Platform-matched Implants Research Articles

Impact of Two Implant-Abutment Connection Types on Crestal Bone Stability: A 3-Year Comparative Split-Mouth Clinical Trial.

This prospective, preliminary controlled clinical trial investigates the comparative effectiveness of platform-switching (PS) versus traditional butt-joint or platform-matching (PM) implant-abutment connections on peri-implant crestal bone stability. Utilizing a split mouth design, 10 systemically healthy patients (n= 20 implants) had adjacent non-restorable maxillary anterior teeth replaced with two different implants (butt-joint connections and platform-switching interfaces). Patients underwent alveolar ridge preservation, followed by implant placement: platform-matching implants were inserted at crestal bone level, and platform-switching implants were placed 1mm subcrestally. Customized Zirconia crowns were then fabricated for both systems. Outcome measures included bleeding on probing (BOP), probing pocket depth (PPD), and marginal bone loss (MBL), which were evaluated through standardized periapical radiographs over 3-year timeframe. Results showed significantly higher initial MBL in the PM group (0.86 ± 0.13 mm) compared to the PS group (0.34±0.29 mm) [p value: p<0.01]. Moreover, at the three-year follow-up, the crestal bone levels remained above the implant shoulder until the third year of the study for the PS subcrestal group (PS: -0.15±0.39 mm) and slightly below the implant platform in the PM crestal group (PM: 0.55±0.19). After 3 years, the PS group also exhibited lower mean BOP percentages (12%) than the butt-joint group (17%). This study suggests that subcrestal placement with PS and internal connections can provide better long-term peri- implant bone preservation, thereby potentially improving implant success and aesthetic outcomes in the anterior maxillary region.

Analysis of 8.5 mm Long Dental Implants Provided with Splinted or Solitary Implant Restorations: A 15-Year Prospective Study.

Background/Objectives: The long-term effects of implant properties, such as implant length, platform switch, and crown splinting, on peri-implant health require more investigation. Therefore, the aim was to assess the long-term peri-implant health and patient satisfaction in a patient cohort, obtained from two prospective randomized controlled trials, who received 8.5 mm long dental implants, with either splinted or solitary suprastructures and with or without a platform switch, over a period of 15 years. Methods: One hundred and twenty-two patients received either one or two 8.5 mm long dental implants (223 dental implants) with and without platform switch, restored with either a solitary (n = 89) or a splinted (n = 134) restoration in the posterior region. Clinical and radiographical parameters and patient satisfaction were prospectively recorded at 1 month, and 1, 5, and 15 years after the placement of the restoration. Patient satisfaction was recorded with a self-administered questionnaire using a 5-point scale and a visual analog scale (0-10). Results: Eighty-one patients with one hundred and fifty-four implants were assessed after a 15-year follow-up. The clinical parameters were low and comparable between the implant types (OsseoTite XP Certain, OsseoTite XP Certain Prevail, NanoTite XP Certain, NanoTite XP Certain Prevail, PalmBeach Gardens, FL, USA) over time. The implants that incorporated a platform switch showed significantly less bone loss than the implants without a platform switch (-0.37 mm, 95% CI -0.69 to -0.05 mm, p = 0.024 and β = -0.47, 95% CI -0.80 to -0.14, p = 0.006). The implants with splinted restorations experienced more bone loss over time compared to the implants with solitary restorations (0.39 mm, 95% CI 0.15-0.63, p = 0.002). Patient satisfaction was high after 15 years. Conclusions: All the tested dental implants with 8.5 mm length provide satisfactory 15-year results with regard to the clinical and radiographical parameters as well as patient satisfaction. The platform-matched implants were associated with more bone loss compared to the platform-switched implants, and the implants with splinted crowns portrayed more bone loss than the solitary implant crowns.

Influence of implant restorative emergence angle and contour on peri-implant marginal bone loss: A systematic review and meta-analysis.

