Short dental spiral implants placed by a progressive steps technique in the atrophic posterior maxilla – a personal 10 years follow‐up on 80 implants

Abstract

Background A recent analysis of the literature shows a growing evidence on the utility of short dental implants (<10 mm) in clinical situations of limited vertical bone height. The most challenge situation is the atrophic posterior maxilla with a residual bone height radiographically ranging from 4.5 to 6 mm. Several surgical techniques and implant morphologies have been suggested in the past to avoid sinus floor elevation, with its postoperative morbidity, higher costs and higher risks of complications. Aim/Hypothesis This report describes a new surgical procedure used for the placement of 80 short spiral implants <10 mm (SPI and ICE implants, Alpha-bio, Israel) by a progressive steps drilling in the posterior maxilla for single tooth restoration, with a follow-up of 10 years. Material and Methods Inclusion criteria was a residual vertical bone height, measured on CT or CBCT, minimum of 4.5 mm (ranging from 4.5 to 6 mm). No data regarding osteoporosis in females where collected as retained unnecessary. Surgery was flapless in 50 cases with low speed bone drilling and irrigation+ no adjunctive bio-material has ever been used+ progressive steps surgical technique (step one-first 2 mm drill of 2 till to the sinus floor with its slow and atraumatic drilling, minimal perforation probed with gauge always with Valsalva test negativity – step two – 2.8 mm drill used only for 2–4 mm – step three – 3.2 mm drill used only for 2 mm in depth) was performed in all cases, without any adjunctive technique, with high insertion torque (up to 50 Ncm). Prostheses were placed 3 months later and were cemented metal-ceramics crowns in 40 cases and screwed hybrid ceramics crowns (Vita Enamic) in the remaining cases+ 35 implants were 6.25 mm in length and the remaining 8 mm all with a diameter of 4.1 mm. Results In all cases a spiral implant longer (from 2 up to 4 mm) than the length pre-operative measured was inserted. One implant was lost 30 days after placement for lack of osseointegration and another implant for parodontal infection of the adjacent tooth, both placed by flapless surgery with healing cap positioning+ one implant showed perimplantitis related to poor hygiene with bone loss around fixture but without mobility, and is still in follow-up. In the remaining cases a good perimplant bone level was always preserved during the follow-up till to date. Spiral implants, even though reduced in length (6.25 mm up to 8 mm), if placed by the surgical technique proposed in this report, promote an excellent bone dislocation in apical direction during implant insertion. The latter provides an increase of exploitable vertical dimension compared to the one measured on radiograms, leading contextually to the insertion of a longer implant and to a high primary stability of the fixtures. Conclusions and Clinical Implications With this report a protocol including spiral morphology of the implant, progressive steps fixture placement, in addition single screwed hybrid ceramics crowns, is suggestable for the single tooth restoration of the posterior maxilla. The suggested protocol shows good results in term of simplicity, predictability, durability and above all acceptability by the patients of such kind of implant treatments for the posterior atrophic maxilla.