Therapy of peri-implantitis with resective surgery. A 3-year clinical trial on rough screw-shaped oral implants. Part II: radiographic outcome

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.

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.

Effectiveness of mechanical and chemical decontamination methods for the treatment of dental implant surfaces affected by peri-implantitis: A systematic review and meta-analysis

OBJECTIVE

To assess which decontamination method(s) used for the debridement of titanium surfaces (disks and dental implants) contaminated with bacterial, most efficiently eliminate bacterial biofilms.

MATERIAL AND METHODS

A systematic search was conducted in four electronic databases between January 1, 2010 and October 31, 2022. The search strategy followed the PICOS format and included only in vitro studies completed on either dental implant or titanium disk samples. The assessed outcome variable consisted of the most effective method(s)-chemical or mechanical- removing bacterial biofilm from titanium surfaces. A meta-analysis was conducted, and data was summarized through single- and multi-level random effects model (p < .05).

RESULTS

The initial search resulted in 5260 articles after the removal of duplicates. After assessment by title, abstract, and full-text review, a total of 13 articles met the inclusion criteria for this review. Different decontamination methods were assessed, including both mechanical and chemical, with the most common method across studies being chlorhexidine (CHX). Significant heterogeneity was noted across the included studies. The meta-analyses only identified a significant difference in biofilm reduction when CHX treatment was compared against PBS. The remaining comparisons did not identify significant differences between the various decontamination methods.

CONCLUSIONS

The present results do not demonstrate that one method of decontamination is superior in eliminating bacterial biofilm from titanium disk and implant surfaces.

Diagnosis and Treatment of Periimplant Mucositis and Periimplantitis: An Overview and Related Controversial Issues

Periimplant mucositis and periimplantitis are common complications of dental implant. This article provides a comprehensive overview of the 2017 World Workshop's new definition, clinical and radiographic presentation, pathogenesis, risk factors, and classification of periimplant diseases. Also, the authors discuss various types of instruments, materials, and techniques commonly used for treatment of nonsurgical and surgical periimplantitis. Lastly, the authors include some controversial topics surrounding this subject.

In vitro evaluation of different protective techniques to reduce titanium particle contamination during implantoplasty

OBJECTIVES

Our aim is to study titanium remains in a bone model during standardized implantoplasty under different isolation and protective modalities.

MATERIAL AND METHODS

Forty implants were placed in artificial spongy bone blocks mimicking a horizontal bone loss and implant neck protrusion of 5 mm. Samples were randomly divided into four groups (n = 10), which were treated as follows: rubber dam (A), a dental adhesive paste (B), bone wax (C), and an unprotected positive control (D). Implantoplasty was performed using carbide and diamond burs under strict water cooling and standardized suction. After removal of the respective isolation materials, the bone blocks were thoroughly rinsed with tap water for 3 min and titanium chips were collected using a filter integrated in the model. The filter paper was removed and dissolved in 37% hydrochloric acid for 2 h at 120 °C and the titanium remnants were quantified using atomic absorption spectrometry.

RESULTS

None of the test groups were able to completely prevent titanium particle contamination. Rubber dam (691 ± 249 µg) and bone wax (516 ± 157 µg) were found to be significantly more protective than the positive control (2313 ± 747 µg) (p < 0.001) with respect to the amount of titanium particles that remained in the bone model after implantoplasty. The adhesive paste group (1863.5 ± 538 µg) was not significantly different from the positive control (p = 0.19).

CONCLUSIONS

Despite some limitations of the present study, titanium particles resulting from a standardized implantoplasty can be assumed to be significantly reduced when the tissues/bone were protected with rubber dam and bone wax, or a combination, depending on individual accessibility.

CLINICAL RELEVANCE

Tissue protective measures to reduce or avoid particle contamination during implantoplasty is possible and should be considered and further clinically assessed to avoid iatrogenic inflammatory reactions.

Non-surgical treatment of peri-implantitis with and without erythritol air-polishing a 12-month randomized controlled trial

BACKGROUND

A variety of interventions have been explored in the non-surgical management of peri-implantitis. In spite of extensive testing of various study protocols, effective treatments largely remain unavailable. The objective of the present 12-month single-centre, examiner-masked, randomized controlled clinical trial was to explore whether a low-abrasive erythritol air-polishing system produces added clinical benefit when used adjunctive to conventional non-surgical management of peri-implantitis and to record any associated patient-centered outcomes.

METHODS

Forty-three patients with mild to severe peri-implantitis including at least one implant either received ultrasonic/curette subgingival instrumentation and erythritol air-polishing (test) or ultrasonic/curette instrumentation only (control) at baseline and at 3, 6, 9, and 12 months. Probing depth (PD), bleeding on probing (BoP), dental plaque, suppuration (SUP), crestal bone level (CBL), and peri-implant crevicular fluid (PCF) were recorded at baseline, 6 and 12 months. Visual Analogue Scale (VAS) scores were collected immediately following subgingival interventions at all time-points.

