Journal of Dental Medicine

Normal 0 false false false EN-US X-NONE AR-SA 1482 patients of 3-5 years ( 56% m/44% f) were selected from Isfahan kindergartens. In 1.4% of them, numeric  dental anomaly was diagnosed of which 0.74 %  had congenital missing teeth, 0.06 % had hyperdontia and 0.6% had geminated teeth. 0.72 % of Congenital missing was seen in boys while 1.2% in girls. Also, Gemination was seen 0.12 % in boys and 1.2% in girls which is 10 times more than boys in total study population. 0.2% of cases had concomitant tooth missing and gemination. Missing was mostly seen in mandibular incisors. Germination was seen  80% in mandibular anterior region. Besides, in 50% of the patients who had primary teeth missing, permanent teeth missing in both sides were also diagnosed by radiography. One case found with supernumerary tooth in maxillary lateral incisor region. In this article, the possible risk factors were analyzed in case and control groups. Any significant relationship between these factors and numeric dental anomalies was concluded.

Background and Aims: Considering the great incidence of implant failures due to high stresses around implant and at bone-implant interfaces, the aim of this study was to compare the effects of three different implant-macro designs on the quantity and distribution pattern of stresses around implants.
Materials and Methods: In this experimental in vitro study, three types of implants including Biohorizon (4×10.5 mm), Iler (4×10 mm), and Swiss Plus (4.1×10 mm) were studied by applying photo-elastic method. The implants were placed within photo-elastic models with dimensions of 50×50×10 mm. Then through open tray impressed method, crowns for each implant were constructed and cemented. Vertical and oblique loads of 100 N and 150 N were applied on the cemented crowns within polariscope machine. Then the photographs were evaluated using Isochromatic Fringe Characteristics table.
Results: Under vertical loads of 100 N and 150 N, the values for Biohorizon, Iler, Swiss Plus fixtures at the cervical region were (2.35, 3.60) N, (2.50, 3.10) N, and (1.39, 2.35) N, respectively and in apical region the values were (1.63, 2.35) N, (1.82, 2.35) N, and (2.50, 3.10) N. Under oblique loads, the measures at the cervical region were (4.00, 5.00) N, (1.82, 5.00) N, and (5.20, 6.00) N and in apical region were
(1.39, 2.00) N, (4.00, 2.35) N, and (2.35, 3.00) N, respectively for mentioned implants.
Conclusion: Under vertical loads, the lowest cervical stresses were observed in Swiss Plus fixture and the lowest apical stress values were recorded for Biohorizon fixture. Under oblique loads, the lowest cervical stresses were found in Iler implant and lowest apical stresses were recorded for Bohorizon.

Background and Aims: Instrumentation of the root canals results in formation of smear layer which covers the dentinal tubules. In infected teeth, it is ideal to achieve a material that has the ability to remove the smear layer besides antimicrobial activity. Therefore, this study was designed to evaluate the antimicrobial effect of Citrus aurantifolia extracts (lime juice and rind extract) on Enterococcus faecalis within dentinal tubules in the presence of smear layer.
Materials and Methods: One-hundred and forty dentin tubes were prepared from bovine incisors. After removal the smear layer, the specimens were infected with Enterococcus faecalis. Then, the smear layer was reformed. Test solutions were used as the irrigants in study roups as follows: group 1: 5.25% NaOCl group 2: 17% EDTA group 3: NaOCl+EDTA group 4: Lime juice group 5: ethanolic rind extract of C.aurantifolia group 6: 96% ethanol. Dentin chips were collected from inner and outer layers of dentinal walls and optical density was measured. The data were analyzed using one-way ANOVA and Tamhane tests.
Results: In outer layer of dentin, the efficacy of rind extract was less than that of NaOCl+EDTA (P<0.05). Also Lime juice was less effective than EDTA, NaOCl and NaOCl+EDTA (P<0.05). In inner layer of dentin, Lime juice was significantly less effective than NaOCl and NaOCl+EDTA (P<0.05). The efficacy of rind extract was less than that of NaOCl+EDTA (P<0.05).
Conclusion: In the presence of smear layer, the antimicrobial activity of Lime juice was less than that of NaOCl but the efficacy of rind extract was similar to that of NaOCl.

  Background and Aims: The increase in the number of complex implant cases has drawn the attention of researchers toward materials having bone regeneration promoting ability. Socket preservation and bone graft are recommended to minimize bone resorption. The aim of this study was to evaluate a kind of xenograft collagenic bone (osteo biol gen_oss) in socket regeneration.

  Materials and Methods: This randomized clinical trial was performed in 12 cases (6 in test and 6 in control groups) with two hopeless teeth. After tooth extraction, in test group, graft material was put in sockets but in the control group the socket was healed naturally. Three months later, during implant placement the specimens from both sites were sent to a pathologist for histologic and histomorphometric evaluations. Data were analyzed using Mc Nemar and Wilcoxan sigh rank test (α=0.05).

  Results: There were no significant differences between two groups in foreign body reaction, inflammation, bone vitality and percentage of bone gain. Average percentage of residual graft in test site was 6.73±1.43.

  Conclusion: Osteobiol gen_oss xenograft is an appropriate biocompatible osteoconductive material that promotes bone regeneration at 3 months following socket preservation in human extraction sockets.