RESUMO
OBJECTIVE: To identify, quantify, and characterize leukocyte populations in PI and periodontitis using flow cytometry. METHODS: Fresh biopsies from human PI and periodontitis lesions were processed to a single-cell suspension. The immune cell types were identified using flow cytometry. RESULTS: Twenty-one biopsies were obtained and analyzed corresponding to fourteen PI and seven periodontitis samples. Participants' average age was 63.95 ± 14.77 years without a significant difference between PI and periodontitis patients, the female/male ratio was 8/12, and mean PD was 8.5 ± 2.17. High similarity was found between periodontitis and PI in the main immune cell types. Out of the leukocytes, the PMN proportion was 40% in PI and 33% in periodontitis. T-cells 22% in PI and 18% in periodontitis. Similar proportions of B-cells 10% and macrophages 6% were found in PI and periodontitis. Dendritic and NK cells were found in low proportions (~ 1%) in PI and periodontitis. T-cell sub-analysis showed that CD4-positive were more prevalent than CD8-positive in both diseases (CD4/CD8 ratio of 1.2). CONCLUSION: With the use of flow cytometry analysis, the leukocyte populations in human peri-implantitis and periodontitis were classified. In PI and periodontitis, we identified similar proportions of specific (CD4/CD8) and innate (dendritic and NK) immune cells. These results corroborate previous histological studies. CLINICAL RELEVANCE: Flow cytometry analysis can be used to identify and quantify immune cells in PI and periodontitis, including sub-classification of T cells (CD4/8) as well as detection of cells that require multiple markers for identification (such as dendritic cells).
Assuntos
Implantes Dentários , Peri-Implantite , Periodontite , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Peri-Implantite/metabolismo , Citometria de Fluxo , Periodontite/metabolismo , LeucócitosRESUMO
The aim of this article was to compare baseline residual ridge height using Cone-beam Computed Tomography (CBCT) and panoramic radiographs. A secondary aim was to examine the magnitude of vertical bone gain 6 months after trans-crestal sinus augmentation and compare it between operators. Thirty patients, who underwent trans-crestal sinus augmentation simultaneously with dental implant placement, were included in this retrospective analysis. Surgeries were done by 2 experienced surgeons (EM and EG) using the same surgical protocol and materials. Preoperative residual ridge height was measured on panoramic and CBCT images. The final bone height and the magnitude of the vertical augmentation were measured on panoramic X ray taken 6 months after surgery. Mean residual ridge height measured preoperatively using CBCT was 6.07 ± 1.38 mm, whereas these same measurements on the panoramic radiographs yielded similar results (6.08 ± 1.43 mm), which were statistically insignificant (P = .535). Postoperative healing was uneventful in all cases. All 30 implants were successfully osseointegrated at 6 months. The mean overall final bone height was 12.87 ± 1.39 mm (12.61 ± 1.21 and 13.39 ± 1.63 mm for operators EM and EG, respectively; P = .19). Likewise, mean postoperative bone height gain was 6.78 ± 1.57 mm, which was 6.68 ± 1.32 and 6.99 ± 2.06 mm for operators EM and EG, respectively (P = .66). A moderate positive correlation was found between residual bone height and final bone height (r = 0.43, P = .002). A moderate negative correlation was found between residual bone height and augmented bone height (r = -0.53, P = .002). Sinus augmentation performed trans-crestally produce consistent results with minimal interoperator differences between experienced clinicians. Both CBCT and panoramic radiographs produced similar assessment of the preoperative residual bone height.
Assuntos
Implantes Dentários , Levantamento do Assoalho do Seio Maxilar , Humanos , Implantação Dentária Endóssea/métodos , Projetos Piloto , Estudos Retrospectivos , Resultado do Tratamento , Levantamento do Assoalho do Seio Maxilar/métodos , Transplante Ósseo/métodos , Seio Maxilar/diagnóstico por imagem , Seio Maxilar/cirurgia , Maxila/cirurgiaRESUMO
Objectives: The aim of this investigation was to evaluate the epidemiological data on dental injuries in permanent teeth among seventh and tenth grade schoolchildren in the Republic of Moldova. Study design: The pathfinder study model was chosen to evaluate the prevalence of Traumatic Dental Injuries (TDI). Schoolchildren ages 12 and 15 years old were examined: In the capital city (four schools), in two other major cities-(two schools each city), and in four villages (one per each village) in accordance with the WHO's recommendations. Results: A total of 720 seventh and tenth grade schoolchildren were examined. The overall prevalence of TDI was found to be 16.4% (total of 118 children). The prevalence of TDI was greater in the older age cohort (p<0.05). Children from rural areas presented with greater prevalence of TDI compared to children who live in urban region (p<0.03). The maxillary central incisors were found to be the most common teeth affected by trauma constituting 57.1% of the evaluated TDI cases. Enamel fracture was the main type of TDI (83%). Conclusions: The TDI mainly involved enamel fractures. Urban schoolchildren show lower rates of TDI compared to rural schoolchildren.