Implant restorative emergence angle and profile may have a negative impact on peri-implant marginal bone level and may increase the risk of developing peri-implantitis. However, the role of these prosthetic features on peri-implant health is still unclear. The aim of this systematic review and meta-analyses was to evaluate the long-term outcomes of implant restorations with an emergence angle of >30° in comparison to those with ≤30° in terms of changes in peri-implant marginal bone level, periodontal parameters, and prevalence rate of peri-implantitis. Electronic databases were searched to identify observational studies that compared implant restorations with an emergence angle of >30° to those with ≤30°. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool. Four studies with 912 dental implants in 397 participants were included in the present review. Of these, 455 implants had restorations with an emergence angle of >30°, while the remaining implants had restorative emergence angle of ≤30°. The follow-up time varied between 3.8 and 10.9 years. Implant restorations with an emergence angle of ≤30° were associated with less changes in peri-implant marginal bone level compared to those with emergence angle of >30°. The difference, however, was not statistically significant (mean difference 0.80; 95% confidence interval (CI) -0.13 to 1.72; p = 0.09). In platform-matched implants, the difference between the two groups was statistically significant in favor of implant restorations with emergence angle of ≤30°. In terms of emergence profile, implant restorations with convex profile had significantly higher rate of peri-implantitis (57.8%) compared to implant restorations with concave or straight profile (21.3%) (risk ratio 2.32; 95% CI 1.12-4.82; p = 0.02). Within the limitation of this review, implant restorations with an emergence angles of >30° or ≤30° seem to have no significant influence on peri-implant marginal bone level. Platform-matched implants with an emergence angle of ≤30° may have positive effects on the peri-implant marginal bone level changes, but the evidence support is of low to moderate certainty.

Long-Term Clinical and Radiographic Analysis of Platform Matching and Platform Switching Implants in the Esthetic Zone: A Retrospective Cohort Study

Background: The aims of this study are to retrospectively compare the clinical, radiographic and esthetic outcomes of platform switching (PS) and platform matching (PM) dental implants in the anterior maxilla after ≥ 10 years of functional loading. Methods: Marginal bone loss (MBL) levels were recorded; furthermore, peri-implant clinical parameters (PPD, BOP, PI) were collected and the Pink and White Esthetic scores (PES/WES) were used to evaluate the esthetic outcomes. Wilcoxon signed rank tests were performed to compare collected parameters among the two groups, with a p-value &lt; 0.05. Results: A final sample of 58 patients was enrolled in this study (PM implants = 29; PS implants = 29). PS implants showed lower MBL levels (1.02 ± 0.81 mm vs. 1.67 ± 0.99 mm, p = 0.028) and PPD values (3.69 ± 1.1 vs. 5.16 ± 1.09 mm, p &lt; 0.001) compared to PM implants. Mean PES values were higher in the PS group compared to the PM group (8.46 ± 0.69 vs. 7.89 ± 0.78, p &lt; 0.005), while there were no differences for WES values (7.82 ± 1.09 vs. 7.71 ± 0.85, p &gt; 0.05) and peri-implant diseases’ prevalence (p &gt; 0.05). Conclusions: After 10 years, PS implants showed statistically significant lower MBL and PPD values and higher PES values compared to PM implants.

Peri-Implant Marginal Bone Changes around Dental Implants with Platform-Switched and Platform-Matched Abutments: A Retrospective 5-Year Radiographic Evaluation.

Preserving the marginal bone level (MBL) is essential for the long-term success of dental implant therapy, and bone remodeling around dental implants is considered to vary with time. Numerous studies comparing the platform-switching (PS) and platform-matching (PM) dental implants have indicated that PS dental implants showed a lesser reduction for the MBL, and the majority of them had a relatively short period. This study aimed to evaluate vertical and horizontal bone defects by using digital periapical radiographs to examine the changes in MBL around PM and PS dental implants over 5 years after functional loading. The vertical MBL (vMBL) was measured from the implant–abutment junction to the first bone-to-implant contact. The horizontal MBL (hMBL) was measured from the implant–abutment junction to the bone crest. All data were presented as means ± standard errors. Paired and independent t-tests with Welch’s correction were used to analyze the data. A total of 61 dental implants in 38 patients after 5 years of functional loading were evaluated. Over time, PS dental implants were more likely to gain bone; by contrast, PM dental implants were more likely to lose bone during the observation time. Changes in vMBL for PS dental implants were significantly less than those for PM dental implants at 1-year (p = 0.045), 3-year (p = 0.021), and 5-year (p = 0.010) loading. Likewise, changes in hMBL for PS dental implants were significantly smaller than in those for PM dental implants at 3-year (p = 0.021) and 5-year (p = 0.006) loading; however, the changes were minimal in both approaches. PS dental implants had a significant increment in the percentage of bone integration, whereas that for PM dental implants dropped over time, with no significance. In PS dental implants that occlude with natural teeth, vertical and horizontal bone gain was observed, and it was significant at 3 years (p = 0.023). A significant horizontal bone gain was observed in the opposing natural teeth at 3-year (p = 0.002) and 5-year loading (p = 0.002). The PS concept appears to preserve more MBL around dental implants by stabilizing the vMBL and hMBL over a 5-year period. A minimal marginal bone change was detected in both concepts. The opposing natural teeth at PS dental implants showed a favorable effect on marginal bone tissues.

