Page 169 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

FOUR-IMPLANT-SUPPORTED OVERDENTURE TREATMENT IN THE MAXILLA
University hospital. This clinical trial has been conducted in full accordance with the Helsinki Declaration (1975) as revised in 2000.
Clinical and radiographic examination
The clinical and radiographic examination of a smaller study cohort up to 21 months has been described previously by Glibert and colleagues.12 After implant placement (t0, baseline) follow-up visits were planned at 3, 6(t1, initial remodeling), 12, 24, and 36(t2) months. Peri-apical radiographs were taken after implant placement (t0, baseline), and after 3, 6(t1, initial bone remodeling), 12, 24, and 36(t2) months. The time period between t0 and t1 is the period considered appropriate for initial bone remodeling, following biologic width establishment. After delivery of the final prosthesis, the measurement of probing pocket depths, bleeding on probing, and plaque scores were executed on four sites per implant to monitor the peri- implant health. The presence of plaque and bleeding on probing was assessed on a dichotomous scale.
Peri-apical radiographs were analyzed after implant placement (t0), after initial remodeling at 6 months (t1), and after 36 months (t2). To standardize the peri- apical radiographs an individualized x-ray holder and Rinn-Sett was used (Rinn XCP, Dentsply Sirona, Charlotte, NC). The radiographs were calibrated preferably by using the length of the implant, otherwise the distance between the threads of the implant, or the diameter of the implant was used. The bone level was determined as the distance between the most crestal bone-to-implant contact and the lower edge of the smooth implant bevel at the implant-abutment interface. The distance was measured on the peri-apical radiograph at the distal and mesial side of the implant and recalculated to a mean bone level on implant level. The bone loss was calculated by the difference of the bone level between two time points.
During all follow-up visits, calculus and plaque were removed and oral hygiene instructions were given tailored to the need of the patient. All patients were advised to use interdental brushes and (electric) toothbrush to maintain the bar construction.
Incidence of peri-implantitis was assessed according to the criteria proposed in the 2017 Consensus report of the World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.13
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