Assuntos
Fraturas dos Dentes , Traumatismos Dentários , Adolescente , Idoso , Criança , Estudos Transversais , Humanos , Incisivo , Moldávia/epidemiologia , Prevalência , Fraturas dos Dentes/epidemiologia , Traumatismos Dentários/epidemiologiaRESUMO
A new periodontitis classification scheme has been adopted, in which forms of the disease previously recognized as "chronic" or "aggressive" are now grouped under a single category ("periodontitis") and are further characterized based on a multi-dimensional staging and grading system. Staging is largely dependent upon the severity of disease at presentation as well as on the complexity of disease management, while grading provides supplemental information about biological features of the disease including a history-based analysis of the rate of periodontitis progression; assessment of the risk for further progression; analysis of possible poor outcomes of treatment; and assessment of the risk that the disease or its treatment may negatively affect the general health of the patient. Necrotizing periodontal diseases, whose characteristic clinical phenotype includes typical features (papilla necrosis, bleeding, and pain) and are associated with host immune response impairments, remain a distinct periodontitis category. Endodontic-periodontal lesions, defined by a pathological communication between the pulpal and periodontal tissues at a given tooth, occur in either an acute or a chronic form, and are classified according to signs and symptoms that have direct impact on their prognosis and treatment. Periodontal abscesses are defined as acute lesions characterized by localized accumulation of pus within the gingival wall of the periodontal pocket/sulcus, rapid tissue destruction and are associated with risk for systemic dissemination.
Assuntos
Doenças Periodontais , Periodontite , Consenso , Humanos , Bolsa Periodontal , PeriodontoRESUMO
The aim of this prospective cohort observational field trial was to examine 1-year survival and success rates of a recently introduced tapered implant system with switched platform conical abutments and to evaluate patient related outcomes of therapy. Partially edentulous patients aged between 18 and 75 years, with available bone height for dental implants ≥10 mm desiring to restore the missing tooth/teeth with implant supported restoration, were recruited by 7 periodontists in their respective private practices. Dental implants were installed according to standard implant therapy protocol. Three to 6 months postoperatively, after evaluating interim implant success, implants were restored by the referring dentists. Patient, Ramfjord teeth, and implant data, including baseline and 1-year postoperative, were collected. A total of 60 patients were recruited and received 117 implants. Complete 1-year clinical and radiographic data were available for 83 and 65 implants, respectively. Two implants failed during the first year, resulting in a 1-year survival rate of 98.3%. Mean implant probing pocket depth was 2.29 ± 0.84 mm. Mean radiographic bone distance from implant's shoulder at the mesial and distal sites at 1 year was 0.66 ± 0.5 and 0.79 ± 0.64mm, respectively, resulting in a success rate of 95.4%. Patient subjective evaluation of therapy exhibited a median pain experience of 1 and median esthetics, function, and general satisfaction evaluation of 10 on a scale of 1 to 10. The tapered conical connection dental implant system, used in private dental practices, shows good 1-year survival and success rates that are similar to other implant systems on the market.
