1,721,160 research outputs found
Microbial colonization at the implant-abutment interface and its possible influence on periimplantitis: A systematic review and meta-analysis
No full textPurpose The aim of this systematic review and meta-analysis was to evaluate the microbial colonization at the implant-abutment interfaces (IAI) on bone-level implants and to identify possible association with peri-implant conditions. Study selection The focus question aimed to answer whether two-piece osseointegrated implants, in function for at least 1 year, in human, relate to higher bacterial count and the onset of periimplantitis, compared to healthy peri-implant conditions. Search strategy encompassed the on-line (MedLine, Google scholar, Cochrane library) literature from 1990 up to March 2015 published in English using combinations of MeSH (Medical Subject Headings) and search terms. Quality assessment of selected full-text articles was performed according to the ARRIVE and CONSORT statement guidelines. For data analysis, the total bacterial count of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, and Fusobacterium nucleatum was calculated and compared to IAI with or without peri-implant pathology. Results A total of 14 articles, reporting data from 1126 implants, fulfilled the inclusion criteria and subjected to quality assessment. The selected studies revealed contamination of the IAI, in patients who received two-piece implant systems. Meta-analysis indicated significant difference in total bacterial count between implants affected by periimplantitis versus healthy peri-implant tissues (0.387 ± 0.055; 95% CI 0.279–0.496). Less bacterial counts were identified in the healthy IAI for all the investigated gram-negative bacteria except for T. forsythia. Conclusions Significantly higher bacterial counts were found for periodontal pathogenic bacteria within the IAI of implants in patients with periimplantitis compared to those implants surrounded by healthy peri-implant tissues
The "hybrid abutment": a new design for implant cemented restorations in the esthetic zones
No full textCemented implant restorations are widely used by many dentists. The traditional abutment design resembles a natural tooth prepared for a crown with a similar taper and a chamfer finish line. A frequent complication associated with implant restorations in the esthetic zones is the recession of buccal gingiva over time. Abutment morphology, among several other prosthetic factors, may play an important role in the stability of the gingival margin in esthetically sensitive areas, but this has never been thoroughly analyzed. Recently, a prosthetic technique called biologically oriented preparation technique (BOPT) has been proposed, which utilizes a feather-edge preparation on natural abutments, and it has been claimed that applying the concepts of this technique to implant abutments could improve long-term gingival margin stability. At present, there is no available evidence to confirm this claim. Moreover, some concerns may arise if this particular design is implemented in every clinical situation. With these considerations in mind, this article proposes the "hybrid abutment" design (HAD), a new design that includes a combination of the two types of features--a feather edge on the buccal side, and a chamfer finish line on the lingual side. The article also presents a rationale for the use of different abutment designs for different situations
Cell growth on Titanium disks treated by Plasma of Argon Experimental study
No full textBACKGROUND: The initial interactions between cellular components and materials play an important role in the stages of the healing process around fixture and implant abutment. These interactions are critically mediated by the state of the surface. Plasma treatment has been used for several decades to increase cellular adherence to polymeric and metallic materials. Recently it was suggested to enhance cell adherence to titanium implant surface. The present experimental study was aimed to analyze wheatear cleaning treatment using plasma of argon could interfere with cellular growth of fibroblasts on titanium turned disks at different time-points.
MATERIALS & METHODS: Sixty titanium disks were dived in two groups: 30 were left untreated (control) and 30 were cleaned using plasma of argon (test). They were immersed in culture of fibroblasts (L-929) and, after preparation, stained using DIPA, staining nuclei, and fluorescent phalloidin , labeling cellular body. Count nuclei and analysis of cellular body was performed using fluorescent microscopy and imaging analysis software. Analysis was performed at different time-points: 2, 8 and 48 hours.
RESULTS: At the end of this study, the control group presented fibroblast adhesion mean values of 135 (±26), 184 (±64), 372 (±67) cells/field respectively at 2,8 and 48h. The test group presented fibroblast adhesion mean values of 181 (±37), 233 (±51), 369 (±84) cells/field respectively at 2,8 and 48h. Test group data demonstrated statistical significantly higher values compared to control group at 2 (p<0.0039) and 8h (p<0.0488). Data at 48h did not presented any statistical significant difference.
