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OBJECTIVES: This in vitro study was designed to compare polyvinyl-siloxane (PVS) monophase and polyether (PE) monophase materials under dry and moist conditions for properties such as surface detail reproduction, dimensional stability, and gypsum compatibility. MATERIALS AND METHODS: Surface detail reproduction was evaluated using two criteria. Dimensional stability was evaluated according to American Dental Association (ADA) specification no. 19. Gypsum compatibility was assessed by two criteria. All the samples were evaluated, and the data obtained were analyzed by a two-way analysis of variance (ANOVA) and Pearson's Chi-square tests. RESULTS: When surface detail reproduction was evaluated with modification of ADA specification no. 19, both the groups under the two conditions showed no significant difference statistically. When evaluated macroscopically both the groups showed statistically significant difference. Results for dimensional stability showed that the deviation from standard was significant among the two groups, where Aquasil group showed significantly more deviation compared to Impregum group (P < 0.001). Two conditions also showed significant difference, with moist conditions showing significantly more deviation compared to dry condition (P < 0.001). The results of gypsum compatibility when evaluated with modification of ADA specification no. 19 and by giving grades to the casts for both the groups and under two conditions showed no significant difference statistically. CONCLUSION: Regarding dimensional stability, both impregum and aquasil performed better in dry condition than in moist; impregum performed better than aquasil in both the conditions. When tested for surface detail reproduction according to ADA specification, under dry and moist conditions both of them performed almost equally. When tested according to macroscopic evaluation, impregum and aquasil performed significantly better in dry condition compared to moist condition. In dry condition, both the materials performed almost equally. In moist condition, aquasil performed significantly better than impregum. Regarding gypsum compatibility according to ADA specification, in dry condition both the materials performed almost equally, and in moist condition aquasil performed better than impregum. When tested by macroscopic evaluation, impregum performed better than aquasil in both the conditions.
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OBJECTIVES: To prevent accidental ingestion of implant hex dive. MATERIALS AND METHODS: Dental floss which is used to stabilize the hex drive is tied to the operator's finger ring to overcome sudden aspiration of fallen instrument. RESULTS: It showed excellent grip of the instrument during stage two uncover time and also saved operators time. CONCLUSIONS: Accidental aspiration or swallowing of the dental instruments during routine implant surgeries can be prevented by tying the implant instruments to the operator's ring with silk ligatures or dental floss.
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OBJECTIVES: (1) To measure the crestal bone levels around implants immediately, and one month, three months, and six months after immediate implant placement, to evaluate the amount of bone level changes in six months. (2) To measure the initial stability in immediate implant placement. MATERIALS AND METHODS: Ten patients were selected and a total of ten implants were placed in the immediate extraction sites. The change in the level of crestal bone was measured on standardized digital periapical radiographs taken at baseline, first month, third month, and sixth months for each patient, using the SOPRO imaging software. The initial stability of implants was measured with resonance frequency analysis (RFA) and an engine-driven torque. The measurements were statistically analyzed. The student's t-test was used, to identify the significance of the study parameters. RESULTS: When mesial and distal bone losses were averaged, the radiographic evaluation with the SOPRO imaging software showed an average of 0.80 mm, with a standard deviation of ± 0.18 mm bone loss at the first month, followed by 1.03 mm with a standard deviation of ± 0.19 mm at the third month, and 1.23 mm with standard deviation of ± 0.6 mm at the sixth month. The initial stability with the RFA instrument showed a mean of 55 implant stability quotient (ISQ) values and the torque showed a value of 36.50 Nm. CONCLUSIONS: The implant has to be placed 2 mm below the crestal bone level to compensate the crestal bone loss. The initial stability is achieved by apical preparation of the socket wall and use of straight screw implants. When the defect is more than 2 mm, autogenous grafts with membranes are the best choice.
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BACKGROUND: Recasting the base metal alloys is done as a routine procedure in the dental laboratories whenever there is casting failure or to decrease the unit cost of a fixed partial denture. However, this procedure may affect the metal ceramic bond. Furthermore, it is unclear, as to which test closely predicts the bond strength of metal-ceramic interface. The aim was to compare the bond strength of nickel chromium (Ni-Cr) and cobalt chromium (Co-Cr) alloys with dental ceramic on repeated castings using shear bond test with a custom made apparatus. MATERIALS AND METHODS: Sixty metal ceramic samples were prepared using Wiron 99 and Wirobond C, respectively. Three subgroups were prepared for each of the groups. The first subgroup was prepared by casting 100% fresh alloy. The second and third subgroups were prepared by adding 50% of fresh alloy and the remnants of the previous cast alloy. The bond load (N) between alloy and dental porcelain was evaluated using universal testing machine using a crosshead speed of 1 mm/min, which had a 2500-kgf load cell. Mean values were compared using oneway analysis of variance with post-hoc Tukey's test and Student's t-test. RESULTS: The mean shear bond load of A0 (842.10N) was significantly higher than the load of A1 (645.50N) and A2 (506.28N). The mean shear bond load of B0 (645.57N) was significantly higher than the load of B1 (457.35N) and B2 (389.30N). CONCLUSIONS: Significant reduction in the bond strength was observed with the addition of the first recast alloy (A1 and B1) compared with the addition of second recast alloy (A2 and B2). Ni-Cr alloys (664.63N) showed higher bond strengths compared to that of Co-Cr alloys (497.41N). The addition of previously used base metal dental alloy for fabricating metal ceramic restorations is not recommended.
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Immunodeficiency associated Burkitt's lymphoma is the most common in patients with HIV/AIDS. It accounts for 30-40% of Non-Hodgkin's lymphomas and may be the first sign of underlying immunosuppression. This report illustrates a case of Burkitt's lymphoma of maxillary alveolar ridge, which was the first manifestation in an HIV positive patient, with a brief discussion on clinicopathologic features, aetiopathogenesis and treatment.