RESULTS

A reduction in PD was observed from baseline to 6 months for the test (p = 0.006) and control (p < 0.001) and from baseline to 12 months for the control (p < 0.001). No intergroup differences were observed for primary outcome variables PD or CBL over time (p > 0.05). At 6 months, a intergroup difference in PCF was observed in favor of the test (p = 0.042). Moreover, a reduction in SUP from baseline to 6 and 12 months was observed in the test (p = 0.019). Overall, patients in the control group experienced less pain/discomfort compared with the test (p < 0.05), females reporting more pain/discomfort than males (p = 0.005).

CONCLUSIONS

This study confirms that conventional non-surgical management of peri-implantitis produces limited clinical improvement. It is shown that an erythritol air-polishing system may not produce added clinical benefits when used adjunctive to conventional non-surgical management. In other words, neither approach effectively resolved peri-implantitis. Moreover, the erythritol air-polishing system produced added pain/discomfort particularly in female patients.

TRIAL REGISTRATION

The clinical trial was prospectively registered in ClinicalTrials.gov with registration NCT04152668 (05/11/2019).

Current Status of Peri-Implant Diseases: A Clinical Review for Evidence-Based Decision Making

BACKGROUND

the prevalence of peri-implant diseases is constantly growing, particularly with the increasing use of dental implants. As such, achieving healthy peri-implant tissues has become a key challenge in implant dentistry since it considers the optimal success paradigm. This narrative review aims to highlight the current concepts regarding the disease and summarize the available evidence on treatment approaches clarifying their indications for usage following the World Workshop on the Classification of Periodontal and Peri-implant Diseases (2017).

METHODS

we reviewed the recent literature and conducted a narrative synthesis of the available evidence on peri-implant diseases.

RESULTS

scientific evidence on case definitions, epidemiology, risk factors, microbiological profile, prevention, and treatment approaches for peri-implant diseases were summarized and reported.

CONCLUSIONS

although there are numerous protocols for managing peri-implant diseases, they are diverse and nonstandardized, with no consensus on the most effective, leading to treatment confusion.

A Systematic Review and Meta-Analysis of the Clinical Outcomes for Adjunctive Physical, Chemical, and Biological Treatment of Dental Implants With Peri-Implantitis

The present systematic review evaluated the efficacy of adjunctive therapies in the treatment of peri-implantitis. Studies comparing the outcome of conventional surgical- or nonsurgical mechanical debridement with the addition of an adjunctive therapeutic modality were identified through an electronic and hand search of available literature. Following data extraction, meta-analyses were performed on the primary outcome measures. The effects of the adjunctive therapies on bleeding on probing (13 studies), probing pocket depth (9 studies), and radiographic bone level changes (7 studies) were analyzed to evaluate potential clinical benefit. Heterogeneity was expressed as the I2 index. Fixed and random effect models were demonstrated. The potential benefit of adjunctive therapies over control procedures was evaluated in 18 studies, representing a total of 773 implants. Quality assessment of the studies found only 3 studies to be at a low risk of bias. Meta-analysis among the different additional modalities revealed chemical therapy demonstrating significant effects in probing pocket depth reduction (0.58 mm; 0.44-0.72) and radiographic bone level gain (0.54 mm; 0.16-0.92). No significant improvements in bleeding on probing reduction were found using any adjunctive therapy. Available evidence on the benefits of adjunctive therapy to nonsurgical or surgical mechanical debridement in the treatment of peri-implantitis is limited by low numbers of standardized, controlled studies for individual therapies, heterogeneity between studies, and a variety of outcome measures. The lack of effect of any adjunctive therapy in reducing bleeding on probing questions the overall effectiveness over conventional treatment. The long-term clinical benefit potential of these therapies is not demonstrated.

Effect of Implantoplasty on Roughness, Fatigue and Corrosion Behavior of Narrow Diameter Dental Implants

Implantoplasty (IP) is used in dental implants with peri-implantitis and aims to remove threads and polish rough surfaces in order to prevent bacterial colonization. As a result of this procedure, implant strength might be compromised. We tested 20 tapered screw-shaped Ti6Al4V dental implants with a simulated bone loss of 50%. Ten implants underwent IP and 10 served as controls. Surface topography (S_a, S_z, S_sk, and S_dr) was analyzed with a confocal optical microscope. Subsequently, a minimum of four series of cyclic loads were applied with a servo-hydraulic mechanical testing machine (5 × 10⁶ cycles at 15 Hz, between a maximal nominal value-starting at 529 N in the IP group and 735 N in the control group-and 10% of that force). We recorded the number of cycles until failure and the type of failure. Implant failure was analyzed by visual inspection and scanning electron microscopy. Open circuit potential and potenctiodynamic tests were carried out with high precision potentiostat using Hank's solution at 37 °C to evaluate the effect of the implantoplasty on the corrosion resistance. Implantoplasty significantly reduced the surface topography values (median) and interquartile range (IQR); S_a from 1.76 (IQR = 0.11) to 0.49 (IQR = 0.16), S_z from 20.98 (IQR = 8.14) to 8.19 (IQR = 4.16), S_sk from 0.01 (IQR = 0.34) to -0.74 (IQR = 0.53) and S_dr from 18.20 (IQR = 2.26) to 2.67 (IQR = 0.87). The fatigue limits of the control and implantoplasty groups were 551 N and 529 N, respectively. The scanning electron micrographs showed fatigue striations indicating fatigue failure. Besides, the fractographic analysis revealed a typical brittle intergranular fracture mechanism. The infinite life range of the dental implants evaluated was largely above the threshold of usual chewing forces. Implantoplasty seems to render a fairly smooth surface and has a limited impact on fatigue resistance. In addition, implantoplasty produces a decrease in the corrosion resistance of the implant. Corrosion current density from 0.019 μA/cm² for as-received to 0.069 μA/cm² in the interface smooth-roughened dental implant. These places between the machining and the rough area of the implant are the most susceptible, with the appearance of pitting.

