The Effect of Tapered Abutments on Marginal Bone Level: A Retrospective Cohort Study

Abstract

Background: Early peri-implant bone loss has been associated to long-term implant-prosthetic failure. Different technical, surgical, and prosthetic techniques have been introduced to enhance the clinical outcome of dental implants in terms of crestal bone preservation. The aim of the present cohort study was to observe the mean marginal bone level around two-part implants with gingivally tapered abutments one year after loading. Methods: Mean marginal bone levels and change were computed following radiological calibration and linear measurement on standardized radiographs. Results: Twenty patients who met the inclusion criterion of having at least one implant with the tapered prosthetic connection were included in the study. The cumulative implant success rate was 100%, the average bone loss was −0.18 ± 0.72 mm, with the final bone level sitting above the implant platform most of the time (+1.16 ± 0.91 mm). Conclusion: The results of this cohort study suggested that implants with tapered abutments perform successfully one year after loading and that they are associated with excellent marginal bone preservation, thus suggesting that implant-connection macro-geometry might have a crucial role in dictating peri-implant bone levels.

Influence of Biologically Oriented Preparation Technique on Peri-Implant Tissues; Prospective Randomized Clinical Trial with Three-Year Follow-Up. Part II: Soft Tissues

“…Platform-switching preserves more bone by placing the implant-abutment interface away from the crestal bone. As a consequence, the soft tissues attempt to sit on top of the dental implant creating a mechanical protective seal [29]. This factor has not been considered in the present investigation since all three groups presented platform switching, so that if this does constitute an influential factor, it would have exerted the same influence in the three groups.…”

“…An increase in probing depth over time, however, conflicts with peri-implant health, and absence of further bone loss following initial healing, which should not be ≥2 mm. These parameters have been used in various trials to analyze peri-implant soft tissue behavior [29][30][31].…”

“…To date, no published research has analyzed implant-supported BOPT crowns compared with a control group or with conventional restorations over a horizontal finishing line, whether cemented or screw-retained. The few works published on implant-supported BOPT-type crowns and peri-implant soft tissue behavior have employed different methodologies making it impossible to carry out absolute comparisons with the present trial [29,30,32,33].…”

“…Various articles have suggested that the accumulation of plaque and marginal inflammation are more frequent around implants with less than 2 mm of keratinized tissue [15]. Few studies have evaluated tissue responses around conical convergent abutments [29,32]. In the present trial, the GBOPT group (cemented crown without finishing line or BOPT), in addition to being the prosthesis that presented the least bone loss, also showed the greatest KMW, obtaining a mean of 2.74 ± 0.72 mm, achieving over 2 mm in all cases.…”

“…Not only could the use of conical abutments improve peri-implant bone levels, but it could also reduce the depth of the peri-implant sulcus. It has been suggested that the biological phenomenon of peri-implant bone preservation is related to the circular stabilization of connective tissue around the abutment and the presence of a superficial sulcus [29,35].…”