Implant Dentistry最新文献

Purpose: The aim of this multicenter study was to examine the residual alveolar bone anatomy and sinus mucosa pattern at maxillary sinus regions in multiple teeth loss.

Materials and methods: This study was conducted with cone beam computed tomography images of 518 patients (267 females and 251 males) with multiple posterior maxillary teeth loss. Variables associated with sinus membrane (SM), sinus dimensions, ostium, septa, sinus neighborhood, alveolar bone height and ridge width, posterior superior alveolar artery, and adjacent roots were evaluated.

Results: No (58.2%) or flat (19.3%) thickening morphology was detected at most of the SMs. Membrane thickening and mucosal-like morphology was more prevalent for male patients (P = 0.005). The mean sinus width was relatively low (3.64 ± 3.33 mm) at the 5-mm level and showed an expected increase toward upper levels. Most of the sinus spaces were dimensionally average (39.5%) or wide (44.7%), and no effect of gender was observed in terms of sinus dimensions (P > 0.05).

Conclusion: Multiple teeth loss plays a role in creating an imaginary sinus anatomy constituted of a relatively narrow space compared with single-tooth loss cases, from 3.6-mm mean coronal width to 11.3 mm in the apical portion.

Purpose: The aim of this systematic review is to provide an overview of finite element analyses comparing standard and short dental implants concerning biomechanical properties and to detect the most relevant parameters affecting periimplant stress concentrations.

Material and methods: After screening the literature and assessment of studies, 36 studies were included in this review.

Results: Eighty-three percent of the studies state that short dental implants have to bear higher stress concentrations compared with standard length implants. At the same time, 44% of articles note that implant diameter can be considered a more effective design parameter than implant length to reduce stress concentrations and to avoid an overload of periimplant bone. Regardless of implant dimension, in all studies, the highest stress concentrations are found in the cortical section around the upper part of the implant.

Conclusions: Unaffected of bone quality, implant diameter is found to play a key role to minimize periimplant stress concentrations. Concerning stress reduction implant length gains increasing relevance with decreasing bone density. Furthermore, splinting of short implants constitute an appropriate tool to avoid crestal overloading.

Purpose: The purpose of this prospective study is to evaluate the relationship between implant diameter, and primary and secondary stability.

Materials and methods: Five hundred fifty-nine implants with diameters of 3.7, 4.0, and 4.3 mm and lengths of 10 and 11.5 mm were placed in 195 patients. The resonance frequency was measured during surgery and at 3, 6, and 12 months.

Results: Related average implant stability quotient (ISQ) values were 69.62 for 3.7-mm implants, 72.02 for 4.0-mm implants, and 69.67 for 4.3-mm implants. Values in men were greater than values in women. Values were greater for the mandible than for the maxilla. There are significant differences between 4.0-mm implants, and 3.7 anterior maxilla and 4.3 posterior maxilla.

Conclusions: There is no relationship between increased ISQ values and increased diameters. We observed a preference regarding sex, with men having significantly greater values for 3.7- and 4.3-mm diameters. The mandible obtained the greatest ISQ values, with significant differences for diameters 3.7 and 4.3 mm.

Purpose: The purpose of this study was to evaluate the effects of the growth factor within platelet-rich fibrin (PRF) in proliferation and differentiation of osteoblast and to observe the effectiveness of PRF.

Materials and methods: The colorimetric MTT assay, cell live and dead assay, alkaline phosphatase staining and activity assay, alizarine red S, and von Kossa staining were performed. Finally, the alterations of biomarkers associated with bone formation were verified at the mRNA level by quantitative polymerase chain reaction (PCR) and quantitative real-time PCR. In in vivo study, 6 adult mongrel dogs were used. The defect was performed and divided into 3 groups: (1) defect left unfilled, (2) defect filled with only 0.25-g Bio-Oss, and (3) defect filled with 0.25-g Bio-Oss mixed with PRF.

Results: MTT and cell live and dead assay showed that PRF did not affect the cell viability in MG-63 cells. The alkaline phosphatase activity, calcification, and mineralization were gradually increased in the MG-63 cells treated with PRF. Furthermore, the mRNA levels of biomarker gene in the MG-63 cells treated with PRF were significantly higher than those of control. In in vivo study, both radiographical and histological evaluations showed that the new bone formations were significantly increased in the defecting bone region transplanted with Bio-Oss and PRF compared with Bio-Oss only at 2 weeks after transplantation.

Conclusion: PRF can promote the bone regeneration without any complications.

