Platform-switched Abutments Research Articles

Evaluation of stress distribution in and around dental implants using three different implant-abutment interfaces with platform-switched and non-platform-switched abutments: A three-dimensional finite element analysis.

A key factor for the success or failure of an implant is how the stresses are transferred to the surrounding bone. The implant‒abutment connection (IAC) is paramount for implant success. The purpose of this finite element analysis (FEA) study was to evaluate the stress distribution in and around three different implant‒abutment interfaces with platform-switched and platform-matched abutments using the finite element method (FEM). Three distinct types of IAC were selected: tri-channel internal connection, conical connection, and internal hex connection. Six models were generated, three in platform-switched and three in non-platform-switched configuration. Computer-Aided Three-Dimensional Interactive Application (CATIA) V5 R20 software was used to generate virtual models of the implants and the mandible. The models were transferred to Analysis of Systems (ANSYS) 15.0 software, in which the models were meshed and underwent FEA. On the crestal bone, the highest von Mises stresses in platform-switched abutments were noticed in the internal hex implant‒abutment system (370 MPa), followed by the tri-channel implant‒abutment system (190 MPa) and conical implant‒abutment system (110 MPa). On the implant and the abutment screw, the highest von Mises stresses were observed in the internal hex implant‒abutment system, followed by the conical implant abutment system and tri-channel implant‒abutment system. Platform-switched implants had a more favorable stress distribution on crestal bone. Within the constraints of the current study, the internal hex connection exhibited the highest stress. In contrast, the conical abutment connection with platform switching configuration had more favorable stress distribution in crestal bone than other implant abutment systems.

One-Year Outcomes of Subcrestal Platform-Switched Implants With and Without Sterile Prosthetic Abutments: A Randomized Controlled Trial.

Surface contaminants on customized implant abutments could trigger an inflammatory response in the peri-implant tissues. The aim of this randomized controlled study was to assess the radiographic bone changes around implants restored with customized, platform-switched abutments, with and without autoclave treatment, 12 months after definitive restoration. Dental implants were placed 1 mm subcrestally in 64 systemically healthy patients (mean age: 63.3 ± 10.0 years; 31 patients had a history of periodontitis) to replace single or multiple missing teeth. According to a randomization list, abutments were subjected to steam and autoclave sterilization (43 implants, test group) or steam cleaning alone (44 implants, control group). Periapical standardized radiographs were taken at implant placement, prosthetic abutment connection, and 12 months after definitive cement-retained restoration. All implants were clinically stable without any sign of infection at the 12-month follow-up. An average marginal bone loss of 0.25 ± 0.19 mm was found in the test group compared to 0.35 ± 0.23 mm in the control group (no statistically significant difference), while the percentage of bleeding sites was significantly higher in the control group (8.7% ± 13.1% vs 19.1% ± 19.8%; P = .035). Autoclave treatment of customized abutments seems to reduce the inflammatory response around subcrestally placed implants.

Influence of Platform-Switched Restoration on Bone Resorption in Patients Treated with Wide-Diameter, External-Hex-Connection Dental Implants: A 10-Year Follow-up Study.

Purpose: To investigate and assess the differences in crestal bone loss (CBL) between wide-diameter, external-hexagon-connection implants restored with platform-switching (PS) and platform-matching (PM) restorations with a follow-up of 10 years. Materials and Methods: This study retrospectively analyzed the updated and enlarged dataset of a 5-year prospective clinical study at 10-year follow-up. The data concerns 182 healthy adult subjects treated in a private dental practice who received a single wide-diameter implant with an external hexagon connection in the molar area, restored with either a PS restoration (test) or PM restoration (control). The amount of CBL was radiographically measured at each annual follow-up, as well as after 5 and 10 years of implant loading. In evaluating the association between the two types of abutments and bone loss (including change over time), a linear mixed effects model was run for longitudinal data. Results: Implants connected with PS restorations exhibited significantly lower reduction (0.25 mm) in CBL than those joined to PM restorations (P < .001; 95% CI from 0.22 to 0.29). However, both groups presented a higher increase in bone loss during the first year (0.58 mm in PS and 0.83 mm in PM) and a linear increment thereafter until the 10-year follow-up (0.046 mm/year; P < .001; 95% CI from .042 to .049). Conclusion: Notwithstanding the limitations of this study, it can be concluded that after 10 years of follow-up, the implant with a wide diameter and external-hexagon connection restored with a PS abutment seems to be more effective in reducing bone loss compared with the PM abutment.

