The adjunctive effect of a resorbable membrane to a xenogeneic bone replacement graft in the reconstructive surgical therapy of peri-implantitis: A randomized clinical trial

Soft-Tissue Phenotype as a Risk Indicator of Peri-Implantitis and Peri-Implant Soft-Tissue Dehiscence-A Cross-Sectional Study

AIM

To investigate the association, as well as to characterize the associated panel of pro- and anti-inflammatory markers, between the different components of the peri-implant phenotype and the presence of peri-implantitis/peri-implant soft-tissue dehiscence (PISTD).

MATERIALS AND METHODS

A total of 324 implants in 112 patients were included. The following components of the peri-implant phenotype were clinically measured through the use of a manual periodontal probe or a digital calliper: keratinized mucosa width (PIKM-W), mucosal thickness (MT), attached mucosa (AM) and vestibulum depth (VD). The presence of peri-implantitis and PISTD was assessed through clinical and radiographic examination. Mixed-models logistic regression analyses were performed to analyse the association between peri-implant phenotype and the presence of peri-implantitis or PISTD, adjusting for relevant confounders. Multiplex immunoassays were employed to evaluate the peri-implant crevicular fluid levels of a panel of pro- and anti-inflammatory markers.

RESULTS

Peri-implant health, peri-implant mucositis and peri-implantitis were diagnosed in 36.6%, 21.4% and 42% of the patients (classified according to their worst implant) and 35.2%, 34.3%, and 30.5% of the implants, respectively. In the multi-level multiple regression model, the absence of PIKM-W (odds ratio [OR] = 9.24; 95% CI: 2.73-31.28), the absence of attached mucosa (OR = 19.58; 95% CI: 6.12-62.56) and a reduced (<4 mm) vestibulum depth (OR = 2.61; 95% CI: 1.05-6.48) were associated with peri-implantitis. Similarly, the absence of PIKM-W (OR = 6.32; 95% CI: 1.67-23.83), a thin (<2 mm) mucosa (OR = 157.75; 95% CI: 14.06-1769.9) and a reduced vestibulum depth (OR = 3.32; 95% CI: 1.02-10.84) were associated with the presence of PISTD. Implants with PIKM-W = 0 mm showed statistically significantly higher levels of interferon-γ in both regular (≥2 maintenance/year) and irregular (<2 maintenance/year) compliers (p = 0.046 and p = 0.012). In irregular compliers, the absence of PIKM-W was also associated with statistically significantly higher levels of interleukin (IL)-1β and IL-21 (p = 0.016, p = 0.046). These associations were independent of the effect of relevant confounders (e.g., plaque, compliance with maintenance, etc.).

CONCLUSIONS

Within their limits, the present findings indicate that (a) peri-implant soft-tissue phenotype appears to be associated with the presence of peri-implantitis and PISTD, and (b) in the absence of PIKM-W, the inflammatory response seems to be dysregulated and the soft-tissue remodelling up-regulated.

Prediabetes and poorly controlled type-2 diabetes as risk indicators for peri-implant diseases:A systematic review and meta-analysis

OBJECTIVE

The study answers the PECO question: "In adults with dental implants (P), do subjects suffering from type-2 diabetes or prediabetes (E) have worse peri-implant conditions (O) than subjects without type-2 diabetes and prediabetes (C)?". Prediabetes (5.7-6.4 % HbA1c), and the different qualities of glycemic control in type-2 diabetes; well-controlled (>8 % HbA1c), and poorly controlled (>8 % HbA1c) individuals; were classified according to the recommendations of the American Diabetes Association.

DATA

Predefined search keys were used with search terms including: Dental implant, diabetes mellitus, glycemic control and HbA1c.

SOURCES

An electronic search in the MEDLINE, Embase, and Cochrane libraries were conducted without any filters or language restrictions. Additionally, manual search of the reference lists were carried out to identify all relevant articles.

STUDY SELECTION

Eligibility criteria were cohort, case-control and cross-sectional studies that answerd our PECO question with at least 1 year of follow-up. From a total of 2660 records, 35 articles (1761 individuals) were included in the analysis. Meta-analytic difference in means for crestal bone loss was 1.2 mm [95 % CI=0.4; 2.1] in patients with prediabetes, 1.8 mm [CI=1.0; 2.7] in poorly controlled patients, whereas 0.4 mm [CI=-0.3; 1.1] in well-controlled individuals. Meta-regression showed that 1 % increase in HbA1c increased crestal bone loss by 0.24 mm.

