In vivo evaluation of a metronidazole-containing gel for the adjuvant treatment of chronic periodontitis: preliminary results.

The present study developed an experimental metronidazole-based gel and evaluated its efficacy for the adjuvant treatment of chronic periodontitis. Sixteen patients were randomly allocated into two groups of eight subjects according to the following proposed treatments: (1) scaling and root planing (active control) or (2) scaling and root planing and direct periodontal intrapocket application of 15% metronidazole-based gel in two sites (≥5 mm in depth) (experimental group). Potential changes in the subgingival microbiota were assessed using a DNA Checkerboard method at three proposed times: baseline and following 7 or 30 days of drug administration. High-performance liquid chromatography (HPLC) monitored metronidazole concentrations in the crevicular fluid during treatment. The metronidazole experimental group presented lower bacterial counts than the control group at the three evaluated times (p<0.01 for baseline, p<0.001 for 7 or 30 days) when the target species were analyzed as a pool of bacteria. Samples revealed significantly lower counts 7 days after drug administration compared with baseline or after 30 days (p<0.05). HPLC analysis detected gel 1 h after application. The metronidazole-based gel significantly decreased the total bacterial count at the three evaluated times. Periodontopathogenic species were not different after gel administration.

Diametral compressive bond strength of composite resin associated with an adhesive system in incremental filling technique.

AIM: The aim of this in vitro study was to evaluate the diametral compressive bond strength between Charisma or TPH composite resin after association or not to an adhesive system in incremental filling technique. METHODS: Twenty cylinders of each composite resin brand were fabricated using a Teflon matrix and divided into four groups, according to the numbers of adhesive layers applied: group 1 Control without adhesive; group 2 one layer; group 3 two layers and group 4 three layers. The bonding system Adper Single Bond was used between composite resin increments. Diametral compression assays were carried out in an EMIC-MEM 2000 universal testing machine, adjusted at 1 mm/min. ANOVA and Tukey's test were used in the statistical analysis. RESULTS: The mean strengths and standard deviations for each group were: Charisma 1= 38.26+/-2.38; 2=46.56+/-2.38; 3=40.57+/-2.38; 4=36.87+/-2.38 (2>1=3=4; P<0.05) and TPH 1=52.17+/-2.38; 2=52.23+/-2.38; 3=44.68+/-2.38; 4=44.11+/-2.38 (1=2>3=4; P<0.05). CONCLUSIONS. It was concluded that TPH presented higher means of compressive bond strength than Charisma, and the association of an adhesive system between the increments may influence the diametral compressive bond strength of composite resins.