Analysis of Biomarkers and Marginal Bone Loss in Platform-Switched and Nonplatform-Switched Implants: A Randomized Clinical Trial.

Objectives To compare the peri-implant crevicular fluid (PICF) biomarker levels, peri-implant status, and marginal bone level (MBL) differences of implants restored with randomly assigned nonplatform-switched (NPS) or platform-switched (PS) abutments. Methods Ninety-four implants in 27 subjects were included in this study. Receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), interleukin-1β (IL-1β), monocyte chemotactic protein-1 (MCP-1) levels in PICF, peri-implant health, and the change in the MBL were evaluated at the time of restoration (T1) and after 12 months (T2). Results The IL-1β levels decreased and the RANKL, OPG, and MCP-1 levels increased from T1 to T2 (P < 0.05) in both groups. RANKL/OPG ratio at T1, MCP-1 levels at T2, and the MCP-1 change from T1 to T2 were lower in the PS group than in the NPS group (P < 0.05). MBL change was lower (0.51 ± 0.31 mm) in the PS group than that (0.75 ± 0.29 mm) in the NPS group at T2 (P < 0.001). Peri-implant health status between the study groups was negligible. Conclusion PS was superior to NPS regarding the preservation of MBL. Higher MCP-1 levels, altered RANKL/OPG ratio, and lower OPG levels in the NPS group could be associated with subclinical peri-implant bone remodeling.

Differences in the progression of experimental peri-implantitis depending on the implant to abutment connection.

The aim was to evaluate the rate of bone loss progression during experimentally induced peri-implantitis using two different implant-abutment connections in implants with identical surface topography. Forty-eight Regular Neck tissue-level SLA implants with a matching implant to abutment connection (TL) and 36 bone-level SLA implants with a switching platform implant to abutment connection (BL) were subjected to experimental peri-implantitis in two independent in vivo pre-clinical investigations. Experimental peri-implantitis was induced by means of silk ligatures during 3 months (induction phase), and followed for one extra month without ligatures (progression phase). Radiographic and clinical outcomes were evaluated longitudinally along both studies and subsequently compared between experiments. During the induction phase, radiographic bone loss was significantly higher in implants with matched abutments compared with those with platform switching connections (2.65 ± 0.66 mm vs 0.84 ± 0.16 mm, respectively, p = 0.001). During the progression phase, both types of implant-abutment connection exhibited similar rates of radiographic bone loss. Similar outcomes were observed clinically. A platform switching connection resulted in a more benign development of peri-implantitis during the experimental induction phase of the disease. These differences, however, disappeared once the ligatures were removed (progression phase). Influence of the implant-abutment connection in peri-implantitis progression may be relevant when considering implant selection in the moment of placement. In this sense, platform switching abutment demonstrated less peri-implantitis development when compared to implant matching connection.

Platform switching in two-implant bar-retained mandibular overdentures: 1-year results from a split-mouth randomized controlled clinical trial.

The concept of platform switching is widely applied in current implant dentistry; however, the influence on peri-implant bone-level alterations (ΔIBL), especially in the field of implant overdentures (IODs), remains inconclusive. Therefore, the present study aimed to test the alternative hypothesis that there is an equivalent ΔIBLs at platform-switching and platform-matching implant abutments in 2-implant bar-retained IODs. Two interforaminal implants were placed in 32 subjects, who were randomly assigned to either an immediate- or a 3-month post-placement loading group. Furthermore, one implant in each subject was randomly assigned to receive a platform-switched abutment (test), and one a platform-matching abutment (control). The implants were splinted with prefabricated, chairside customized bars. ΔIBL was recorded by using customized radiograph holders at implant placement, implant loading, 3months, 6months, and 12months after loading. After 1year, equivalent ΔIBL could be identified (test: -0.51mm±0.49 versus control: -0.56mm±0.52; p<.001). ΔIBL increased over time and was more pronounced in the delayed-loaded implants (-0.87mm±0.61) relative to the immediately loaded implants (-0.35mm±0.43; p=.022). The prosthetic concept of platform switching does not necessarily lead to reduced bone loss. Immediate-loading of implants, primarily splinted with a bar, might be beneficial regarding peri-implant bone-level alterations over a short-term period.