CONCLUSIONS

Within the limitations of the study, patients with poorly controlled type-2 diabetes or prediabetes may have worse peri-implant conditions compared to patients without diabetes and well-controlled type-2 diabetes. Well-controlled type-2 diabetes is not a risk indicator for peri-implant diseases.

CLINICAL SIGNIFICANCE

Clinicians should measure blood HbA1c levels when planning implant-supported restorations, thus patients with undiagnosed or poorly controlled type-2 diabetes can be identified, that allows for glycemic level adjustment prior to dental implant surgery, ensuring peri-implant health. PROTOCOL REGISTRATION NUMBER: (CRD42022375263).

Comparative effectiveness of interventions for the treatment of peri-implantitis: A systematic review with network meta-analysis

STATEMENT OF PROBLEM

Extensive research has been carried out on the various aspects of diagnosing and treating peri-implantitis. However, clinical guidelines for the management of peri-implantitis based on high quality evidence are lacking.

PURPOSE

The purpose of this systematic review with network meta-analysis was to analyze the current evidence on nonsurgical and surgical interventions for the treatment of peri-implantitis and synthesize clinical guidelines based on high quality evidence.

MATERIAL AND METHODS

A search was conducted for trials published in Medline, Scopus, PubMed, and Cochrane Central Register of Controlled Trials from inception until July 2023. The study was registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023451056). A network meta-analysis was performed on data from randomized controlled trials that assessed nonsurgical and surgical interventions for the treatment of peri-implantitis. The interventions were ranked according to their efficacy using surface under the cumulative ranking (SUCRA) system. The grading of recommendations, assessment, development, and evaluations (GRADE) approach was used to assess the level of certainty of evidence.

RESULTS

A total of 45 articles were included in the quantitative analysis. The GRADE approach determined a moderate to high level of certainty of evidence. Among the nonsurgical interventions, mechanical debridement with adjunctive systemic antibiotics was significant in improving probing depth at 3 months and beyond 6 months, clinical attachment loss at 3 months, and clinical attachment loss beyond 6 months. Mechanical debridement with adjunctive topical antibiotics was significant in improving probing depth beyond 6 months, clinical attachment loss at 3 months, clinical attachment loss beyond 6 months, and radiographic bone loss beyond 6 months. Mechanical debridement with adjunctive photodynamic therapy was significant in improving probing depth beyond 6 months, clinical attachment loss at 3 months, clinical attachment loss beyond 6 months, and radiographic bone loss beyond 6 months. Mechanical debridement with adjunctive systemic antibiotics and photodynamic therapy was significant in improving probing depth beyond 6 months. Among surgical interventions, open flap debridement with implant surface decontamination and open flap debridement with decontamination and adjunctive photodynamic therapy were significant in improving probing depth at 3 months.

CONCLUSIONS

Mechanical debridement with adjunctive systemic antibiotics or photodynamic therapy results in improved clinical outcomes.

Long-term outcomes and prognostic factors of surgical treatment of peri-implantitis - A retrospective study

AIM

To evaluate long-term outcomes and prognostic factors of non-reconstructive surgical treatment of peri-implantitis.

MATERIALS AND METHODS

One hundred forty-nine patients (267 implants) were surgically treated for peri-implantitis and followed for an average of 7.0 (SD: 3.6) years. The primary outcome was implant loss. Additional bone loss and surgical retreatment were secondary outcomes. Patient/implant characteristics, as well as clinical and radiographic parameters collected prior to initial surgery, were evaluated as potential predictors of implant loss. Flexible parametric survival models using restricted cubic spline functions were used; 5- and 10-year predicted rates of implant loss were calculated according to different scenarios.

RESULTS

Fifty-three implants (19.9%) in 35 patients (23.5%) were lost during the observation period. Implant loss occurred after a mean period of 4.4 (SD: 3.0) years and was predicted by implant surface characteristics (modified surface; HR 4.5), implant length (HR 0.8 by mm), suppuration at baseline (HR 2.7) and disease severity (baseline bone loss: HR 1.2 by mm). Estimates of 5- and 10-year implant loss ranged from 1% (best prognostic scenario; initial bone loss <40% of implant length, turned implant surface and absence of suppuration on probing (SoP)) to 63% (worst prognostic scenario; initial bone loss ≥60% of implant length, modified implant surface and SoP) and from 3% to 89%, respectively. Surgical retreatment was performed at 65 implants (24.3%) in 36 patients (24.2%) after a mean time period of 4.5 (3.1) years. In all, 59.5% of implants showed additional bone loss, were surgically retreated or lost.

