Objectives: Heat-polymerized acrylic resin has been the most commonly used denture base material for over 60 years. However, the mechanical strength of acrylic resin is not adequate for long-term clinical performance of dentures. Consequently, fracture is a com- mon clinical occurrence, which often occurs in the midline of denture base.This study aimed to evaluate the efficacy of cold cure and heat cure acrylic resins, rein- forced with glass fibers, polyethylene fibers, and metal wire for denture base repair.

Materials and Methods: Ninety specimens were prepared and allocated to nine groups. Ten specimens were included in the control group, and 80 were allocated to 8 experi- mental groups. In the experimental groups, the specimens were sectioned into two halves from the middle, and were then divided into two main groups: one group was repaired with heat cure acrylic resin, and the other with cold cure acrylic resin. Each group was di- vided into 4 subgroups: unreinforced, reinforced with glass fibers, polyethylene fibers, and metal wire. All specimens were then subjected to a 3-point bending test, and the flexural strength was calculated.

Results: The group repaired with heat cure acrylic resin and reinforced with glass fiber showed the highest flexural strength; however, the group repaired with cold cure acrylic resin and reinforced with polyethylene fibers had the lowest flexural strength. There was no significant difference between the groups repaired with heat cure and cold cure acrylic resins without reinforcement.

Conclusion: Repairing denture base with heat cure acrylic resin, reinforced with glass fi- bers increases the flexural strength of denture base.

Objectives: Early diagnosis of incipient and non cavitated carious lesions is crucial for performing preventive treatments. The aim of this study was to compare the effi- ciency of three diagnostic methods of bite-wing radiography, DIAGNOdent, and visu- al examination in diagnosing the incipient occlusal caries of permanent first molars.

Materials and Methods:  In this diagnostic cross-sectional study, 109 premanent first molar teeth of 31 patients aged 7-13 years were examined visually by bite-wing radi- ograghy, and DIAGNOdent. Scoring of visual and radiography examinations were based on the Ekstrand classification. Visual examination after pit and fissure opening was used as the gold standard. ROC curve (Receiver Operating Characteristics) was used to define the best cut-off point for DIAGNodent compareing with gold standard and inter-examiner reproductibility of visual, radiography were assessed using Kappa test and ICC (Intraclass Correlation) wase used for DIAGNOdent values.

Results: The sensitivity of detecting caries that had extended into the enamel was 81.4%, 86.3%, and 81.4% for visual examination, DIAGNOdent, and radiography, respectively. Moreover, the specificity was 100%, 71.4%, and 100% for visual obser- vation, DIAGNOdent, and radiography, respectively in the enamel. The Kappa index for inter-examiner correlation was 0.7 and 0.8 for visual examination and radiog- raphy, respectively. The ICC (Intraclass Correlation) was 0.98 for the values read by DIAGNOdent.

Conclusion: Visual examination is rendered as the first choice in the diagnosis of in- cipient caries. In suspicious cases, radiography and laser DIAGNOdent can be used as adjunct procedures.

Objectives: Smoking may impact oral self-care (OSC).  This study aimed to analyze the role of smoking in OSC among Iranian dental health professionals.

Materials and Methods: The cross-sectional data were collected at two annual dental meetings and seven randomly selected dental schools in Iran. A total of 1,459 respond- ents composed of 967 general dental practitioners (GDPs), 229 dental educators (DE), and 263 senior dental students (DS) anonymously completed a self-administered ques- tionnaire inquiring about smoking status and OSC.

Results: Thirty percent of the men and 12% of women reported smoking with no dif-ference according to their professional status. Women reported better OSC than did men, but only 26% of the women and 17% of the men followed the three most important recommendations for OSC. Smoking was associated with infrequent tooth brushing and flossing, irregular use of fluoride containing toothpaste, consumption of sugary snacks, and weak adherence to the recommended OSC guidelines.

Conclusion: Dental health education should place more emphasis on smoking counsel-ing and cessation among dental health professionals.

Objective: Increased levels of oxidative stress markers in periodontitis have been reported by recent studies. Malondialdehyde (MDA) and superoxide dismutase (SOD) are both in- creased during oxidative stress. The aim of this study was to detect and measure the level of oxidative stress markers in peri-implant crevicular fluid (PICF). Their correlation with peri-implant clinical parameters was investigated as well.

Materials and Methods: PICF samples of 50 dental implants were collected in 31 pa- tients. Peri-implant clinical parameters including probing pocket depth (PPD), gingival index (GI) and bleeding on probing (BOP) were recorded. Levels of oxidative stress markers including MDA, SOD and total antioxidant capacity (TAC) in PICF were deter- mined.

Results:  Twenty  four  implants  showed  signs  of  inflammation  and  26  implants  had healthy  peri-implant tissues. MDA and TAC were seen in all samples, but SOD was not detected around 31 implants. The differences between the two groups with respect to the levels of MDA, TAC and SOD in PICF, were not statistically significant (P> 0.05).  In addition, significant positive correlations were observed between PPD and TAC and MDA level (P<0.05).

Conclusion: Significant correlations exist between PPD and level of MDA and TAC. Moreover, level of oxidative stress markers (MDA, SOD and TAC) in PICF does not sig- nificantly change in peri-implantitis compared to healthy implants. Measuring these mark- ers in PICF does not seem to be helpful for discrimination of peri-implant health and dis- ease status.

