The Effect of Platform-Matching Versus Platform-Switching Dental Implants on Peri-implant Hard and Soft Tissue Healing

Thirty patients will have a dental implant placed. Fifteen patients will be randomly selected by a coin toss to receive a platform-switched implant while the other fifteen will receive platform-matched implant. Each patient will receive a diagnostic work-up including standardized radiographs (periapicals), study casts, clinical photographs, and a clinical examination of teeth adjacent to the edentulous sites. Pre-surgical preparation will include detailed oral hygiene instructions. Baseline data will be collected at initial exam, and at 2, 4, 6, and 12 months. Parameters measured will include: plaque index, gingival index, probing depth, keratinized tissue, bleeding on probing, and digital radiographic examination. Pre-surgical measurements will include: cemento-enamel junction to osseous crest on adjacent teeth by direct measurement at surgery, and by radiograph at baseline, 2, 4, 6, and 12 months, periodontal form, periodontal biotype, tooth shape, and papilla harmony. Patients will be randomly selected for treatment group assignment using a coin toss before surgery by the mentor. One investigator who is unaware of group assignment will perform all baseline examinations and all follow-up examinations. Means and standard deviations will be calculated for all parameters. A paired t-test will be used to evaluate the statistical significance of the differences between initial and final data. An unpaired t-test will be used to evaluate statistical differences between the test and control groups. A sample size of 15 gives 80% statistical power to detect a difference of 0.5 mm of implant bone loss between groups. All surgical procedures will be completed by one operator under the direction of one mentor. Pre-surgical measurements will be taken first. Local anesthesia will be administered. The surgical procedure will consist of the reflection of full thickness flaps to expose the alveolar crest. The implant platform will be placed 3 to 4 mm apical to the mid-facial gingival margin using dental implant osteotomy drills for preparation of the site. The surgical procedures will be documented with clinical photographs. Sutures will be used to close the flap and bury the implant under the tissue. Records will be kept of healing periodically for the first 8 weeks, then at 4, 6 and 12 months. The test group will use a BioHorizons Tapered Internal Plus "platform-switched" implant. The control group will be BioHorizons standard Internal "platform-matched" implant. All patients will be seen at 1-2, 4, 6 and 8 weeks to monitor healing. At week 8 the implant will be uncovered surgically and provisionalized, and at the 4 month visit the final crown will be placed. Subsequent examinations will take place at 6 and 12 months. Post-surgically, patients will take an antibiotic (doxycycline hyclate 100 mg once a day for two weeks), an analgesic (Vicodin ES every 4-6 hours as needed for pain), and an anti-inflammatory agent (Naproxen 375mg every 12 hours for one week). At post-operative visits plaque removal, and oral hygiene instruction, as needed, will be performed along with clinical photographs and standardized radiographs as scheduled. The results of this study will allow comparison of peri-implant soft and hard tissue healing following placement of a BioHorizons "platform-switched" Tapered Internal Plus implant versus a standard Internal "platform-matched" implant in terms of the effect on marginal bone loss, buccal recession, and papilla fill.