Assuntos
Perda do Osso Alveolar , Implantes Dentários , Prótese Dentária Fixada por Implante , Medidas de Resultados Relatados pelo Paciente , Adolescente , Adulto , Idoso , Implantação Dentária Endóssea , Planejamento de Prótese Dentária , Falha de Restauração Dentária , Seguimentos , Humanos , Pessoa de Meia-Idade , Prática Privada , Estudos Prospectivos , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Endothelial progenitor cells (EPCs) participate in angiogenesis and induce favorable micro-environments for tissue regeneration. The efficacy of EPCs in regenerative medicine is extensively studied; however, their safety profile remains unknown. Therefore, our aims were to evaluate the safety profile of human peripheral blood-derived EPCs (hEPCs) and to assess the long-term efficacy of hEPCs in bone tissue engineering. METHODS: hEPCs were isolated from peripheral blood, cultured and characterized. ß tricalcium phosphate scaffold (ßTCP, control) or 106 hEPCs loaded onto ßTCP were transplanted in a nude rat calvaria model. New bone formation and blood vessel density were analyzed using histomorphometry and micro-computed tomography (CT). Safety of hEPCs using karyotype analysis, tumorigenecity and biodistribution to target organs was evaluated. RESULTS: On the cellular level, hEPCs retained their karyotype during cell expansion (seven passages). Five months following local hEPC transplantation, on the tissue and organ level, no inflammatory reaction or dysplastic change was evident at the transplanted site or in distant organs. Direct engraftment was evident as CD31 human antigens were detected lining vessel walls in the transplanted site. In distant organs human antigens were absent, negating biodistribution. Bone area fraction and bone height were doubled by hEPC transplantation without affecting mineral density and bone architecture. Additionally, local transplantation of hEPCs increased blood vessel density by nine-fold. CONCLUSIONS: Local transplantation of hEPCs showed a positive safety profile. Furthermore, enhanced angiogenesis and osteogenesis without mineral density change was found. These results bring us one step closer to first-in-human trials using hEPCs for bone regeneration.
Assuntos
Regeneração Óssea/fisiologia , Células Progenitoras Endoteliais/fisiologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/sangue , Engenharia Tecidual/métodos , Animais , Fosfatos de Cálcio/química , Fosfatos de Cálcio/metabolismo , Células Progenitoras Endoteliais/transplante , Humanos , Masculino , Osteogênese/fisiologia , Ratos Nus , Crânio , Microtomografia por Raio-XRESUMO
AIM: The aim of this study was to retrospectively evaluate the association between shallow vestibular depth (VD) and peri-implant parameters. MATERIAL AND METHODS: Peri-implant parameters were evaluated in 61 periodontal patients under regular supportive periodontal therapy. Clinical parameters included gingival index (GI), plaque index (PI), bleeding on probing (BOP), peri-implant pocket depths (PPD), mucosal recession (MR), relative attachment level (RAL), width and thickness of keratinized mucosa (KMW, KMT) and VD. Radiographic bone level (RBL) was measured on peri-apical radiographs. RESULTS: Sites with shallow VD (≤ 4 mm) were associated with higher MR (0.91 mm versus 0.47 mm, p ≤ 0.009), higher RAL (4.23 mm versus 3.59 mm, p ≤ 0.0001) and higher RBL (2.18 mm versus 1.7 mm, p = 0.05) when compared with adequate vestibular depth sites (VD > 4 mm). Moreover, sites with shallow VD presented lower KMW compared with sites with adequate VD (1.24 mm versus 2.38 mm, respectively, p ≤ 0.0001). Slightly greater BOP, and GI were recorded for the shallow VD compared with adequate sites. According to multivariate analysis, factors that could predict RAL included: VD, GI, age, supporting periodontal therapy, implant type and design. CONCLUSIONS: Based on this study, inadequate vestibular depth around dental implants may be associated with increased peri-implant bone loss and mucosal recession. Further prospective and intervention studies will be required to fully understand this phenomenon.
Assuntos
Implantes Dentários , Implantes Dentários/efeitos adversos , Índice de Placa Dentária , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Estudos RetrospectivosRESUMO
BACKGROUND: The aim of this research was to study the efficacy of endothelial progenitor cells (EPC) with ß tri-calcium phosphate (ß-TCP) and barrier in the treatment of experimental peri-implantitis. METHODS: Thirty implants were placed in five American foxhounds. Following osseointegration, ligature-induced peri-implantitis was initiated. EPC were isolated from peripheral blood. Two months later, open flap debridement was performed and implants' surface was decontaminated with 24% EDTA. The sites were grafted with ß-TCP and collagen membrane (ß-TCP group) or ß-TCP loaded with EPC and covered with membrane (EPC group) or left un-grafted (OFD group). At 3 months, animals were killed and specimens sent for histomorphometric and micro-CT analysis. Bone height and %BIC served as primary and secondary outcomes. RESULTS: EPC group showed shorter distance to first BIC (3.29 ± 0.69 mm) compared to 4.2 ± 0.92 mm (ß-TCP) and 3.82 ± 0.73 mm (OFD). Mean histological BIC was 2-3 folds higher in the EPC group (17.65 ± 3.3%) compared with OFD (7.55 ± 2.24%, p = 0.01) and ß-TCP (5.68 ± 2.91%, p = 0.05). BIC greater than 25% was found only in the EPC group. The distance between the implant shoulder to 1st BIC was 2.51 ± 0.7 mm (lingual sites) compared to 3.64 ± 0.8 mm for buccal sites (p < 0.0001). CONCLUSION: ß-TCP loaded with EPC and covered with a membrane-enhanced bone formation around previously contaminated dental implants in an experimental peri-implantitis canine model.