Soft Tissue Parameters and Esthetic Index Changes in Platform Switching Implant: A Systematic Review and Meta-Analysis

&lt;p&gt;Purpose: The purpose of this study was to perform a systematic review and meta-analysis to critically evaluate the available literature to statistically analyze the effects of platform matched (PM) and platform switching (PS) implants on the peri-implant soft tissue changes and esthetic outcomes. Materials and methods: Electronic databases of the Cochrane Library, Embase, CINAHL and PubMed were searched for human randomized controlled trials (RCTs) with clearly outcome measurement in comparison between PM and PS implant. Primary outcomes included midfacial keratinized gingiva (KG) thickness, width of KG, marginal gingiva height gain, papilla height, and pink esthetic score. Secondary outcomes included bone level, probing depth, plaque index, and sulcus bleeding index. All the included studies had to follow up for at least 1 year after function. Results: A total of 7 RCTs were included in the meta-analysis. Midfacial KG thickness (weighted mean difference (WMD) = 1.34 mm, P &lt; 0.0001), marginal gingiva height (WMD = 0.30 mm, P = 0.01), papilla height (WMD = 0.18 mm, P = 0.003), bone level (WMD = 0.34 mm, P &lt; 0.00001) and probing depth (WMD = -0.22 mm, P = 0.002) demonstrated statistically difference in comparison of PS and PM implants. The result of width of KG (P = 0.92), PES score (P = 0.73), plaque index (P = 0.97) and sulcus bleeding index (P = 0.78) showed no statistical difference. Conclusion: Meta-analysis showed better performance of midfacial KG thickness, marginal gingiva height and papilla height in PS implant than that in PM implants. No statistically difference was found in width of KG and PES score between PS implants and PM implants.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Platform-Switching Concept in Dental Implants: A Systematic Review and Meta-analysis of Randomized Controlled Trials with a Minimum Follow-up of 3 Years

To evaluate studies with a minimum follow-up of 3 years to find the peri-implant marginal bone loss (MBL) and rate of implant failure with platform-switching (PS) and platform-matching (PM) implant-abutment connections. A systematic review and meta-analysis was done based on the preferred reporting items for systematic reviews and meta-analyses guidelines, with a focused question on population, intervention, comparison, and outcome. The Cochrane Collaboration's Risk of Bias tool was used to assess bias. Randomized controlled trials (RCTs) comparing peri-implant MBL and implant failure in patients receiving PS implants and PM implants only were included. The risk ratio (RR) of the implant-abutment connection and implant failure was calculated, and peri-implant MBL was expressed in mean differences (MD) at 95% confidence intervals (CIs). Three hundred eighty-one articles were obtained after an initial literature search. Finally, nine articles were included in the study that fulfilled the inclusion criteria. Four hundred twenty-six PS and 411 PM implants were placed with 16 implant failures (8 PS and 8 PM). The implant survival rate was 98.12% for the PS group, and 98.05% for the PM group, with no statistically significant difference (P = .97). The mean peri-implant MBL with the PS implant was lower (0.33 ± 0.41 mm) compared with the PM implant (0.66 ± 0.42 mm). A significant effect of PS implants was found in reducing peri-implant MBL (MD: -0.70, 95% CI: -1.25,-0.15; P = .01) compared with PM implants. The MD of peri-implant MBL between the PS and PM implants decreases with increased follow-up: MD of 0.69 (P = .15) with follow-up of ≥ 3 years but < 5 years, and MD of 0.62 (P = .04) with follow-up of ≥ 5 years. Reduced peri-implant MBL was found with the PS concept. The peri-implant MBL decreases with an increased mismatch between the abutment and implant platform. The difference in peri-implant MBL in PS and PM implants in the maxilla was greater and favored the PS concept. Bone-level implants with single crowns or splinted prostheses better preserved the peri-implant marginal bone with the PS concept.

