Clinical and Radiographic Comparison between Platform-Shifted and Nonplatform-Shifted Implant: A One-Year Prospective Study

Do dental implants installed in different types of bone (I, II, III, IV) have different success rates? A systematic review and meta-analysis

Purpose

The objective of this systematic review and meta-analysis was to evaluate the survival rate of implants installed in bone type IV (Lekholm and Zarb, 1995) compared to that of implants installed in bone types I, II, and III.

Material and methods

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) and was registered in the PROSPERO International Database of Systematic Reviews (CRD42021229775). The PubMed/MEDLINE, Scopus, and Cochrane databases were searched through July 2021. The PICO question was: "Dental implants installed in type IV bone have a lower success rate when compared to implants installed in type I bone, II and III?". The established inclusion criteria were: 1) controlled and randomized clinical trials (RCT), 2) prospective and retrospective studies with at least 10 participants with dental implants, and 3) patients with dental implants installed in bone tissue types I, II, III, and IV (Lekholm and Zarb, 1985). The minimum followup duration was 1 year.

Results

After searching the identified databases, 117 articles were selected for full reading and 68 were excluded. Thus, 49 studies were included for qualitative and quantitative analyses. The total number of participants included was 12,056, with a mean age of 41.56 years and 29,905 implants installed. Bone types I, II, and III exhibit a lower implant failure rate when compared to bone type IV.

Conclusion

Dental implants installed in bone types I, II, and III showed significantly higher survival rates than those installed in type IV. The bone type I success rate was not significantly different than that of type II; however, the success rate of bone type I and II was higher than that of type III.

The efficacy of immediate implant placement in the anterior maxilla with dehiscence in the facial alveolar bone: A case series

BACKGROUND

There is no clear evidence that immediate implant placement can be applied to cases with dehiscence in the facial alveolar bone prior to extraction.

PURPOSE

To evaluate the results of immediate implant placement in the anterior maxilla with facial alveolar bone dehiscence.

MATERIALS AND METHODS

We super positioned pre- and post-operative cone-beam computed tomography (CBCT) three-dimensional reconstruction images. A CBCT was taken before tooth extraction (T0), when the definitive restoration was placed (T1), and 1 year after placing the definitive restoration (T2). The depth and width of the dehiscence at T0, and the height and width of the facial hard and soft tissues are measured at the implant site at T1 and T2. We calculated the change in the amount of hard and soft tissues from T1 to T2 and determined the correlation between preoperative facial alveolar bone morphology and postoperative gingival recession.

RESULTS

13 women and 7 men were recruited. A total of 20 implants were evaluated. The implant survival rate was 100%. The mean facial alveolar bone dehiscence width was 3.9 ± 1.6 mm, and the mean depth from platform level was 2.9 ± 1.7 mm. The mean implant body exposure on the buccal was 4.8 ± 1.7 mm, and the mean socket width gap was 2.1 ± 0.8 mm. At T1, the mean facial hard tissue width was 2.1 ± 0.7 mm, and the mean height was 2.0 ± 0.7 mm. The mean change in vertical gingival recession from T1 to T2 was 0.5 ± 0.5 mm. We found a positive correlation between facial alveolar bone dehiscence width and gingival recession (r = 0.46, p-value = 0.04) and between dehiscence depth and gingival recession (r = 0.48, p-value = 0.03).

CONCLUSIONS

The results of our CBCT superposition method indicated that immediate implant placement can be considered in patients with facial alveolar bone dehiscence. However, there may be a higher risk of gingival recession with wide or deep dehiscence.

Multivariate analysis of the influence of prosthodontic factors on peri-implant bleeding index and marginal bone level in a molar site: A cross-sectional study

BACKGROUND

Peri-implant tissue condition can result from prosthodontic, surgical and bacteriological factors.

PURPOSE

This study investigated the effects of prosthodontic factors on peri-implant tissue.

MATERIALS AND METHODS

Subjects were 140 patients with 310 implants from Osaka University Dental Hospital. Prosthodontic factors examined were the connection type, the suprastructure retention type, the material of the abutment and the mesiodistal and buccolingual prosthetic form of the superstructure as emergence angle. The objective variables were the modified bleeding index (mBI) and marginal bone level (MBL). Statistical analysis was used as a generalized estimation equation.

RESULTS

The taper joint had a significantly smaller MBL than the butt joint (P < .001). There was no significant difference in mBI and MBL between cement and screw retaining. Zirconium and titanium resulted in a significantly smaller mBI than gold alloy (zirconium/gold alloy: P = .037, titanium / gold alloy: P = .021), but there was no significant difference in the MBL. Both mBI and MBL tended to be smaller when the emergence angle was around 20° to 40°, although this difference was not significant.

CONCLUSION

As a result of multivariate analysis, our findings suggest that to reduce MBL from the perspective of prosthodontic factors it is preferable to use an implant with a taper joint connection positioned with an emergence angle of 20° to 40°.

Radiographic and clinical outcomes of rooted, platform-switched, microthreaded implants with a sandblasted, large-grid, and acid-etched surface: A 5-year prospective study

BACKGROUND

There is no data available on the long-term outcomes of a rooted, platform-switched, microthreaded implant with a sandblasted, large-grid, and acid-etched surface.

PURPOSE

This prospective, longitudinal study evaluated the clinical and radiographic outcomes of rooted, platform-switched, microthreaded and sandblasted, large-grid, and acid-etched (SLA) surface implants for 5 years.

MATERIALS AND METHODS

Sixty implants were placed in sixty patients with partially edentulous maxillae or mandibles. The permanent prostheses were inserted 2-4 months after implant placement. Clinical and radiographic examinations were performed at follow-up visits scheduled postoperation, prosthesis installation, 1 year, and 5 years after surgery, to assess implant survival and success rates, biological and mechanical complications, and marginal bone loss.

RESULTS

After 5 years' follow-up, four patients withdrawn from the study, and 56 implants achieved a 100% survival rate and 98.2% success rate. Three prosthetic complications occurred, resulting in a success rate for prostheses of 94.6%. The incidence of peri-implant mucositis was 9.1% and no peri-implantitis was diagnosed. The average marginal bone loss at the mesial aspect was 0.46 ± 0.27 mm after 1 year and 0.48 ± 0.27 mm after 5 years. The average marginal bone loss at the distal aspect was 0.46 ± 0.32 mm after 1 year and 0.50 ± 0.35 mm after 5 years.

CONCLUSION

After 5 years of loading, the rooted, platform-switched, microthreaded, and SLA surface implants showed high survival and success rates, steady crestal bone levels, and excellent long-term clinical outcomes in the soft tissue. Overloading may be related to the marginal bone loss around implants, but the surgical protocol, different sites, and jaw position did not correlate with crestal bone loss.