Early crestal bone loss: Is it really loss?

Effects of bone type and occlusal loading pattern on bone remodeling in implant-supported single crown: A finite element study

PURPOSE

To assess the influence of bone types and loading patterns on the remodeling process over 12 months according to the variations in stress, strain, strain energy density (SED), and density allocation in the bone of implant-supported single crown.

MATERIALS AND METHODS

A three-dimensional finite element of a single crown implant was modeled in five different bone types (D1-D4, and grafted bone). A 200 N load was applied on an implant crown with three occlusal loading patterns (nonfunctional contact, functional contact at center, and at 2-mm offset loading). During the first 12 months after implant placement, the SED was employed as a mechanical stimulus to simulate cortical and cancellous bone remodeling.

RESULTS

Functional contact at 2-mm offset loading led to a higher bone remodeling rate and stress compared to functional contact at center and nonfunctional contact. Under 2-mm offset loading, the greatest remodeling rate after 12 months was achieved with D3 and D4, D2, grafted, and D1 cortical bone with an average peri-implant density of 1.95, 1.77, 1.56, and 1.50 g/cm3 , respectively. Meanwhile, the highest von Mises stresses were found in D4 (22.2 MPa) and D3 (21.9 MPa) bones.

CONCLUSIONS

A greater stress concentration and remodeling rate were found when an off-axial load was applied on an implant placed in low bone density. Although the fastest remodeling processes resulting in increased bone density and strength were found in D3 and D4 bone types with greater off-axial loading that may provide greater bone engagement, it could increase stress concentrations that are susceptible to inducing implant failure.

Analysis of risk factors for early crestal bone loss in osseointegrated, submerged implants prior to restoration

BACKGROUND

Evidence on the etiology behind bone loss around submerged, prosthetically nonloaded implants is still limited. The long-term stability and success of implants with early crestal bone loss (ECBL), especially when placed as two-stage implants, is uncertain. Hence, the aim of this retrospective study is to analyze the potential patient-level, tooth- and implant-related factors for ECBL around osseointegrated, submerged implants, before restoration as compared with healthy implants with no bone loss.

METHODS

Retrospective data were collected from patient electronic health records between 2015 and 2022. Control sites included healthy implants with no bone loss and test sites included implants with ECBL, both of which were submerged. Patient, tooth and implant level data were collected. ECBL was assessed using periapical radiographs obtained during implant placement and second-stage surgeries. Generalized estimating equation logistic regression models were used to account for multiple implants within patients.

RESULTS

The total number of implants included in the study was 200 from 120 patients. Lack of supportive periodontal therapy (SPT) was shown to have nearly five-times higher risk of developing ECBL and was statistically significant (p < 0.05). Guided bone regeneration (GBR) procedures before implant placement had a protective effect with an odds ratio of 0.29 (p < 0.05).

CONCLUSIONS

Lack of SPT was significantly associated with ECBL, while sites that received GBR procedures prior to implant placement were less likely to exhibit ECBL. Our results underscore the importance of periodontal treatment and SPT for peri-implant health, even when the implants are submerged and unrestored.

Peri-implant diseases diagnosis, prognosis and dental implant monitoring: a narrative review of novel strategies and clinical impact

BACKGROUND

The diagnosis of peri-implantar and periodontal relies mainly on a set of clinical measures and the evaluation of radiographic images. However, these clinical settings alone are not sufficient to determine, much less predict, periimplant bone loss or future implant failure. Early diagnosis of periimplant diseases and its rate of progress may be possible through biomarkers assessment. Once identified, biomarkers of peri-implant and periodontal tissue destruction may alert the clinicians before clinical signs show up. Therefore, it is important to consider developing chair-side diagnostic tests with specificity for a particular biomarker, indicating the current activity of the disease.

METHODS

A search strategy was created at Pubmed and Web of Science to answer the question: "How the molecular point-of-care tests currently available can help in the early detection of peri-implant diseases and throws light on improvements in point of care diagnostics devices?"

RESULTS

The PerioSafe® PRO DRS (dentognostics GmbH, Jena) and ImplantSafe® DR (dentognostics GmbH, Jena ORALyzer® test kits, already used clinically, can be a helpful adjunct tool in enhancing the diagnosis and prognosis of periodontal/peri-implantar diseases. With the advances of sensor technology, the biosensors can perform daily monitoring of dental implants or periodontal diseases, making contributions to personal healthcare and improve the current status quo of health management and human health.

CONCLUSIONS

Based on the findings, more emphasis is given to the role of biomarkers in diagnosing and monitoring periodontal and peri-implant diseases. By combining these strategies with traditional protocols, professionals could increase the accuracy of early detection of peri-implant and periodontal diseases, predicting disease progression, and monitoring of treatment outcomes.

Impact of Platform Switched Implants on Marginal Bone Level in Mandibular Overdentures: A Six-Year Follow-Up Longitudinal Study

PURPOSE

To evaluate the impact of the platform-switched implant on marginal bone loss (MBL) and the probing pocket depth (PPD) in patients wearing mandibular overdenture.

PATIENTS AND METHODS

This longitudinal study included 40 completely edentulous patients aged 51-64 years. All patients received complete dentures and were distributed into two groups randomly; 20 patients each. The first group GI received two platform switched implants; however, the 2nd group GII received two platform matched implants (3.6 × 11.5 mm) in the canine region of the mandible. The radiographic evaluations were carried out every year for six years, whereas probing pocket depth was evaluated every six months for 72 months for both groups. The data were analyzed by repeated ANOVA, Friedman's, and Student's t-test.

