Introduction: There are many available Nickel Titanium (Ni-Ti) rotary systems that are used for canal cleaning and shaping of the permanent teeth. The new emerging concept in pediatric dentistry is the use of rotary files for canal instrumentation in primary teeth. In literature, there are no clinical studies comparing three different rotary systems in primary teeth. The aim of this study was to compare and evaluate the quality of obturation and instrumentation time using three rotary file systems in primary mandibular molars. Materials and Methods: A total of 45 primary mandibular molars were included in the study and were randomly allotted to one of the three groups. Group 1: ProTaper files; Group 2 Kedo-S files and Group 3: RaCe files. Standardized digital radiographs were taken to the assess quality of obturation as underfill, optimal fill and overfill. Statistical analysis was done using SPSS software version 17.0. An intergroup comparison of the quality of obturation and instrumentation time was done using Chi-square test and ANOVA with the level of significance set at 0.05. Results: No significant difference was observed in the quality of obturation among the three groups (P = 0.661). However, a statistically significant was noted in the instrumentation time among the groups (P < 0.05). In Kedo-S files group 80% of the teeth were optimally filled followed by 60% in ProTaper files and 46.67 % in RaCe files group. The instrumentation time was least in RaCe files 31.67 secs followed by ProTaper files 45.93 secs and Kedo-S (78.53 secs). Conclusion: No significant difference was noted with respect to quality of obturation using S2 ProTaper files, Kedo-S files and RaCe files in primary teeth. There was a significant difference in instrumentation time among the three groups with least working time with RaCe files.

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Introduction: The asymmetry of mandibular ascending ramus leads to serious orthodontic problems in the dentofacial complex. This study was aimed to assess the effects of gender bone properties difference on biomechanics of distraction osteogenesis that used for ascending ramus lengthening with different forces. Materials and Methods: A 3D mandibular model was constructed and an oblique osteotomy line was made. The force was applied perpendicular to the osteotomy line in a bidirectional manner with three different distraction rates (5 mm, 10 mm and 15 mm). Results: Male and female models showed the same maximum Von Mises stress value and the same distribution with the same force, the maximum stress value for 5mm, 10mm and 15mm rates were greater than the ultimate tensile stress for the human bone. The displacement within the three rates in X, Y and Z directions was higher for male than female. The displacements in all three directions were more prominent in the mandibular chin area. Conclusion: No gender difference in stress values and distribution with more anterior displacement in male than female. This site of distraction results in forward and anti-clockwise rotation of the mandible resulting in reducing anterior facial height.

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Maxillary sinus hypoplasia (MSH) is a rare condition characterized by underdevelopment or decrease in the volume of the maxillary sinus. It is thought that MSH may be embryological in origin but acquired etiologies have also been discussed in the literature. MSH is usually detected upon radiographic examination of the maxillofacial area. Three types have been described based on variations in sinus anatomy. A case of bilateral maxillary sinus hypoplasia with concurrent hemimandibular hypertrophy is presented, and pertinent clinical and cone beam computed tomography findings are reported.

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Introduction: Head and neck squamous cell cancer (HNSCC) is a common cancer worldwide. It has been associated with TP53 mutation and chronic inflammation. The control genes of inflammation, Tumor Necrosis Factor Receptor Superfamily (TNFRSF) in HNSCC has not been widely reported. The impact of the TNFRSF and survival and cell death regulation signalling (SCDRS) can be studied at protein, gene, mRNA and transcription level. In this manuscript, the association of mRNA of TNFRSF and SCDRS genes in treatment naïve HNSCC with TP53 mutation is studied. Materials and Methods: TP53 mutation, tobacco use and mRNA levels of TNFRSF and SCDRS genes of 520 HNSCC cases were collated and analysed. Statistical and differential expression (DE) analysis was performed. Results: A total of 12 genes of the 51 genes studied were DE between TP53 subgroups. They were SCDRS genes (BAD, CASP9, GSK3B, NFKB2, TGFBR1, TGFBR2) and TNFRSF genes (TNFRSF10A/11B/14/25/6B/9). The network analysis and subsequent KEGG pathway analysis identified several key pathways including vital cancer pathways and transcriptional pathways in cancer. The key genes in the network that modulate TNFRSF and SCDRS mRNA expression in wild and mutant TP53 situation are presented. Conclusion: The present work identified certain key TNFRSF and SCDRS mRNAs that could differ based on TP53 status and count with tobacco use. Also this study identified certain pathways where the gene network could potentially alter the HNSCC progression, treatment response and prognosis. This adds to our knowledge of TP53 and inflammation in HNSCC carcinogenesis.