Influence of Abutment Design and Platform Switching on Peri-implant Marginal Bone Level: A Randomized Controlled Clinical Trial with 1-Year Results.

The purpose of this randomized clinical study was to evaluate the efficacy of platform-switching (PS) vs platform-matching (PM) implants when paired with a newly designed marginless abutment (MA) vs a conventional abutment (CA) in maintaining peri-implant tissue stability. Marginal bone level (MBL) and probing depth were measured up to 1 year postloading. Eighty implants were inserted in 42 patients and randomly assigned to one of four groups, each with a different implant/abutment configuration: Group 1 (PM+CA), Group 2 (PM+MA), Group 3 (PS+CA), and Group 4 (PS+MA). Data were collected at implant placement (T0), abutment placement (T1), final crown placement (T2), and 1 year postloading (T3). At the 1-year follow-up, MBL was more stable in Groups 3 and 4 compared to Groups 1 and 2. These results suggest that the role played by the implant-abutment connection (PS vs PM) is more important than the type of abutment preparation (MA vs CA).

Role of Platform Switching in Success of Dental Implants- A Meta-Analysis

Aim: To analyze through systematic review and meta-analysis of implant failure rates, marginal boneloss (MBL) in patients who received platform-switched implants and platform-matched implants and todetermine literature based evidence.Materials and Methods :Data: Search terms used in combination are dental implant, platform switch, platform mismatch, switchedplatform, implant – abutment design.Sources : An electronic search engine without time/ language restrictions was taken from Google Scholar,Pubmed.Clinical Significance: Platform switching for maintaining peri-implant bone levels has gained popularityover last few years. As philosophies of treatment alter over , a periodic review of different concepts arenecessary to refine techniques thereby forming a basis for optimum treatment.

Soft tissue healing around platform-switching and platform-matching single implants: A randomized clinical trial.

Implants with platform-switching (PS) design have been demonstrated to reduce marginal bone loss. However, the influence on peri-implant soft tissue healing is unclear. This study was designed to investigate its effect on peri-implant soft tissue healing after implant uncovery. Non-smokers needing two implants in different quadrants were recruited in this study. For each individual, one PS and one platform-matching (PM) implants were placed using two-stage protocol. Following 2 to 8 months of healing, all implants were uncovered and connected to the corresponding healing abutments. Clinical measurements and peri-implant crevicular fluid (PICF) were taken at 1-, 2-, 4-, and 6-week after 2nd stage surgery. The cytokine concentrations in PICF were analyzed. Peri-implant mucosa (1 × 2 × 2mm) was harvested around the healing abutment for the analysis of gene expression at uncovery and 6-week post-uncovery. Eighteen participants (nine males; 51.7 ± 14.9 years) were recruited. Compared to PM, PS showed significantly lower probing depth (PD) at 1- and 2-week as well as modified sulcus bleeding index (mSBI) at 1-, 4-, and 6-week (P<0.05). Over time, a decrease in osteoprotegerin and interleukin-1β concentrations in PICF along with an increase in receptor activator of unclear factor kappa-B ligand, periostin, and peroxidasin gene expressions in peri-implant mucosa were noted within both groups (P<0.05) without significant intergroup differences. Within the limits, implants with PS design rendered significant benefits over PM design in PD and mSBI reduction during a 6-week healing. However, molecular changes within PICF and peri-implant mucosa as a response to PM and PS appear negligible.

Quality Assessment of Systematic Reviews on Platform-Switching vs Platform-Matched Implants: An Overview.

The objective of this study was to perform a quality analysis of systematic reviews with meta-analyses that focused on the comparison of platform-switching (implant-abutment mismatching) and platform-matched (PM) implants. The assessment of multiple systematic reviews (AMSTAR) and Glenny (Checklist) Scales were used to qualify the studies. PubMed, Scientific Electronic Library Online (SciELO), Web of Science (formerly ISI Web of Knowledge), and Cochrane databases were searched, by topic, for systematic reviews on dental implants with switching platforms. A total of 8 systematic reviews, including 7 studies with meta-analyses, were selected. The AMSTAR scale indicated a high (n = 6) to moderate (n = 2) score for the included studies. The quantitative analysis indicated that platform-switching implants preserved more bone tissue when compared with platform-matched implants (6 meta-analyses; P < .001, smaller mean difference: -0.29 mm, 95% CI: -0.38, -0.19 and greater mean difference: -0.49 mm, 95% CI: -0.73, -0.26). Quantitative analysis based on 7 systematic reviews with meta-analysis indicated positive peri-implant bone preservation for implants restored with an implant-abutment mismatching (PSW). Further, there is evidence to improve the design of current systematic reviews. Future systematic reviews in this thematic area should consider searches in gray literature and different databases and include only randomized controlled clinical studies.