Assuntos
Células Progenitoras Endoteliais , Peri-Implantite , Animais , Desbridamento , Implantes Dentários , Cães , Masculino , OsseointegraçãoRESUMO
BACKGROUND: Traumatic dental injuries (TDI) are a widespread pathology with serious dental public health concerns. OBJECTIVES: The aim of this pathfinder study was to collect initial epidemiological data on oral health in Republic of Georgia. As part of this study, the prevalence and severity of TDI in permanent teeth among seventh- and tenth-grade schoolchildren were evaluated. METHODS: Schoolchildren were examined in four schools in the capital city of Tbilisi, two schools in two other major cities, and one school in four additional villages. In addition to demographical data, the following parameters were collected and recorded: Overjet (OJ), lip competence, number and type/location of the teeth with TDI and Type of TDI. The study population comprised of children aged 12 (seventh grade) and 15 years old (10th grade). RESULTS: A total of 823 7th- and 10th-grade schoolchildren were examined. The overall prevalence of TDI among Georgian population was found to be 10.4% (86 children). The prevalence of TDI was greater in the older age cohort (P < 0.05). Lip posture did not seem to have a marked effect on TDI. Children with an OJ greater than 5 mm were more likely to present with dental injuries compared to children with an OJ equal to or smaller than 5 mm (P < 0.05). Children from rural areas presented with greater prevalence of TDI compared to their urban counterparts (P < 0.05). The maxillary central incisors were the most common teeth to be affected by trauma accounting for 85.2% of the TDI cases. Enamel fracture was the main type of TDI (91.3%). CONCLUSIONS: The prevalence of TDI in Georgian schoolchildren, as presented in this survey, population was found to be rather moderate and involved mainly minor superficial injuries. Rural communities have shown in this report substantial higher rates; thus, educational program might be directed mostly to these regions to children, teachers, and healthcare providers.
Assuntos
Traumatismos Dentários , Adolescente , Criança , Estudos Transversais , Feminino , República da Geórgia , Humanos , Incisivo , Masculino , Prevalência , Fraturas dos DentesRESUMO
AIM: To retrospectively assess tooth-survival rate and its association with patient and oral variables in periodontal office patients, followed up to 18 years. MATERIAL AND METHODS: Patients in a private periodontal office whose files included initial examination (T0 ), reevaluation (TRe ) and ≥ 10 years after T0 (TF ) chartings, and received periodontal therapy and supportive periodontal therapy (SPT) after TRe were included. General health, plaque scores (PI), probing depth (PPD), bleeding on probing (BOP) at six points/tooth, tooth extractions, and SPT visits were extracted from patient files at T0 , TRe , and TF . Descriptive statistics and Cox regression analysis were performed. RESULTS: Fifty patients (mean 26 ± 4 teeth/patient, 1301 teeth) fulfilled inclusion criteria. About 20 and 129 teeth respectively were extracted before/after TRe , 96 of them for periodontal causes. PPD>7 mm at TRe (HR = 17.7, 95%CI 8.6, 36.6), age above 60 years (HR = 3.3, 95%CI 1.5, 7.2), multi-rooted teeth (HR = 1.9, 95%CI 1.2, 3.1) and SPT<3 times/year (HR = 1.8, 95%CI 1.1, 2.9), were the best prognostic factors for tooth loss during follow-up. (p < 0.05, Cox regression analysis). A continuous, statistically significant reduction was observed in mean PPD among teeth that survived follow-up [4.3 ± 1.8 mm, 3.5 ± 1.4 mm, 3.2 ± 1.3 mm, at T0 , TRe , TF , respectively. (p < 0.001, Repeated-measures test)]. CONCLUSION: Regular SPT was associated with low tooth-loss rates and continuous reductions in probing depth. PPD after initial therapy, age above 60, multi-rooted teeth and infrequent SPT were strong negative prognostic factors for long-term tooth survival among periodontal patients.
