Dental Research Journal
Volume:14 Issue: 6, Nov 2017

The anterior loop is an important structure in the interforaminal area of the mandible. The aim of the present study was to assess the prevalence and length of the anterior loop of mental nerve using cone beam computed tomography (CBCT) scan and to compare the differences between age, gender, and side.
A total of 180 projections were analyzed in different sectional planes. The inferior alveolar nerve was determined. To measure the length of anterior loop in tangential plane, two parallel lines from the anterior point of mental foramen and anterior point of anterior loop were drawn. The distance between these two lines was measured by drawing a perpendicular line on them. The data were analyzed by SPSS (version 22). McNemar’s test, Chi‑square test, and t‑test were performed to compare the significance of findings regarding side, age, and gender. P The results showed that 32.8% of images had anterior loop. The mean lengths of anterior loop in the right and left sides were 2.69 mm (standard deviation [SD] = 1.56) and 2.36 mm (SD = 1.16), respectively. There were no statistically significant differences between the mean lengths of the anterior loop in both sides (P = 0.18).
Great care is required when placing implants in proximity to mental foramen to avoid anterior loop injury. Because of the variations of anterior loop length in each patient, a fixed distance anterior to the mental foramen is not safe, and the anterior loop length should be determined for each individual. The use of CBCT provides accurate measurements of the length of anterior loop.

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland neoplasm. Central MEC (CMEC) is a rare primary intraosseous bony lesion with an incidence of 2%–4.3% of all MECs reported. In this article, we present a rare case of a CMEC in the anterior region of maxilla at a 43‑year‑old female patient that was arising from a dentigerous cyst. CMECs are extremely rare tumor. They are usually low‑grade lesions with favorable prognosis. Odontogenic cysts are one of the origins of this lesion. Treatment of impacted tooth is necessary in the early stage for prevention of this neoplasm.

The treatment of furcation area defects remained as a challenging issue in periodontal treatments. Regeneration treatment of furcation defects is the most discussed periodontal treatment. Although not completely hopeless in prognosis, the presence of the furcation involvement significantly increases the chance of tooth loss. The current research was conductedeto compare theeadditive effect of combined guided tissue regeneration (GTR) and platelet‑rich growth factor (PRGF) on the treatment of furcation bony defects.
A randomized, triple‑blinded, split‑mouth study was designed. It included patients with a moderate to severe chronic periodontitis with bilateral Grade II furcation involvement of first or second mandibular molars. Each side of mouth was randomly allocated for the treatment with either Bio‑Gide American Society of Anesthesiologists GTR or a PRGF or PRGF by itself. Plaque index, gingival index, vertical clinical attachment level, vertical probing depth, recession depth (REC), horizontal probing depth, fornix to alveolar crest (FAC), fornix to base of defect (FBD), furcation vertical component and furcation horizontal component (FHC) were recorded. The current research was conducted to compare the additive effect of combined GTR and PRGF on treatment of furcation bony defects. Altman’s nomogram, Kolmogorov–Smirnov test, Friedman test, general linear model, repeated measures, and paired t‑test were used as statistical analysis in this research. P Eight patients were finally enrolled for this study. Overly, general and specific clinical and furcation parameters were improved except REC that was deteriorated insignificantly and FAC improved not significantly. Intergroup comparison revealed better improvement of FHC in GTR/ PRGF group (P = 0.02).
A significant improvement in the Grade II furcation defects treated with either GTR or PRGF/GTR was noticed. Further large‑scale trials are needed to reveal differences of mentioned treatment in more details.

The functional and esthetic rehabilitation of patients with atrophic maxilla or posterior maxillary defect is often challenging. The aim of this study was to determine patient demographics, indications, success rate, and complications following the use of zygoma implants.
All patients who had zygoma implant placement in our clinic between 1998 and 2013 were retrospectively assessed for implant outcome. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 16 and Microsoft Excel 2007 test for significance (ρ) using Pearson’s Chi‑square (χ2) set at 0.05.
A total of 28 patients consisting of 22 females (78.6%) and 6 males (21.4%) were treated, and their age ranged from 41 years to 83 years with a mean age of 60.3 ± 10.6 years. The main indication for zygoma implant placement was atrophic maxilla 12 (42.9%). In the prosthetic rehabilitation of the patients, 2 had epithetic prostheses, and 2 had obturators while 18 patients had conventional removable dental prostheses. Four patients (14.3%) had perimplantitis and one implant was accidentally placed into the maxillary sinus. A cumulative success rate of 88.1% was obtained from this retrospective analysis.
A cumulative success rate of 88.1% reported in this study is lower than the reports from other studies. The difference in success rates may be related to different criteria for assessment of zygoma implant success and to the difference in inclusion criteria and follow‑up period.