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Introduction: The aim of this study was to compare the shear bond strength at the resin/bracket interface of metal brackets sandblasted with aluminum oxide particles of 25 µm, 50 µm and 110 µm. Materials and Methods: Sixty metal brackets were recycled and randomly assigned into four groups according to the aluminum oxide (Al₂O₃) particle size (µm) used during sandblasting. Brackets of the first three groups (Group 1, n = 15; Group 2, n = 15 and Group 3, n = 15) were sandblasted with 25µm, 50µm, and 110µm Al₂O₃ particle size, respectively. The control group (Group 4, n = 15) included brackets without sandblasting. Shear bond strength was evaluated before and after sandblasting. Brackets with some variation in shape or structure were excluded. Intragroup and intergroup comparisons were performed with paired t-test and one-way analysis of variance (ANOVA) followed by Scheffé test, respectively. Results: The recycled sandblasted brackets showed greater shear bond strength approximately 4 to 6 Mpa more than those that did not receive sandblasting. There were no statistically significant differences between the sandblasted groups (P > 0.05). However, Group 3 (110µm) showed a numerically greater mean value of shear bond strength (9.34 ± 4.18 Mpa). Conclusion: Similar share bond strength at the resin/bracket interface can be expected after bracket sandblasting with 25µm, 50µm, and 110µm Al₂O₃ particle size. Independently of the particle size used, the sandblasted brackets showed greater shear bond strength than brackets without sandblasting.

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Introduction: This study evaluates the trends in the disinfection of the dental X-ray machines in North American dental schools. The methods of disinfection were compared to the Centers for Disease Control (CDC) guidelines. Materials and Methods: A survey posed the question of whether plastic barrier wrap, bag, disinfecting wipes, or a combination were used for infection control of the tube head. Additional information was gathered from the dental schools’ infection policy guides and clinic manuals available online. Results: Of the forty-two Canadian and US dental schools surveyed, 24% used disinfectant wipes, 19% used bags, 19% used plastic surface barriers, and 38% used a combination. Conclusion: The majority of schools used a combination of the three methods, and all institutions abided by the CDC guidelines. As bags are more cumbersome to use with a rectangular collimator, wipes and barriers are arguably better methods to disinfect the X-ray tube head.

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Introduction: The aim of this study was to compare the effect of four different salivary pH levels on the shear bond strength (SBS) of two orthodontic adhesive systems for bracket placement. Materials and Methods: This in-vitro experimental study was performed on 72 premolars extracted for orthodontic reasons. They were randomly assigned into two groups according to the adhesive system employed: Orthocem (light-cure adhesive, FGM^®) or Transbond-XT (3M Unitek). Each group involved nine specimens incubated in artificial saliva at four pH levels regarding previous studies: acidic pH (4.8 and 5.8), control pH (6.8) and alkaline pH (7.8), during two months. Once removed, shear bond strength with a universal testing machine was applied. The SBS comparisons between adhesive systems was obtained using t-test and for salivary pH levels in each group one-way ANOVA and Tukey tests were used (P < 0.05). Results: Transbond-XT adhesive system showed the greater SBS, mainly in the neutral salivary pH (11.18 ± 2.82 Mpa) followed by the alkaline (10.33 ± 2.49 Mpa) (P > 0.05). Significant differences were found regarding to both acidic pH levels (pH 4.8 and 5.8) with values between 6 and 8 MPa (P < 0.05). Moreover, Orthocem adhesive system had lower SBS values, with greater value in the neutral salivary pH (6.24 Mpa), don’t achieved significant differences with the other pH levels; 4.74 Mpa for pH 4.8 and 5.05 Mpa for pH 5.8. Conclusion: Transbond XT orthodontic adhesive system showed only greater values of SBS only for the control and alkaline pH levels; for acidic pH levels there was no difference between the two systems. This situation must be taken into account by clinicians.