Assuntos
Bolsa Periodontal/complicações , Perda de Dente/etiologia , Adulto , Fatores Etários , Idoso , Índice de Placa Dentária , Feminino , Seguimentos , Nível de Saúde , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Dente Molar/patologia , Índice Periodontal , Bolsa Periodontal/terapia , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Taxa de Sobrevida , Extração Dentária , Resultado do TratamentoRESUMO
INTRODUCTION: Endothelial progenitor cells (EPC) participate in angiogenesis and osteogenesis, therefore, have the potential to enhance extra-cortical bone formation. AIM: To enhance extra-cortical bone formation following local transplantation of human peripheral blood-derived EPC (hEPC) in a guided bone regeneration (GBR) nude rat calvaria model. MATERIALS AND METHODS: hEPC were isolated from peripheral blood of healthy volunteers. Cells were cultured and characterized by flow cytometry for specific endothelial markers. Following exposure of nude rat calvaria, gold domes were filled with 10(6) hEPC mixed with ßTCP (n = 6). Domes filled with ßTCP served as control (n = 6). Rats were sacrificed after 3 months. New bone formation and blood vessel density were analysed by histology and histomorphometry. Transplanted hEPC were located in the regenerated tissue using immunohistology. RESULTS: Abundant vasculature was observed adjacent to the newly formed bone. According to histomorphometric analysis: blood vessel density was 7.5 folds higher in the hEPC compared with the control group. Similarly, gained extra-cortical bone height (2.46 ± 1.1 mm versus 0.843 ± 0.61 mm, p = 0.01) and bone area fraction (19.42 ± 7.48% versus 4.81 ± 3.93%, p = 0.001) were elevated following hEPC transplantation. Moreover, hEPC expressing human-specific CD31 were integrated into blood vessel walls adjacent to newly formed bone. CONCLUSION: In nude rat GBR calvaria model, transplantation of hEPC significantly enhanced vasculogenesis and osteogenesis.
Assuntos
Células Endoteliais/fisiologia , Neovascularização Fisiológica/fisiologia , Osteogênese/fisiologia , Células-Tronco/fisiologia , Animais , Materiais Biocompatíveis/química , Sangue , Vasos Sanguíneos/crescimento & desenvolvimento , Regeneração Óssea/fisiologia , Fosfatos de Cálcio/química , Técnicas de Cultura de Células , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Fibronectinas/química , Regeneração Tecidual Guiada/métodos , Xenoenxertos/transplante , Humanos , Masculino , Osso Parietal/cirurgia , Ratos , Ratos Nus , Transplante de Células-Tronco/métodos , Alicerces Teciduais/químicaRESUMO
UNLABELLED: Periodontitis is a ubiquitous and irreversible inflammatory condition and represents a significant public health burden. Severe periodontitis affects over 11% of adults, is a major cause of tooth loss impacting negatively upon speech, nutrition, quality of life and self-esteem, and has systemic inflammatory consequences. Periodontitis is preventable and treatment leads to reduced rates of tooth loss and improved quality of life. However, successful treatment necessitates behaviour change in patients to address lifestyle risk factors (e.g. smoking) and, most importantly, to attain and sustain high standards of daily plaque removal, lifelong. While mechanical plaque removal remains the bedrock of successful periodontal disease management, in high-risk patients it appears that the critical threshold for plaque accumulation to trigger periodontitis is low, and such patients may benefit from adjunctive agents for primary prevention of periodontitis. AIM: The aims of this working group were to systematically review the evidence for primary prevention of periodontitis by preventing gingivitis via four approaches: 1) the efficacy of mechanical self-administered plaque control regimes; 2) the efficacy of self-administered inter-dental mechanical plaque control; 3) the efficacy of adjunctive chemical plaque control; and 4) anti-inflammatory (sole or adjunctive) approaches. METHODS: Two meta-reviews (mechanical plaque removal) and two traditional systematic reviews (chemical plaque control/anti-inflammatory agents) formed the basis of this consensus. RESULTS: Data support the belief that professionally administered plaque control significantly improves gingival inflammation and lowers plaque scores, with some evidence that reinforcement of oral hygiene provides further benefit. Re-chargeable power toothbrushes provide small but statistically significant additional reductions in gingival inflammation and plaque levels. Flossing cannot be recommended other than for sites of gingival and periodontal health, where inter-dental brushes (IDBs) will not pass through the interproximal area without trauma. Otherwise, IDBs are the device of choice for interproximal plaque removal. Use of local or systemic anti-inflammatory agents in the management of gingivitis has no robust evidence base. We support the almost universal recommendations that all people should brush their teeth twice a day for at least 2 min. with fluoridated dentifrice. Expert opinion is that for periodontitis patients 2 min. is likely to be insufficient, especially when considering the need for additional use of inter-dental cleaning devices. In patients with gingivitis once daily inter-dental cleaning is recommended and the adjunctive use of chemical plaque control agents offers advantages in this group.
