Microbiologic effect of two topical anti-infective treatments on ligature-induced peri-implantitis: A pilot study in dogs.

BACKGROUND: The aim of this split-mouth design pilot study in dogs was to assess microbiologic effects of two topical anti-infective treatment protocols on dental implants subjected to ligature-induced peri-implantitis, without use of systemic antibiotics. METHODS: Eight adult Beagle dogs each received four dental implants in contralateral, edentulated, mandibular jaw quadrants. After 8 weeks, silk ligatures were installed, to be removed after another 8 weeks. After 6 additional weeks, induced peri-implantitis lesions were subjected to either antimicrobial photodynamic therapy (aPDT) or a topical tetracycline (TTC) hydrochloride (50 mg/mL) solution. Microbiologic samples were collected from the deepest proximal peri-implantitis site in each jaw quadrant before and after treatment. The samples were analyzed using DNA-DNA hybridization checkerboard technique. RESULTS: Peri-implantitis induction successfully produced lesions with microbiologic characteristics similar to those found in humans. Overall results showed effective bacterial count reductions for both protocols. aPDT demonstrated major reductions of the red complex, but no statistical differences between groups were observed when adjusted for multiple comparisons. CONCLUSION: aPDT and TTC successfully decontaminated infected implant surfaces. Implant decontamination with aPDT appears to be a viable alternative to TTC in the management of peri-implantitis infection.

Comparison between two antimicrobial protocols with or without guided bone regeneration in the treatment of peri-implantitis. A histomorphometric study in dogs.

OBJECTIVES: This study used a dog model to evaluate two antimicrobial protocols with or without guided bone regeneration (GBR) in the surgical reconstruction of peri-implantitis defects. MATERIAL AND METHODS: Eight beagle dogs subject to ligature-induced peri-implantitis were used. The animals either received antimicrobial photodynamic therapy or topical tetracycline hydrochloride combined with GBR or as stand-alone surgical interventions. Block biopsies of the defect sites for histological analysis were obtained at euthanasia, 12 weeks postsurgery. The primary outcome of the study was re-osseointegration; secondary outcomes included alveolar bone gain and remaining defect characteristics. The effects of the implant site, early exposure, and type of antimicrobial protocol on bone regeneration were also evaluated. RESULTS: No significant differences were observed between the two antimicrobial protocols, and the adjunctive use of GBR failed to significantly improve re-osseointegration or bone gain using either protocol. Buccal sites and implant early exposure negatively affected bone regeneration. CONCLUSION: Both antimicrobial therapies stand-alone or combined with GBR allowed similar and limited bone gain.

Adjunctive effect of antimicrobial photodynamic therapy to nonsurgical periodontal treatment in smokers: a randomized clinical trial.

The aim of this study was to investigate the adjunctive effect of antimicrobial photodynamic therapy (aPDT) to scaling and root planing (SRP) in smokers with chronic periodontitis. Twenty subjects had two contralateral teeth randomly assigned to receive SRP (SRP group) or SRP + a single episode of aPDT (SRP + aPDT group), with a diode laser and a phenothiazine photosensitizer. Plaque index, bleeding on probing, probing depth (PD), clinical attachment level (CAL), and gingival recession were recorded, and gingival crevicular fluid was collected for assay of IL-1ß and matrix metalloproteinase (MMP)-8 levels. There was a significant PD reduction (SRP 1.81 ± 0.52 mm/SRP + aPDT 1.58 ± 1.28 mm; p < 0.001) and a significant CAL gain (SRP 1.60 ± 0.92 mm/SRP + aPDT 1.41 ± 1.58 mm; p < 0.001) for both groups. Significant differences were not observed in between-group comparisons. IL-1ß level in gingival crevicular fluid was higher in SRP group after 1 week (SRP 24.65 ± 18.85 pg/µL/SRP + aPDT 34.07 ± 24.81 pg/µL; p = 0.048), and MMP-8 level was higher in SRP group after 12 weeks (SRP 303.31 ± 331.62 pg/µL/SRP + aPDT 534.23 ± 647.37 pg/µL; p = 0.024). There were no statistically significant differences in intragroup comparisons. The adjunctive effect of aPDT did not warrant improvements on clinical parameters in smokers. However, it resulted in a suppression of IL-1ß and MMP-8 when compared with SRP alone.