Purpose: The purpose of this study was to evaluate the fit of nonoriginal abutments to implants at the implant abutment junction.

Materials and methods: Twenty titanium implants from a single manufacturer were randomly divided into 2 groups of ten each. Ten titanium premachined original abutments (group I) and ten titanium premachined nonoriginal abutments (from different manufacturer-group II) were connected to the implants with the recommended manufacturer torque level and then embedded into autopolymerizing clear acrylic resin blocks. After overnight curing, these blocks were vertically sectioned using water jet sectioning machine and evaluated under scanning electron microscope following the sequential cleaning procedures. The microgap at the implant-abutment interface for all the samples was measured using pixel counting software and subjected to statistical analysis using nonparametric Mann-Whitney U test.

Results: The mean microgap at the implant-abutment interface at the external, middle, and internal points was 1.597, 1.399, and 1.831 µm, respectively, for group I and 2.395, 2.488, and 3.339 µm, respectively, for group II samples. Nonparametric Mann-Whitney U test showed statistically significant difference between 2 groups at the midpoint for the nonoriginal abutments compared with the original ones.

Conclusion: Within the limitations of the study, the mean microgap at the implant-abutment interface at the platform level at the external, middle, and internal points for both original abutments and nonoriginal abutments was found to be within clinically acceptable limits.

Introduction: Osseodensification is a technique that aims at bone preservation and compaction either through nonsubtractive drilling or implants with a special thread design. This can increase quantity and density of periimplant bone. This review represents a summary and a critical appraisal of the studies regarding osseodensification in the literature.

Materials and methods: Three databases were searched: PubMed (MEDLINE), Cochrane Library, and Latin American and Caribbean center on health sciences information (LILACS). Studies were screened by title/abstract according to predetermined eligibility criteria. Full texts of 7 eligible articles were read among which 2 were excluded and 5 articles were included and underwent qualitative synthesis.

Discussion: Studies advocating osseodensification are sparse and mainly animal studies of low evidence level. High risk of bias and low correlation between used animal models and human bone were detected in most of the studies.

Conclusion: Although osseodensification seems to be a very promising technique, the findings are inconclusive and should be cautiously interpreted. Well-designed animal and human studies of longer follow-up periods are required before implementing such technique in regular daily practice.

Purpose: The purpose of this study was to assess the effectiveness of a polyglycol dimethacrylate-based adhesive in preventing bacterial leakage through implant-abutment interfaces (IAIs).

Materials and methods: After implant installation, the adhesive was applied in the experimental group (n = 10). None was applied in the control group (n = 10). Samples were collected from the inner walls of implants on days 0 and 90. The real-time polymerase chain reaction was used to detect bacterial DNA.

Results: All samples from the control group, versus 30% from the experimental group, harbored bacterial DNA on day 90.

Conclusions: This polyglycol dimethacrylate-based adhesive may be used to seal the IAI. Further studies are warranted to verify its effectiveness over longer time periods.

Introduction: The purpose of this review was to evaluate the available published clinical studies to understand the current data on the decontamination efficacy of various agents used in the treatment of periimplantitis and reosseointegration.

Materials and methods: An electronic PubMed literature search was conducted for studies published from 1998 until 2018. Literature on clinical studies was included in the review. Of the 189 studies retrieved from the literature search, 33 articles were selected for the review.

Discussion: The available studies reviewed had great heterogeneity to conclude a single treatment of choice for implant surface decontamination for the surgical treatment of periimplantitis.

Conclusions: Existent data do not favor any decontamination approaches and fail to show the influence of a particular decontamination protocol on surgical therapy. Further clinical investigations are needed to determine the superiority of a decontamination method if existing.

Purpose: A literature search was performed in a number of health care databases for articles published until January 2018.

Discussion: A number of anatomical factors, risk indicators, possible aesthetic complications, and financial implications have to be taken into consideration before treatment commences. When diagnosed early, periimplant mucositis is a problem that can be easily managed as long as the patient is motivated and maintains good levels of oral hygiene. Periimplantitis is more difficult to treat and results can be unpredictable. Nonsurgical therapy has limited effectiveness on the treatment of periimplantitis, but it should always precede a surgical intervention. Clinically predictable surgical outcomes seem to rely mainly on the configuration of the bone defect, the position of the affected implant, and the patient's ability to perform good oral hygiene.

Conclusions: Thorough treatment planning of periimplant diseases is paramount for the success of the treatment that follows. Local and general factors as well as patients' expectations have to be considered before proceeding, but treatment planning should also allow for a degree of flexibility, which will accommodate the unknown parameters.