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PURPOSE: To evaluate the stability of interdental papilla filling using hyaluronic acid (HA) to treat black triangles in esthetic regions. METHODS: The protocol was registered in PROSPERO. Six databases (PubMed, Scopus, Embase, Lilacs, SciELO, and Web of Science) were used as primary search sources, and OpenGrey and OpenThesis were used to capture the "gray literature." Only before-after studies were included. The JBI Checklist assessed the risk of bias. Only four studies met the inclusion criteria and were considered for the analyses. The studies were published from 2010 to 2016. All studies presented a low risk of bias. Considering the studies do not have control groups, a weighted average by sample size was calculated to obtain a general estimate of the percentage of papillary filling after 6 months and the number of HA applications. RESULTS: The studies showed the percentage of papillary reconstruction after 6 months of application, the weighted average by sample size was 77.41% (SD = 20.68), with an average number of applications of 3.17 (SD = 0.31). CONCLUSION: The application of HA may be used to repair anesthetic defects in the papilla. CLINICAL SIGNIFICANCE: Interdental papilla reconstruction with injectable HA is an option of nonsurgical treatment for interdental papilla deficiencies. However, there is still concern about the quality of the evidence available, considering that studies with different experimental designs can produce contradictory results. Moreover, further understanding is required on the stability of tissue gain promoted by HA in black triangles.
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Gengiva , Ácido Hialurônico , Estética Dentária , Gengiva/anatomia & histologia , HumanosRESUMO
BACKGROUND: The aim of this study was to assess the volumetric stability and bone formation in grafts with Bio-Oss and autogenous bone at different proportions in rabbit calvaria. Material and Methods. Ten rabbits received four titanium cylinders in their calvaria and randomly divided into the following groups: Group I: Bio-Oss (100%), Group II: Bio-Oss (75%) + autogenous bone (25%), Group III: Bio-Oss (50%) + autogenous bone (50%), and Group IV: autogenous bone (100%). After twelve weeks, the animals were euthanized, and samples were collected for clinical and histological analysis. RESULTS: Clinical analysis showed that Groups I (90.43 ± 8.99) and II (90.87 ± 7.43) had greater dimensional stability compared to Group IV (P=0.0005). Histologically, Groups I, II, and III showed areas of bone formation with particles of biomaterial remaining in close contact with the newly formed bone. However, there were no significant differences between the groups regarding the newly formed bone area. CONCLUSION: It was concluded that the use of Bio-Oss either alone or associated with the autogenous bone at a proportion of 25% showed superior dimensional stability compared to the use of autogenous bone in the proposed experimental model.
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ABSTRACT: Considering that success of dental implants is not only related to osseointegration, but also with their survival rates, the aim of this study was to perform a literature review about bone remodeling around osseointegrated implants. A detailed search strategy was used for this, and articles published between the years 1930 and 2012 were selected. The rare data found in the literature demonstrated that implants are osseointegrated 30 days after their placement. However, active bone remodeling with osteoclasts and osteoblasts working in synchrony continues to occur. Therefore, after osseointegration, the initially formed bone, which presents characteristics of spongy bone, is gradually resorbed and replaced by compact bone after 90 days. Furthermore, other portions of bone tissue a little more distant from the interface, which establish direct contact with the implant, are also damaged during the drilling process, and therefore, they also need to be remodeled. Among the rare studies found in the literature about bone remodeling after osseointegration, there were no verified studies on the possible influence of implant surface treatments on bone remodeling that occurs after osseointegration. Only studies involving implants with machined surfaces have been conducted up to now.
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Humanos , Osteoblastos , Osteoclastos , Osso e Ossos , Implantes Dentários , Remodelação ÓsseaRESUMO
PURPOSE: We sought to evaluate the effectiveness of bone substitutes in circumferential peri-implant defects created in the rabbit tibia. METHODS: Thirty rabbits received 45 implants in their left and right tibia. A circumferential bone defect (6.1 mm in diameter/4 mm depth) was created in each rabbit tibia using a trephine bur. A dental implant (4.1 mm × 8.5 mm) was installed after the creation of the defect, providing a 2-mm gap. The bone defect gaps between the implant and the bone were randomly filled according to the following groups: blood clot (CO), particulate Bio-Oss(®) (BI), and Bio-Oss(®) Collagen (BC). Ten animals were euthanized after periods of 15, 30, and 60 days. Biomechanical analysis by means of the removal torque of the implants, as well as histologic and immunohistochemical analyses for protein expression of osteocalcin (OC), Runx2, OPG, RANKL, and TRAP were evaluated. RESULTS: For biomechanics, BC showed a better biological response (61.00±15.28 Ncm) than CO (31.60±14.38 Ncm) at 30 days. Immunohistochemical analysis showed significantly different OC expression in CO and BC at 15 days, and also between the CO and BI groups, and between the CO and BC groups at 60 days. After 15 days, Runx2 expression was significantly different in the BI group compared to the CO and BC groups. RANKL expression was significantly different in the BI and CO groups and between the BI and BC groups at 15 days, and also between the BI and CO groups at 60 days. OPG expression was significantly higher at 60 days postoperatively in the BI group than the CO group. CONCLUSIONS: Collectively, our data indicate that, compared to CO and BI, BC offered better bone healing, which was characterized by greater RUNX2, OC, and OPG immunolabeling, and required greater reversal torque for implant removal. Indeed, along with BI, BC presents promising biomechanical and biological properties supporting its possible use in osteoconductive grafts for filling peri-implant gaps.