Assuntos
Gengivite/prevenção & controle , Periodontite/prevenção & controle , Prevenção Primária , Anti-Inflamatórios/uso terapêutico , Dispositivos para o Cuidado Bucal Domiciliar , Placa Dentária/prevenção & controle , Dentifrícios/uso terapêutico , Humanos , Higiene Bucal , Autocuidado , Escovação Dentária/métodosRESUMO
BACKGROUND: Systemic sclerosis (SSc) is a chronic disease with prominent vasculopathy, inflammation, production of autoantibodies, and tissue fibrosis. Periodontitis is a chronic inflammatory oral condition manifesting as microbial infection, inflammation and destruction of the alveolar bone. In both conditions tumor necrosis factor-alpha (TNFα) and other proinflammatory cytokines play an important role in pathogenesis. OBJECTIVES: To assess the periodontal status in SSc patients and compare these parameters to TNFα level in gingival crevicular fluid (GCF) of SSc patients and healthy controls. METHODS: Twenty SSc patients and 20 controls underwent periodontal examination, including probing depth (PD), plaque index (PI), gingival-index (GI), bleeding on probing (BOP), and measurement of TNFα levels in collected GCF. RESULTS: SSc patients had a greater PD (3.74 ± 0.32 mm vs. 3.35 ± 0.31 mm, P > 0.003), GI (1.53 ± 0.34 vs. 1.12 ± 0.54, P > 0.049), and non-significantly higher BOP than controls. TNFα levels in GCF were higher in SSc patients (1.63 ± 0.36 vs. 1.15 ± 0.34 pg/ml, P = 0.001). Periodontitis parameters correlated with several SSc variables; PI in particular was higher in patients with longer disease duration, sclerodactyly, more severe skin involvement, and SSc activity score. CONCLUSIONS: Patients with SSc have higher indices of periodontal inflammation and higher TNFα level in GCF than did healthy individuals. These changes probably reflect the complexity of factors that influence oral health in SSc. Common pathologic pathways may be responsible for the association between SSc and periodontitis, which requires further study.
Assuntos
Líquido do Sulco Gengival/metabolismo , Doenças Periodontais/epidemiologia , Periodontite/epidemiologia , Escleroderma Sistêmico/fisiopatologia , Fator de Necrose Tumoral alfa/metabolismo , Adulto , Estudos de Casos e Controles , Citocinas/metabolismo , Índice de Placa Dentária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Índice de Gravidade de Doença , Fatores de TempoRESUMO
AIM AND OBJECTIVES: The aim of this study was to evaluate the influence of fluid environment mimicking intra-oral conditions on fatigue performance of standard diameter, 3.75-mm implants. Dental implants placed intra-orally are repeatedly submitted to mastication loads in the oral environment, which differ substantially from room-air standard laboratory conditions. Several studies that examined fracture surfaces of intra-orally fractured dental implants have identified corrosion fatigue as the main failure mechanism. Yet, fatigue performance of dental implants has been essentially studied in room air, based on the premise that the implant material is relatively resistant to corrosion in the intra-oral environment. MATERIAL AND METHODS: Thirty-two 3.75-mm titanium alloy implants were tested under cyclic compressive loading. The tests were performed in artificial saliva substitute containing 250 ppm of fluoride. The loading machine stopped running when the implant structure collapsed or when it completed 5 × 10(6) cycles without apparent failure. The load vs. number of cycles was plotted as curve for biomechanical fatigue analysis (S-N curve). The S-N curve plotted for the artificial saliva test was compared to the curve obtained previously for the same implants tested in a room-air environment. Failure analysis was performed using scanning electron microscopy (SEM). RESULTS: A comparison of the S-N curves obtained in artificial saliva and in room air showed a considerable difference. The S-N curve obtained in the artificial saliva environment showed a finite life region between 535N and 800N. The transition region was found below 465N, with a probability of survival of 50%, while in room air, the transition region was between 810N and 620N and an infinite life region below 620N was identified. CONCLUSIONS: The results of this study show that environmental conditions adversely affect implants' fatigue performance. This fact should be taken into account when evaluating the mechanical properties of dental implants.
