The Institutional Review Board (IRB) for the Medical Sciences at the University of Michigan, Ann Arbor, MI, reviewed and approved this study before enrollment of participants began (IRB number HUM00142371). In addition, the study was conducted according to the principles outlined in the Declaration of Helsinki on experimentation involving human subjects, as revised in 2000. Informed consent was obtained from all participants before involvement in the study.
Inclusion criteria for study participants were as follows: individuals of any gender, aged 20 years or older, scheduled for implant surgery, and willing to comply with all study requirements. The exclusion criteria included patients undergoing immediate implant surgery, flapless implant procedures, surgeries involving a lateral sinus lift, individuals who were pregnant or planning to become pregnant, or uncertain about their pregnancy status, as well as patients with a history of intravenous bisphosphonate use or history of radiation therapy in the head and neck area within four years prior to implant placement.
The surgical technique and research measurements involved in this study did not impact the standard patient care provided during the implant surgery visit. Measurements taken during surgery included the initial alveolar bone ridge width (RWt0), ridge width after osteotomy (RWt1), ridge width after expansion with the implant fixture (RWt2), buccal bone thickness post-osteotomy (BBTt1), and buccal bone thickness post-implant placement (BBTt2), as well as vertical soft tissue height and buccal soft tissue thickness (Figs. 1 and 2). These measurements were taken at various stages of the implant placement procedure to evaluate the changes in relation to factors such as implant site, diameter, design, bone density, and repeated use of the term "implant location" in points 1 and 4.
Following flap reflection, reference points for measurement were marked 2mm below the crest on both the buccal and lingual sides of the osteotomy site. The initial ridge width (RWt0) was measured at this level using a ridge mapping instrument. RWt1 was captured after osteotomy completion by the attending clinician, using the same reference points. BBTt1 was gauged by placing a calibrated periodontal probe perpendicularly to the implant bed. Subsequent to implant placement using a tapered screw design, insertion torque values were recorded, along with RWt2 and BBTt2 measurements. Bone quality at the site was assessed and recorded according to the classification system proposed by Lekholm and Zarb [3, 13], based on both preoperative radiographic appearances and the tactile feedback during site preparation and implant placement.
Statistical analysis involved the use of a comprehensive statistical software package. Descriptive statistics were employed to summarize variables. Paired samples t-tests were utilized to ascertain the presence of significant differences between the ridge widths RWt0, RWt1, and RWt2, as well as between the buccal bone thickness measurements BBTt1 and BBTt2. A P-value of less than 0.05 was considered indicative of statistical significance.