Application of Tissue Engineering in Manufacturing Absorbable Membranes to Improve the Osteopromoting Potential of Collagen

The membranes are an important biomaterial that contribute to osteopromotion. This study aimed to evaluate the osteopromotive potential of collagen membranes associated with Hydroxyapatite (HA) in critical size calvaria rat's defects. Ninety-six Albinus Wistar rats were divided into four groups: (CG) negative control: clot only (CG); positive control: porcine collagen membrane (BG); fish collagen membrane associated with HA (CP); bovine collagen membrane associated with HA (CB), analyzed at 7, 15, 30, and 60 postoperative days. At 30 days, membrane integrity was observed in the CB and fragments in the CP and BG groups were dispersed in the center of the defect. At 60 days, BG demonstrated better results with no statistical difference for the CP group (p = 0.199) and a statistically significant difference for the CB group (p = 0.013). The inflammatory profiles of the BG and CP groups were similar. Immunohistochemistry demonstrated at 60 days moderate osteopontin staining for the BG and CP groups, light staining for the CB, and intense osteocalcin staining for the BG, while the CB and CP groups demonstrated moderate staining. Microtomography revealed the highest mean bone volume (14.247 mm³) in the BG, followed by the CB (11.850 mm³), and CP (9.560 mm³) group. The collagen membranes associated with HA demonstrated an osteopromotive potential.

Investigation of Topographical Alterations in Titanium-Zirconium-Alloy Implant Threads following Er:YAG Irradiation

The aim of the current experimental study was to comparatively assess the surface alterations in titanium and titanium-zirconium alloy implants in terms of thread pitch topography after irradiation with an Er:YAG laser, which is recommended in the literature for its sterilizing effect in the treatment of contaminated implant surfaces. Roxolid^® and SLA^® (Sand-blasted, Large-grit, Acid-etched) implants from Straumann^® company with the same macro topography were investigated. The surface treatment was carried out using a wavelength of 2940 nm, 60 s irradiation time, a frequency of 10 Hz, and energies between 120 mJ and 250 mJ. The alterations were quantitatively analyzed by conducting roughness analysis via white light interferometry and qualitatively using SEM images. Roxolid^® could particularly maintain its surface topography at a level of 160 mJ. At an energy level of 250 mJ, the surface properties of the pitch could be significantly altered for the first time. Compared to the Standard Plus dental implants studied, no distinct removal of the material from the surface was detected. The alloy properties of Roxolid^® confirm the manufacturer's statement in terms of stability and could offer advantages in peri-implantitis management if decontamination has been selected. However, as a part of a respective strategy, smoothening of a Roxolid^® implant surface requires a significantly higher energy level compared to SLA-Standard^® dental implants.

Preventing Peri-implantitis: The Quest for a Next Generation of Titanium Dental Implants

Titanium and its alloys are frequently the biomaterial of choice for dental implant applications. Although titanium dental implants have been utilized for decades, there are yet unresolved issues pertaining to implant failure. Dental implant failure can arise either through wear and fatigue of the implant itself or peri-implant disease and subsequent host inflammation. In the present report, we provide a comprehensive review of titanium and its alloys in the context of dental implant material, and how surface properties influence the rate of bacterial colonization and peri-implant disease. Details are provided on the various periodontal pathogens implicated in peri-implantitis, their adhesive behavior, and how this relationship is governed by the implant surface properties. Issues of osteointegration and immunomodulation are also discussed in relation to titanium dental implants. Some impediments in the commercial translation for a novel titanium-based dental implant from "bench to bedside" are discussed. Numerous in vitro studies on novel materials, processing techniques, and methodologies performed on dental implants have been highlighted. The present report review that comprehensively compares the in vitro, in vivo, and clinical studies of titanium and its alloys for dental implants.

Strength of titanium-zirconium alloy implants with a conical connection after implantoplasty

STATEMENT OF PROBLEM

Peri-implantitis occurs around dental implants, and implantoplasty has been used to address this ongoing disease; however, the changes to the physical properties of an implant after implantoplasty have not been well documented.

PURPOSE

The purpose of this in vitro study was to determine the effect of implantoplasty on fracture strength and the load required for plastic deformation after cyclic fatigue on dental implants.

