RESUMO
AIM: A new implant system encompassing implants with a tri-oval cross-sectional design and a simplified site preparation protocol at low speed and no irrigation has been developed. The objective of this study was to assess the safety and efficacy of the new implant system using the minipig intraoral dental implant model. METHODS: Eight Yucatan minipigs were included. Twelve weeks after extractions, four implants per animal were randomly placed and allowed to heal transmucosal for 13 weeks: two Ø3.5 × 10 mm implants with a back-tapered collar and circular cross-section (control) and two Ø3.5 × 11 mm implants with tri-oval collar and cross-section (test). MicroCT and histological analysis was performed. RESULTS: Thirty-two implants were placed; one implant for the control group was lost. Histologically, BIC was higher in the test compared with the control group (74.1% vs. 60.9%, p < .001). At the platform level, inflammation was statistically significantly higher albeit mild in the test compared with the control group. No other significant differences were observed between groups. MicroCT analysis showed that bone-to-implant-contact (BIC) and trabecular thickness were statistically significantly higher for the test than the control group. Test group had significantly higher first BIC distance than controls on lingual sites. CONCLUSIONS: The present study results support the safety and efficacy of the new dental implant system and simplified site preparation protocol; human studies should be carried out to confirm these findings.
Assuntos
Implantação Dentária Endóssea , Implantes Dentários , Animais , Estudos Transversais , Implantação Dentária Endóssea/métodos , Osseointegração , Suínos , Porco MiniaturaRESUMO
BACKGROUND: Natural (bovine-/equine-/porcine-derived) or synthetic hydroxyapatite (HA) biomaterials appear to be the preferred technologies among clinicians for bone augmentation procedures in preparation for implant dentistry. The aim of this study was to screen candidate HA biomaterials intended for alveolar ridge augmentation relative to their potential to support local bone formation/maturation and to assess biomaterial resorption using a routine critical-size rat calvaria defect model. METHODS: Eighty adult male Sprague Dawley outbred rats obtained from a approved-breeder, randomized into groups of ten, were used. The calvaria defects (ø8 mm) either received sham surgery (empty control), Bio-Oss (bovine HA/reference control), or candidate biomaterials including bovine HA (Cerabone, DirectOss, 403Z013), and bovine (403Z014) or synthetic HA/ß-TCP (Reprobone, Ceraball) constructs. An 8 wk healing interval was used to capture the biomaterials' resolution. RESULTS: All biomaterials displayed biocompatibility. Strict HA biomaterials showed limited, if any, signs of biodegradation/resorption, with the biomaterial area fraction ranging from 22% to 42%. Synthetic HA/ß-TCP constructs showed limited evidence of biodegradation/erosion (biomaterial area fraction ≈30%). Mean linear defect closure in the sham-surgery control approximated 40%. Mean linear defect closure for the Bio-Oss reference control approximated 18% compared with 15-35% for the candidate biomaterials without significant differences between the controls and candidate biomaterials. CONCLUSIONS: None of the candidate HA biomaterials supported local bone formation/maturation beyond the native regenerative potential of this rodent model, pointing to their limitations for regenerative procedures. Biocompatibility and biomaterial dimensional stability could suggest their potential utility as long-term defect fillers.
