensions. The measurements were performed at three reference points, which were 4 mm apical to CEJ (R1), midpoint between 4 mm to CEJ and mid-root (R2), and mid-root (R3). The results revealed that the facial alveolar bone thickness seemingly decreased apically in every type of tooth. The mean facial bone thickness of maxillary teeth was between 0.67±0.75 to 1.04±0.67 mm. The majority of examined teeth in this study exhibited Class I SRP (overall 92.87 %; central incisor 93.87 %, lateral incisor 89.85 %, and canine 95.56 %). Class II SRP was found to be 5.4 %, 5.22 % and 2.27 % in lateral incisor, central incisor and canine respectively. Class IV SRP was found only 1.73 % (lateral incisor 1.45 %, central incisor 1.50 % and canine 2.22 %). But Class III SRP did not present in this study. Simple correlation test showed no statistically significance between the facial alveolar bone thickness and root position. In conclusion, the anterior maxillary teeth have a high prevalence of thin facial alveolar bone wall. These findings may consider risking of facial alveolar bone dehiscence, fenestration or soft tissue recession after immediate implant placement. The majority of the root position is SRP class I which is favorable for the implant – alveolar bone engagement of immediate implant placement.

The objective of this study is to determine whether air exposure of different disinfectant wipes by un-capping the container alter the bactericidal efficacy. Three commercially available disinfectant wipes with different active ingredients consisting of CaviWipes™ (QAC & Isopropyl alcohol), SporeClear™ (QAC & Biguanides) and Optim 33TB (Ionized H2O2) were used in the experiment. Forty milliliters of stimulated saliva were collected from 15 healthy volunteers in the morning before performing daily oral hygiene care. The saliva was spread on sterilized leather surfaces and air dry. The surfaces were then used to test the effectiveness of disinfectant wipes those had been air exposed for 1, 4 and 18 hours compared with a group that tightly cap the container. The remaining CFU/mL of bacteria on the surfaces were calculated to compare log reduction. Data were statistically analyzed by Kruskal-wallis test and Mann-Whitney U test. A value of p<0.05 was considered significant. This study revealed that air exposure seems to marginally affect the antibacterial capability of disinfectant wipes with different active ingredients as determined by log reduction. Despite non-alcohol containing formula of SporeClear™, air exposure seems to worsen its activity, though no statistically significant difference was observed. Bactericidal activity of CaviWipes™ and Optim 33TB were quite stable regardless of prolonged air exposure or the order of sheet pulled out from the container. The outermost sheet of SporeClear™ was more affected by prolonged air exposure. To sum up, bactericidal efficacy of disinfectant wipes was minimally affected by duration of air exposure. Activity of SporeClearTM, a non-alcohol containing formula, was greater affected by time and order of sheet dependent according to its texture.