MATERIAL AND METHODS

Twenty-six titanium/zirconium (TiZr) alloy implants (Roxolid Bone Level Implant; 4.1×10 mm) were embedded with 50% thread exposure and divided into 4 groups based on whether they had implantoplasty treatment by using different diamond rotary instruments and/or cyclic loading at 250 N for 2 million cycles: C0 (control, no cyclic loading), T0 (test, no cyclic loading), CM (control, cyclic loading), and TM (test, cyclic loading). After implantoplasty and/or cyclic loading, all implants underwent a load-to-failure test. The maximum fracture strength (FS) and load required for the onset of plastic deformation (PD) were recorded in Newtons. One-way ANOVA and nonparametric comparisons with control by using the Dunn and Wilcoxon method for joint ranking were used for statistical analysis.

RESULTS

The mean ±standard deviation FS for C0, CM, T0, and TM was 1465.2 ±86.4 N, 1480.7 ±64.1 N, 1299.3 ±123.8 N, and 1252.1 ±85.7 N, respectively. The mean ±standard deviation load for onset of PD for C0, CM, T0, and TM was 860.2 ±88.1 N, 797.0 ±130.5 N, 776.5 ±181.8 N, and 631.3 ±84.5 N, respectively. The TM group had a significantly lower FS and PD than the C0, CM, and T0 groups (P<.05) CONCLUSIONS: Both fracture strength (FS) and the onset of plastic deformation (PD) were significantly reduced after a TiZr alloy implant received implantoplasty and cyclic loading.

Titanium implant surface roughness after different implantoplasty protocols: A laboratory study

OBJECTIVE

To compare the surface roughness of sandblasted, large grit, acid-etched (SLA) surfaced titanium discs, after implantoplasty (IP) with different combinations of rotating instruments without or with the subsequent use of a silicone polisher.

METHODS

Titanium discs (n = 12 per group) with an SLA surface were treated with the following IP protocols: (1) Tungsten carbide bur sequence from company 1 (Komet Dental) without or with polishing (P) with a silicone polisher (Brownie®), (2) tungsten carbide bur sequence from company 2 (Hager & Meisinger GmbH) without or with P, and (3) diamond bur sequence (125, 40, 15-μm grit) without or with P. Pristine turned (T) and SLA titanium discs were used as negative and positive controls, respectively. Surface roughness measurements were taken with a contact profilometer rendering R_a and R_z values.

RESULTS

All IP protocols, even without P, resulted in significantly reduced surface roughness compared to the SLA group. The tungsten carbide bur protocols, even without P, resulted in a surface roughness similar to or significantly lower than that in the T group in terms of R_a and R_z , respectively. IP with the diamond bur sequence resulted in a significantly rougher surface compared to that achieved with the carbide burs. In all IP groups, P with a silicone polisher resulted in a significantly smoother surface.

CONCLUSIONS

IP with dedicated tungsten carbide burs without or with the subsequent use of a silicone polisher resulted in a surface roughness similar to or significantly lower than that of commercially available turned surfaces. IP with a diamond bur sequence required additional polishing to achieve a comparable surface roughness to that of commercially available turned surfaces.

Fracture analysis of one/two-piece clinically failed zirconia dental implants

OBJECTIVES

Analyzing factors that may have led to fracture of zirconia implants by macro/micro-fractography.

METHODS

Six one-piece and ten two-piece full-ceramic zirconia implants from two manufacturers, Z-Systems and CeraRoot, were retrieved after clinical failure. The time-to-failure ranged from 3 to 49 months. Optical and scanning electron microscopy (SEM) were used to analyze the fracture planes at the macro- and microscopic level. Treatment planning, surgical protocol, fracture-origin location and characteristic fracture features were assessed.

RESULTS

The fracture of all implants seemed to have been primarily due to overload in bending mode, while the fracture-initiation sites varied for the one- and two-piece implants. The fracture of all one-piece implants originated in the constriction region between two threads in the endosseous implant part. For two-piece implants, the abutment neck, internal abutment-implant connections and inner threads were found to be the main fracture-initiation sites. Surface defects at the root area for one-piece implants and damages at the abutment surface for two-piece implants were connected to the fracture origins. Importantly, the clinical failures of implants were often found to result from combined effects related to patient aspects, treatment planning/protocols, a high bending moment at the weakest link, implant-surface conditions and specific implant designs.

SIGNIFICANCE

This study provided information to be considered for future optimization of treatment planning and the surgical protocol for zirconia implants. Optimization of the surface conditions and the zirconia-starting powder were also suggested.

Prognostic factors associated with implant loss, disease progression or favorable outcomes after peri-implantitis surgical therapy

BACKGROUND

The treatment of the peri-implantitis remains complex and challenging with no consensus on which is the best treatment approach.

PURPOSE

To examine the key local and systemic factors associated with implant loss, disease progression, or favorable outcomes after surgical peri-implantitis therapy.