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.

Manutenção da tábua óssea vestibular em alvéolos pós-extração / Buccal bone plate preservation in post-extraction alveolar sockets

A reabsorção alveolar após extrações dentais é uma condição que pertence ao processo de cicatrização. Consequentemente, as paredes do alvéolo sofrerão mudanças quantitativas, as quais serão mais pronunciadas na tábua óssea vestibular. Assim, a utilização de cirurgias sem retalho e de técnicas regenerativas poderia compensar estas alterações ocorridas no processo alveolar. Desta forma, o objetivo deste artigo foi oferecer bases científicas histológicas sobre o remodelamento ou a preservação da tábua óssea vestibular e lingual após a extração dental, utilizando cirurgias sem retalho, com ou sem biomaterial. De acordo com os resultados apresentados, pode-se dizer que a tábua óssea vestibular possui um biotipo mais fino e um osso mais cortical. Portanto, a ausência de retalhos mantém a nutrição da tábua óssea, evitando um aumento no processo de reabsorção. Na presença de um biotipo gengival mais fino, não foi possível prevenir a perda em altura da tábua vestibular, mesmo sem a realização de retalhos. Adicionalmente, o uso de biomateriais não alterou o processo de reabsorção da tábua óssea vestibular, mas modificou o processo de mineralização após a extração dental...

Alveolar bone resorption after tooth extraction is an inherent condition of the healing process. The edentulous site of the alveolar process will undergo quantitative changes that will be more pronounced in the buccal bone. The bone graft placement in the extraction socket and the flapless surgery should offset the catabolic processes observed within the crestal ridge. The aim of this paper is to provide histological scientifi c bases on remodeling or preservation of the buccal and lingual bone plates after tooth extraction using the flapless approach with or without biomaterial placement. According to previous results, the buccal bone plate has a thinner and more cortical bone. So, flapless surgery preserves the periosteal vascularization and reduces the buccal bone plate resorption. For situations where a thinner gingival biotype was found, it was not possible to prevent buccal bone loss even without flap raising. Additionally, the bone grafting did not change the resorption process of the buccal bone plate but modified the mineralization process after tooth extraction...

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.

Manutenção da tábua óssea vestibular com implantes imediatos / Buccal bone plate preservation with immediate implants

A instalação de implantes osseointegráveis imediatamente após as extrações dentais é uma terapia cada vez mais procurada pelos pacientes em função da redução do número de procedimentos cirúrgicos e, portanto, do tempo total de tratamento. A preocupação do implantodontista, entretanto, enfoca as possíveis alterações nos tecidos duros e moles, as quais influenciarão diretamente os resultados relacionados com a sobrevivência dos implantes e o sucesso das próteses implantossuportadas. O objetivo deste artigo foi oferecer bases científicas histológicas sobre o remodelamento ou a preservação da tábua óssea vestibular e lingual após a instalação de implantes em alvéolos frescos.

Immediate dental implant placement after tooth extraction is an increasingly popular therapy among patients because of the reduction in the number of surgical procedures and total treatment time. However, the implantodontist is faced with possible changes in hard and soft tissues, which directly affects the results regarding implant survival and success of implant-supported prostheses. The aim of this paper is to provide histological scientific bases on remodeling or preservation of the buccal and lingual bone plates after implant placement in fresh extraction sockets

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.

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.

Effects of periodontal therapy on glycemic control and inflammatory markers.

