Discussion : Novel expandable short dental implants in situations with reduced vertical bone height—technical note and first results [2]
Several investigators analysed the preferred indications of short dental implants in the posterior mandible or maxilla and outlined the cost efficiency compared to additional vertical augmentations. In the present trial, we used a new short implant in both jaws and nearly all possible indication categories were represented, which proves the broad versatility (Table 4).
In our study, two implant failures occurred early in the prosthetic period and under loading. In a former systematic review, 11 studies reported more short implant failures before loading, while 7 studies reported more implant failures after loading [39]. Regarding the implant success rate in the present study, it must be considered that the lost implants were associated with difficult surgical conditions. Besides biological failures, in this study cohort, no technical complications were observed. In accordance with earlier comparative studies, it is evident that when using short implants, there is a lower risk of complications compared to augmentation [4, 7, 8] and nerve lateralisation [40].
Why design modifications? This is a matter of reduction of the healing period [46], the gain of stability under difficult conditions and increased bone-to-implant contact [27, 49,50,51] and the fact that most complications of short implants occur in the preprosthetic period [39]. It is also a question of long-term crestal bone stability. Earlier biomechanical finite-element studies confirmed that apical expansion results in favourable stress reduction in the crestal bone of nearly 10% [52]. It is assumable that additionally to the microthread and platform-switching concept [53], the periimplant bone strain could be reduced by apical expansion. This issue requires separate consideration in further studies. The employed implant design (especially its 7-mm length) combines several favourable biomechanical features, which were considered in this study (Fig. 1a, d).
According to Gehrke and co-authors, and in relation to the present study, the apical implant design influences the implant stability and bone-to-implant contact [54]. The expansion procedure presents an additional bicortical anchorage [17] in the oro-vestibular direction. In hard bone, this might be a disadvantage and lead to asymmetrical expansion. Manufacturers’ recommendations for hard bone should be strongly considered.
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]
- 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