Assuntos
Substitutos Ósseos , Durapatita , Animais , Masculino , Bovinos , Cavalos , Ratos , Suínos , Durapatita/farmacologia , Osteogênese , Materiais Biocompatíveis/farmacologia , Substitutos Ósseos/farmacologia , Regeneração Óssea , Fosfatos de Cálcio , Ratos Sprague-Dawley , Crânio/cirurgiaRESUMO
OBJECTIVES: The objective of this report was to provide a review of the minipig intraoral dental implant model including a meta-analysis to estimate osseointegration and crestal bone remodeling. METHODS: A systematic review including PubMed and EMBASE databases through June 2021 was conducted. Two independent examiners screened titles/abstracts and selected full-text articles. Studies evaluating titanium dental implant osseointegration in native alveolar bone were included. A quality assessment of reporting was performed. Random-effects meta-analyses and meta-regressions were produced for bone-implant contact (BIC), first BIC, and crestal bone level. RESULTS: 125 out of 249 full-text articles were reviewed, 55 original studies were included. Quality of reporting was generally low, omissions included animal characteristics, examiner masking/calibration, and sample size calculation. The typical minipig model protocol included surgical extraction of the mandibular premolars and first molar, 12±4 wks post-extraction healing, placement of three narrow regular length dental implants per jaw quadrant, submerged implant healing and 8 wks of osseointegration. Approximately 90% of studies reported undecalcified incandescent light microscopy histometrics. Overall, mean BIC was 59.88% (95%CI: 57.43-62.33). BIC increased significantly over time (p<0.001): 40.93 (95%CI: 34.95-46.90) at 2 wks, 58.37% (95%CI: 54.38-62.36) at 4 wks, and 66.33% (95%CI: 63.45-69.21) beyond 4 wks. Variability among studies was mainly explained by differences in observation interval post-extraction and post-implant placement, and implant surface. Heterogeneity was high for all studies (I2 > 90%, p<0.001). CONCLUSIONS: The minipig intraoral dental implant model appears to effectively demonstrate osseointegration and alveolar bone remodeling similar to that observed in humans and canine models.
Assuntos
Implantes DentáriosRESUMO
AIM: Evaluate supportive periodontal therapy (SPT) consisting of oral prophylaxis with oral hygiene instructions as sole intervention (test) or combined with subgingival instrumentation removing/disrupting the subgingival biofilm (control). MATERIAL AND METHODS: Sixty-two treated periodontitis patients (50.97 ± 9.26 years, 24 smokers) were randomly assigned to receive, every 3 months during 2 years, either test or control treatment. Examination included periodontal probing depth (PPD), bleeding on probing (BOP) and clinical attachment loss (CAL). Generalized estimating equations were used for analyses. RESULTS: Baseline demographics and smoking were similar between groups. However, at baseline, mean PPD was greater in test group than in control group (2.32 mm vs. 2.17 mm, p = .03), but similar after 2 years (2.23 mm vs. 2.15 mm, respectively). With time, significant PPD and BOP decrease and CAL increase were observed although without significant differences between groups. At sites ≥ 5 mm, PPD decrease was greater in test group than in control group irrespective of sex and smoking habit (p = .034). The distribution of sites gaining or losing attachment ±2 mm was similar between groups. CONCLUSION: Oral prophylaxis with oral hygiene instructions alone or in combination with subgingival instrumentation was able to maintain the previously obtained periodontal condition to a comparable extent during 2 years of SPT.
Assuntos
Periodontite , Biofilmes , Humanos , Perda da Inserção PeriodontalRESUMO
BACKGROUND: It is well established that electrochemical anodization of implant surfaces contributes to osseointegration and long-term implant survival. Few studies have investigated its effect on soft tissue healing. PURPOSE: To evaluate the safety and efficacy of a novel abutment surface prepared by electrochemical oxidation compared to commercially available machined titanium abutments. MATERIALS AND METHODS: Twelve 16-19 months-old, Yucatan mini-pigs received three dental implants in each mandibular jaw quadrant. Each side was randomized to receive either an anodized or a machined titanium abutment. Titanium healing caps were placed on both abutments. Animals were euthanized at 6 and 13 weeks. Radiographic and histological analyses were performed. RESULTS: No significant differences were observed histologically between groups in regard to inflammation, epithelium length, mucosal height, bone-to-implant contact, or bone density for any time point. Radiographically, crestal bone level change from baseline to 6 weeks was significantly lower for anodized than machined abutments (P = 0.046); no significant differences were observed at 13 weeks (P = 0.12). CONCLUSIONS: The novel anodized abutment showed a comparable effect on soft and hard tissue healing/remodeling and inflammation reaction to standard titanium abutments. Clinical studies should confirm these findings and explore the positive radiographic results observed at the early time point.
