Background: Masticatory forces generate various degrees of stress and strain in the periodontium of teeth which determine the clinical functions and load-bearing capacity of the teeth. There are few in vitro studies that have analyzed stress generated due to combined forces acting on the teeth. Thus, the objective of the present study was to do a comparative analysis of the influence of various stresses on the periodontal ligament and alveolar bone of maxillary central incisor with normal bone height and reduced bone height under simulated standard masticatory using finite element stress analysis. Methodology: A 3D model of the tooth was obtained with the help of ANSYS software. These models were subjected to various oblique forces, i.e., 100N and 235.9N, applied at 45° angle on the lingual surface of the maxillary central incisor and stress values were recorded in three dimensions. The results from FE analysis were analyzed using 3D Von Mises Criteria. Results: It was observed that in healthy periodontium; it was observed that among the periodontal structure studied, the maximum stress levels were exerted on root followed by cortical bone, cancellous bone, and PDL, irrespective of the force, as compared to the diseased periodontium, in which the bone height was reduced, the maximum stresses were on root followed by cortical bone, PDL, and cancellous bone. Conclusion: The main factor governing the success of any periodontal procedure depends on the height of the remaining bone and the amount of force exerted on to the tooth and the stress generated within the tooth. The finite element method could be of substantial importance in this respect as it can assess the stresses of various occlusal forces on the periodontal ligament, root, cortical bone, and cancellous bone of teeth in a periodontally healthy and diseased state.

Transverse maxilla-mandibular discrepancies are a major component of several malocclusions. Surgically assisted rapid palatal expansion (SARPE) is a common treatment modality for older patients in the correction of a maxillary transverse deficiency. In such cases, retention of the appliance plays an important role and this becomes a problem in patients having enamel hypoplasia. Therefore, the design was modified of a tooth-borne rapid maxillary expansion appliance with provision for miniscrew skeletal anchorage in a Class II malocclusion case having anterior open bite with bilateral posterior crossbite and enamel hypoplasia.

INTRODUCTION: The most important property of Fluoride is anti-cariogenic property which aids in remineralization of incipient carious lesions in enamel thereby inhibiting enamel demineralization i.e. it helps in arresting or reversal of incipient enamel lesions. A prolonged exposure of incipient carious lesions to uoride in the aqueous phase achieves the cariostatic effect. OBJECTIVES: The aim of the present study is to evaluate the amount of uoride released by three different Restorative Materialsi.e. Glass Ionomer Cement, Resin Modied Glass Ionomer Cement, Cention on 1st,7th and 15th day followed by Recharge and Re-release after recharging with various Flouride applications. MATERIALS AND METHODOLOGY: Fifteen Disk-shaped specimens for each group (8.5 mm diameter; 3 mm thickness) were prepared from three different restorative materials using cylindrical Teon molds according to manufacturer's instructions. The specimens in each individual group were incubated in a 95% relative humid environment at 37°C for 24 hours. Specimens of each group were immersed in 20 ml deionized water in plastic bottles and stored in the incubator at 37°C, Fluoride concentration was measured using a UV Spectrophotometer after 1st ,7th & 15 days. The samples from each group were now divided into: 3 Sub Groups of ve each. Sub Group A - Control group – No topical uoride application. Sub Group B - The samples were recharged with 2% Neutral Sodium Fluoride solution for 4 minutes and washed with copious deionized water for 10 sec and dried on absorbent paper. Sub Group C - The samples were recharged by hand brushing with a Fluoridated brushing Dentifrice for four minutes and then wiped clean with a tissue and rinsed for 10 sec using copious deionized water and dried. Measurement of uoride Re-release is done by UV Spectrophotometer after 1st ,7th and 15thday after recharge.The results were statistically analysed using analysis of variance (one-way ANOVA) and Tukey Kramer multiple comparison tests (p≤0.05). RESULTS: Independent of the observation time period of thestudy the Conventional GIC released the highest amount of uoride followed by RMGIC & CENTION. The initial burst effect was seen with GIC'S but not with RMGIC, CENTION. After topical uoride application uoride re-release was highest in Sub Group B and GIC had a greater recharging ability followed by RMGIC & CENTION. The uoride re-release was greatest on 1st day followed by rapid return tonear exposure levels. CONCLUSION: From the study it was concluded that, the initialFluoride release was highest from Conventional GIC followedby Resin Modied GIC, CENTION. The Fluoride release was high when recharging with professional regime (2%NaF) as compared to home regime (Toothpaste).

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