Material and methods : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [1]
The study was designed as a prospective monocentric longitudinal cohort study according to the STROBE criteria. The participants of this study were recruited at the university hospital of Martin Luther University Halle-Wittenberg, Department of Oral and Plastic Maxillofacial Surgery, implantological consultation from 2014 (June) until 2015 (June). Inclusion and exclusion criteria of adult patients interested in implantological treatment are summarised in Table 1. Written informed consent was obtained from all individual participants included in this study.
As a “proof of concept”, the pilot study was designed to investigate the intraoperative handling and to evaluate the feasibility and safety of a new short implant system. Therefore, sample size calculation was not performed. The primary outcome variable was implant success rate, which was calculated considering known success criteria (implant in function, no sign of infection or pain, no mobility, no radiolucent area around the implant) [32, 33]. The implant survival was calculated according to the Kaplan-Meyer method. Secondary measures were implant stability (initial and secondary) and periimplant crestal bone changes. Implant stability was measured by resonance frequency analysis (RFA; Osstell AB, Göteborg, Sweden).
Primary stability was measured immediately after implant insertion and completed expansion (see below), and secondary stability after the submerged healing period (3 months in the mandible, 6 months in the maxilla; Table 2) during the re-entry operation just before the healing abutments were inserted. Implant stability quotient (ISQ) values were obtained using the Smartpegs (type 17 and 35). According to each measurement, implant stability was classified as low with ISQ values < 60, medium with ISQ values 60–70, and high with ISQ values > 70 [34].
Digital radiograms (orthopantomogram, standard periapical radiograms) were taken prior to surgery, after implant insertion and re-entry, and at yearly follow-up examinations for crestal and periapical bone evaluation (see below).
In this study, a short expandable titanium screw implant (PYRAMIDION dental implant, DenTack Implants Ltd., Kfar-Saba, Israel) was used, which leads to dynamic condensing of the apical bone. The implants had the following dimensions and special characteristics: 5, 6 and 7 mm in length, 3.75 and 4.1 mm in diameter and an internal (7-mm length) or external (5- and 6-mm length) hexagon platform. The apical expansion is performed after implant insertion using a special expansion tool and a ratchet torque, resulting in a pyramid shape (Fig. 1a–f). The implant expansion process using the expansion tool is visualised in the movie clip (Additional file 1).
Serial posts:
- Abstract : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Introduction : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [1]
- Introduction : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [2]
- Material and methods : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [1]
- Material and methods : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [2]
- Material and methods : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [3]
- Results : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [1]
- Results : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [2]
- Discussion : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [1]
- Discussion : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [2]
- Discussion : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [3]
- Discussion : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [4]
- Discussion : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [5]
- Conclusion : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Abbreviations : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- References : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [1]
- References : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [2]
- References : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [3]
- References : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [4]
- References : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [5]
- References : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [6]
- References : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [7]
- Acknowledgements : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Author information : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [1]
- Author information : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [2]
- Ethics declarations : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Additional files : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Rights and permissions : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- About this article : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Table 1 Patient recruitment : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Table 2 Surgical treatment protocol : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Table 3 Prosthetic treatment protocol : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Table 4 Clinical characteristics of the study cohort : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results
- Fig. 1. a Closed short expandable dental implant (4.1 × 7 mm). The implant-abutment connection is characterised by an internal hexagon for rotation stability, combining the advantages of conical and parallel surfaces to reduce microgaps and micromovement [68]. The microthread concept and platform switching concept are implemented in the implant shoulder to reduce periimplant bone strain [53]. b Manual fixation of the expansion tool. Take note of the distance between both yellow rings. c Completion of the expansion process using the ratchet. Take note of the contact between both yellow rings. d Opened short expandable dental implant (4.1 × 7 mm). The expanded implant provides an increased bone-to-implant interface (pyramid shape) in the apical portion [54]. e Cross-section view of the implant apex. The apical expansion process is characterised by the unfolding of four wings, which are connected by four foils. D1: diameter of the closed implant. D2: diameter of the opened implant. fTop v
- Fig. 2. Cumulative implant survival over the follow-up period. The Kaplan-Meyer diagram visualises the analysis of implant survival in the maxilla and in the mandible (log rank test, p = 0.173) over the follow-up period up to 37 months (Table 4) : Novel expandable short dental implant
- Fig. 3. a Primary implant stability. The histogram visualises the distribution of the implant stability quotients (ISQ) for both jaws measured by resonance frequency analysis (Osstell AB, Göteborg, Sweden). b Secondary implant stability. The histogram shows the distribution of the implant stability quotients (ISQ) of osseointegrated implants. According to the measurement implant stability was classified as low with ISQ values < 60, medium with ISQ values 60–70, and high with values ISQ > 70 [34] : Novel expandable short dental implant
- Fig. 4. a–h Prosthetic restauration—follow-up examination. Intraoral and perioral views of a rehabilitated female patient. (She asked explicitly only for implantological treatment in the mandible.) : Novel expandable short dental implant
- Fig. 5. a Postoperative orthopantomogram. b Follow-up orthopantomogram. c Follow-up standard periapical radiogram (implants i42 and i44). d Follow-up standard periapical radiogram (implants i32 and i34) : Novel expandable short dental implant