Assuntos
Dente Suporte , Implantes Dentários , Animais , Implantação Dentária Endóssea , Osseointegração , Distribuição Aleatória , Propriedades de Superfície , Suínos , Porco Miniatura , TitânioRESUMO
BACKGROUND: A newly developed dental implant system combining advancements in surface chemistry, topography, nanostructure, color, and surface energy aims to address biological challenges and expand clinical applications. PURPOSE: To assess the short- and long-term safety and efficacy of a novel, gradually anodized dental implant surface/anodized abutment. MATERIALS AND METHODS: Twenty-four Yucatan mini pigs (20-24 months old) received two dental implants in each jaw quadrant. Each site was randomized to receive either a commercially available anodized implant/machined abutment or a gradually anodized implant/anodized abutment with a protective layer. Animals were euthanized at 3, 6, and 13 weeks. Microcomputed tomography and histological analyses were performed. RESULTS: No significant histological differences in inflammation scores, epithelium length, bone-to-implant contact, or bone density were observed between groups for any healing time. Mucosal height was significantly higher at 3 weeks for controls (Δ = 0.2 mm); no differences were observed at 6 and 13 weeks. No significant differences in radiographic bone volume, bone-to-implant contact, trabecular thickness, and crestal bone levels were observed, irrespective of healing time. Trabecular spacing was borderline significant at 3 weeks in favor of the test implant sites; no differences were observed at 6 weeks. No significant differences were observed between experimental groups at 13 weeks. CONCLUSIONS: The new implant system yielded results comparable to a commercially available predicate device.
Assuntos
Implantes Dentários , Planejamento de Prótese Dentária , Osseointegração , Animais , Implantação Dentária Endóssea , Propriedades de Superfície , Suínos , Porco Miniatura , Titânio , Microtomografia por Raio-XRESUMO
OBJECTIVE: To screen candidate biomaterials intended for alveolar augmentation relative to their potential to enhance local bone formation using a routine critical-size (ø8-mm) rat calvaria defect model. METHODS: One hundred and forty male Sprague Dawley outbred rats, age 11-12 weeks, weight 325-375 g, obtained from USDA approved breeder, randomised into 14 groups of 10 animals, each received one of the following treatments: sham-surgery (empty control), Bio-Oss (bovine HA/reference control), or candidate biomaterials including bovine HA, synthetic HA/ß-TCP and calcium phosphate constructs, mineralised/demineralised human bone preparations, a ß-TCP/calcium sulphate and an HA/calcium sulphate putty. A 4-week healing interval was chosen to discern local bone formation using incandescent and polarised light microscopy. Statistical analysis used one-way ANOVA followed by Bonferroni for pairwise comparisons. RESULTS: Candidate biomaterials all displayed biocompatibility. They exhibited limited, if any, appreciable bioerosion or biodegradation. No statistically significant differences in mean linear defect closure were observed among experimental groups, sham-surgery displaying the highest score (48.1 ± 24.3%). Sham-surgery also showed a significantly greater bone area fraction than all other groups (19.8 ± 13.9%, p < .001). The HA/calcium sulphate putty showed a significantly greater residual biomaterial area fraction than all other groups (61.1 ± 8.5%, p < .01). CONCLUSION: Within the limitations of this animal model, although biocompatible, none of the tested biomaterials enhanced local bone formation beyond the innate regenerative potential of this craniotomy defect.
