Platform Switching vs Regular Platform Implants. One Year Results From a RCT

The present study tested the hypothesis that Platform Switching (PS) and Regular Platform (RP) implants would have different outcomes in the bilateral single tooth replacements against the alternative hypothesis of no difference.

This study was designed as a randomised, controlled, split-mouth trial. Eighteen patients, with bilaterally missing single bicuspid or molar had one of the sites to be restored randomly assigned to be treated according to the platform-switching concept with (PS group), or with matching implant-abutment diameters, (RP group). A total of 36 implants, (18 Nobel Replace Tapered Groovy PS, 18 Nobel Replace Tapered Groovy), were bilaterally installed. All the implants were inserted with an insertion torque between 35 and 45 Ncm, in healed healthy bone and the healing abutment was connected at the same time. Both implants were delayed loaded with screw retained temporary crowns 3 months after implant insertion and with screw retained definitive crowns 2 months later. Outcome measures were implant survival, biological and prosthetic complications, radiographic marginal bone-level changes, soft tissue parameters (PPD and BOP). Clinical data were collected at baseline 6 and 12 months. Statistical analyses were conducted using computational program SAS (version 9.2), with 1-away ANOVA and F-test. Statistical significance was tested at the 0.05 probability level, and all values were presented as mean and standard deviation with 95% confidence intervals.

This study was designed as a randomised, controlled, split-mouth trial. all enrolled patients needed single bilateral fixed implant-supported prosthesis in molar area. A total of 18 consecutive patients were enrolled. In each eligible patient, the right molar was randomly selected to receive either Nobel Replace Tapered Groovy implant; (Nobel Biocare®, Goteborg, Sweden) with Platform Switching (PS) or Regular Platform (RP)

This study was designed as a randomised, controlled, split-mouth trial. all enrolled patients needed single bilateral fixed implant-supported prosthesis in molar area. A total of 18 consecutive patients were enrolled. In each eligible patient, the left molar was randomly selected to receive either Nobel Replace Tapered Groovy implant; (Nobel Biocare®, Goteborg, Sweden) with Platform Switching (PS) or Regular Platform (RP)

Nobel Replace Tapered Groovy PS implant; (Nobel Biocare®, Sweden), Nobel Replace Tapered Groovy implant with Replace Select connection (Nobel Biocare®, Sweden)

Both sites received tapered implants with an anodised surface, one site received: Nobel Replace Tapered Groovy PS implant; (Nobel Biocare, Goteborg, Sweden), with diameters of 4.3 or 5.0 mm and lengths of 10 or 8 mm, (PS group), the contralateral site received Nobel Replace Tapered Groovy implant with Replace Select connection with diameters of 4.3 or 5.0 mm and lengths of 10 or 8 mm, (RP group). Healing abutments were connected to implants at the same time of surgery , then flaps were sutured with Vicryl 4.0 sutures (Vicryl, Ethicon J&J International, St-Stevens-Woluwe, Belgium).

implant survival: The removal of implants was dictated by instability, progressive marginal bone loss, infection or implant fracture.

Marginal bone levels: Peri-implant marginal bone levels were evaluated on intraoral digital radiographs taken with the parallel technique at the time of implant placement, at 6 months and 12 months. If radiographs were inconclusive, they were repeated. A blinded radiologist (F.G.), unaffiliated with the study centre, interpreted all radiographs. The distances from the mesial and distal interproximal bone to the reference point (the horizontal interface between the implant and abutment) were measured with a software measurement tool (NIH Scion Image programme version 4.0.2, Frederick, MD, USA) calibrated against the space between two threads to the nearest 0.1 mm, and the mean of these two measurements was calculated for each implant. The measurements were recorded with reference to the implant axis.

Peri-implant mucosal response: Probing pocket depth (PPD) and bleeding on probing (BOP) were measured by a blinded operator (A.D.) with a periodontal probe (PCP-UNC 15, Hu-Friedy Manufacturing, Chicago, IL, USA) at 6 and 12 months. Three vestibular and 3 lingual values were collected for every implant by the same dentist.

Inclusion Criteria: need for single bilateral fixed implant-supported prosthesis in molar area stable interocclusal contacts ≥18 years of age provided written informed consent residual bone height ≥10 mm residual bone thickness ≥6 mm with at least 5 mm of keratinised gingiva crestally Exclusion Criteria: general contraindications to implant surgery lack of occluding dentition in the area intended for immediate loading periodontitis bruxism immunosuppression previous history of irradiation of the head and neck area uncontrolled diabetes heavy smoker (>10 cigarettes/day) poor oral hygiene current or past treatment with bisphosphonates substance abuse psychiatric disorder inability to complete follow-up ≥1 year lactation implant insertion torque less than 35 Ncm