Implant success and survival rates in daily dental practice: 5-year results of a non-interventional study using CAMLOG SCREW-LINE implants with or without platform-switching abutments

BackgroundThe performance of dental implants in controlled clinical studies is often investigated in homogenous populations. Observational studies are necessary to evaluate the outcome of implant restorations placed in real-life situations, according to standard practice, and to assess the needs of the patients. The aim of this non-interventional study was to reveal the survival, success, and general performance of CAMLOG SCREW-LINE implants and their restorations in daily dental practice.MethodsSeventeen private practices across five countries participated in this prospective multicenter study. Patients received implants in the maxilla and mandible which were restored either with platform-matching or platform-switching abutments. Patients were followed-up for up to 5 years post-loading. Radiographs and clinical parameters were evaluated and patient satisfaction was evaluated.ResultsFrom a total of 196 patients planned, 185 patients with 271 implants were restored with abutments and fulfilled the follow-up inclusion criteria. Three implant failures were recorded, resulting in a cumulative survival rate of 98.6% after 5 years post-loading. One persistent complication of peri-implantitis occurred. The soft tissue health remained stable, and the papilla height improved after loading. At 5-year follow-up, the mean crestal bone loss was − 0.28 ± 0.60 mm; over 99% of patients reported satisfaction with the restoration as excellent or good.ConclusionsImplants placed and restored with both platform-matching and platform-switching abutments in daily dental private practice achieved excellent clinical outcomes with highly satisfied patients after 5 years of function, confirming the results obtained in well-controlled clinical trials.

Plasma of Argon Cleaning Treatment on Implant Abutments in Periodontally Healthy Patients: Six Years Postloading Results of a Randomized Controlled Trial.

The aim of this randomized, match-paired, triple-blinded, controlled clinical trial was to assess the 6-year radiographic changes around customized platform-switched abutments placed according to the one abutment-one time concept, with and without plasma of argon cleaning treatment. A total of 20 periodontally healthy patients received one maxillary implant between the premolars. Immediately before stage 2 surgery and abutment connection, patients were randomly assigned to the control (cleaning protocol by steam) or test group (plasma of argon treatment). Periapical standardized digital radiographs were taken at the time of crown connection (T₀) and at 12 (T₁), 24 (T₂), 48 (T₄), 60 (T₅), and 72 months (T₆) after the final restoration delivery. Primary outcome measures were the success rates of the implants and prostheses and the occurrence of any technical and biologic complications during the follow-up period. Secondary outcome measures were peri-implant marginal bone level changes, bleeding on probing, and plaque score. Two patients (one in test and one in control group) dropped out at the last follow-up. Neither implant nor prosthetic complications were detected in the analyzed patients of both groups during the 6-year follow-up examinations. Radiographic analysis revealed a statistically significant higher mean bone loss in the control group than in the test group at T₂ (0.4 ± 0.28 mm; P = .018), T₄ (0.52 ± 0.63 mm; P = .037), T₅ (0.61 ± 0.70 mm; P = .038), and T₆ (0.71 ± 0.66 mm; P = .011), but not at T₁ (P = .131). From baseline to the 6-year follow-up, intragroup comparisons showed an absence of statistically significant difference in the test group (P = .08). Conversely, significant differences were found in the control group (P = .01). All implants demonstrated successful periodontal parameters, with no significant differences between groups. The results of this present study indicate that contaminant and bacterial removal from abutments in two-stage implants using plasma of argon could represent a positive strategy to minimize peri-implant bone resorption and longitudinally stabilize esthetic outcomes.

