Surgical treatment of experimental peri-implantitis using mechanical and chemical decontamination procedures: A pre-clinical in vivo study

Peri-implantitis induction and resolution around zirconia versus titanium implants

BACKGROUND

This study compared titanium and zirconia implant ligature-induced peri-implant defect progression and response to regenerative surgical intervention.

METHODS

Eight tissue-level endosseous implants were placed in 6 mixed-breed foxhounds, with 2 zirconia and 2 titanium alternating in each hemimandible. Cotton ligatures were placed subgingivally for 16 weeks followed by 8 weeks of spontaneous progression. Standardized radiographs were captured every 2 weeks to evaluate the rate of bone loss. Regenerative surgery was performed utilizing water-jet decontamination, enamel matrix derivative, and locally harvested autogenous bone. After 16 weeks of healing, final radiographic bone levels as well as probing depths, recession, and clinical attachment levels were assessed.

RESULTS

All 48 implants integrated successfully. The final average post-ligature radiographic defects were 2.88 and 3.05 mm for titanium and zirconia implants, respectively. There was no significant difference between materials in the rate of radiographic bone loss (p = 0.09). Following regenerative surgery, the total average amount of radiographic bone gain was 1.41 and 1.20 mm for titanium and zirconia, respectively. The percentage of defect fill was 51.56% and 37.98% (p = 0.03) for titanium and zirconia, respectively. Inter-group differences were minimal for clinical parameters at the time of sacrifice including periodontal pocket depths (p = 0.81), recession (p = 0.98), or clinical attachment levels (p = 0.51).

CONCLUSIONS

No significant difference was found in the rate of peri-implant defect development between titanium and zirconia implants. Both materials gained significant radiographic bone following regenerative surgery with significantly greater defect percentage fill in titanium implants. The final clinical parameters were similar in both groups.

Development and applications of peri-implantitis mouse models

OBJECTIVE

Peri-implantitis is one of the most common complications of implants. However, its pathogenesis has not been clarified. In recent years, mouse models are gradually being used in the study of peri-implantitis. This review aims to summarize the methods used to induce peri-implantitis in mice and their current applications.

METHOD

Articles of peri-implantitis mouse models were collected. We analyzed the various methods of inducing peri-implantitis and their application in different areas.

RESULTS

Most researchers have induced peri-implantitis by silk ligatures. Some others have induced peri-implantitis by Pg gavage and LPS injection. Current applications of peri-implantitis mouse models are in the following areas: investigation of pathogenesis and exploration of new interventions, comparison of peri-implantitis with periodontitis, the interaction between systemic diseases and peri-implantitis, etc. CONCLUSION: Silk ligature for 2-4 weeks, Pg gavage for 6 weeks, and LPS injection for 6 weeks all successfully induced peri-implantitis in mice. Mice have the advantages of mature gene editing technology, low cost, and short time to induce peri-implantitis. It has applications in the study of pathogenesis, non-surgical treatments, and interactions with other diseases. However, compared with large animals, mice also have a number of disadvantages that limit their application.

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.

Bone formation in large/moderate gap after immediate implantation in response to different treatments: a pre-clinical study in the canine posterior mandible

OBJECTIVES

This study aims to investigate different treatments on new bone formation around immediate implants in the canine posterior mandible with varying sized mesial-distal gap.

MATERIALS AND METHODS

The 4th premolar and the 1st molar of six Labrador dogs were extracted from the mandible, and 4 dental implants were placed 1 mm below the level of the buccal bone crest. Moderate/large mesial-distal gaps between the implants and the sockets were treated with one of four methods and divided into the following groups: (1) the blank group, (2) the collagen membrane (CM) group, (3) the deproteinized bovine bone mineral (DBBM) group, and (4) the DBBM + CM group. Sequential fluorescent labeling was performed at 4, 8, and 10 weeks after the operation. After 12 weeks, the dogs were euthanized, and specimens were collected for micro-CT scanning and histological analysis.

RESULTS

The survival rate of immediate implant was 100%. Micro-CT showed significant differences in bone mineral density (BMD) and bone volume fraction (BVF) among groups (P = 0.040, P = 0.009); other indicators were not significantly different among groups. Histological analysis showed the proportion of new bone formation and bone-to-implant contact were not significantly different among groups. No significant difference in bone reduction height around dental implant among four groups and varied mesial-distal gap size.

