Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results

Abstract

PurposeShort implants often have the disadvantage of reduced primary stability. The present study was conducted to evaluate the feasibility and safety of a new expandable short dental implant system intended to increase primary stability.MethodsAs a “proof of concept”, a prospective clinical cohort study was designed to investigate intraoperative handling, primary and secondary implant stability (resonance frequency analysis), crestal bone changes, implant survival and implant success, of an innovative short expandable screw implant. From 2014 until 2015, 9 patients (7–9-mm vertical bone height) with 30 implants (length 5–7 mm, diameter 3.75–4.1 mm) were recruited consecutively.ResultsAll 30 implants in the 9 patients (age 44 to 80 years) could be inserted and expanded without intraoperative problems. Over the 3-year follow-up period, the implant success rate was 28/30 (93.3%). The mean implant stability quotients (ISQ) were as follows: primary stability, 69.7 ± 10.3 ISQ units, and secondary stability, 69.8 ± 10.2 ISQ units (p = 0.780), both without significant differences between the maxilla and mandible (p ≥ 0.780). The mean crestal bone changes after loading were (each measured from the baseline) as follows: in the first year, 1.0 ± 0.9 mm in the maxilla and 0.7 ± 0.4 mm in the mandible, and in the second year, 1.3 ± 0.8 mm and 1.0 ± 0.7 mm, respectively.ConclusionsCompared to other prospective studies, in this indication, the success rate is acceptable. Implant stability shows high initial and secondary stability values. The system might present an extension of functional rehabilitation to the group of elderly patients with limited vertical bone height. Further long-term investigations should directly compare this compressive implant with standard short implants.Electronic supplementary materialThe online version of this article (10.1186/s40729-017-0107-1) contains supplementary material, which is available to authorized users.

Clinical Performance of Short Expandable Dental Implants for Oral Rehabilitation in Highly Atrophic Alveolar Bone: 3-year Results of a Prospective Single-Center Cohort Study

“…Implant positions, prosthetic treatments, and success rates are summarized in Table 3 . This table also contains nine patients (indicated by “#”) whose short-term results have previously been published [ 24 ]. In terms of validating the initial outcome, these individuals are included in the present analysis because of long-term follow-up.…”

“…The implant was submitted to all mechanical fatigue tests in vitro (ISO 14801:2016 standard and FDA guidance for root-form endosseous dental implants and endosseous dental implant abutments). Apical expansion was performed after implant insertion using a special expansion tool and ratchet torque, which resulted in a pyramid shape [ 24 ]. The implants had the following dimensions and special characteristics: 5 mm, 6 mm, and 7 mm in length; 3.75 mm and 4.1 mm in diameter; internal (7 mm length) or external (5 mm and 6 mm length) hexagon platform.…”

“…Prosthetic treatment was initiated after a minimum of 2 weeks following surgical re-entry. This required three sessions for fixed dentures, four sessions for removable dentures with ball attachments, six sessions for combined fixed-removable dentures, and seven sessions for removable dentures with jaw bars [ 24 ]. The abutment screws were fixed with a torque of 15Ncm, according to the manufacturer’s recommendation.…”

“…Based on technical notes and initial experiences [ 24 ], this larger long-term trial sought to reevaluate a short dental implant system with an apically expandable macro-design. We hypothesized that the expandable macro-design of this short dental implant provides a reliable implant success rate, increases OHRQOL, ensures sufficient implant stability in a reduced vertical alveolar bone, and maintains peri-implant crestal bone.…”

Influence of short implants geometry on primary stability

“…Reich et al ( 23 ) reported 66.9 ± 8.9 ISQ in 5-7mm long implants placed in D3 and D4 bone of the maxilla. These results are similar to those obtained in D3 bone for PHIA/SHORT-I (66.43 ± 4.49 ISQ) short implants of our study.…”