MATERIALS AND METHODS

Records of patients treated for peri-implantitis were screened. Patient-, implant- and surgery-related variables on and prior to the day of the surgery were collected (T0: time of peri-implantitis treatment). If the treated implant was still in function when the data was collected, the patient invited to participate for a recall study visit (T1, longest follow-up after treatment). Impacts of the variables on the implant survival, success, and peri-implant bone change after treatment were investigated.

RESULTS

Eighty patients with 121 implants with a mean follow-up of 42.6 ± 26.3 months were included. A total of 22 implants (18.2%) were removed during the follow-up period. When relative bone loss (%) was in range 25%-50%, risk for implant removal increased 15 times compared to lower bone loss <25% (OR = 15.2; CI: 2.06-112.7; p = 0.008). Similarly, relative bone loss of >50% increased 20 times the risk of implant failure compared to the <25% (OR = 20.2; CI: 2.42-169.6; p = 0.006). For post-treatment success rate, history of periodontitis significantly increased the risk of unsuccess treatment (OR = 3.07; p = 0.04) after resective surgery).

CONCLUSION

Severe bone loss (>50%) poses significantly higher risk of treatment failure.

Implantoplasty- provoking or reducing inflammation? - a systematic scoping review

OBJECTIVES

To evaluate clinical parameters associated with inflammation after adjunctive implantoplasty in conjunction with surgical treatment of peri-implantitis.

MATERIALS AND METHODS

A systematic literature search was performed in 2 databases until 29. December 2020 to find publications that report on clinical parameters after surgical peri-implantitis treatment which included adjunctive implantoplasty. Clinical studies on implantoplasty reporting on BoP as outcome were included, but other clinical or radiographic outcomes were also considered.

RESULTS

The search resulted in 18 articles that fulfilled the inclusion criteria. The results indicated improvements of BoP and clinical parameters following surgical peri-implantitis treatment with adjunctive implantoplasty.

CONCLUSIONS

Within its limits, the findings of the present scoping review indicated that BoP is reduced following surgical peri-implantitis treatment with adjunctive implantoplasty, and that this improvement is in line with surgical peri-implantitis treatment without adjunctive implantoplasty.

Surgical therapy of peri-implantitis

Peri-implantitis is caused by a bacterial challenge; therefore, anti-infective treatment strategies should be employed to manage the disease. As nonsurgical approaches demonstrate limited efficacy in most cases of peri-implantitis, surgical interventions are often required. Treatment outcomes improve following access flap surgery, with or without adjunctive resective and/or augmentation measures. Whereas nonaugmentative therapies (ie, access flap surgery and resective techniques) primarily aim to resolve inflammation and arrest further disease progression, augmentation approaches also seek to regenerate the bony defect and achieve reosseointegration. Currently, limited evidence supports the superiority of augmentative surgical techniques for peri-implantitis treatment over nonaugmentation methods, and human histologic evidence for reosseointegration is sparse. For patients involved in regular postoperative maintenance programs, success of peri-implantitis surgical treatment based on various definitions of success was obtained in over half of the cases after 5-7 years. Despite surgical treatment, cases of further disease progression that required retreatment or led to implant loss were reported.

Esthetic complications in implant dentistry

Esthetic complications in implant dentistry have become a significant consideration for patients and practitioners. This review presents an appraisal on the current knowledge of the physiological peri-implant soft-tissue dimensions and factors that may compromise peri-implant tissue esthetics. Factors such as papilla fill adjacent to the implant and midfacial mucosal height are critical parameters that determine the esthetic success of implant-supported restorations. Papilla fill adjacent to a single dental implant appears to depend upon the clinical attachment level of the neighboring tooth. A horizontal inter-implant distance of at least 3 mm is necessary to ensure optimal interproximal mucosal embrasure between two adjacent implants in the anterior maxilla. In cases where implants cannot be placed at least 3 mm apart, a single implant with a cantilever bridge should be considered. Buccolingual implant positioning plays a major role in midfacial mucosal height. Soft-tissue volume grafting following immediate implant placement in the presence of a thin soft-tissue phenotype or simultaneous to surgical peri-implantitis therapy might help to overcome facial mucosa recession.

Implantoplasty Improves Clinical Parameters over a 2-Year Follow-Up: A Case Series

Background and Objectives: Peri-implantitis treatment is still undefined. Regenerative treatment is expensive and technically demanding due to the need to handle biomaterials, membranes and different methodologies of decontamination. Resective treatment and implantoplasty might be a viable solution. This case series presents a 24 month retrospective observational study of 10 peri-implantitis patients treated with implantoplasty. Materials and Methods: In the present case series, 10 peri-implantitis patients (20 implants) were treated with a resective approach and implantoplasty. Previous to implantoplasty, all patients underwent non-surgical treatment. This surgery consisted in a full-thickness flap and implant surface exposure. The exposed non-osseointegrated implant body was submitted to implantoplasty. The flap was apically repositioned and sutured. Patients were accompanied for 24 months. Results: The mean initial probing depth (PD) (PD = 5.37 ± 0.86 mm), bleeding on probing (BoP = 0.12 ± 0.06%) and suppuration (Sup = 0.01 ± 0.01%) decreased significantly at the 12 month evaluation (PD = 2.90 ± 0.39 mm; BoP = 0.01 ± 0.01% and Sup = 0.00 ± 0.00%). Between the 12 and 24 month evaluations, there were no significant clinical changes (PD = 2.85 ± 0.45 mm; BoP = 0.01 ± 0.01% and Sup = 0.00 ± 0.00%). Mucosal recession (MR) had a significant increase between the baseline and the first 12 months (0.69 ± 0.99 mm vs. 1.96 ± 1.33 mm), but there were no significant changes between the 12th and 24th month (1.94 ± 1.48 mm). The success rate was 100% without implant fracture or loss. Conclusions: Resective surgery and implantoplasty might be a valid option in some specific peri-implantitis cases. Properly designed clinical trials are needed to confirm this possibility.