Assuntos
Implantes Dentários , Falha de Restauração Dentária , Corrosão , Ligas Dentárias/química , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Saliva Artificial/química , Estresse Mecânico , Propriedades de Superfície , Titânio/químicaRESUMO
The relationship of dental implants with neighboring teeth will affect both occlusal relationship and distribution of forces; thus, the purpose of this study was to examine implants' axial relationship with adjacent and opposing teeth/implants. Data of dental implants patients was retrieved. Panoramic X rays were digitized. Computer-based software was used to measure the angular relationship between the implants and adjacent/opposing teeth and implants. Data was further sorted by the mode of placement and implants position. 50 patients (219 implants) were included. Mean angle to adjacent tooth/implant was 178.71° ± 9.18° (range 129.7°-206°). Implants were more parallel to adjacent teeth (180.99° ± 1.06°) than to adjacent implants (176.32° ± 0.54°; P = .0001). Mean angular relationship to opposite tooth was 167.88° ± 8.92° (range 137.7°-179.8°). Implants that were placed freehand or with positional guide had similar intra-arch relationship (178.22° and 178.81°, respectively) and similar inter-arch angulations (164.46° and 167.74°). Molars had greater deviation of the angular relationship (175.54°) compared to premolars (181.62°) and incisors (180.55°, P = .0001). Implants placed in the maxilla had smaller axial deviation compared to implants in the mandible (180.41° ± 0.64 vs 177.14° ± 1.02; P = .0081). Good axial relationship may be obtained in most implants placed by an experienced clinician, even when placed freehand. The mandibular posterior region is more prone to axial deviation and as such requires special attention.
Assuntos
Implantes Dentários , Dente/diagnóstico por imagem , Adolescente , Adulto , Idoso , Dente Pré-Molar/diagnóstico por imagem , Implantação Dentária Endóssea/métodos , Oclusão Dentária , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Incisivo/diagnóstico por imagem , Masculino , Mandíbula/diagnóstico por imagem , Maxila/diagnóstico por imagem , Pessoa de Meia-Idade , Dente Molar/diagnóstico por imagem , Radiografia Panorâmica/métodos , Estudos Retrospectivos , Estresse Mecânico , Adulto JovemRESUMO
The causative agents in periodontal disease are periopathogenic bacteria; however, viruses have been implicated. The aim of this study was to examine the prevalence of different HHVs in the saliva of chronic periodontitis patients and to compare it to two groups of healthy controls. Three groups were included: chronic periodontitis patients (CP), periodontally healthy patients (NP) and oral health providers with a healthy periodontium (NPOHP). For each subject, 1 ml of unstimulated whole saliva was collected and mixed with 2 ml lysis buffer. HHVs assays were performed using real-time PCR. Fifteen percent of the subjects in the CP group tested positive for CMV compared to none in the NP and NPOHP groups (p = 0.04). Recurrent herpes was more frequent in females (51.7 %) than in males (33.3 %), and this was statistically significant (p = 0.038). The higher prevalence of CMV in the unstimulated saliva of CP patients suggests that CMV may play a role in the pathogenesis of chronic periodontitis.
Assuntos
Periodontite Crônica/virologia , Odontólogos/estatística & dados numéricos , Infecções por Herpesviridae/epidemiologia , Herpesviridae/metabolismo , Saliva/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Infecções por Herpesviridae/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Fatores Sexuais , Adulto JovemRESUMO
AIM: To enhance vertical bone formation in a rat calvarium following combination of guided bone regeneration (GBR) and transplantation of bone marrow derived mesenchymal stem cells (bmMSC). MATERIALS AND METHODS: Gold domes (7 mm radius, 5 mm height) were filled with 5 × 10(5) bmMSC or osteogenic transformed bmMSC (otMSC) that were isolated from tibia of inbred rats and mixed with ßTCP. Domes filled with ßTCP served as control. Rats were sacrificed after 3 months. New bone formation was analysed by histology and histomorphometry. RESULTS: In all rats hard tissue filled the space under the dome. In the lower part of the specimens the newly formed mature bone was continuous with the original calvaria, whereas the upper (distal) part of the augmented tissue contained residual scaffold surrounded by connective tissue. Histomorphometric analysis revealed that cell transplantation doubled vertical bone height: (bmMSC 4.13 ± 0.5 mm, otMSC 4.14 ± 0.3 mm ßTCP 2.29 ± 0.22 mm, p ≤ 0.001). Bone area fraction (%) was significantly increased following transplantation of otMSC (47.2 ± 2.5%) when compared with bmMSC (37.3 ± 3.35%) and with ßTCP (31.09 ± 2.7%) (p ≤ 0.031 versus bmMSC, p ≤ 0.0004 versus control) CONCLUSION: In a rat calvaria model transplantation of both otMSC and bmMSC, when combined with GBR significantly enhanced bone formation.