Platform-switched implants vs platform-matched implants placed in different implant-abutment interface positions: A prospective randomized clinical and microbiological study.

Placement of the implant-abutment interface (IAI) away from the bone crest has been suggested to have positive impacts on maintenance of peri-implant tissues. To assess the effects of platform-switched and platform-matched implants, taking into consideration the IAI at different positions relative to the bone crest, on clinical, radiographic, and microbiological outcomes during 12 months following functional loading. The present prospective randomized study was performed upon 70 patients. Group I (n = 23) implants presenting a platform-switched implant-abutment connection design was inserted 1 mm subcrestally. Group II (n = 22) implants with similar properties were inserted crestally. Group III (n = 25) implants presenting a platform-matched approach with an internal hexagon connection design was inserted crestally. The periodontal parameters were assessed at baseline, and 3, 6, and 12 months postloading. Radiographic marginal bone level (MBL) changes were analyzed at the 12-month follow-up. The amount of DNA copies of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Provetalla intermedia and total bacterial mean load in peri-implant sulcus fluid (PISF) were assessed at the same periods. There were no significant differences among the groups with respect to the periodontal parameters for all time periods. At 12-month follow-up, the MBL changes were 0.16 ± 0.29 mm and 0.17 ± 0.23 mm for group I, 0.15 ± 0.25 mm and 0.17 ± 0.26 mm for group II, 0.17 ± 0.26 mm and for group III in mesial and distal sites, respectively. The mean total bacterial load was found significantly higher for group III compared to the other groups in the three interval times (P < .05). Implants restored with platform-switching and platform-matching performed equally regarding clinical and radiographic outcomes. Platform-matched implants inserted at the crestal level presented higher the mean bacterial total load in PISF.

The Impact of Platform-Switched Implants on the Marginal Bone Level and Soft Tissue Dimensions

Objectives: The objective of this study is to compare the characteristics of the concept of platform-switched implants (PSW) that have recently emerged in implant dentistry and its effects on the marginal bone loss (MBL) around the implant with platform-matched implants (PMI).Data: In the study, PSW implant-abutment connection system, MBL, and peri-implant hard and soft tissue changes were examined. The research terms used in the study are dental implant, platform switching concept, switched platform, platform mismatch, platform-matched implants, and dental implant-abutment design. Sources: In the electronic research, the language was selected as English and studies conducted until March 2018 were investigated without year limitation. The electronic studies include the National Library of Medicine, PubMed/Medline, Web of Science, Cochrane Oral Health Group Trials, and Cochrane Central Register of Controlled Trials. Study selection: Studies, retrospective or prospective clinical human studies, either randomized systematic review and meta-analyses, and finite element analyses (FEA) were examined. Case reports and studies of animal experiments were excluded from the review. Conclusions: It was observed that clinical trials consisted of short and medium-term follow-ups and biomechanical studies were limited. It was observed that PSW implant systems obtain positive results in reducing the MBL and are more aesthetic in terms of soft tissue formation compared to PMI systems, and interest has been gradually increasing in the PSW system in recent years. It was revealed that long-term clinical trials for the PSW system are required.