Evaluation of periimplant bone level around implants with platform-switched abutments inserted using computed tomography-based software planning and computer-aided design/computer-aided manufacturing guided surgical template

Background: The maintenance of periimplant bone is a major factor in the prognosis of prosthetic rehabilitation supported by implants. In an attempt to improve long-term bone maintenance around dental implants, a new implant-to abutment connection referred to as “platform switching” has been proposed.1Lazzara R.J. Porter S.S. Platform switching: a new concept in implant dentistry for controlling postrestorative crestal bone levels.Int J Periodontics Restorative Dent. 2006; 26: 9-17PubMed Google Scholar Objectives: To compare the crestal bone height changes around dental implants with platform- and nonplatform-switched abutment inserted using computed tomography-based software planning and computer-aided design/computer-aided manufacturing (CAD/CAM) guided surgical template. Methods: A total of 14 implants were placed and patients were divided into two groups. Seven implants with a diameter of 4.6 mm and restored with platform-switched abutments (3.5 mm) served as the test group. Seven implants with a diameter of 4.6 mm and restored with a horizontally matching abutment diameter served as the control group. Standardised digital panoramic images were obtained for evaluation of marginal bone levels at the time of placements of prosthesis (baseline), 6 and 12 months follow-up. All implants were placed with CAD/CAM-generated surgical guides after virtual planning of implant placement. Findings: The platform-switched implants exhibited statistically significant less bone loss at time of insertion of the definitive prosthesis (0.93 ± 0.10 mm versus 1.40 ± 0.26, P < 0.05) and at one year (1.47 ± 0.15 versus 2.19 ± 0.15 mm, P < 0.05) when compared to the nonplatform-switched implants. Conclusion: It can be concluded that platform switching is capable of reducing or eliminating crestal bone loss.

Assessment of Marginal Bone Loss around Platform-Matched and Platform-Switched Implants - A Prospective Study.

The aim of the present study was to perform a software-assisted radiographic assessment of the effect of platform-switching on marginal bone loss (MBL) around dental implants. Forty patients requiring a dental implant in non-grafted partially edentulous mandibles were enrolled and categorized into implants receiving a platform-matched abutment (control group) or implants with a platform-switched abutment (test group). Standardized digital periapical radiographs were taken at the time of implant placement (T0), at implant loading (T1) and 1-year after functional loading (T2). Software-assisted radiographic assessment of the MBL horizontal, vertical and area changes was performed and compared between time intervals (T1-T0, T2-T1 and T2-T0). Mean radiographic horizontal MBL (hMBL) and vertical MBL (vMBL) from implant placement to 1-year after implant loading (T2-T0) were significantly increased around platform-matched when compared to platform-switched abutments (1.04 mm vs 0.84 mm, p<0.05) and (0.99 mm vs 0.82 mm, p<0.05), respectively. Additionally, bone loss area (BLa) was greater (0.77 mm2 vs 0.63 mm2; p<0.05) for platform-matched compared to platform-switched abutments. Platform-switching has a positive impact upon the amount of bone modeling after loading implants with internal hexagon connection.

Immediate vs non-immediate loading post-extractive implants: a comparative study of implant stability quotient (ISQ).

This study aims to evaluate differences in implant stability between post-extractive implants vs immediately placed post-extractive implants by resonance frequency analysis (RFA). Patients were grouped into two different categories. In Group A 10 patients had an immediate post-extractive implant, then a provisional, acrylic resin crown was placed (immediate loading). In Group B (control group) 10 patients only had an immediate post-extractive implant. Both upper and lower premolars were chosen as post-extractive sites. Implant Stability Quotient (ISQ) was measured thanks to RFA measurements (Osstell®). Five intervals were considered: immediately after surgery (T0) and every four weeks, until five months after implant placement (T1, T2, T3, T4,T5). A statistical analysis by means of Student's T-test (significance set at p<0.05) for independent sample was carried out in order to compare Groups A and B. The ISQ value between the two groups showed a statistically significant difference (p<0.02) at T1. No statistically significant difference in ISQ was assessed at T0, T2, T3, T4 and T5. After clinical assessment it is possible to confirm that provisional and immediate prosthetic surgery in post-extraction sites with cone-shaped implants, platform-switching abutment and bioactive surface can facilitate osseointegration, reducing healing time.