RESULTS

This study included 36 patients; 56 ± 3.6 years was the mean age; 17 females (47%) and 19 males (53%) completed the study. Statistically significant differences were observed in MBL and PPD in each of GI and GII after 6 years, p ≤ 0.05. Between GI and GII after 6 years, a statistically insignificant difference was detected in MBL or PPD, p ≥ 0.05, except in PPD at loading, 2 and 6 years, p ≤ 0.05.

CONCLUSION

Time positively affected MBL and PPD in platform switched and matched implants retained mandibular overdentures. Platform switching influences probing pocket depth in implants retained mandibular overdentures.

What Does Bone Corticalization around Dental Implants Mean in Light of Ten Years of Follow-Up?

The phenomenon of peri-implant bone corticalization after functional loading does not yet have a definite clinical significance and impact on prognosis. An attempt was made to assess the clinical significance of this phenomenon. This prospective study included 554 patients. Standardized intraoral radiographs documenting the jawbone environment of 1556 implants were collected. The follow-up period was 10 years of functional loading. Marginal alveolar bone loss (MBL) and radiographic bone structure (bone index, BI) were evaluated in relation to intraosseous implant design features and prosthetic work performed. After five years, bone structure abnormalities expressed by a reduction of BI to 0.47 ± 0.21 and MBL = 0.88 ± 1.27 mm were observed. Both values had an inverse relationship with each other (p < 0.0001). Reference cancellous bone showed BI = 0.85 ± 0.18. The same relationship was observed after ten years of functional loading: BI = 0.48 ± 0.21, MBL = 1.49 ± 1.94 mm, and again an inverse relationship (p < 0.0001). Increasing corticalization (lower BI) is strongly associated with increasing marginal bone loss and increasing corticalization precedes future marginal bone loss. Marginal bone loss will increase as corticalization progresses.

Restorative angle of zirconia restorations cemented on non-original titanium bases influences the initial marginal bone loss: 5-year results of a prospective cohort study

Aim

To assess radiographic, restorative, clinical and technical outcomes as well as patient satisfaction of directly veneered zirconia restorations cemented on non‐original titanium bases over 5 years.

Material and Methods

Twenty‐four patients with a single missing tooth in the aesthetic zone were recruited. All patients received a two‐piece implant with a screw‐retained veneered zirconia restoration cemented extraorally on a titanium base abutment. Marginal bone levels (MBL), marginal bone changes, technical complications, patient satisfaction and clinical parameters including probing depth, bleeding on probing and plaque index were assessed at crown delivery (baseline), at 1 year (FU‐1) and 5 years (FU‐5) of follow‐up. To investigate the relationship between restorative angle and MBL as well as marginal bone changes (bone loss/bone gain), correlation tests and linear regression models were carried out.

Results

Twenty‐two patients were available for re‐examination at 5 years. The mean MBL amounted to 0.54 ± 0.39 mm at baseline, and to 0.24 ± 0.35 at FU‐5 (=bone gain) (p < .001). At FU‐1, a positive correlation (r = .5) between the mesial restorative angle and mesial MBL was found (p = .012). Marginal bone changes between baseline and FU‐1 at mesial sites were also positively correlated with the mesial restorative angle (r = .5; p = .037). Linear and logistic regression models confirmed that mesial marginal bone loss was significantly associated with the mesial restorative angle at FU‐1 (p < .05). At 5 years, these significant associations at mesial sites disappeared (p > .05). At distal sites, no correlations or associations between the restorative angle and MBL or marginal bone changes were found regardless of the time point. During the 5‐year follow‐up, 5 technical complications occurred, mainly within the first year and mostly chippings. All patients were entirely satisfied with their implant‐supported restoration at 5 years.

Conclusion

Within the limitations of the present study, the restorative angle of implant‐supported crowns on non‐original titanium bases might influence the initial marginal bone loss but without affecting their favourable long‐term clinical performance. A restorative angle of <40° may limit the initial marginal bone loss at implant‐supported crowns with titanium bases.

Short vs. regular length implants to rehabilitate partially edentulous mandible: a 2-year prospective split-mouth clinical study

Many studies have evaluated short implants (SIs); however, it is still unclear whether SIs are reliable and can be used to simplify surgical and prosthetic protocols with successful clinical outcomes. The aim of this non-random, conveniently sampled, prospective, split-mouth study was to compare the clinical outcomes when short (SI) (≤8 mm) or regular-length implants (RIs) (>10 mm) were used in the posterior mandible two years after the delivery of splinted reconstructions. Each participant (N=10) received four implants in the posterior mandible; two SIs were placed on one side, and two RIs were placed contra-laterally. Implants were restored with splinted, screw-retained, porcelain-fused-to-metal reconstructions. Survival and success rates, peri-implant marginal bone level (MBL), and soft tissue parameters were evaluated. No participant drop-outs were recorded. Both types of implants showed 100% success and survival rates. From prosthetic delivery to 24 months post-loading, bone remineralization of +0.40 mm for the SIs and +0.36 mm for the RIs was observed without statistically significant differences in MBL between the implant types (p=0.993). SIs showed significantly higher (p=0.001) clinical attachment level (CAL) and probing depth (PD) values. Chipping occurred in one situation in the RI group resulting in a 97.5% prosthetic success rate, which was 100% for the SIs. After 2 years, SIs with splinted reconstructions showed comparable clinical outcomes to those of RIs. Further long-term controlled clinical studies with balanced experimental designs evaluating random and larger populations are required to corroborate these findings.