Effect of platform switching on peri-implant bone: A 3D finite element analysis

Statement of problemA consensus regarding the effects of platform switching on peri-implant marginal bone levels is lacking. Finite element studies have reported contradictory results. PurposeThe purpose of this finite element analysis study was to evaluate stress distribution in platform-switched (PS) and platform-matched (PM) implants and their surrounding bone. Material and methodsAn implant (4.5×11 mm) was modeled and screwed into a human mandibular bone block using a computer-aided design (CAD) software program. Two separate models were generated: (1) PM, 4.5-mm implant with 4.5-mm-wide abutment and (2) PS, 4.5-mm implant with 3.5-mm-wide abutment. Implant components were modeled with linear isotropic properties and bones with anisotropic properties. Vertical (200 to 800 N) and oblique (50 to 150 N) forces were applied to each model to simulate occlusal loads. Linear elastic analysis was performed using ANSYS Workbench 16. von Mises equivalent stresses in the implant assemblies and peri-implant bone were calculated and compared with independent samples t test (α=.05). Resultsvon Mises equivalent stress values under simulated axial and nonaxial occlusal loads were lower for PM than for PS implant assemblies. However, the differences were not statistically significant. Stress within the peri-implant bone was significantly higher for the PM group than for the PS group (P<.001). ConclusionsPlatform switching decreased stress within peri-implant bone and may help limit marginal bone resorption.

Dental Implant Surrounding Marginal Bone Level Evaluation: Platform Switching versus Platform Matching-One-Year Retrospective Study.

The benefits and feasibility of platform switching have been discussed in several studies, reporting lesser crestal bone loss in platform-switched implants than in platform-matched implants. Objective. The aim of the present study was to observe the changes in vertical and horizontal marginal bone levels in platform-switched and platform-matched dental implants. Materials and Methods. 51 patients received 60 dental implants in the present study over a 1-year period. Measurement was performed between the implant shoulder and the most apical and horizontal marginal defect by periapical radiographs to examine the changes of peri-implant alveolar bone before and 12 months after prosthodontic restoration delivery. Results. These marginal bone measurements showed a bone gain of 0.23 ± 0.58 mm in the vertical gap and 0.22 ± 0.53 mm in the horizontal gap of platform matching, while in platform switching a bone gain of 0.93 ± 1 mm (P < 0.05) in the vertical gap and 0.50 ± 0.56 mm in the horizontal gap was found. The average vertical gap reduction from the baseline until 12 months was 0.92 ± 1.11 mm in platform switching and 0.29 ± 0.85 mm in platform matching (P < 0.05). Conclusions. Within the limitations of the present study, platform switching seemed to be more effective for a better peri-implant alveolar bone vertical and horizontal gap reduction at 1 year.

Platform switching of implants may decrease bone loss.

PubMed/Medline, Web of Science and the Cochrane Oral Health Group Trials Register, clinicaltrials.gov, www.centerwatch.com/clinical-trials , www.clinicalconnection.com supplemented by a manual search of dental implants-related journals. Clinical studies, either randomised or not, comparing implant failure rates, marginal bone level (MBL) and/or postoperative infection in any group of patients receiving platform-switched implants or platform-matched implants were considered. Study quality was assessed using the Newcastle-Ottawa scale (NOS).Only randomised clinical trials (RCTs) were considered for meta-analysis. Implant failure and postoperative infection were the dichotomous outcomes measures evaluated. Weighted mean differences were used for MBL. Twenty-eight studies (18 RCTs, six CCTs and four retrospective analyses) were included. Twenty-six studies were considered to be of high quality. Twelve hundred and sixteen platform-switched implants were included with 16 failures (1.32%) and 1157 platform-matched implants and 13 failures (1.12%). Twenty studies had no implant failures. In a meta-analysis for the outcome MBL (18-RCTs) there was less MBL loss at implants with platform-switching than at implants with platform-matching (mean difference -0.29, 95% CI −0.38 to −0.19; P<0.00001) The results of the present study suggest that there is a significantly less MBL loss at implants with platform-switching than on implants with platform-matching. The results of the present review should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies, most of them with short follow-up periods.

Evaluation of marginal bone loss around platform-switched implants by digital subtraction radiography

Purpose: This study is to evaluate the clinical significance of the platform switching concept by comparing the marginal bone loss around platform-matched and platform-switched implants. Materials and Methods: Date of implant placement, diameter, length, implant-abutment connection type and absence of splinting prosthesis were investigated on patients who performed treatment with implant placement at Wonkwang University Dental Hospital Implant Center. To measure the marginal bone loss around implants, periapical radiographs of patient were used when implant was placed and when visited the center most recently by using the program, Emago advanced v5.6. Results: As a result of observing on 150 implants of 82 patients for 6 - 63 months, platformmatched implants showed 1.16 ± 0.54 mm, platform-switched implants showed 0.68 ± 0.27 mm of marginal bone loss. Conclusion: It was considered that there is the positive effect to reduce marginal bone loss around platform-switched implants. (J Dent Rehabil Appl Sci 2015;31(1):33-44)

Influence of platform switching on periimplant bone loss: a systematic review and meta-analysis.

