RESUMO
OBJECTIVES: Previous efforts led to the development of two different polymeric biomaterials for periodontal regeneration with antibacterial photodynamic surface activity. The present study aimed to investigate osseointegration and bone formation of both materials in an ovine model. METHODS: Both biomaterials: 1) urethane dimethacrylate-based Biomaterial 1 (BioM1) and 2) tri-armed oligoester-urethane methacrylate-based Biomaterial 2 (BioM2) are enriched with beta-tri-calcium phosphate and the photosensitizer meso-tetra(hydroxyphenyl)chlorin (mTHPC). These materials were implanted in non-critical size bone defects in the sheep femur (n = 16) and tibia (n = 8). Empty defects served as controls (n = 16). Polyfluorochrome sequential bone labeling was carried out at baseline and after 3, 6, and 12 months. Animals were sacrificed after 12 months. Bone specimens (n = 40) were fixed and subjected to microtomographic analysis (µCT) for the evaluation of the bone-volume-fraction (BV/TV), trabecular number and trabecular thickness. Subsequently, histological sections were arranged and polyfluorochrome sequential bone labeling was analyzed by confocal laser scanning microscopy (cLSM). RESULTS: cLSM analysis revealed that highest remodeling and bone formation activity occurred during the second half of the study period (6-12 months). Bone formation in the tibia was significantly lower for the control (2.71 ± 1.26%) as compared to BioM1 (6.01 ± 2.99%) and BioM2 (6.45 ± 2.12%); (p = 0.006, p = 0004). Micro-computed tomography revealed a BV/TV volume fraction of 44.72 ± 9.01% in femur defects filled with BioM1 which was significantly higher compared to the control (32.27 ± 7.02%; p = 0.01). Bone architecture (trabecular number, trabecular thickness) did not significantly differ from the self-healed defects. SIGNIFICANCE: Both biomaterials, especially BioM1 showed good osseointegration and bone formation characteristics and can be recommended for further examination in periodontal regeneration studies.
RESUMO
OBJECTIVE: To determine whether multiple examiners can demonstrate consistent plaque removal advantages for an oscillating-rotating power toothbrush versus a manual toothbrush. METHODS: This was a replicate-use, single brushing, examiner-blind, randomized, two-treatment, four-period crossover clinical trial involving four examiners. Subjects were randomized to one of four treatment sequences involving two toothbrushes: an oscillating-rotating power toothbrush or a manual toothbrush. At each of the four visits, subjects arrived having abstained from oral hygiene for 24 h prior, and brushed with their assigned toothbrush and a marketed fluoride dentifrice under supervision unaided by a mirror. Plaque was assessed by each examiner using the Turesky-Modified Quigley-Hein Plaque Index at each study period before and after brushing. Data was analysed separately for each examiner using the analysis of covariance for crossover design. RESULTS: Ninety-five subjects between the ages of 18 and 70 met the entrance criteria and were enrolled in the study. Eighty-seven subjects completed all four periods of the study. Both brushes delivered a significant plaque reduction when compared to baseline. Significant treatment differences were observed for all four examiners - ranging from 0.10 to 0.16 - in favor of the oscillating-rotating brush (P < 0.001). There were no adverse events reported or observed for either brush. CONCLUSIONS: All four examiners demonstrated the power toothbrush removed significantly more plaque after a single brushing than the standard manual toothbrush. Both brushes were well tolerated.
