The aim of the present study was the histological evaluation of Enamel Matrix Derivative (EMD) effectiveness for regeneration of periodontal defects. EMD activates cementum synthesis, PDL and bone during the maturation stage of follicole. In this research, EMD was used in surgical defects of premolar teeth in four adult sheep. Muccoperiosteal flap was reflected in buccal site of teeth. The buccal bone plate was removed from mesial to distal in 4 mm depth. After eliminating the cementum by bur and its etching, EMD was applied on exposed dentine and flap was sutured. In opposite sites of those teeth (control sites) the same process was performed without etching. After 100 days, sheep were sacrificed and histological study through light microscopic was performed on black sections of operation sites. The results showed that in test sites, regeneration of cementum and bone was 62/5% and 42/5-50% respectively. But in control sites regeneration of cementum and bone was 37.5% and 32/5-42/5% respectively. Also the migration of junctional epithelium in control sites was 8-10% more than test sites. The important point is that in test sites, cementum was completely attached to undermining dentine. But, in control sites, the gap between cementum and dentine was visible. As a result, this study suggests that EMD promotes periodontal regeneration, and EMD application is a successful achievement in regenerative periodontal therapy.

Background and aim: Palatal groove as a growth-developmental anomaly can lead to periodontal problems, therefore diagnosis and treatment of its complications is of high importance.The aim of this study was to evaluate clinically the efficacy of enamel matrix derivative (EMD) in the treatment of periodontal defects due to palatal groove.Materials and Methods: Ten patients with palatal groove on maxillary lateral incisor with pocket depth ≥4mm were chosen from those referred to department of periodontics, Faculty of Dentistry Tehran University of Medical Sciences, and private office (2002-2003). During the surgical procedure, a full thickness flap was elevated and respective root thoroughly planed. After groove saucerization, EMD was used to cover the defect. The flap was then coronally positioned and secured with 3-0 silk sutures.Clinical measurements were taken at baseline, 1 and 3 months post-surgery. These parameters included pocket probing depth (PPD) and clinical attachment level (CAL). Statistical analysis was performed by the test of difference between means.Results: mean PPD and CAL before surgery were 5.7mm and 6.2mm, respectively that changed to 1.5mm and 2.05mm at 3 months post-surgery-statistically significant gain of attachment (71.05%) was observed 3 months after surgery (p-value <0.000).Conclusion: The results of this study suggest that EMD can be used successfully for periodontal attachment gain in teeth with palatal groove.

Background: White spot formation is one of the common side effects in orthodontic treatments and multiple enamel conditioning might happen even during on session of fixed orthodontic treatments. The aim of the present study was to evaluate the impact of multiple enamel conditioning with different methods on enamel micro‑, hardness (MH). Materials and Methods: In this In vitro experimental study, the buccal surfaces of 105 extracted premolars were evaluated in seven groups: One control and six experimental groups. The enamel conditioning was performed in three ways: Etching with phosphoric acid 37%, etching with phosphoric acid 37% followed by primer application and conditioning with self‑, etch primer. The conditioning process in each way was also performed twice consecutively. The specimens were submitted in pH cycling model with demineralization and re‑, mineralization solutions for 14 days. Afterward Vickers MH test was applied with 0. 981N force on the teeth for 10 s indentation time. Data were analyzed using One‑, Way ANOVA and Tukey HSD (honestly significant difference) test for multiple comparisons. A value of P < 0. 05 was considered statistically significant. Results: MH analysis showed statistically significant differences between the control group and the other conditioned groups (P < 0. 05). The groups conditioned with acid‑, etch and primer, particularly twice, showed the lowest amount of MH in comparison to other groups. Self‑, etch primer had the least effect on MH of the enamel. Single time etching without using primer, made no considerable difference when compared to multiple etching. Conclusion: Etching process and covering the enamel with primer decrease enamel MH. Using self‑, etch primer is a more conservative method of enamel conditioning.

Introduction. Glass ionomer materials have been, used for years as liners, bases and temporary restoration for children. Their bonding properties allow temporization, which would be difficult with conventional cements of restorative materials. The desirable properties include easy and rapid application, fluoride release, biocompatibility and adhesion to dentin and enamel tend to be used in children specially for precooperative or handicapped children and preclude the need for treatment using general anesthesia of sedation in this research, shear bond strength of glass ionomer in two groups, including normal group and hypoplastic enamel group is tested. Methods. For this purpose, 2 groups each including 12 samples of normal anterior deciduous teeth and hypoplastic anterior deciduous teeth (with attention to hypoplastic indices) were chosen. The labial surface of teeth were prepared with medium and fine size discs, chem fil glass ionomer cement was bonded to prepared surfaces of teeth, and then samples were fixed in special site of self curing acrylic. The specimens were tested with a model 4031 instron machine. A shear load was applied to the base of the bonded glass ionomer cylinder with a knife edge rod (width, 0.5 mm) at a cross head speed of 0.5 mm/mm.Results. The mean of obtained sbs for 2 groups was 16.35 and 11.63 KGF/mm2.Conclusions. Statistical analysis of the results showed significant defferences between studied groups. But with attention to desirable properties, application of glass ionomer cement in hypoplastic defects of enamel in children is recommended.

Dental enamel is the end product of monogenesis, which can be considered to take place in three interrelated phases. When this complex sequence of cytological and physicochemical events disrupted by genetic or environmental factors, the function of the ameloblasts may be disrupted permanently or temporarily. The result shows qualitative and quantitative defects that may range from a complete absence of enamel or a slight discoloration. The aim of this study was to determine the prevalence of enamel defects by DDE index in a randomly selection group of 1637 students age 7-12 years old in Isfahan (<0.2-0.3 PPMF). Enamel defects were present on one or more teeth in 27% of the cases. The most common affected tooth was the central maxillary and then first molar of maxilla. The most common affected surfaces were buccal. Hypo plastic defects were found in first molar; however premolar and canine were affected by diffuse white lines opacity.