Analyzing cellular body, at 2 hours the cellular body is flatter and more spread , i.e. the process of cellular adherence is in a more advanced stage in the treated sample.
CONCLUSIONS: Removal of organic and inorganic contamination on the surface of titanium disks using plasma of argon seems to accelerate fibroblast adhesion in the early stage (2-8h). This effect disappears in the long run due to the space saturation. According to the presented data, plasma cleaning could be applied in prosthetic treatment of implant supported rehabilitation, enhancing soft tissue response to the abutment insertion
The "hybrid abutment": a new design for implant cemented restorations in the esthetic zones
No full textEarly implant loading after vertical ridge augmentation (VRA) using e-PTFE titaniumreinforced membrane and nano-structured hydroxyapatite: 2-year prospective study
No full textAims: This 2-year prospective multi-centre study aimed to evaluate the survival of implants loaded 14 weeks after vertical ridge augmentation (VRA).
Materials and methods: Twenty consecutive patients scheduled for VRA around implants were selected for this study in three private centres. Nano-structured Mg-enriched hydroxyapatite (Mg-e HAP) was used as the only augmentation filler material. It was covered with a titanium reinforced extended polytetrafluoroethylene (e-PTFE) membrane (Gore-Tex). A total of 42 rough-surface implants were inserted in the same surgical session. Healing abutments 2 mm long were used instead of cover screws to optimise aesthetics. All patients underwent a second surgery after 3 months. Thereafter, definitive restorations were seated within 2 weeks using a platform-switching concept. Outcome measures were amount of vertical bone gain, prosthesis and implant success, complications and radiographic marginal bone level changes assessed at 12 and 24 months of prosthetic loading. Frequency resonance analysis expressed using ISQ (implant stability quotient) values was performed at implant insertion (T0), when definitive restoration was seated (T1) and after 24 months of prosthetic loading (T2).
Results: At the end of the study, no patient dropped out, all implants were clinically stable and no prosthesis failed. Initial clinical evaluations showed an average defect height of 4.1 mm. Only one late membrane exposure was registered. Complete bone filling of the regeneration volume was obtained in 19 out of 20 cases. The mean bone height gain was 5.6 mm. Radiographic assessments of inter-implant regenerated bone levels after 24 months of loading presented a mean value of 1.0 mm (SD 0.48 mm), stable compared to the same analysis at the 12-month follow-up. A statistically significant loss of peri-implant bone level occurred over time. Mean peri-implant bone levels were 0.3 mm at the time of prosthetic loading, 0.90 mm after 1 year and 0.98 after 2 years. ISQ values statistically significantly increased over time. At implant placement the mean ISQ value was 49.3, at delivery of the final restoration it was 63.9 and after 2 years of loading it was 73.6.
Conclusion: This clinical study suggests that VRA around rough-surface implants using e-PTFE membrane and nano-structured Mg-e HAP can be successful even in cases with early loadin
Peri-implant hard tissue response to glow-discharged abutments: Prospective study. Preliminary radiological results
No full textIn the literature has been demonstrated that when an implant is placed in the oral environment, changes in peri-implant hard tissue level may occur. Several clinical procedures have been advocated to clinically minimize this bone resorption. However, minimal attention was paid to the soft- and hard-tissue abutment interaction. The present clinical preliminary study is intended to radiologically analyze the effect of glow-discharged abutments on hard tissue level changes after 18 months of prosthetic loading.Five patients needing an implant supported restoration in the anterior maxillary area with thin gingival tissue biotype and healed bone were recruited. An implant was inserted and a titanium abutment was glow-discharged with an Argon plasma treatment in a plasma reactor and, immediately after, definitively screwed at 30. N. Provisional restoration was therefore positioned. Three months later, definitive restoration was performed. Digital periapical standardized radiographs were taken at the time of surgery, 6 and 18 months thereafter. Radiographic analysis was carried out using image analysis software. At baseline, interproximal radiographs revealed no bone defect around implants in both groups. After 6 months from baseline, the postoperative interproximal radiographs revealed an average bone loss of 0.09. mm (range 0.0-0.3. mm, SD = 0.144. mm). After 18 months from baseline, the periapical X-ray showed a stable condition of bone remodeling (mean value: 0.09, range 0.0-0.5. mm, SD = 0.08. mm).Within the limit of this study, glow-discharged abutments have been demonstrated to positively affect hard tissue reaction to implant restoration. © 2012 Elsevier GmbH
