Retrospective clinical analysis of risk factors associated with failed short implants

The influence of two distinct surface modification techniques on the clinical efficacy of titanium implants: A systematic review and meta-analysis

PURPOSE

To compare the effectiveness of anodized and sandblasted large-grit acid-etched surface modification implants in clinical applications.

METHODS

This systematic review has been registered at PROSPERO (CRD42023423656). A systematic search was performed using seven databases. The meta-analysis was performed using the RevMan 5.4 program and Stata 17.0 software. An analysis of the risk of bias in the included studies was conducted using the Cochrane Handbook for Systematic Reviews of Interventions and the Newcastle-Ottawa scale.

RESULTS

A comprehensive analysis of 16 studies, which collectively encompassed a total of 2768 implants, was finished. Following a five years follow-up, the meta-analysis showed that the cumulative survival rate of implants was lower in the anodized group compared to the sandblasted large-grit acid-etched group (RR, 3.47; 95 % confidence interval [CI], 1.23 to 9.81; P = 0.02). Furthermore, the anodized group and the sandblasted large-grit acid-etched group had similar marginal bone loss over the one to three years follow-up period. However, it was observed that the marginal bone loss increased at the five years follow-up period in the anodized group in comparison to the sandblasted large-grit acid-etched group (SMD, 2.98; 95 % CI, 0.91 to 5.06; P = 0.005). In terms of biological complications, plaque index, bleeding on probing, and probing pocket depth, we found no statistically significant differences between the anodized and sandblasted large-grit acid-etched group.

CONCLUSIONS

The sandblasted large-grit acid-etched group exhibited higher implants cumulative survival rate and less marginal bone loss compared to the anodized group. Moreover, both groups demonstrated similar incidences of biological complications, plaque index, bleeding on probing, and probing pocket depth, suggesting overall equivalence in these aspects.

Analysis of implant loss risk factors after simultaneous guided bone regeneration: A retrospective study of 5404 dental implants

PURPOSE

The purpose was to analyze the risk factors for implant loss after simultaneous guided bone regeneration (GBR).

MATERIALS AND METHODS

Patients who underwent implant placement with simultaneous GBR between January 2011 and December 2018 were screened for this study. The cumulative survival rate (CSR) was calculated using the life table method. Log-rank test and Kaplan-Meier survival estimates were used to identify potential risk factors for implant loss. The association between the investigated variables and implant loss was determined using hazard ratios (HRs) obtained from a multivariate Cox regression analysis.

RESULTS

A total of 3973 patients with 5404 implants were included in this study. The CSRs of the implants at 1, 5, and 10 years were 99.6%, 98.9%, and 98.7%, respectively. Male patient (HR = 2.94, 95% CI: 1.41-6.14), periodontitis (HR = 4.26, 95% CI: 2.05-9.86), tissue-level implants (HR = 3.02, 95% CI: 1.30-6.98), narrow implants (HR = 2.71, 95% CI: 1.12-6.57), and implant length ≤10 mm (HR = 2.91, 95% CI: 1.41-6.02) significantly increased the risk of implant loss (p < 0.05). The risk of implant loss was significantly higher in the maxillary posterior region (HR = 2.26, 95% CI: 1.04-4.90) than in the maxillary anterior region (p < 0.05). Compared to Straumann, Nobel (HR = 4.07, 95% CI: 1.75-9.44) and other implant systems (HR = 14.23, 95% CI: 4.32-46.85) showed a significantly higher risk of implant loss (p < 0.05).

CONCLUSION

Male patient, periodontitis, maxillary posterior region, Nobel implant system, other implant systems, tissue-level implants, narrow implants, and implant length ≤10 mm were considered risk factors for implant loss after simultaneous GBR.

The biomechanical profile of an osseo-integrated rectangular block implant: A pilot in vivo experimental study

OBJECTIVE

A novel implant design, the rectangular block implant (RBI), was investigated as a possible solution to the restoration of the posterior resorbed ridge.