Assuntos
Materiais Biocompatíveis , Substitutos Ósseos , Animais , Regeneração Óssea , Fosfatos de Cálcio , Bovinos , Humanos , Masculino , Osteogênese , Ratos , Ratos Sprague-Dawley , CrânioRESUMO
Dendritic cells (DCs) are specialized antigen-presenting cells that play a pivotal role in the pathogenesis of periodontitis. The use of animal models to study the role of DCs in periodontitis has been limited by lack of a method for sustained depletion of DCs. Hence, the objectives of this study were to validate the zDC-DTR knockin mouse model of conventional DCs (cDCs) depletion, as well as to investigate whether this depletion could be sustained long enough to induce alveolar bone loss in this model. zDC-DTR mice were treated with different dose regimens of diphtheria toxin (DT) to determine survival rate. A loading DT dose of 20ng/bw, followed and maintained with doses of 10ng/bm every 3days for up to 4weeks demonstrated 80% survival. Animals were weighed weekly and peripheral blood was obtained to confirm normal neutrophil counts. Five animals per group were euthanized at baseline, 24h, 1 and 4weeks. Bone marrow (BM), spleen (SP) and gingival tissue (GT) were harvested, and cells were isolated, separated and stained for Pre-DCs precursors (CD45R-MHCII+CD11c+Flt3+CD172a+) in BM, cDCs (CD11c+MHCII+CD209+) in spleen, and DCs in GT (CD45R+MHCII+CD11c+ DC-SIGN/CD209+). Pre-DCs in BM were significantly depleted at 24h and depletion maintained for up to 4weeks, as compared to blank (PBS) controls. Circulating cDCs in spleen demonstrated a non-significant trend to deplete in 1week with high variability among mice. GT also showed a similar non-significant trend to deplete in 24h. The zDC-DTR model seems to be viable for evaluating the role of DCs immune homeostasis disruption and alveolar bone loss pathogenesis in response to long-term oral infection.
Assuntos
Células Dendríticas/imunologia , Modelos Animais de Doenças , Periodontite/imunologia , Animais , Células da Medula Óssea/imunologia , Células Dendríticas/patologia , Toxina Diftérica/administração & dosagem , Toxina Diftérica/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Baço/citologia , Baço/imunologia , Fatores de TempoRESUMO
OBJECTIVE: This observational study aimed to compare the estimation of clinical attachment loss (CAL) as measured by direct (CALD ) and indirect (CALI ) methods. METHODS: Periodontitis patients (n = 75; mean age: 50.9 ± 8.02 years; 72.2% women; 50.6% smokers) received a periodontal examination (six sites/tooth) to determine the presence of visible plaque and calculus, the gingival bleeding index (GBI), periodontal probing depth (PPD), bleeding on probing (BOP), CALD and gingival recession (GR). CALI values resulted from the sum of PPD and GR values. Statistical analysis considered only data from sites with visible GR (e.g. the gingival margin apical to the cemento-enamel junction; n = 4,757 sites) and determined the mean difference between CALI and CALD measurements. Based on the mean difference, univariate and multivariate analyses were also performed. RESULTS: Mean CALD and CALI values were 3.96 ± 2.07 mm and 4.47 ± 2.03 mm, respectively. The indirect method overestimated CAL compared with the direct method (mean difference: 0.51 ± 1.23 mm; P < 0.001). On uni- and multivariate analyses, absence of GBI and BOP, PPD and proximal site location had significant influences on the overestimation of CAL by the indirect method (all P ≤ 0.01). The indirect method increased the CAL value by 0.38 mm for each additional 1 mm in PPD. CONCLUSIONS: To decrease the number of probing errors in daily practice it is suggested that direct examination is more appropriate than the indirect method for estimating CAL.
Assuntos
Perda da Inserção Periodontal/diagnóstico , Placa Dentária/diagnóstico , Índice de Placa Dentária , Feminino , Hemorragia Gengival/diagnóstico , Retração Gengival/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Índice PeriodontalRESUMO
Completely and partially edentulous patients with Sjogren's syndrome (SS) experience severe hyposalivation, xerostomia, and considerable difficulty in using tissue-supported prosthesis. This clinical paper describes the management, treatment, and 6-year follow-up of a patient diagnosed with SS type II, who uses corticosteroids and antihyperglycemic drugs. The patient received restorative, periodontal, and surgical treatments followed by implant-supported fixed prosthesis. Radiographic evaluation and probing depth showed gingival health and no bone loss after 6 years. Treatment with implant-retained dental prosthesis greatly increased comfort and function, offering an alternative to patients with SS.