CONCLUSIONS

Recurrence of disease is common following surgical treatment of peri-implantitis. The strongest predictor for implant loss was implant surface characteristics. Implant length as well as suppuration and disease severity at baseline were also relevant factors.

Etiology, pathogenesis and treatment of peri-implantitis: A European perspective

Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants. It is characterized by inflammation in the peri-implant mucosa and progressive loss of supporting bone. Over the last 30 years, peri-implantitis has become a major disease burden in dentistry. An understanding of the diagnosis, etiology and pathogenesis, epidemiology, and treatment of peri-implantitis must be a central component in undergraduate and postgraduate training programs in dentistry. In view of the strong role of European research in periodontology and implant dentistry, the focus of this review was to address peri-implantitis from a European perspective. One component of the work was to summarize new and reliable data on patients with dental implants to underpin the relevance of peri-implantitis from a population perspective. The nature of the peri-implantitis lesion was evaluated through results presented in preclinical models and evaluations of human biopsy material together with an appraisal of the microbiological characteristics. An overview of strategies and outcomes presented in clinical studies on nonsurgical and surgical treatment of peri-implantitis is discussed with a particular focus on end points of therapy and recommendations presented in the S3 level Clinical Practice Guideline for the prevention and treatment of peri-implant diseases.

Selecting biomaterials in the reconstructive therapy of peri-implantitis

Peri-implantitis is a pathogenic inflammatory condition characterized by progressive bone loss and clinical inflammation that may compromise the stability of dental implants. Therapeutic modalities have been advocated to arrest the disorder and to establish peri-implant health. Reconstructive therapy is indicated for bone defects exhibiting contained/angular components. This therapeutic modality is based upon the application of the biological and technical principles of periodontal regeneration. Nonetheless, the comparative efficacy of reconstructive therapy and nonreconstructive modalities remains unclear. Therefore, the aim of this narrative review is to address major clinical concerns regarding the efficacy, effectiveness, and feasibility of using biomaterials in peri-implantitis therapy. In particular, the use of bone grafting materials, barrier membranes, and biologics is comprehensively explored.

Effect of functionalized titanium particles with dexamethasone-loaded nanospheres on macrophage polarization and activity

OBJECTIVE

The aim of this study was to determine the effect of titanium micro particles (TiP) previously functionalized with nanoparticles doped with dexamethasone (Dex) and doxycycline (Dox), on macrophage polarization and activity.

METHODS

Macrophages RAW264.7 were cultured in the presence TiP loaded with dexamethasone -NPs (Dex)- and doxycycline -NPs (Dox)-, and as control, TiP with or without doped NPs. Cells were tested with and without previous bacterial lipopolysaccharide endotoxin (LPS) stimulation. Their morphology, proliferation, cytotoxicity, phenotypic change, and cytokines release were assessed by LIVE/DEAD, DNA release, metabolic activity, brightfield and scanning electron microscopy. The test Kruskall-Wallis was used for comparisons, while the cytokine expression profiles were examined by hierarchical clustering (p < 0.05).

RESULTS

Upon exposure with TiP macrophages were activated and polarized to M1, but without depicting cytotoxic effects. The particles were phagocytised, and vacuolized. When exposed to functionalised TiP with NPs(Dex) and NPs(Dox), the ratio M1/M2 was up to forty times lower compared to TiP alone. When exposed to LPS, TiP reduced cell viability in half. Functionalised TiP with NPs(Dex) inhibited the cytokine release exerted by TiP on macrophages. When macrophages were exposed to functionalised TiPs with NPs(Dex) with and without LPS, the effect of TiP on cytokine secretion was inhibited.

SIGNIFICANCE

Functionalised TiPs with NPs(Dex) and NPs(Dox) may potentially have beneficial effects on modulating titanium and LPS-related inflammatory reactions.

Microbiota associated with peri-implantitis-A systematic review with meta-analyses

AIM

To answer the following PECO question: "In systemically healthy human subjects (P), which are the differences between peri-implantitis (E) and peri-implant health/mucositis (C) in terms of bacterial presence/count (O)?"