Implant Abutment Cleaning by Plasma of Argon: 5-Year Follow-Up of a Randomized Controlled Trial.

Contamination of implant abutments could potentially influence the peri-implant tissue inflammatory response. The aim of the present study is to assess the radiographic bone changes around customized, platform-switched abutments placed according to the "one-abutment-one-time" protocol, with and without plasma of argon cleaning treatment. Thirty healthy patients with thin gingival biotype (<1 mm) and history of periodontal disease received one maxillary implant each. Immediately before abutment connection, patients were randomly assigned to control group (cleaning protocol by steaming) or test group (plasma of argon treatment). Outcome measures were: 1) success rate of implants and prostheses; 2) biologic and prosthetic complications; 3) peri-implant marginal bone loss (MBL); 4) esthetic and periodontal parameters; and 5) patient satisfaction. Neither implants nor prostheses were lost in either group at the 5-year follow-up examination. Overall, both groups showed a slight amount of peri-implant bone loss from baseline to 5 years. A statistically higher mean MBL was found in the control group compared with the test group at 6, 24, and 60 months after crown connection. Nevertheless, during the entire follow-up period, intragroup comparison demonstrated statistically significant mean MBL in the control group, but not in the test group. The test group showed a higher mean gain at the soft tissue margin, but not for the papilla. All implants showed good periodontal parameters, with no significant differences between groups. Plasma of argon could be used to disinfect implant abutments before insertion to minimize future peri-implant bone resorption.

Effect of platform switching on crestal bone levels around implants in the posterior mandible: 3 years results from a multicentre randomized clinical trial.

ObjectiveEvaluation of differences in the clinical performance and crestal bone levels between implants restored with single crowns with platform‐matched or platform‐switched abutments after 3 years.Material and MethodsThe study enrolled adult patients missing two or more adjacent teeth in the posterior mandible with natural teeth mesial to the implant site. Randomization followed open‐flap implant insertion and the corresponding matching or switching healing abutments placed at surgery. Conventional loading was made with cemented crowns. Clinical follow‐up took place annually after loading up to 3 years. Bone level changes were measured in standardized radiographs as the variation in crestal bone from one evaluation to the next.ResultsSixty‐three patients with a total of 135 implants (66 platform matching, 69 platform switching) were analysed. From surgery to 36 months, mean bone loss was 0.28 ± 0.56 mm for the platform‐switching group and 0.68 ± 0.64 mm for the platform‐matching group. A statistically significant difference was found between groups (p = 0.002) with an estimate of 0.39 mm (0.15–0.64, 95% CI) in favour of platform switching.ConclusionsAfter 3 years, platform‐switching restorations showed a significant effect in the preservation of marginal bone levels compared to platform‐matching restorations.

Morse taper dental implants and platform switching: The new paradigm in oral implantology.

The aim of this study was to conduct a literature review on the potential benefits with the use of Morse taper dental implant connections associated with small diameter platform switching abutments. A Medline bibliographical search (from 1961 to 2014) was carried out. The following search items were explored: “Bone loss and platform switching,” “bone loss and implant-abutment joint,” “bone resorption and platform switching,” “bone resorption and implant-abutment joint,” “Morse taper and platform switching.” “Morse taper and implant-abutment joint,” Morse taper and bone resorption,” “crestal bone remodeling and implant-abutment joint,” “crestal bone remodeling and platform switching.” The selection criteria used for the article were: meta-analysis; randomized controlled trials; prospective cohort studies; as well as reviews written in English, Portuguese, or Spanish languages. Within the 287 studies identified, 81 relevant and recent studies were selected. Results indicated a reduced occurrence of peri-implantitis and bone loss at the abutment/implant level associated with Morse taper implants and a reduced-diameter platform switching abutment. Extrapolation of data from previous studies indicates that Morse taper connections associated with platform switching have shown less inflammation and possible bone loss with the peri-implant soft tissues. However, more long-term studies are needed to confirm these trends.