Efficacy of alternative or adjunctive measures to conventional non-surgical and surgical treatment of peri-implant mucositis and peri-implantitis: a systematic review and meta-analysis

Purpose

To evaluate the efficacy of alternative or adjunctive measures to conventional non-surgical or surgical treatment of peri-implant mucositis and peri-implantitis.

Material and methods

Prospective randomized and nonrandomized controlled studies comparing alternative or adjunctive measures, and reporting on changes in bleeding scores (i.e., bleed0ing index (BI) or bleeding on probing (BOP)), probing depth (PD) values or suppuration (SUPP) were searched.

Results

Peri-implant mucositis: adjunctive use of local antiseptics lead to greater PD reduction (weighted mean difference (WMD) = − 0.23 mm; p = 0.03, respectively), whereas changes in BOP were comparable (WMD = − 5.30%; p = 0.29). Non-surgical treatment of peri-implantitis: alternative measures for biofilm removal and systemic antibiotics yielded higher BOP reduction (WMD = − 28.09%; p = 0.01 and WMD = − 17.35%; p = 0.01, respectively). Surgical non-reconstructive peri-implantitis treatment: WMD in PD amounted to − 1.11 mm favoring adjunctive implantoplasty (p = 0.02). Adjunctive reconstructive measures lead to significantly higher radiographic bone defect fill/reduction (WMD = 56.46%; p = 0.01 and WMD = − 1.47 mm; p = 0.01), PD (− 0.51 mm; p = 0.01) and lower soft-tissue recession (WMD = − 0.63 mm; p = 0.01), while changes in BOP were not significant (WMD = − 11.11%; p = 0.11).

Conclusions

Alternative and adjunctive measures provided no beneficial effect in resolving peri-implant mucositis, while alternative measures were superior in reducing BOP values following non-surgical treatment of peri-implantitis. Adjunctive reconstructive measures were beneficial regarding radiographic bone-defect fill/reduction, PD reduction and lower soft-tissue recession, although they did not improve the resolution of mucosal inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40729-021-00388-x.

Effect of implantoplasty on the elastic limit of dental implants of different diameters

BACKGROUND

Implantoplasty reduces both implant diameter and the thickness of its walls, subsequently reducing the ability of the implant to resist fracture in response to functional load. In combination with an increase in the crown-implant ratio due to bone loss, this could increase the lever effect, which in presence of high masticatory forces or parafunctional habits, could lead to complications such as fracture of the implant or loosening of the prosthetic screw.

OBJECTIVES

To determine the elastic limits of internal connection, dental implants of different designs and diameters after an implantoplasty.

MATERIALS AND METHODS

This in vitro study included 315 tapered internal connection titanium dental implants, the threads of which were removed with an industrial milling machine-for standardized implantoplasty (IMP1; n = 105)-or with the conventional approach-manually, using high-speed burs (IMP2; n = 105). The remaining 105 implants were used as controls. The final implant diameters were recorded. The quality of the newly polished surfaces was assessed by scanning electron microscopy. All implants were subjected to a mechanical pressure resistance test. A Tukey's test for multiple comparisons was used to detect differences in the elastic limit and final implant diameters between the implant groups.

RESULTS

There were statistically significant differences in the elastic limit between the IMP1, IMP2, and control groups (p < 0.05). Furthermore, the implant diameter was significantly smaller in the IMP1 and IMP2 groups (p < 0.05). Scanning electron microscopy revealed smooth implant surfaces in the IMP1 and IMP2 groups, with some titanium particles visible in the IMP1 group.

CONCLUSIONS

Implantoplasty significantly decreased the elastic limit of internal connection titanium dental implants, especially in those with a smaller diameter (3-3.5 mm).

Reduced fracture load of dental implants after implantoplasty with different instrumentation sequences. An in vitro study

OBJECTIVES

To assess the mechanical stability of implants after implantoplasty and thermocyclic loading, the residual thickness of the instrumented areas and neighbouring tooth injury due to implantoplasty.

MATERIALS AND METHODS

Using a phantom head simulator and maxillary model implants were subjected to an implantoplasty procedure. Thirty implants were randomly assigned to receive one of three instrumentation sequences. After instrumentation, injury on neighbouring teeth was assessed. Instrumented implants and non-instrumented controls were subjected to 1.2 million cycles of thermo-mechanical loading in a chewing machine. Afterwards, maximum fracture load for all implants and an additional five pristine control implants was tested.