MATERIALS AND METHODS

Cross-sectional studies fulfilling specific inclusion criteria established to answer the PECO question were included. Two review authors independently searched for studies, screened the titles and abstracts, did full-text analysis, extracted the data from the included reports, and performed the risk of bias assessment through an adaptation of the Newcastle/Ottawa tool for cross-sectional studies and of the JBI critical appraisal checklist. In case of disagreement, a third reviewer author took the final decision. Study results were summarized using random effects meta-analyses.

RESULTS

A total of 12 studies were included, involving 1233 participants and 1513 implants. Peri-implantitis was associated with the presence of S. epidermidis (Odds ratio, OR = 10.28 [95% Confidence interval, CI: 1.26-83.98]), F. nucleatum (OR = 7.83 [95% CI: 2.24-27.36]), T. denticola (OR = 6.11 [95% CI: 2.72-13.76]), T. forsythia (OR = 4.25 [95% CI: 1.71-10.57]), P. intermedia (OR = 3.79 [95% CI: 1.07-13.35]), and P. gingivalis (OR = 2.46 [95% CI: 1.21-5.00]). Conversely, the presence of A. actinomycetemcomitans (OR = 3.82 [95% CI: 0.59-24.68]), S. aureus (OR = 1.05 [95% CI: 0.06-17.08]), and C. rectus (OR = 1.48 [95% CI: 0.69-3.17]) was not associated with peri-implantitis.

CONCLUSIONS

Peri-implantitis is associated with the presence of S. epidermidis and specific periodontopathogens (P. gingivalis, T. forsythia, T. denticola, F. nucleatum, and P. intermedia). (CRD42021254589).

Clinical efficacy of guided bone regeneration in peri-implantitis defects. A network meta-analysis

Guided bone regeneration (GBR) at peri-implantitis-related bone defects involves the placement of bone-filler particles in the intrabony defects and the application of a barrier membrane. The efficacy of different GBR-supported reconstructive measures as well as their potential superiority compared to non-GBR-supported treatment strategies for bone defects at peri-implantitis sites, however, remains unclear. Therefore, this analysis was designed to evaluate the long-term (≥12 months) clinical efficacy of GBR-supported reconstructive surgical therapy for peri-implantitis-related bone defects. In terms of resolving inflammation, the implementation of GBR protocols applying xenogenic bone substitutes yielded a higher reduction of bleeding on probing and probing depth value compared to the GBR protocol applying autogenous bone. Furthermore, for the changes in bleeding on probing and probing depths, GBR approaches using xenogenic bone showed superiority over the non-GBR treatments. Xenogenic bone with or without a barrier membrane was associated with improved radiographic bone levels and less soft tissue recession compared to the use of a GBR protocol implementing autogenous bone. Nonetheless, when interpreting this findings, the limited number of available studies with low to serious risk of bias and the short follow-up periods limited to 12 months should be considered.

Surgical peri-implantitis treatment with and without guided bone regeneration. A randomized controlled trial

OBJECTIVE

To evaluate the efficacy of reconstructive peri-implantitis treatment.

MATERIALS AND METHODS

Forty participants, with peri-implantitis and a contained intraosseous defect, were randomized to access flap (control) or access flap with xenograft and collagen membrane (test). All received systemic antimicrobials. Blinded examiners recorded probing depths (PD), bleeding and suppuration on probing (BOP & SOP), soft tissue levels, and marginal bone levels (MBL) at baseline and 12 months. Patient reported outcomes were recorded. The primary outcome was PD change.

RESULTS

All 40 participants (40 implants) completed the 12-month study. The mean (standard deviation) PD reduction (deepest site) was 4.2 (1.8) mm in the control and 3.7 (1.9) mm in the test group. MBL gain (deepest site) was 1.7 (1.6) mm in the control and 2.4 (1.4) mm in the test group. Absence of BOP & SOP was observed at 60% of both control and test implants. Buccal recession was 0.9 (1.6) mm in the control and 0.4 (1.1) mm in the test group. A successful outcome (absence of PD ≥ 5 mm with BOP, absence of SOP and absence of progressive bone loss) was achieved for 90% of the control and 85% of test group implants. No statistically significant differences in clinical or radiographic parameters were found between treatment groups. 30% of participants experienced mild gastro-intestinal disturbances. Reporting followed CONSORT guidelines.

CONCLUSION

Similar clinical and radiographic improvements at 12 months were observed with high levels of patient satisfaction for both the access flap and xenograft covered by collagen membrane groups. Registered clinical trials.gov. ID:NCT03163602 (23/05/2017).