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BACKGROUND: The erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser has been widely used in the dental clinic; however, few studies have demonstrated the advantages of the use of this laser for bone osteotomies. The purpose of this study is to evaluate and compare the bone repair process of defects generated by the Er,Cr:YSGG laser or conventional drills. METHODS: Ninety-six rats were divided into two groups of 48 animals (drill group and laser group). After surgical exposure of the right tibia, the animals were subjected to a 2-mm-diameter osteotomy created by conventional drills (drill group) or by the Er,Cr:YSGG laser (laser group). The animals were sacrificed 0, 3, 7, 14, 30, and 60 days after the creation of the defect, and histologic sections were obtained and used for histomorphometric and immunohistochemical analyses for the detection of osteocalcin, osteoprotegerin, receptor activator of nuclear factor κ-B ligand, vascular endothelial growth factor, and caspase-3. RESULTS: The osteotomy with the drill produced well-delimited and smooth walls, whereas the osteotomies in the laser group were irregular and presented an amorphous basophilic line and bone necrosis that was slowly resorbed during the repair process. Despite these characteristics, bone repair was similar between groups at various time points, and, at 60 days, the defects in both groups were completely repaired by newly formed bone. CONCLUSION: The repair process of osteotomies created by the Er,Cr:YSGG laser, despite producing thermal damage to bone tissue, is comparable to that with conventional drills.
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Osteotomia , Animais , Cromo , Érbio , Gálio , Lasers de Estado Sólido/uso terapêutico , Ratos , Escândio , Fator A de Crescimento do Endotélio Vascular , ÍtrioRESUMO
PURPOSE: To evaluate the effect of implant osteotomy on immediate bone cell viability, comparing guided surgery for implant placement with the classic drilling procedure. MATERIALS AND METHODS: For this study, 20 rabbits were used. The animals were divided into a guided surgery group (GG) and a control group (CG) and were then divided into 4 subgroups--subgroups 1, 2, 3, and 4--corresponding to drills used 10, 20, 30, and 40 times, respectively. All animals received 5 osteotomies in each tibia, by use of the classic drilling procedure in one tibia and guided surgery in the other tibia. The osteotomized areas were removed and processed immunohistochemically for detection of osteocalcin, receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and caspase 3. RESULTS: Immunohistochemical analysis showed that osteocalcin expression was initially higher in the CG and remained constant after drill reutilization. Although the expressions of RANKL and OPG were not statistically different for the GG and CG, the RANKL/OPG ratio tended to be higher for the GG. Moreover, caspase 3 expression was elevated in the GG, proportionally to the number of osteotomies, indicating an increase in the apoptosis index in the GG. CONCLUSIONS: The classic drilling procedure is more favorable to cell viability than guided surgery.