BACKGROUND: Periodontitis, a complication of diabetes mellitus (DM), can induce or perpetuate systemic conditions. This double-masked, placebo-controlled study evaluated the effects of periodontal therapy (scaling and root planing [SRP]) on the serum levels of glycated hemoglobin (HbA1c) and on inflammatory biomarkers. METHODS: Thirty subjects with type 2 DM and periodontitis were treated with SRP + placebo (SRP; N = 15) or with SRP + doxycycline (SRP+Doxy; N = 15), 100 mg/day, for 14 days. Clinical and laboratory data were recorded at baseline and at 3 months after treatment. RESULTS: After 3 months, the reduction in probing depth was 0.8 mm for the SRP group (P <0.01) and 1.1 mm for the SRP+Doxy group (P <0.01) followed by a 0.9% (SRP; P = 0.17) and 1.5% (SRP+Doxy; P <0.01) reduction in HbA1c levels. A significant reduction in interleukin (IL)-6; interferon-inducible protein 10; soluble fas ligand; granulocyte colony-stimulating factor; RANTES; and IL-12 p70 serum levels were also verified (N = 30). To our knowledge, this is the first report on the effects of periodontal therapy on multiple systemic inflammatory markers in DM. CONCLUSIONS: Periodontal therapy may influence the systemic conditions of patients with type 2 DM, but no statistical difference was observed with the adjunctive systemic doxycycline therapy. Moreover, it is possible that the observed improvement in glycemic control and in the reduction of inflammatory markers could also be due to diet, which was not controlled in our study. Therefore, a confirmatory study with a larger sample size and controlled diet is necessary.

Regeneração tecidual guiada no tratamento de defeito intra-ósseo. Relato de caso clínico / Guided tissue regeneration for the treatment of periodontal intrabony defect. Case report

Fatores relacionados ao paciente, ao defeito periodontal, ao procedimento cirúrgico e aos cuidados pós-operatórios determinam a previsibilidade dos resultados da terapia de regeneração tecidual guiada (RTG). Este trabalho relata um caso clinico de um paciente tratado na clínica de pós-graduação da Forp-USP, com diagnóstico de periodontite crônica generalizada e severa. Após o devido tratamento periodontal dos demais sítios da cavidade bucal, foi realizada a técnica de RTG associada ao enxerto de vidro bioativo para tratamento de um defeito intra-ósseo de duas paredes ósseas localizado na região mesial do dente 13, o qual apresentava 9 mm de profundidade de sondagem e 10 mm de perda de inserção clínica e que estava associado a uma deiscência óssea vestibular. No pós-operatório de seis meses, o exame radiográfico evidenciou a formação óssea com presença de lâmina dura bem definida na região do defeito e o exame clínico constatou uma redução de 6 mm da profundidade de sondagem e um ganho clínico de inserção de 7 mm. Os exames clínico e radiográfico, após 30 meses da realização da RTG, demonstraram a estabilidade destes resultados. Dessa forma, concluimos que os excelentes resultados clínicos podem ser alcançados no tratamento de defeitos intraósseos através da terapia de RTG associada ao enxerto de vidro bioativo, desde que os inúmeros fatores capazes de afetar a previsibilidade sejam observados e controlados.

Factors related to the patient, periodontal defect, surgical treatment, and postoperative period determine the predictability of guided tissue regeneration (GTR). The aim of this paper is to report a clinical case of a patient diagnosed with severe generalized chronic periodontitis, and treated with GTR in combination with the graft of bioactive glass. Following the elevation of a mucoperiosteal flap, a 2-wall intrabony defect localized on the mesial of the maxillary right canine with probing depth of 9 mm, and clinical attachment level of 10 mm, and associated to buccal bone dehiscence, was debrided, the exposed root surface was scaled and planned, and the regenerative therapy was performed. At the 6-month postoperative visit, the radiographic exam demonstrated the formation of a new bone with the presence of a well-defined lamina dura, and in the clinical exam, it was observed a reduction in probing depth of 6 mm, and a clinical attachment gain of 7 mm. These results have been maintained for 30 months. Conclusion: excellent clinical results can be achieved in the GTR treatment of periodontal intrabony defects, since many factors, which may affect the predictability of the results, have been observed, and controlled.