Ridge Expansion in Two Surgical Stages Using the Transitional Implant Technique. Case Series with 8-Year Follow-Up

Abstract

Extremely wide bony ridges require surgical procedures in order to insert dental implants. When less than 3 mm is present, different procedures are available, with ridge splitting being one of the most commonly used. The main limitation of this procedure is the angulation of the inserted implant. The two-stage split with transitional implants was created to overcome this drawback and achieve greater bone volume in the intervention area. This case series shows patients treated with this novel procedure. Material and Method: We retrospectively analysed patients who had undergone two-stage ridge expansion (using transitional implants) with at least 9 years of follow-up from the loading of the definitive implant, both in the maxilla and mandible. Data collection was performed by two independent examiners (different from those performing the prosthetic or surgical phase). All data were entered into a database which was managed by computer for the subsequent statistical analysis. The implant was the unit of analysis for descriptive statistics in terms of location, implant dimensions, and radiographic measurements. The primary variable was implant survival and as secondary variables mesial and distal bone loss and final bone crest width achieved after transitional implant integration, before replacement, were recorded. Results: Thirteen patients were recruited, and 30 transitional implants were inserted for width expansion in two surgical stages. These transitional implants were subsequently replaced by definitive implants at 5 months in the maxilla and at 3 months in the mandible. The mean initial ridge width of all two-stage split sites was 2.65 mm (+/- 0.63), range 1.32 to 3.70 mm. After placement of the transitional implants and bone healing, the final mean width of the specimen was 7.60 mm (+/- 0.26), range 4.31 to 12.20 mm. The mean mesial bone loss after loading of the final implant was 0.80 mm (+/- 0.26) and the mean distal bone loss was 0.85 mm (+/- 0.25). Conclusion: The two-stage split technique to achieve a gain in width of the residual bone crest is minimally invasive, predictable and the implants placed in the final (definitive) stage have a high survival rate, as we have seen in the present study with 9 years of follow-up.