Distinguishing predictive profiles for patient-based risk assessment and diagnostics of plaque induced, surgically and prosthetically triggered peri-implantitis
No full textObjective: To investigate whether specific predictive profiles for patient-based risk assessment/diagnostics can be applied in different subtypes of peri-implantitis. Materials and methods: This study included patients with at least two implants (one or more presenting signs of peri-implantitis). Anamnestic, clinical, and implant-related parameters were collected and scored into a single database. Dental implant was chosen as the unit of analysis, and a complete screening protocol was established. The implants affected by peri-implantitis were then clustered into three subtypes in relation to the identified triggering factor: purely plaque-induced or prosthetically or surgically triggered peri-implantitis. Statistical analyses were performed to compare the characteristics and risk factors between peri-implantitis and healthy implants, as well as to compare clinical parameters and distribution of risk factors between plaque, prosthetically and surgically triggered peri-implantitis. The predictive profiles for subtypes of peri-implantitis were estimated using data mining tools including regression methods and C4.5 decision trees. Results: A total of 926 patients previously treated with 2812 dental implants were screened for eligibility. Fifty-six patients (6.04%) with 332 implants (4.44%) met the study criteria. Data from 125 peri-implantitis and 207 healthy implants were therefore analyzed and included in the statistical analysis. Within peri-implantitis group, 51 were classified as surgically triggered (40.8%), 38 as prosthetically triggered (30.4%), and 36 as plaque-induced (28.8%) peri-implantitis. For peri-implantitis, 51 were associated with surgical risk factor (40.8%), 38 with prosthetic risk factor (30.4%), 36 with purely plaque-induced risk factor (28.8%). The variables identified as predictors of peri-implantitis were female sex (OR = 1.60), malpositioning (OR = 48.2), overloading (OR = 18.70), and bone reconstruction (OR = 2.35). The predictive model showed 82.35% of accuracy and identified distinguishing predictive profiles for plaque, prosthetically and surgically triggered peri-implantitis. The model was in accordance with the results of risk analysis being the external validation for model accuracy. Conclusions: It can be concluded that plaque induced and prosthetically and surgically triggered peri-implantitis are different entities associated with distinguishing predictive profiles; hence, the appropriate causal treatment approach remains necessary. The advanced data mining model developed in this study seems to be a promising tool for diagnostics of peri-implantitis subtypes
Horizontal Ridge Augmentation using GBR with a Native Collagen Membrane and 1:1 Ratio of Particulated Xenograft and Autologous Bone: A 1-Year Prospective Clinical Study
No full textAim: To clinically and radiographically evaluate bone regeneration of severe horizontal bone defects. Materials and Methods: This study was designed as a single cohort, prospective clinical trial. Partially or fully edentulous patients, having less then 4 mm of residual horizontal bone width were selected and consecutively treated with resorbable collagen membranes and a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, 7 months before implant placement. Tapered body implants were inserted and loaded 3 to 6 months later with a screw retained crown or bridge. Outcomes were: implant survival rate, any biological and prosthetic complications, horizontal alveolar bone dimensional changes measured on cone beam computed tomography (CBCT) taken at baseline and at implant insertion, peri-implant marginal bone level changes measured on periapical radiographs, plaque index (PI), and bleeding on probing index (BoP). Results: Eighteen consecutive patients (11 females, 7 males) with a mean age of 56.8 years (range 24–78) and 22 treated sites received 55 regular platform implants. No patient dropped-out and no implants failed during the entire follow-up, resulting in a cumulative implant survival rate of 100%. No prosthetic or biological complications were recorded. Supraimposition of pre- and 7-month post-operative CBCT scans revealed an average horizontal bone gain of 5.03 ± 2.15 mm (95% CI: 4.13–5.92 mm). One year after final prosthesis delivery, mean marginal bone loss was 1.03 ± 0.21 mm (95% CI 0.83–1.17 mm). PI was 11.1% and BoP was 5.6%. Conclusion: Within the limitation of the present study, high implant survival rate and high average bone augmentation seem to validate the use of collagen resorbable membranes with a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, for the reconstruction of severe horizontal ridge defects