Allergic rhinitis (AR) may be overdocumented in cases of dental caries because of controversies in the literature This study was conducted to investigate the potential relationship between AR and dental caries in children.
A total of 296 children were included in this cross‑sectional study. Participants were evaluated using the decay‑missing‑filled (DMF) index, and their AR status was evaluated by physical examination and through a standard questionnaire. Baseline demographics and clinical characteristics were compared among groups using Student’s t‑test or the Mann– Whitney U‑test, the Chi‑square test, and/or Fisher’s exact test as appropriate. A level of P Evidence of AR was found in 77 (35.1%) participants. There was no significant difference in the rate of tooth decay or DMF between participants with or without AR (P = 0.07), but a significant difference was observed in the number of missing and filled teeth between those with and without AR (P 0.05 in all cases) between AR‑positive and AR‑negative patients. Fluoride therapy and oral breathing were identified as confounding factors and controlled using log‑linear analysis. The mean rate of DMF in patients who also had AR was 20% greater than in the AR‑negative group (odds ratio [OR] = 1.21, confidence interval [CI]: 1.05–1.35) and 15% greater in among children who breathed orally than those who did not (OR = 1.15 CI: 1.02–1.31).
AR and oral breathing may have an effect on oral health and dental condition, leading to an increased rate of tooth loss, oral fillings, and development of dental caries.

The aim of this study was to compare the in vitro effects of four different root canal sealers on the fracture resistance of endodontically treated teeth.
Seventy‑five freshly extracted human mandibular premolars were used for the study. Teeth were divided into five groups based on type of root canal sealers used. Gutta‑percha was used for all the samples: Group I: AH Plus root canal sealer, Group II: MTA Fillapex root canal sealer, Group III: Apexit root canal sealer, Group IV: Conventional zinc oxide‑eugenol (ZOE) sealer, Group V: Control (unobturated teeth). The teeth were embedded in acrylic resin blocks and fracture force was measured using a universal testing machine (Asian Test Equipments). Data obtained were statistically evaluated using one‑way ANOVA and post hoc test (Tukey’s test). All groups showed statistically significant result (P Group I and Group II showed higher resistance to fracture than other three groups. There was comparable difference in fracture force between Group I and Group II. Moreover, there was no statistically significant difference between Group III and Group IV and between Group IV and Group V.
Based on this in vitro study, resin‑based sealer was more effective as compared to other sealers and the control group. However, no significant differences were observed between ZOE and control group.

Masking ability of a restorative material plays an important role to cover discolored tooth structure; however, this ability has not yet been well understood in zirconia‑based restorations. This study assessed the masking ability of a zirconia ceramic on composite resin substrates with different shades.
Ten zirconia disc specimens, with 0.5 mm thickness and 10 mm diameter, were fabricated by a computer‑aided design/computer‑aided manufacturing system. A white substrate (control) and six composite resin substrates with different shades including A1, A2, A3, B2, C2, and D3 were prepared. The substrates had a cylindrical shape with 10 mm diameter and height. The specimens were placed onto the substrates for spectrophotometric evaluation. A spectrophotometer measured the L*, a*, and b* values for the specimens. ΔE values were calculated to determine the color differences between the groups and the control and then were compared with a perceptional threshold (ΔE = 2.6). Repeated measures ANOVA and Bonferroni tests were used for data analysis (P The mean and standard deviation of ΔE values for A1, A2, A3, B2, C2, and D3 groups were 6.78 ± 1.59, 8.13 ± 1.66, 9.81 ± 2.64, 9.61 ± 1.38, 9.59 ± 2.63, and 8.13 ± 1. , respectively. A significant difference was found among the groups in the ΔE values (P = 0.006). The ΔE values were more than the perceptional threshold in all the groups (P Within the limitations of this study, it can be concluded that the tested zirconia ceramic could not thoroughly mask different shades of the composite resin substrates. Moreover, color masking of zirconia depends on the shade of substrate.

Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator. It plays a vital role in immune response against the oral disease. MIF is a regulator of innate immunity, and bacterial antigens can stimulate serum level of this protein. In experimental gingivitis, the expression level of MIF increases and this increment positively correlates with oral plaque index. The single nucleotide polymorphisms in the gene encoding the MIF protein can control the function of MIF. The aim of the present study was a clarification of the associations between MIF‑173 G/C, MIF 95 bp, and 189 bp insertion/deletion (I/D) polymorphisms and chronic periodontitis (CP) compared with healthy controls.
This case–control study was carried out on 210 CP patients and 100 normal subjects. MIF‑173 G/C and MIF 95 bp and 189 bp I/D polymorphisms were genotyped, using polymerase chain reaction–restriction fragment-length polymorphism (PCR-RFLP) and PCR, respectively. Allele and genotype frequencies of the variants were compared between patients and controls using Chi‑square. test. The value of P The study findings showed that MIF‑173 G/C polymorphism, especially the Callele increased the risk of CP. The 95‑bp I/D polymorphism was not associated with CP and the 185‑bp I/D variant was not polymorphic in our population.
Therefore, MIF‑137 G/C variant increased the risk of CP in the South East of the Iranian population. In other words, polymorphisms in MIF gene influence clinical outcome of CP infection and influence the susceptibility to disease. Further studies with larger sample sizes and different ethnicities are required to validate our findings.

Adequate Vitamin D is essential for dental and skeletal health in children and adult. The purpose of this study was to assess the correlation of serum Vitamin D level with external‑induced apical root resorption (EARR) following fixed orthodontic treatment.
In this cross‑sectional study, the prevalence of Vitamin D deficiency (defined by25‑hydroxyvitamin‑D) was determined in 34 patients (23.5% male; age range 12–23 years; mean age 16.63 ± 2.84) treated with fixed orthodontic treatment. Root resorption of four maxillary incisors was measured using before and after periapical radiographs (136 measured teeth) by means of a design‑to‑purpose software to optimize data collection. Teeth with a maximum percentage of root resorption (%EARR) were indicated as representative root resorption for each patient. A multiple linear regression model and Pearson correlation coefficient were used to assess the association of Vitamin D status and observed EARR. P The Pearson coefficient between these two variables was determined about 0.15 (P = 0.38). Regression analysis revealed that Vitamin D status of the patients demonstrated no significant statistical correlation with EARR, after adjustment of confounding variables using linear regression model (P > 0.05).
This study suggests that Vitamin D level is not among the clinical variables that are potential contributors for EARR. The prevalence of Vitamin D deficiency does not differ in patients with higher EARR. These data suggest the possibility that Vitamin D insufficiency may not contribute to the development of more apical root resorption although this remains to be confirmed by further longitudinal cohort studies.

During sliding mechanics, the frictional force (FF) is an important counterforce to orthodontic tooth movement. The purpose of this in vitro study was to investigate the static and kinetic FFs of S silica‑insert ceramic (SIC) brackets with Teflon‑coated (TC) and conventional S stainless steel (SS) archwires.
The target group of this study included 80 maxillary canine 0.022 inch slot SIC brackets. Forty SS brackets were used as the control. TC and conventional uncoated SS archwires of different dimensions (0.016, 0.018, 0.016 × 0.022, and 0.018 × 0.025 inch) were examined. All tests were carried out under artificial saliva injected condition. Scanning Electron Micrographs were prepared for two samples of coated and uncoated archwires. Analysis of variance and Tukey post hoc tests were used for statistical purposes (level of significance P SIC brackets showed significantly lower levels of FFs than SS brackets. TC archwires had greater frictional values than conventional uncoated ones. They also exhibited an unusual behavior of increasing kinetic FFs with time. Indentation and delamination of coating were obvious under scanning electron microscopy observations.
From the standpoint of friction, SIC brackets may serve well, even better than SS brackets, in sliding mechanics. The coating layer of the archwires may delaminate and lost, causing an impediment to tooth movement.