CONCLUSION

Owing to the restricted sample size, this pilot study lacks conclusive findings. Within the limitation, this study demonstrated that although DBBM significantly increase BMD and BVF, the use of DBBM/CM didn't significantly improve bone formation and healing in extraction sockets around the implants in both moderate and large mesial-distal gap.

CLINICAL RELEVANCE

The use of deproteinized bovine bone in conjunction with collagen is a common practice in immediate implantation procedures in the posterior mandible. However, there is a lack of conclusive evidence regarding the timing and circumstances under which they should be employed.

Decontamination of biofilm-contaminated implant surfaces: An in vitro evaluation

OBJECTIVES

The aim of the present study was to evaluate the cleaning efficacy of two mechanical and two chemical protocols in the decontamination of implant surfaces.

METHODS

In total, 123 commercially available implants were mounted in plastic models mimicking peri-implant circumferential intra-bony defects. A multispecies biofilm was grown on implant surfaces. Mechanical (air-polishing (AP), rotating titanium brush (TiB)) and chemical decontamination (alkaline electrolyzed water, N-acetyl-L-cysteine) protocols were used. Cleaning efficacy in terms of residual biofilm area, chemical surface properties, and bacterial counts were analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and quantitative polymerase chain reaction.

RESULTS

Surface decontamination protocols including use of an AP device or a rotating TiB were superior in terms of biofilm removal and in reducing atomic% of Carbon on implant surfaces when compared to methods restricted to wiping with gauze. The use of chemical agents as adjuncts to the mechanical cleaning protocols provided no relevant overall benefit over saline. No treatment modality, however, resulted in complete biofilm removal.

CONCLUSION

Air-polishing and rotating TiB were more effective implant surface decontamination protocols than wiping with gauzes. Use of chemical agents did not improve cleaning efficacy.

The efficacy of implant surface decontamination using chemicals during surgical treatment of peri-implantitis: A systematic review and meta-analysis

AIM

To answer the following PICOS question: "In adult patients with peri-implantitis, what is the efficacy of surgical therapy with chemical surface decontamination of implant surfaces in comparison with surgical therapy alone or surgery with placebo decontamination, on probing pocket depth (PD) reduction and bleeding on probing (BoP)/suppuration on probing (SoP), in randomized controlled clinical trials (RCTs) and non-RCTs with at least 6 months of follow-up?"

MATERIALS AND METHODS

Six databases were searched from their inception up to 20 May 2022. Data on clinical outcome variables were pooled and analysed using mean differences (MDs), risk ratios (RRs), or risk differences (RDs) as appropriate, 95% confidence intervals (CIs), and prediction intervals (PIs) in the case of significant heterogeneity. Primary outcomes were determined as changes in PD and BoP/SoP. Secondary outcomes were radiographic marginal bone loss (MBL), implant loss, and disease resolution. PROSPERO registration number: CRD42022325603.

RESULTS

Six RCTs-two with moderate, three with high, and one with low risk of bias (RoB)-were included. These studies test the adjunctive effect of photodynamic therapy (PDT), chlorhexidine (CHX), and administration of local antibiotics (LAbs) during surgery on the clinical outcome. In a single 12-month study, the adjunctive use of local antibiotics showed a clinically relevant reduction of PD [MD = 1.44; 95%CI (0.40 to -2.48)] and MBL [MD = 1.21; 95%CI (0.44-1.98); one trial, 32 participants]. PDT showed a small but significant reduction in BoP [MD = 7.41%; 95%CI (0.81-14.00); p = 0.028; two trials; 42 participants]. Treatment with CHX resulted in no significant changes in PD, BoP, or MBL compared to placebo (saline solution). None of the interventions affected disease resolution and implant loss. Certainty of the evidence was very low for all outcome measures assessed.

CONCLUSIONS

Within the limitations of this systematic review and the meta-analysis, adjunctive use of chemicals such as PDT, CHX, and LAbs for surface decontamination during surgery of peri-implantitis cannot be recommended as superior to standard debridement procedures (mechanical debridement with or without saline).