การศึกษาในห้องปฏิบัติการมีวัตถุประสงค์เพื่อเปรียบเทียบค่ามัธยฐานของค่าเฉลี่ยรอยซึมเล็กของสารผนึกหลุมและร่องฟัน 3 ชนิด โดยทำในฟันกรามน้อยบนจำนวน 102 ซี่ สุ่มแบ่งเป็น 3 กลุ่ม กลุ่มที่ 1 ผนึกหลุมและร่องฟันชนิดเรซินที่มีฟลูออไรด์ กลุ่มที่ 2 ผนึกหลุมและร่องฟันชนิดเรซินที่ไม่มีฟลูออไรด์ และกลุ่มที่ 3 ผนึกหลุมและร่องฟันด้วยกลาสส์ไอโอโนเมอร์ ตามวิธีการที่บริษัทกำหนด จากนั้นนำฟันไปแช่ในเครื่องควบคุมอุณหภูมิแบบร้อนเย็นเป็นจังหวะที่อุณหภูมิ 5 องศาเซลเซียสสลับกับ 55 องศาเซลเซียส จำนวน 500 รอบแล้วทาน้ำยาทาเล็บให้ทั่วฟัน โดยเว้นบริเวณที่ห่างจากขอบของสารผนึกหลุมและร่องฟันออกมา 1 มิลลิเมตร นำฟันไปแช่ในสารละลายเมทิลีนบลูความเข้มข้นร้อยละ 0.5 ที่อุณหภูมิห้องเป็นเวลา 24 ชั่วโมง ตัดฟันในแนวใกล้แก้มใกล้ลิ้นด้วยเครื่องตัดฟันยี่ห้อไอโซเมท และวัดรอยซึมเล็กด้วยกล้องจุลทรรศน์สเตอริโอกำลังขยาย 100 เท่า เมื่อเปรียบเทียบค่ามัธยฐานของค่าเฉลี่ยของรอยซึมเล็กทั้ง 3 กลุ่ม ด้วยสถิติทดสอบครัสคัล-วอลลิส ที่ระดับนัยสำคัญ 0.05 พบว่ามีความแตกต่างอย่างมีนัยสำคัญ (p<0.001) เมื่อพิจารณาเป็นคู่ของกลุ่มศึกษาด้วยสถิติทดสอบแมนวิทนีย์ ยู ที่ระดับนัยสำคัญ 0.0083 พบว่าค่ามัธยฐานของค่าเฉลี่ยรอยซึมเล็กของกลุ่มสารผนึกหลุมและร่องฟันชนิดกลาสส์ไอโอโนเมอร์กับชนิดเรซินที่มีฟลูออไรด์ และระหว่างกลุ่มสารผนึกหลุมและร่องฟันชนิดกลาสส์ไอโอโนเมอร์กับชนิดเรซินที่ไม่มีฟลูออไรด์ รวมทั้งระหว่างกลุ่มที่ผนึกหลุมและร่องฟันชนิดเรซินที่มีฟลูออไรด์กับชนิดเรซินที่ไม่มีฟลูออไรด์ มีความแตกต่างอย่างมีนัยสำคัญ (p<0.001) สรุปว่า สารผนึกหลุมและร่องฟันชนิดกลาสส์ไอโอโนเมอร์ เกิดรอยซึมเล็กมากกว่าสารผนึกหลุมและร่องฟันชนิดเรซินที่มีและไม่มีฟลูออไรด์

The purpose of this study is to investigate the relationship between the level of hardness or toughness evaluation and electromyography parameters of some Thai foods in 32 healthy young Thai adults who did not have masticatory problems. The subjects were given 5 Thai foods with different hardness and toughness to chew and afterward were tested for those levels by using visual analog scale (VAS) and electromyography. The result showed that the scores of each parameter obtained from VAS were significantly correlated with those obtained by electromyography (p<0.05, and r=0.224-0.384). A weak to moderate correlation between two test methods which may be due to the adaptability of masticatory muscles to the hardness and toughness of the food. Therefore, the evaluation of hardness and toughness level of food using a VAS questionnaire could partly reflect the functions of masticatory muscles.

There is very little available information on the root characteristics of mesially impacted mandibular second molars (7M). This study investigates occlusal inclination, root curvatures and calcification stage of unilateral 7M versus their normal counterparts (7N). Inclination and curvature of the mandibular first molars on the affected (6M) and control side (6N) were also assessed. Fifty-one digital panoramic radiographic images from study participants with unilateral 7M were examined with image J software. Occlusal inclination and degrees of root curvature at middle third and apical third level of mesial and distal root of 7M, 7N, 6M, 6N were measured and compared. Association between 7M occlusal inclination and degree of root curvature was tested. Calcification stage of 7M and 7N was evaluated by Demirjian Index. There were significant differences of occlusal inclination between 7M and 7N (P<0.01), and between 6M and 6N (P<0.01). In 7M, apical third of mesial root tended to curve mesially (P<0.01), whereas in 6M, apical third of both roots tended to curve distally (P<0.01) but the middle third of distal root tended to curve mesially (P<0.05). No association between the degree of root curvature and occlusal inclination was found for 7M. About one-quarter of 7M had delayed calcification compared to 7N. In conclusion, there were differences in root curvature between 7M and 7N, and 6M and 6N. 6M tended to be more upright than 6N. The degrees of root curvature and occlusal inclination of 7M were not related.