AIM

To maximally load test the osseo-integrated RBI in shear and tensile loads and relate these findings to known human masticatory loads as biomechanical proof of the study concept.

MATERIALS AND METHODS

Twelve RBIs were design-manufactured and placed into posterior mandibular saddles in 3 mature greyhound dogs.-2 per left and right. After 12 weeks of healing, osseo-integration was confirmed using resonance frequency analysis (RFA) and wrench torque tests. Three bone blocks each with two RBIs were dissected and mounted in acrylic. Micro-computerized tomography (μ-CT) was performed to assess bone to implant contact (BIC), and load analysis was performed using a Universal Test System. Three force applications were conducted until failure: pull-out (tensile), buccal push from the lingual (shear) and distal push from the mesial (shear). The osteotomy sites were examined using light magnification and scanning electron microscopy (SEM).

RESULTS

Pull-out, buccal and distal force failures occurred at differing levels. Post-detachment sites showed complex patterns of bone failure, including trabecular and cortical fracture, as well as shearing at varying distances from the BIC. Interfacial shear strength was calculated at 14.4 MPa.

CONCLUSION

The osseo-integrated RBIs were able to withstand simulations of the demanding axially, bucco-lingually and mesio-distally oriented biomechanical challenges of the posterior saddle, under conditions of reduced bone volume. These values exceeded equivalent force components of maximal masticatory loads in humans.

The survival rates and risk factors of implants in the early stage: a retrospective study

Background

Few large-sample studies in China have focused on the early survival of dental implants. The present study aimed to report the early survival rates of implants and determine the related influencing factors.

Methods

All patients receiving dental implants at our institution between 2006 and 2017 were included. The endpoint of the study was early survival rates of implants, according to gender, age, maxilla/mandible, dental position, bone augmentation, bone augmentation category, immediate implant, submerged implant category, implant diameter, implant length, implant torque, and other related factors. Initially, SPSS22.0 was used for statistical analysis. The Chi-square test was used to screen all factors, and those with p < 0.05 were further introduced into a multiple logistic regression model to illustrate the risk factors for early survival rates of implants.

Results

In this study, we included 1078 cases (601 males and 477 females) with 2053 implants. After implantation, 1974 implants were retained, and the early survival rate was 96.15%. Patients aged 30–60 years (OR  2.392), with Class I bone quality (OR  3.689), bone augmentation (OR  1.742), immediate implantation (OR  3.509), and implant length < 10 mm (OR  2.972), were said to possess risk factors conducive to early survival rates.

Conclusions

The early survival rate of implants in our cohort exceeded 96%, with risk factors including age, tooth position, bone quality, implant length, bone augmentation surgery, and immediate implantation. When the above factors coexist, implant placement should be treated carefully.

Impact of peri-implant bone resorption, prosthetic materials, and crown to implant ratio on the stress distribution of short implants: a finite element analysis

The purpose of this study was to determine the effects of prosthetic materials and crown/implant (C/I) ratio on short implants with a marginal bone resorption. Three-dimensional finite element analysis was used to simulate stress distribution under static loading in non-resorption and resorption scenarios (3-mm vertical bone loss) in implants restored with single crowns and C/I ratios of 1:1, 1.5:1, and 2:1 were evaluated. Different crown materials were used: porcelain-fused to metal, porcelain-fused to zirconia, monolithic zirconia, and zirconia-based crown veneered with indirect composite resin. The C/I ratio, the peri-implant bone resorption, and the loading conditions were the key factors affecting the generated stress in short implants. In non-resorption models, von Mises stress ranged between 50 and 105 MPa whereas in resorption models, the values ranged from 168 to 322 MPa, both increasing with the higher C/I ratio under oblique forces. Under axial loading, the C/I ratio did not influence the stress values as the presence of resorption was the only parameter increasing, 57 MPa for the non-resorption models and 101 MPa for the resorption models, respectively. Preference of a prosthetic material was ineffective on the distribution of stress in the bone and implant structure under static loading in any models. The peri-implant bone resorption and a higher C/I ratio in short implants increase the stress values under both axial and oblique forces, whereas the crown material does not influence stress distribution in the surrounding bone and implant structure.