EFFECT OF IMPLANT PLATFORM SWITCHING ON STRAIN DEVELOPED AROUND IMPLANTS WITH STRAIGHT AND ANGLED ABUTMENTS

Statement of the problem. Implant placement in an ideal position where stresses are transmitted vertically along the long axis of the implant rarely if ever coincides with the most esthetically pleasing position dictated by prosthetic planning. This situation could be dealt with by placing the implant at an angle in the most favourable position surgically and using angled abutments to compensate for the deviation from the previously planned prosthetic site of the final restoration. This may lead to excessive stresses on the inclined side of the implant which could cause bone resorption. Purpose. The aim of this study was to evaluate the effect of implant platform switching on strain developed around implants with straight and angled abutments. Materials and Methods. Twenty root-form titanium implants were inserted in epoxy resin blocks. According to the direction of implant insertion in the epoxy resin block, the twenty implants were divided into two main groups: Group I: (n=10) Straight implants with straight abutments. Group II :( n=10) Inclined implants with angled abutments (15 degrees). Each group was sub-divided into two sub-groups according to the abutment diameter in relation to the implant diameter: Sub-group A :( n=5) 4.5 mm diameter Implants received 4.5 mm diameter abutments. Sub-group B:(n=5) 4.5 mm diameter Implants received smaller 3.75 mm diameter abutments (platform switching). The 20 implant abutments received Ni-Cr full metal crowns. The blocks were trimmed to 1mm thickness around the implant then each sample received four strain gauges to represent the mesial, distal, buccal and lingual surfaces around the implant. A computerized universal testing machine was used for loading the implants by 300N, at a rate of 1 N/Sec. The load was applied progressively starting from zero to 300 N during which readings from the strain meter were recorded on the computer. Results. It was found that Group II (Angled abutments) with matching diameter Sub-group A showed statistically significantly (P ≤ 0.05) highest mean micro-strains (435.1± 215.7) followed by Group I (Straight abutment) with matching diameter Sub-group A (346.2 ± 175.3) followed by Group II (Angled abutments) with platform switching Sub-group B (307.1 ± 135.0). Group I (Straight abutment) with platform switching Sub-group B showed statistically significantly lowest mean micro-strains (239.0± 165.4) . Conclusions. Straight implants with straight platform-switched abutments were associated with the least micro-strain values.

Effect of the gonadal integrity and the gender on responses of bone crestal levels in dogs with two dental prosthetic abutment types

Fourteen adult mongrel dogs (5 intact and 9 neutered) comprising seven males and seven females were used to evaluate change in levels of alveolar crestal bone after implanting two types of dental abutments. Implants were surgically placed in both mandibular fourth premolar zones and restored with conventional (CONV) and platform switching (PFS) abutments. Both abutments were evaluated in each dog. The study lasted 180 days; restoration was performed at Day 60 postsurgical-placed implants and alveolar crestal bone levels was evaluated on Days 0, 30, 60, and 90 post-restoration (cemented crown) through indirect measurement using a digital X-ray sensor. Experimental data were analysed using a completely randomized design: the experimental unit was the dog (random effect), the treatment was the abutment type (fixed effect), and crestal bone level of each implant side (mesial and distal) was the observation. In addition, the gonadal integrity (intact and neutered) and the gender (male and female) were included in the statistical analysis to evaluate their role on the magnitude of changes (interactions) on alveolar crestal bone levels. The average of crestal bone loss was 0.400 ± 0.186 mm. In general, dogs with CONV had a greater (27.3%, P 0.77) between gender and abutment type. Similarly, as a sole factor of variation, gender had no effect (P = 0.26) on crestal bone level responses to abutment type (-0.401 vs -0.385 mm for males and females, respectively). Regardless of the type of abutment, males and females had a similar (P = .65) crestal bone loss (-0.405 vs. -0.393), while neutered dogs showed a greater (30.8%, P < 0.01) crestal bone loss compared with intact dogs. In conclusion, dogs with PFS showed less crestal bone loss than CONV; however, regardless of gender, this response only was maintained in intact dogs; therefore the gonadal condition has an effect on the magnitude of changes of the alveolar crestal bone levels in their response to abutment type in dogs with dental implants.