RESULTS

Generally, damage of neighbour teeth was a frequent finding (33 ± 56% of all cases) with considerable inter-group differences. No considerable inter-group difference for the residual implant thickness was found for different areas assessed. No implant fractured during cyclic loading. Fracture load was reduced after cyclic loading of uninstrumented implants from 2,724 ± 70 N to 2,299 ± 127 N, and after implantoplasty to 1,737 ± 165 N, while no effect by the instrumentation sequence could be observed.

CONCLUSIONS

Both implantoplasty and cyclic loading were shown to reduce the implants' maximum bending strength. Cyclic loading in a laboratory masticator, simulating a five-year equivalent of chewing, did not result in fractured implants. Since neighbouring tooth injury was assessed often, care should be taken with the selection of suitable instruments.

Prevalence and risk indicators for peri-implant diseases: A literature review

Peri-implant diseases are known as undesirable conditions that can occur after implant therapy. Although several risk indicators are becoming clear, the causes of peri-implant diseases have not been completely investigated. The purpose of this review was to summarize the prevalence and risk indicators for peri-implant diseases by referring to current papers from various angles. Many studies have reported the varied prevalence of peri-implant mucositis (23.9%-88.0% at the patient level and 9.7%-81.0% at the implant level) and peri-implantitis (8.9%-45% at the patient level and 4.8%-23.0% at the implant level). Additionally, several studies concluded that poor oral hygiene and lack of regular maintenance were strongly correlated with the development of both peri-implant mucositis and peri-implantitis. Diabetes and a history of periodontitis were revealed as risk indicators for peri-implantitis. However, there was no definitive conclusion about the correlations between peri-implant diseases and other factors such as smoking, the shape of the implant superstructure, and the condition of the keratinized mucosa. Further studies useful for evidence-based decision-making are needed for predictable implant therapy in the long term.

Resolution of peri-implantitis by means of implantoplasty as adjunct to surgical therapy: A retrospective study

BACKGROUND

There is a paucity of data on the effectiveness of implantoplasty as adjunct to the surgical management of peri-implantitis.

PURPOSE

To evaluate the resolution of peri-implantitis by means of implantoplasty as adjunct to surgical resective (RES) and reconstructive (REC) therapies and supportive maintenance.

METHODS

Patients that underwent surgical therapy to manage peri-implantitis with a follow-up of ≥12 months and enrolled in a regular peri-implant supportive care were recruited. RES group consisted of two interventions that included osseous recontouring and apically position flap (APF) and soft tissue conditioning (STC). REC was performed in the infra-osseous compartment of combined defects. Implant survival rate was recorded. Clinical and radiographic parameters were evaluated to define a "dogmatic" (case definition #1) and a "flexible" (case definition #2) therapeutic success. Univariate and multivariate multilevel backward logistic regression were applied for statistical analysis.

RESULTS

Overall, 43 patients (n_implants  = 135) were retrospectively assessed. Mean observational period was ∼24 months. Implant survival rate was 97.8%, being significantly higher for APF, STC, and APF + STC (RES) when compared with REC (P = 0.01) therapy, in particular for advanced lesions (>50% of bone loss). The overall therapeutic success rate at implant-level was 66% and 79.5% for case definition #1 and #2, respectively. APF group displayed more efficient disease resolution when considered success definition #1 (72%). Contrarily, when the data were adhered to success definition #2, STC group showed a slightly higher disease resolution rate (87%). For RES group, location, favoring anterior (P = 0.04) and defect type, favoring class II (P = 0.02) displayed statistical significance for therapeutic success. For REC group, implants exhibiting a wider band of keratinized mucosa (KM) demonstrated higher therapeutic success (P = 0.008).

CONCLUSION

Implantoplasty as an adjunct to surgical therapy proved effective in terms of disease resolution and implant survival rate. Implant location, defect morphology as well as the buccal width of KM are indicators of therapeutic success.

A Mini Review on Non-augmentative Surgical Therapy of Peri-Implantitis—What Is Known and What Are the Future Challenges?

Non-augmentative surgical therapy of peri-implantitis is indicated for cases with primarily horizontal bone loss or wide defects with limited potential for bone regeneration and/or re-osseointegration. This treatment approach includes a variety of different techniques (e.g., open flap debridement, resection of peri-implant mucosa, apically positioned flaps, bone re-contouring, implantoplasty, etc.) and various relevant aspects should be considered during treatment planning. The present mini review provides an overview on what is known for the following components of non-augmentative surgical treatment of peri-implantitis and on potential future research challenges: (1) decontamination of the implant surface, (2) need of implantoplasty, (3) prescription of antibiotics, and (4) extent of resective measures.