This meta-analysis aims to systematically review and draw a comparison between conventional implant designs and "platform-switched" implants in terms of crestal bone loss. Electronic (PubMed) and hand searches were conducted. Literature, clinical studies, and case reports pertaining to reduction of crestal bone loss and obtaining better esthetic outcome by platform switching were reviewed till October 2011. Controlled trials comparing marginal bone-level changes around platform-switched and platform-matched implants were selected. For the assessment of accuracy, meta-analysis was performed. The marginal bone loss around platform-switched implants was significantly lesser than platform-matched implants (mean difference [MD]: -0.34; 95% confidence interval [CI]: -0.37 to -0.30; P < 0.00001). According to this review and meta-analysis, platform switching seems to preserve periimplant bone and soft tissue levels. However, long-term clinical studies on the proper diameter of abutment without deformation and the effective degree of platform switching in terms of the bone resorption are still awaited.

Influence of Vertical Soft Tissue Thickness on Crestal Bone Changes Around Implants with Platform Switching: A Comparative Clinical Study

Numerous studies have shown the superiority of platform-switched implants in preserving crestal bone as compared with platform-matched implants. However, the influence of initial soft tissue thickness on development of crestal bone loss has not been addressed in previous studies; thus, further research is needed. To evaluate crestal bone levels around platform-switched implants placed in thin and thick mucosal tissue. Eighty patients (38 male and 42 female, mean age 44 ± 3.34 years) received 80 bone-level implants of 4.1 mm in diameter with platform switching (Institut Straumann AG, Basel, Switzerland). Tissue thickness was measured, and cases were distributed to Group 1, with thin soft tissue (2 mm or less, n = 40), and Group 2, with thick tissue (more than 2 mm, n = 40). Implants were placed with a one-stage approach and restored with screw-retained restorations. Radiographic examination was performed after implant placement, 2 months after healing, after restoration, and at 1-year follow-up post-reconstruction. Crestal bone loss was calculated. The Mann-Whitney U-test was applied, and significance was set to p ≤ .05. Implants in Group 1 (thin tissue) showed 0.79 mm of bone loss after 2 months. After 1-year follow-up, bone loss was 1.17 mm. Implants in Group 2 (thick tissue) showed bone loss of 0.17 mm after 2 months of implant placement and 0.21 mm after 1-year follow-up. The differences between groups were significant (p < .001) at both time points. It can be concluded that platform switching does not prevent crestal bone loss if, at the time of implant placement, mucosal tissue is thin. In thick soft tissue, use of platform-switched implants maintained crestal bone level with minimal remodeling.

Impact of platform switching on marginal peri‐implant bone‐level changes. A systematic review and meta‐analysis

ObjectiveTo address the focused question, is there an impact of platform switching (PS) on marginal bone level (MBL) changes around endosseous implants compared to implants with platform matching (PM) implant-abutment configurations?Material and methodsA systematic literature search was conducted using electronic databases PubMed, Web of Science, Journals@Ovid Full Text and Embase, manual search for human randomized clinical trials (RCTs) and prospective clinical controlled cohort studies (PCCS) reporting on MBL changes at implants with PS-, compared with PM-implant-abutment connections, published between 2005 and June 2013.ResultsTwenty-two publications were eligible for the systematic review. The qualitative analysis of 15 RCTs and seven PCCS revealed more studies (13 RCTs and three PCCS) showing a significantly less mean marginal bone loss around implants with PS- compared to PM-implant-abutment connections, indicating a clear tendency favoring the PS technique. A meta-analysis including 13 RCTs revealed a significantly less mean MBL change (0.49 mm [CI95% 0.38; 0.60]) at PS implants, compared with PM implants (1.01 mm [CI95% 0.62; 1.40] (P < 0.0001).ConclusionsThe meta-analysis revealed a significantly less mean MBL change at implants with a PS compared to PM-implant-abutment configuration. Studies included herein showed an unclear as well as high risk of bias mostly, and relatively short follow-up periods. The qualitative analysis revealed a tendency favoring the PS technique to prevent or minimize peri-implant marginal bone loss compared with PM technique. Due to heterogeneity of the included studies, their results require cautious interpretation.