Flávia Adelino Suaid

Histologic evaluation of the buccal and lingual bone plates in anterior dog teeth: possible influence on implant dentistry.

BACKGROUND Recent studies in animals have shown pronounced resorption of buccal bone plate after immediate implantation. The sectioning of experimental material for histologic evaluation of the bone plates could provide valuable information about the possible effect of bone exposure in periodontal and implant surgeries. METHODS Twenty-four incisors were collected from dogs. After decalcification, the blocks were immersed in paraffin and bucco-lingual histologic sections were examined under light microscope. Some sections were reserved for immunohistochemical analysis. RESULTS The bone density, the width of the bone plates, and the percentage of vessels presented in the periodontal ligament and periosteum were analyzed in the buccal and lingual bone plates, which were divided corono-apically into thirds. The buccal bone plates showed statistically higher bone density compared to the lingual bone plates in the coronal thirds. The width of both bone plates increased from the coronal to the apical third, but all the buccal thirds were significantly thinner compared to the lingual thirds. No statistically significant differences were found between the bone plates for the percentage of area occupied by the blood vessels in the periodontal ligament or periosteum. CONCLUSION It is reasonable to conclude that the higher bone density, represented by the lower number of marrow spaces, in association with the thinner aspect of the buccal bone plates made them more fragile to absorb compared to the lingual bone plates, especially during mucoperiosteal procedures.

Buccal Bone Plate Remodeling After Immediate Implant Placement With and Without Synthetic Bone Grafting and Flapless Surgery: Radiographic Study in Dogs

Recent studies in animals have shown pronounced resorption of the buccal bone plate after immediate implantation. The use of flapless surgical procedures prior to the installation of immediate implants, as well as the use of synthetic bone graft in the gaps represent viable alternatives to minimize buccal bone resorption and to favor osseointegration. The aim of this study was to evaluate the healing of the buccal bone plate following immediate implantation using the flapless approach, and to compare this process with sites in which a synthetic bone graft was or was not inserted into the gap between the implant and the buccal bone plate. Lower bicuspids from 8 dogs were bilaterally extracted without the use of flaps, and 4 implants were installed in the alveoli in each side of the mandible and were positioned 2.0 mm from the buccal bone plate (gap). Four groups were devised: 2.0-mm subcrestal implants (3.3 × 8 mm) using bone grafts (SCTG), 2.0-mm subcrestal implants without bone grafts (SCCG), equicrestal implants (3.3 × 10 mm) with bone grafts (ECTG), and equicrestal implants without bone grafts (ECCG). One week following the surgical procedures, metallic prostheses were installed, and within 12 weeks the dogs were sacrificed. The blocks containing the individual implants were turned sideways, and radiographic imaging was obtained to analyze the remodeling of the buccal bone plate. In the analysis of the resulting distance between the implant shoulder and the bone crest, statistically significant differences were found in the SCTG when compared to the ECTG (P = .02) and ECCG (P = .03). For mean value comparison of the resulting linear distance between the implant surface and the buccal plate, no statistically significant difference was found among all groups (P > .05). The same result was observed in the parameter for presence or absence of tissue formation between the implant surface and buccal plate. Equicrestally placed implants, in this methodology, presented little or no loss of the buccal bone. The subcrestally positioned implants presented loss of buccal bone, even though synthetic bone graft was used. The buccal bone, however, was always coronal to the implant shoulder.

Antimicrobial photodynamic therapy associated to nonsurgical periodontal treatment in smokers: Microbiological results

BACKGROUND Studies suggest that smokers present more or greater numbers of potential periodontal pathogens than non-smokers. The aim of this study was to investigate the microbiologic effects of adjunctive aPDT on nonsurgical periodontal treatment in smokers with chronic periodontitis (CP). METHODS Twenty smokers with CP had two contralateral teeth randomly assigned in a split-mouth design to receive SRP (CG) or SRP + a single episode of aPDT (TG), with a diode laser and a phenothiazine photosensitizer. Levels of 40 subgingival species were measured using checkerboard DNA-DNA hybridization at baseline and 1, 4 and 12 weeks after periodontal treatment. RESULTS All 40 bacterial species evaluated were detected in different levels at baseline, with no statistic significant differences between groups. After periodontal treatment, the levels of some bacterial species decreased, while some other species presented an increase. Despite this variation, the statistical analysis was not able to identify significant differences neither at intragroup nor at intergroup comparisons. CONCLUSION Periodontal treatment with SRP or SRP + aPDT was not able to reduce levels of 40 subgingival species in smokers with CP. These outcomes indicate that smoking impairs periodontal healing after nonsurgical treatment even associated with aPDT.

