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: Different surgical techniques have been proposed for crown exposure among patients under orthodontic treatment. The aim of this study was to investigate periodontal indices in closed flap OPERATION technique used for impacted teeth crown exposure.Materials and Methods: In this descriptive study (2001-2003) 20 patients (15 females and 5 males), age ranging from 15 to 20 years, were participated. Following the performance of closed flap OPERATION technique, in 12 patients impacted canine and central incisors were exposed and treated orthodontically. Periodontal parameters including sulcular depth, width of keratinized gingiva and attachment loss were recorded. Results: The mean of gingival sulcus depth was 1.50±0.43, the means of keratinized gingival in central incisors and canines were 3.07±0.53 and 2.30±0.42, respectively. In one patient, attachment loss was reported.Conclusion: Considering the optimal sulcular depth and keratinized gingiva, the closed flap OPERATION technique seems suitable.

Different ossificant materials have been used used for induction of bone repair in many studies, and bone MATRIX gelatin which contains bone morphogenic proteins one of the best ones.In present study we evaluated the role of this mat erial in acceleration of bone repair in rabbit tibia.A hole of 305mm diameter was made on right tibia of 10 and 12 rabbits as study and control group respectively, In the experiment group, in addittion to Bone Wax, we applied bone MATRIX glatin in the hole. Radiographic images were taken in days 0, 20, 40 and 53 after OPERATION In 6 rabbits of each group, photographic pictures were also taken after exposure of entire bone. In 6 controls less degree of restoration were seen on day 53. In 4 experimental animals restoration were completed by this time and in 2 speciments repair processing were better then controls. This results shows that bone MATRIX gelatin can be used as an acclerator of bone repair.

The appropriate and optimum OPERATION of reservoir system of dams ranks among the most important issues considered by experts of water industry all over the word. In most reservoir system of the world, control curves are known as the main pattern of water OPERATION. The curves indicate the optimum volumes of supplied water or yielding system versus various conditions of reservoirs during different month of the year. There are various methods of determining the OPERATION pattern of water reservoirs which are classified into three methods: simulation, optimization and probability MATRIX. In traditional methods, reservoir systems are designed based merely on the historical data of river currents and not using of function indices of reservoir. These methods are based on the assumption that in future there will not happen draught more severe than the recoded critical periods, an assumption the truth of which is far from being definite. The purpose of this research is to demonstrate a method to determine the control curves of reservoir dams based on their functional indices (such as time reliability, vulnerability and resiliency). To achieve this goal, we provided at first, using methods of temporal series AR(1), Valencia Schaake one thousand series of data of currents of the rivers entering the reservoir dam of Mahabad and Shahar chai in west Azarbaijan. We continued with using the improved SPA methods and Gold probability MATRIX, conducting the necessary analysis and providing ultimately appropriate control curves to obtain various combinations of the quantity of demand and functional indices. The obtained results display a good accordance between the results obtained by SPA and probability MATRIX methods. There occurred the maximum difference between the methods in minimum sustainability and the minimum difference in maximum sustainability. In the site of Mahabad the maximum difference is 13.5 MCM and the minimum difference 0.37 MCM. In the site of Shahar chai the maximum difference is 9.88 MCM and the minimum difference 0.098 MCM.

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.