Analysis of Effectiveness of Different Rotational Instruments in Implantoplasty: An In Vitro Study.

OBJECTIVE: To analyze the temperature increase in the implant, adjacent bone, procedure time, and roughness provided by different rotatory instruments in the implantoplasty procedure. MATERIAL AND METHODS: Three types of rotational instruments were used to evaluate the implant surface wear, divided according to their surface features: Group 1 (G1) diamond, Group 2 (G2) tungsten carbide, and Group 3 (G3) multilaminar. For the roughness test, a control group was included for comparison with the test groups. RESULTS: The temperature variation was statistically significant in the implant (P < 0.05) where G2 showed the lowest variation. There was no statistically significant difference between the 3 groups regarding the temperature increase measured in the bone (P > 0.05). The difference of wear time was statistically significant (P < 0.05) with faster results for G3. In the surface roughness analyses, there was a statistically significant difference (P < 0.05) between the control group and the test groups. Among the 3 test groups, the difference between measurements was not statistically significant (P > 0.05). CONCLUSION: All tested rotatory instruments performed the same level of surface roughness in the implantoplasty. The tungsten carbide bur caused a minor change in the implant temperature. The multilaminar bur performed a faster wear time. More in vivo studies are necessary to conclude which is the best rotatory instrument for implantoplasty.

Effects of inorganic mercury exposure in the alveolar bone of rats: an approach of qualitative and morphological aspects.

BACKGROUND: In comparison to organic mercury (MeHg), the environmental inorganic mercury (IHg) can be found in some skin-lightening cosmestics were considered "harmless" for a long time. However, recent studies have shown that long-term exposure to low doses of IHg may affect biological systems. Therefore, this study investigated the effects of IHg long-term exposure to the alveolar bone of adult rats. METHODS: Adult Wistar rats were distributed in control and HgCl2 exposed (0.375 mg/kg/day). After 45 days, the rats were euthanized and both blood and hemimandibles were collected. Total blood Hg levels were measured and both inorganic and organic components of the alveolar bone were determined through XRD and ATR-FTIR. The microstructure of the alveolar bone was assessed by using micro-CT and the morphometric analysis was performed by using stereomicroscopy. RESULTS: Alterations in the physicochemical components of the alveolar bone of exposed animals were observed. The bone changes represented a tissue reaction at the microstructural level, such as bone volume increase. However, no significant dimensional changes (bone height) were observed. CONCLUSION: Exposure to IHg at this dose can promote microstructural changes and alteration in the organic and inorganic components in the alveolar bone.