Buccal bone plate remodeling after immediate implants with or without synthetic bone grafting and flapless surgery: a histomorphometric and fluorescence study in dogs

OBJECTIVE The aim of this study was to evaluate the buccal bone plate remodeling after immediate implantation using the flapless approach with or without bone graft into the gap between the implant and the buccal bone. MATERIAL AND METHODS Eight dogs had the mandibular bicuspids extracted without flaps, and four implants were installed on each side, totaling eight implants per animal. Randomly, in one side, the implants were positioned at the bone crest level (equicrestal), and on the opposite side, the implants were positioned 2 mm subcrestal. All the implants were positioned 2.0 mm from the buccal bone plate (gap) and associated or not with grafting material. Therefore, the following treatments were performed: implants subcrestal test (SCTG) with bone graft and control (SCCG) without bone graft, and equicrestal test (ECTG) with bone graft and control (ECCG) without bone graft. One week following the surgeries, metallic prostheses were installed. Bone markers were administered 1, 2, 4, and 12 weeks after implant placement for fluorescence analysis. Ground sections were prepared from 12-week healing biopsies, and histomorphometry was performed. RESULTS The histomorphometric evaluation presents significant better results for the ECTG in the vertical crestal bone resorption, but the other parameters showed better results for the SCCG. The fluorescence evaluation in adjacent areas showed numerically different results between groups with a small decrease at 12 weeks, except for the SCCG, which was higher at this time. The distant area showed a continuous increase in the marked bone. CONCLUSION The equicrestally placed implants presented little or no loss of the buccal bone wall. The subcrestally positioned implants presented loss of buccal bone, regardless of the use of bone graft. However, the buccal bone was always coronal to the implant shoulder. Both the equicrestal and subcrestal groups were benefited in the early stages of bone healing as evidenced by the fluorescence analysis.

Buccal bone remodeling after tooth extraction using the flapless approach with and without synthetic bone grafting. A histomorphometric study in dogs.

OBJECTIVE The aim of this study was to evaluate buccal bone remodeling of fresh sockets following tooth extraction using the flapless approach, with or without synthetic graft materials. MATERIAL AND METHODS Eight dogs had the mandibular bicuspids extracted without flaps, and two alveoli on each side (total of 4) were selected. The following groups were devised: one socket on each side received a grafting material (test group), and the other remained only with a blood clot (control group). Ground sections were prepared from 12-week healing biopsies, and histomorphometry was performed. RESULTS The buccal crest level (BCL) relative to the new bone (i), in the test group, showed numerically better data when compared with the control group, but without statistical relevance. The BCL relative to the old bone (ii) was very similar for the groups without statistical relevance. The alveolar ridge width (ARW) showed similar results without statistically significant difference between the groups. The total bone area (TBA) showed statistically significant differences between the test (38.60%) and control (47.18%) groups. The new bone area (NBA) presents a numerical difference between the test (15.62%) and control (22.24%), but without statistically significant differences. The old bone and the bone marrow were similar for both groups. CONCLUSION It was observed that there was no loss of the buccal bone crest in relation to the lingual bone crest, especially in the test group.

The Bone Formation Capabilities of the Anorganic Bone Matrix-Synthetic Cell-Binding Peptide 15 Grafts in an Animal Periodontal Model: A Histologic and Histomorphometric Study in Dogs

BACKGROUND The aim of this study is to verify the regenerative potential of particulate anorganic bone matrix-synthetic peptide-15 (ABM-P-15) in class III furcation defects associated or not with expanded polytetrafluoroethylene membranes. METHODS Class III furcation defects were produced in the mandibular premolars (P2, P3, and P4) of six dogs and filled with impression material. The membranes and the bone grafts were inserted into P3 and P4, which were randomized to form the test and control groups, respectively; P2 was the negative control group. The animals were sacrificed 3 months post-treatment. RESULTS Histologically, the complete closure of class III furcation defects was not observed in any of the groups. Partial periodontal regeneration with similar morphologic characteristics among the groups was observed, however, through the formation of new cementum, periodontal ligament, and bone above the notch. Histologic analysis showed granules from the bone graft surrounded by immature bone matrix and encircled by newly formed tissue in the test group. The new bone formation area found in the negative control group was 2.28 + or - 2.49 mm(2) and in the test group it was 6.52 + or - 5.69 mm(2), which showed statistically significant differences for these groups considering this parameter (Friedman test P <0.05). There was no statistically significant difference among the negative control, control, and test groups for the other parameters. CONCLUSIONS The regenerative potential of ABM-P-15 was demonstrated through new bone formation circumscribing and above the graft particles. The new bone also was accompanied by the formation of new cementum and periodontal ligament fibers.