Biomechanical investigations of the expanded platform-switching concept in immediately loaded small diameter implants

Statement of problemUse of a small diameter implant may increase the stress on bone around the implant neck; however, an expanded platform design may mitigate these stress concentrations. To date, no study has compared the biomechanical effect of regular platform and extended platform designs on an implant. PurposeThe purpose of this in vitro study was to evaluate the biomechanical effects of an expanded platform-switching design for immediately loaded small diameter implants on bone strains. Material and methodsThree groups of artificial jawbone models were prepared for small diameter (3.25-mm) and standard diameter (4.0-mm) implants with expanded or regular platform designs. Platform-switching implant design was implemented by assembling implants with a smaller connected abutment. Specimens were tested under both vertical and lateral static loads at 190 N. Peak values of the principal microstrain of bone were recorded and analyzed statistically with Kruskal-Wallis test and multiple comparisons Bonferroni test (α=.05). The initial stability of each implant was also measured for 3 types of implant. ResultsUnder vertical loading, the bone strain was lowest for the regular type of immediately loaded small diameter implant. Under lateral loading, peak bone strain around the expanded platform small diameter implant with platform switched abutment was up to 74.9% lower than that of the regular type of small diameter implant. Increasing the implant diameter from 3.25 mm to 4.0 mm on the expanded platform implants reduced the bone strain by approximately 10% and 30% under lateral and vertical loading, respectively. The initial implant stability did not vary significantly among the implants tested. ConclusionsUsing the expanded platform small diameter implant with a platform-switched abutment may decrease the marginal bone strains around immediately loaded small-diameter implants under lateral loading.

A retrospective study of six fractured platform-switching abutments

To explore the reasons for platform-switching abutment fracture, the treatment and prevention methods. Between March 2009 and December 2014, all of the fractured platform-switching abutments were evaluated. The fracture rate of platform-switching abutments was calculated and the gender, age, implant site, implant size, abutment size, prosthetic type, loading time and crown materials were analyzed. A total of 2 487 platform-switching implants were placed during this period and 6 abutments were fractured. The fracture rate was 0.24% (6/2 487). All of the 6 fractured abutments were placed in molar region. All occlusal planes were made of metal material. Five patients were male. All the fracture abutments could not be removed and the implants had to be removed and reimplanted. Without special abutment removing instruments, it is difficult to remove the fractured platform-switching abutment. In molar region, platform-switching implant system should be carefully used. Increasing implants number and splinting crowns with porcelain occlusal planes might reduce the abutment fracture risk.

Evaluation of Human Periimplant Soft Tissues Around Nonsubmerged Machined Standard and Platform-Switched Abutments

Evaluation of Human Periimplant Soft Tissues Around Nonsubmerged Machined Standard and Platform-Switched Abutments

Evaluation of Human Periimplant Soft Tissues Around Nonsubmerged Machined Standard and Platform-Switched Abutments

This study evaluated the effect of the platform-switching phenomenon, the use of a smaller diameter abutment on a larger diameter implant platform. Clinical and histological outcomes of the periimplant mucosa around titanium abutments in a nonsubmerged implant were evaluated. Ten healthy adult patients, ranging from 27 to 65 years, participated in the study. A minimum of 2 endosseous implants with immediate abutment connection was placed per patient, 1 conventional and 1 platform-switched abutment. All sites for implant placement had an adequate zone of keratinized mucosa before surgical intervention. No clinical signs of inflammation were observed in the periimplant soft tissue mucosa, and healing was uneventful throughout the study period. Histological findings showed abnormally thick stratified squamous epithelium for both groups with few inflammatory cells in the connective tissue and none on the surface of the epithelium. Histological findings for both conventional and platform-switched implant-abutment configurations showed a similar composition of the soft tissue. These findings were in direct agreement with previous studies.