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Osso e Ossos/citologia , Implantação Dentária Endóssea/métodos , Cirurgia Assistida por Computador , Animais , Osso e Ossos/metabolismo , Caspase 3/biossíntese , Caspase 3/genética , Sobrevivência Celular , Implantação Dentária Endóssea/instrumentação , Temperatura Alta/efeitos adversos , Masculino , Modelos Anatômicos , Osteocalcina/biossíntese , Osteocalcina/genética , Osteoprotegerina/biossíntese , Osteoprotegerina/genética , Ligante RANK/biossíntese , Ligante RANK/genética , Coelhos , Cirurgia Assistida por Computador/efeitos adversos , Tíbia/cirurgia , Tomografia Computadorizada por Raios XRESUMO
It has been demonstrated that histamine interferes with the recruitment, formation and activity of osteoclasts via H(1)- and H(2)-receptors. Cimetidine is a H(2)-receptor antagonist used for treatment of gastric ulcers that seems to prevent bone resorption. In this study, a possible cimetidine interference was investigated in the number of alveolar bone osteoclasts. The incidence of osteoclast apoptosis and immunoexpression of RANKL (receptor activator of nuclear factor κB ligand) was also evaluated. Adult male rats were treated with 100 mg kg(-1) of cimetidine for 50 days (CimG); the sham group (SG) received saline. Maxillary fragments containing the first molars and alveolar bone were fixed, decalcified and embedded in paraffin. The sections were stained by H&E or submitted to tartrate-resistant acid phosphatase (TRAP) method. TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) method and immunohistochemical reactions for detecting caspase-3 and RANKL were performed. The number of TRAP-positive osteoclasts, the frequency of apoptotic osteoclasts and the numerical density of RANKL-positive cells were obtained. Osteoclast death by apoptosis was confirmed by transmission electron microscopy (TEM). In CimG, TRAP-positive osteoclasts with TUNEL-positive nuclei and caspase-3-immunolabeled osteoclasts were found. A significant reduction in the number of TRAP-positive osteoclasts and a high frequency of apoptotic osteoclasts were observed in CimG. Under TEM, detached osteoclasts from the bone surface showed typical features of apoptosis. Moreover, a significant reduction in the numerical density of RANKL-positive cells was observed in CimG. The significant reduction in the number of osteoclasts may be due to cimetidine-induced osteoclast apoptosis. However, RANKL immunoexpression reduction also suggests a possible interference of cimetidine treatment in the osteoclastogenesis.
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Apoptose/efeitos dos fármacos , Cimetidina/farmacologia , Antagonistas dos Receptores H2 da Histamina/farmacologia , Osteoclastos/fisiologia , Periodonto/fisiologia , Ligante RANK/metabolismo , Animais , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Masculino , Microscopia Eletrônica de Transmissão , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Periodonto/efeitos dos fármacos , Periodonto/metabolismo , RatosRESUMO
Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is not completely understood and difficult to treat. Even though the occurrence of BRONJ is mainly related to the therapy with intravenous bisphosphonates (BPs), this article reports a case of long-term oral BP use and BRONJ occurrence. In addition, a literature review provides some additional information about BPs, BRONJ, and also a guideline for the prevention and treatment of BRONJ stages. A 79-year-old patient presented intense and persistent pain, purulent secretion, and exposed bone at the right side of the lower jaw. Thus, she was submitted to anamnesis, radiologic and tomographic examinations, and bacterial culture and sensitivity tests. These procedures were followed by surgical debridement of the bone and surrounding tissues/cyst and antibiotic prescription and histopathologic analysis of the fragments. Together, the examinations performed showed the occurrence of stage 2 BRONJ. Moreover, the antibiotic prescription, discontinuation of oral BP, and surgical procedures ensure that the patient had no more symptoms. Therefore, considering the presented case, we believe that an accurate approach is promising to diagnose and treat stage 2 BRONJ and other associated pathologic findings.
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Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/diagnóstico por imagem , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/terapia , Idoso , Terapia Combinada , Diagnóstico Diferencial , Feminino , Humanos , Fatores de Risco , Tomografia Computadorizada por Raios XRESUMO
Osteoclasts, the multinucleated bone-resorbing cells, arise through fusion of precursors from the myeloid lineage. However, not all osteoclasts are alike; osteoclasts at different bone sites appear to differ in numerous respects. We investigated whether bone marrow cells obtained from jaw and long bone differed in their osteoclastogenic potential. Bone marrow cells from murine mandible and tibiae were isolated and cultured for 4 and 6 days on plastic or 6 and 10 days on dentin. Osteoclastogenesis was assessed by counting the number of TRAP(+) multinucleated cells. Bone marrow cell composition was analyzed by FACS. The expression of osteoclast- and osteoclastogenesis-related genes was studied by qPCR. TRAP activity and resorptive activity of osteoclasts were measured by absorbance and morphometric analyses, respectively. At day 4 more osteoclasts were formed in long bone cultures than in jaw cultures. At day 6 the difference in number was no longer observed. The jaw cultures, however, contained more large osteoclasts on plastic and on dentin. Long bone marrow contained more osteoclast precursors, in particular the myeloid blasts, and qPCR revealed that the RANKL:OPG ratio was higher in long bone cultures. TRAP expression was higher for the long bone cultures on dentin. Although jaw osteoclasts were larger than long bone osteoclasts, no differences were found between their resorptive activities. In conclusion, bone marrow cells from different skeletal locations (jaw and long bone) have different dynamics of osteoclastogenesis. We propose that this is primarily due to differences in the cellular composition of the bone site-specific marrow.