Assuntos
Regeneração Óssea , Regeneração Tecidual Guiada/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Engenharia Tecidual/métodos , Animais , Transplante de Medula Óssea , Substitutos Ósseos , Fosfatos de Cálcio , Técnicas de Cultura de Células , Diferenciação Celular , Masculino , Ratos , Ratos Endogâmicos Lew , Crânio/cirurgia , Alicerces TeciduaisRESUMO
OBJECTIVES: To examine bone formation in dehiscence defects using biphasic hydroxyapatite/ß-tricalcium phosphate plus biphasic calcium sulfate (BCP/BCS). MATERIAL: After extractions, 24 mandibular buccal dehiscence defects (3 × 3 mm) were treated with BCP/BCS (E), membrane (MC), or control (NC). Histology and histomorphometric analysis were performed. RESULTS: After 6 weeks, bone formation was noticeable in most sites. In subsequent phases, the woven bone was gradually remodeled into lamellar bone and marrow. Vertical new bone height in the E and MC groups (1.06 and 0.85 mm.) was substantially greater than that in the NC group (-0.28 mm). For all groups, there was an overall increase in the height of the newly formed bone through the observation. At week 12, the vertical bone height was 1.95, 2.07, and 0.29 mm, respectively. The mean new bone area in the E and MC groups was much greater than that in the NC group (2.85, 2.80, and -0.20 mm, respectively). Percent new bone in all 3 groups was similar (36.25%, 34.84%, and 28.34%, respectively). CONCLUSIONS: This study demonstrates the efficacy of BCP/BCS graft for bone augmentation in dehiscence-type extraction socket defect.
Assuntos
Aumento do Rebordo Alveolar/métodos , Materiais Biocompatíveis/uso terapêutico , Substitutos Ósseos/uso terapêutico , Sulfato de Cálcio/uso terapêutico , Implantação Dentária Endóssea/métodos , Hidroxiapatitas/uso terapêutico , Mandíbula/cirurgia , Deiscência da Ferida Operatória/cirurgia , Aumento do Rebordo Alveolar/instrumentação , Animais , Regeneração Óssea , CãesRESUMO
BACKGROUND: Previous studies focused on the influence of buccal mucosa thickness on peri-implant bone loss and inflammation, with inconclusive results. We observed substantially thicker palatal mucosal tissues at peri-implantitis sites. Therefore, we hypothesize that thick palatal peri-implant mucosa may be associated with deeper pockets and disease severity. PURPOSE: To compare the thickness of the palatal tissue between natural teeth and implants in periodontal health and disease. METHODS: Adult, non-smoker, healthy patients who visited our department for periodontal examination or treatment with restored implants in the posterior maxilla were recruited. Probing depth (PD), plaque index (PI), gingival index (GI) and radiographic measurements were recorded around implant and the contralateral tooth. Palatal tissue thickness was measured using a 30G needle that was inserted perpendicular into the mucosa at the bottom of the periodontal/peri-implant pocket and 3 mm coronally. Differences in the palatal tissue thickness between teeth and implants (in the same patient) was performed using t-test; as well as between peri-implantitis and non-peri-implantitis sites (among patients). RESULTS: Sixty patients were included. Thirty-four implants were diagnosed with peri-implantitis and 26 healthy/mucositis implants with corresponding 24 healthy/gingivitis teeth and 36 teeth with attachment loss. Mean PD was higher around implants (4.47 ± 1.57 mm) than teeth (3.61 ± 1.23 mm, p = 0.001). The thickness of implants' palatal mucosa was higher than in teeth, at the base of the pocket and 3 mm coronally (4.58 ± 1.38 mm vs. 3.01 ± 1.11, p = 0.000; 3.58 ± 2.15 vs. 1.89 ± 1.11, p = 0.000, respectively). Mean palatal tissue thickness was 4.32 ± 2.35 mm for the peri-implantitis group while only 2.61 ± 1.39 in healthy implants, 3 mm coronal to the base of the pocket (p = 0.001). Palatal thickness at peri-implantitis sites was higher (4.32 ± 2.35) compared to periodontitis sites (2.23 ± 0.93), p = 0.000. Implant sites with palatal mucosa >4 mm (n = 32) had deeper mean pockets (5.58 ± 1.98) compared with thinner (≤4 mm) sites (n = 28) (4.48 ± 1.18, p = 0.018). CONCLUSION: Thicker palatal tissue around implants is associated with deeper palatal pockets. Thick palatal tissue was found around implants diagnosed with peri-implantitis.