Immediate Loading of Fixed Complete Denture Prosthesis Supported by 4–8 Implants Placed Using Guided Surgery: A 5-Year Prospective Study on 66 Patients with 356 Implants
No full textBackground: High primary implant stability is considered one of the main factors necessary for achieving predictable treatment outcomes with immediately loaded implant-supported screw-retained fixed complete denture prosthesis (FCDP). Purpose: To evaluate the 5-year clinical and radiographic outcomes of immediately loaded implants placed in edentulous patients using computer-assisted template-guided surgery to support a FCDP. Materials & Methods: Patients in need to be restored with a FCDP in the mandible or maxilla were included in this prospective study/ and treated using computer-assisted template-guided surgery. Implant sites were prepared in order to achieve an insertion torque ranging between 35–45 Ncm in the mandible and 45–55 Ncm in the maxilla. A prefabricated screw-retained provisional prosthesis was delivered the day of the surgery. Outcomes were: implant and prosthesis cumulative survival rate (CSR), any complications, and peri-implant marginal bone loss (MBL). Results: Sixty-six patients received 356 implants to support 68 FCDPs. Each patient received 4–8 implants. Seven implants failed in six patients, resulting in a CSR of 98.1%. Two definitive prostheses failed resulting in CSR of 97.1%. Mean MBL of 1.62 ± 0.41 mm was reported at the 5-year follow-up. Five implants (1.4%) showed a mean mesio-distal peri-implant bone loss greater than 3.0 mm and received nonsurgical therapy. Conclusions: immediately loaded implants placed in edentulous patients using computer-assisted template-guided surgery to support a FCDP is a valid treatment concept in the medium term follow-up, for edentulous patients
Influence of plasma cleaning procedure on the interaction between soft tissue and abutments: a randomized controlled histologic study
No full textIntroduction: Plasma application can lead to an improved adhesion between soft tissue and abutments and promotes cell spreading. Objective: A triple-blinded randomized controlled clinical trial was performed to in vivo test the effect of cleaning abutment titanium surfaces with plasma of argon on cell adhesion and collagen fiber orientation at an early healing time. Material and methods: Thirty healthy patients with 30 submerged implants, at the second surgery, randomly received either a specially designed abutment with no additional treatment (as they come from industry; control group, G1) or cleaned by plasma of argon (test group, G2). Two weeks thereafter, a small biopsy including abutment and soft tissues around the abutment was performed. Abutments were analyzed using scanning electron microscopy to assess cell adhesion to the abutment surface. Outcome measures were the following: percentage of area occupied by cells, the presence or absence of cells, aspect of adhered cells, and the presence of contaminants. At the same time, the soft tissue histological analysis evaluated density and orientation of collagen fibers. Statistical analysis was performed using the Kolmogorov–Smirnov normality test and Levene variance homogeneity test. Data were analyzed using a nonparametric ranking test. The associations between the different qualitative variables were studied using Pearson's chi-squared test. The Mann–Whitney U-test (for two independent samples) was applied for quantitative variables. Results: Mean percentages of area occupied by cells were 15.14% (range 2.91–44.27) and 33.75% (range 2.37–68.4) for G1 and G2, respectively. Differences were close to significance (P = 0.089). The proportion of samples presenting adhered cells was homogeneous between the two groups (P = 0.142). In all cases, cells presented a flattened aspect, but not in three cases in the G2; in 17 cases, cells were efficiently adhered, and in 11 cases, cells presented filopodia with no statistical differences between groups (P > 0.05). No case from G2 showed contamination with cocobacteria with statistical differences between groups (P = 0.006). Collagen fiber density was higher in the basal, medial, and coronal area of G2 compared to G1 with a statistical difference in the internal area (P < 0.05). The orientation of the fibers varied according to the coordinate area with oblique fibers predominant in G2 than in G1. Conclusion: Plasma of argon may promote cell adhesion and positively influence collagen fiber orientation. A greater sample is necessary to confirm these preliminary results
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