Objectives: The aim of this study was to determine the cementum thickness in the first molars of patients with localized aggressive periodontitis (LAP) compared to healthy individuals.

Materials and Methods: This case-control study compared eight first molar teeth af-fected by LAP with eight third molar teeth of healthy individuals. The teeth were dis- infected by immersion in 10% buffered formalin solution for three days and were then sectioned. External mesial root surfaces (middle one-third) were evaluated under a ste- reomicroscope by a blinded pathologist to determine the mean thickness of cementum. SPSS software (version 16.0) and t-test were used for statistical analysis.

Results: Histological examination revealed a significant difference between the two groups in terms of the amount of cementogenesis (P<0.001) .The thickness of cemen- tum was higher in the control group (105.16±11.5 μm) than in LAP patients (86.44±7.3 μm).

Conclusion: This study demonstrated the presence of cementum hypoplasia in mesial root surfaces of first molars affected by LAP.

Objectives: The aim of this study was to assess the cytotoxic effects and osteogenic activity of recombinant human bone morphogenetic protein (rhBMP2) and nano-hydroxyapatite (n- HA) adjacent to MG-63 cell line.

Materials and Methods: To assess cytotoxicity, the 4,5-dimethyl thiazolyl-2,5-diphenyl tetrazolium bromide (MTT) assay was used. Alkaline phosphatase (ALP) activity and oste- ogenic activity were evaluated using Alizarin red and the von Kossa staining and analyzed by one-way ANOVA followed by Tukey’s post hoc test.

Results: The n-HA/CS mixture significantly promoted cell growth in comparison to pure calcium sulfate (CS). Moreover, addition of rhBMP2 to CS (P=0.02) and also mixing CS with n-HA led to further increase in extracellular calcium production and ALP activity (P=0.03).

Conclusion: This in vitro study indicates that a scaffold material in combination with an osteoinductive material is effective for bone matrix formation.

Objectives: This study aimed to compare a number of new nanocomposites capable of pro- tecting the jaw from ionizing radiation.

Materials and Methods: Four different types of nano-powders [Ti, Zr (IV) oxide, Ag and Co] were mixed in a polymer matrix to create nano-composites with doping values of 8% in weight. Small-angle X-ray scattering (SAXS) analysis was performed using a HECUS- SAXS system with 50 kV- 50 mA. Co nano-composites (Co-pnm) yielded the most prom- ising values of the 4 nanocomposites tested in terms of x-ray absorption. Thus, 4x2 cm Co- pnm samples of different thicknesses (0.20, 0.50, 0.57 and 0.60 cm) were prepared, and SAXS analysis was performed in order to assess the effects of material thickness on x-ray absorption. An experimental multi part shield was constructed from Co-pnm around tooth

#36 to test the effect of nanomaterial on the image quality under X-ray beam.

Results: Logarithmic distributions of the transmitted intensity values (I) showed that 0.20 cm Co-pnm had the highest transmission value (16.05) followed by 0.50 cm Co-pnm (15.44), 0.57 cm Co-pnm (15.07) and 0.60 cm Co-pnm (15.06). The 0.2 cm Co-pnm had an effective radius of the nano-aggregation value (77.44 Å) lower than that of the other thick- nesses (0.50, 0.57 and 0.60 cm) of Co-pnm, which had similar values ranging from 66.22-66.34 Å. The 0.50 cm Co-pnm had the lowest Dmax value of the different thicknesses of Co- pnm tested.

Conclusion: Co nanocomposite can be used as a protection shield for the harmful effects of dental X-ray.

Lichen planus (LP) is a chronic mucocutaneous disease widely recognized in adults, but uncommon in children. The purpose of this paper is to report two cases of LP in children. The diagnosis was made based on clinical and histopathological findings. The treatment consisted of antifungal and multivitamin therapy. Regression of lesions was observed. The patients are still under follow up.

Although LP is uncommon in children, it is necessary to have adequate knowledge about this condition for proper diagnosis and treatment.

A case of multiple pulp stones, a supernumerary tooth and a congenitally missed tooth accompanied by several developmental dental anomalies concurrently affect- ing the upper and lower anterior teeth in an Iranian healthy girl is reported. Devel- opmental tooth abnormalities are usually found in conjunction with certain diseases or conditions. In the present case, although the patient had consanguineous parents and the role of genetics should be considered particularly for autosomal recessive traits, based on the child’s family and medical history, no correlation could be es- tablished between dental findings and systemic or metabolic diseases.

Fusion is an anomaly manifested in both deciduous and permanent dentitions. Fu- sion of dental tissues in the primary dentition is of clinical significance owing to the challenges in treatment of the affected teeth and aberrations encountered in development and eruption of their successors. Triple tooth refers to the union of three separate tooth entities. It can occur by fusion, germination, concrescence or a combination of both fusion and germination. Triplication is rarely encountered in the deciduous dentition. The case presented herein describes triplication of de- ciduous incisors and a supernumerary tooth. The diagnosis was confirmed with the help of radiographs, CT imaging and histological examination. Retention of the triple tooth had led to crossbite. Extraction was performed for the triplicated tooth and crossbite was corrected using a composite inclined plane.