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Introduction: Oral submucous fibrosis (OSMF) is a pre-malignant condition highly prevalent in India with a malignant transformation rate of 2–8%. Its incidence amongst younger population has risen due to increased consumption of commercial preparations of areca. p63, a homolog of p53, has a role in epithelial proliferation and is frequently altered in dysplasia and associated with tumorigenesis. CD31 is a highly specific endothelial marker with varied expression in epithelial dysplasia and carcinoma. Epithelial proliferation and underlying angiogenic support are vital processes for malignant transformation. Therefore the present study aims to determine if p63 and CD31 expression is associated with increased malignant transformation of OSMF. Materials and Methods: A cross-sectional study wherein n = 36 OSMF samples were histologically graded into Group I (Early-Ea), II (Moderately advanced-MA) and III (Advanced-Ad) and analysed for anti-p63 and anti-CD31 antibodies. The expression was evaluated quantitatively and by pattern of distribution across the groups and statistically analysed with Chi-Square and Kruskal-Wallis tests (SPSS v2.0). Results: p63 expression of epithelium in Group I ∼100% (basal, suprabasal), II − 60.9% (basal, spinous), III − 62.5% (basal, spinous, granular) with a significant P-value < 0.001*. Predominant pattern of CD31 positive vessels in Group I ∼60% (constricted), II > 50% (normal diameter) and III ∼ 75% (dilated) with a significant P-value of 0.02*. Conclusion: A significant linear increase in nuclear staining of p63 and involvement of epithelial strata observed from Ea → MA → Ad grade of OSMF. CD31 expression exhibited more dilated vessels as OSMF grade increased from Ea → Ad. Therefore p63 and CD31 could be used as quantitative predictive biomarkers of malignant transformation of OSMF.

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Introduction: Ameloblastoma is the most common neoplasm of odontogenic epithelium with locally aggressive behavior resulting in recurrence and malignant transformation. Odontogenic cysts are common lesions of the jaws with different biological behavior. Odontogenic keratocyst (OKC) and calcifying odontogenic cyst (COC) with ameloblastoma-like epithelium (ameloblastic type) are more aggressive than other odontogenic cysts. Therefore, these lesions were classified as odontogenic tumors by WHO. Transforming growth factor beta 1 (TGF-β1) is a secretory protein with diverse cellular functions including epithelial differentiation during tooth development and pathological processes such as tumorigenesis. It can function as a strong tumor suppressor gene during initial stages of tumor development. The aim of this study was to evaluate the TGF-β1 expression in ameloblastoma, OKC and COC with varying biological behavior. Materials and Methods: We examined TGF-β1 expression in epithelial and stromal cells of 15OKCs, 15COCs (ameloblastic type) and 15 ameloblastomas by immunohistochemistry. Results: Immunoreactivity was observed in epithelial and stromal cells of all lesions with different degrees. There was statistically significant reduced immunoexpression in epithelial cells of ameloblastomas and COCs compared to OKCs, whereas significant reduced immunoreactivity was reported in stromal cells of OKCs. There was no statistically significant difference between COCs and ameloblastomas in both stromal and epithelial cells immunoreactivity which shows their similar bilological behavior. Conclusion: Reduced TGF-β1 immunoexpression in epithelial cells of ameloblastomas and COCs compared to OKCs could be associated with the primitive phenotype and more invasive biological behavior of these lesions. Reduced stromal expression of TGF-β1 in OK1Cs could be explained by its looser stroma than other studied lesions.

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Introduction: Majority of rural dental outreach programs focus on screening the subjects attending the programs and providing oral health education for them. There has only been limited emphasis on the provision of care as a part of the outreach activities for the geographically disadvantaged rural population. The objective of this study is to check whether the basic clinical data as collected in the form of number of decayed teeth can be a valid and reliable predictor in calculation of requisite time for provision of restorative services by developing a predicting equation from the data obtained on 400 subjects in outreach activities and subsequently testing the predicting general linear equation for predictive accuracy. Materials and Methods: The number of decayed teeth in each of the participants was recorded along with collection of demographic data from the study participants. Data obtained from the 400 participants was used to generate a predicting equation after running a backward stepwise multiple linear regression. The equation was subsequently tested among a subsample of 200 participants from the exploratory sample and an independent validatory sample of 200. SPSS version 20 software, multiple linear regression, Wilcoxon signed rank test, Mann Whitney U test were used in data analysis. Results: Number of decayed teeth was observed to be a single, significant predictor of the man hours required in provision of restorative care. The predicting equation generated had good predictive accuracy and predictive stability as observed from the non-significant differences between the requisite time calculated using the predicting equation and that clinically determined by the calibrated examiner among both the subsample of exploratory sample and the validatory sample. Conclusion: The predicting equation generated in this study accurately and consistently estimated the requisite man hours necessary for provision of restorative oral health care in outreach programs.

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