Three-Year Retrospective Comparative Study between Implants with Same Body-Design but Different Crest Module Configurations

Crest module can be defined as the portion of a two-piece implant designed to retain the prosthetic components and to allows the maintenance of the peri-implant tissues in the transition zone.

AIM

To evaluate the three-year after loading clinical and radiographic data, collected from patients that received a prosthetic rehabilitation on conical connection implants with partial machined collar (PMC; CC Group) and same body-designed implants, with flat-to-flat connection and groovy neck design (FC Group).

MATERIALS AND METHODS

A retrospective chart review of previously collected data, including documents, radiographs, and pictures of patients who received at least one implant-supported restoration on NobelReplace CC PMC or NobelReplace Tapered Groovy implants was performed. Patients with at least three years of follow-up after final loading were considered for this study. Outcomes measures were implant and prosthesis failures, any biological or technical complications, marginal bone loss.

RESULTS

Eight-two patients (44 women, 38 men; average age 55.6) with 152 implants were selected and divided in two groups with 77 (CC group) and 75 (FC group), respectively. Three years after final loading, one implant in CC group failed (98.7% survival rate), while no implants failed in FC group (100% survival rate). One restoration failed in CC group (98.7% survival rate) with no restoration failing in the FC one (100% survival rate). Differences were not statistically significant (p = 1.0). Three years after final loading, mean marginal bone loss was 0.22 ± 0.06 mm (95% CI 0.2-0.24) in CC group and 0.62 ± 0.30 mm (95% CI 0.52-0.72) in FC group. The difference was statistically significant (0.40 ± 0.13 mm; 95% CI 0.3-0.5; p = 0.003).

CONCLUSION

with the limitation of this retrospective comparative study, implants with conical connection and partial machined collar seem to achieve a trend of superior outcomes if compared with implants with flat connection and groovy collar design.

Is oral lichen planus a risk factor for peri-implant diseases? A systematic review and meta-analysis

Background

To evaluate whether oral lichen planus (OLP) is a risk factor for peri-implant diseases (PIDs) with a systematic review and meta-analysis.

Methods

Five electronic databases including Medline, Embase, Web of Science, the Cochrane Library and Scopus were searched. The included studies are observational human studies written in English. The population of interest included those with/without OLP who received dental implant treatment. The follow-up time after implantation was from 1 month to 20 years. The quality of the included articles regarding risk of bias and methodology were assessed with the Newcastle-Ottawa Scale or the Agency for Healthcare Research and Quality. The data involving exposure (OLP), primary outcomes (implants having PIDs) and secondary outcomes (probing depth/PD, bleeding on probing/BOP and bone loss/BL) and potential confounders were extracted. Heterogeneity was assessed by I² test. Dichotomous data are expressed as the risk ratio (RR) and 95% confidence interval (CI) which were calculated with a fixed effect model.

Results

Of the 66 articles, two studies were enrolled and evaluated as high quality, which totally contained 68 participants receiving 222 (OLP vs. non-OLP, 112 vs. 110) implants with 12 to 120-month follow-up time. Proportions of implants with PIDs between OLP and non-OLP groups were as follows: 19.6% (22/112) vs. 22.7% (25/110) for PIM and 17.0% (19/112) vs. 10.9% (12/110) for PI. The meta-analysis revealed no recognizable difference in number of implants with PIDs (PI: RR = 1.49, 95% CI 0.77–2.90, P = 0.24; PIM:RR = 0.88, 95% CI 0.53–1.46, P = 0.61; PIDs: RR = 1.08, 95% CI 0.75–1.55, P = 0.68) or BOP (RR = 0.90, 95% CI: 0.70–1.15, P = 0.40) between OLP and non-OLP groups.

Conclusions

Available articles regarding the effects of OLP on PIDs remains very limited. Existing evidence does not support OLP as a suspected risk factor for PIDs. Large-scale prospective trials are required to validate the findings.