Peri-Implantitis: A Clinical Update on Prevalence and Surgical Treatment Outcomes

Dental implants may be considered a reliable routine procedure in clinical practice for the replacement of missing teeth. Results from long-term studies indicate that implant-supported dental prostheses constitute a predictable treatment method for the management of fully and partially edentulous patients. Implants and their restorations, however, are not free from biological complications. In fact, peri-implantitis, defined as progressive bone loss associated to clinical inflammation, is not a rare finding nowadays. This constitutes a concern for clinicians and patients given the negative impact on the quality of life and the sequelae originated by peri-implantitis lesions. The purpose of this narrative review is to report on the prevalence of peri-implantitis and to overview the indications, contraindications, complexity, predictability and effectiveness of the different surgical therapeutic modalities to manage this disorder.

Assessment of soft and hard tissue dimensions following different treatment approaches of ligature-induced peri-implantitis defects

OBJECTIVES

To evaluate peri-implant tissue dimensions following nonsurgical (NS) and surgical therapy (S) employing different decontamination protocols of advanced ligature-induced peri-implantitis in dogs.

MATERIAL & METHODS

Peri-implantitis defects (n = 5 dogs, n = 30 implants) were randomly and equally allocated in a split-mouth design to NS or S treatment using either an Er:YAG laser (ERL), an ultrasonic device (VUS), or plastic curettes + local application of metronidazole gel (PCM), respectively. Horizontal bone thickness (hBT) and soft tissue thickness (hMT) were measured at different reference points: (v0) at the marginal portion of the peri-implant mucosa (PM); (v1) at 50% of the distance from PM to bone crest (BC); (v2) at the BC; (v3) at the most coronal extension of the bone-to-implant contact. Vertical peri-implant tissue height was calculated from PM to BC.

RESULTS

All of the treatment groups showed a gradual hMT increase from v0 to the v2 reference point, followed by a reduction from v2 to the v3 region. The S-VUS subgroup tended to be associated with higher hMT values at the v0 region than the NS-VUS subgroup (0.44 mm versus 0.31 mm). PM-BC distance varied from 2.22 to 2.83 mm in the NS group, and from 2.07 to 2.38 in the S group.

CONCLUSION

Vertical and horizontal peri-implant tissue dimensions were similar in different treatment groups.

Influence of Removing or Leaving the Prosthesis after Regenerative Surgery in Peri-Implant Defects: Retrospective Study: 32 Clinical Cases with 2 to 8 Years of Follow-Up

PURPOSE

The aim of this retrospective study was to compare the influence of removing or not removing a prosthesis after regenerative surgery on peri-implant defects.

METHODS

Two different groups were compared (Group 1: removing the prosthesis; Group 2: maintaining the prosthesis), analyzing radiographic bone filling (n = 32 implants) after regenerative treatment in periapical radiographs. The peri-implant defects were measured before and after regenerative treatment using Bio-Oss^® (Geistlich Pharma, Wohhusen, Switzerland) and a reabsorbable collagen membrane (Jason^®, Botis, Berlin, Germany), the healing period was two years after peri-implant regenerative surgery. Statistical analysis was performed, and a Chi square test was carried out. To determine the groups that made the difference, corrected standardized Haberman residuals were used, and previously a normality test had been applied; therefore, an ANOVA or Mann-Whitney U test was used for the crossover with the non-normal variables in Group 1 and Group 2.

RESULTS

The results obtained suggest that a regenerative procedure with xenograft, resorbable membrane, and detoxifying the implant surface with hydrogen peroxide form a reliable technique to achieve medium-term results, obtaining an average bone gain at a radiographic level of 2.84 mm (±1.78 mm) in patients whose prosthesis was not removed after peri-implant bone regenerative therapy and 2.18 mm (±1.41 mm) in patients whose prosthesis was removed during the healing period.

CONCLUSIONS

There are no statistically significant differences in the response to treatment when removing or keeping the prosthesis after regenerative surgery in peri-implant defects.

Assessment of peri-implant tissue dimensions following surgical therapy of advanced ligature-induced peri-implantitis defects

Background

To evaluate peri-implant tissue dimensions following implantoplasty and/or regenerative therapy of advanced ligature-induced peri-implantitis in dogs.

Material and methods

At all defect sites (n = 6 dogs, n = 48 implants), the intrabony component was filled with a particulate bovine-derived natural bone mineral (NBM). The supracrestal component was treated by either the application of an equine bone block (EB) or implantoplasty. In a split-mouth design, NBM and EB were soak-loaded with rhBMP-2 or sterile saline. All sites were covered using a native collagen membrane and left to heal in a submerged position for 12 weeks. The horizontal mucosal thickness (hMT) and bone thickness (hBT) were measured at four reference points: (v0) at the level of implant shoulder (IS), (v1) 50% of the distance IS-bone crest (BC), (v2) at the BC, and (v3) at the most coronal extension of the bone-to-implant contact.

Results

The general tendency indicated a gradual increase in hMT from the IS (v0) toward BC (v2), which was more pronounced at implant sites treated with the regenerative approach. The hBT values increased from v2 to v3, with the highest values at the v3 region measured for implant sites treated with adjunctive rhBMP-2. For sites treated with implantoplasty, the linear regression model demonstrated an inverse correlation between hMT and hBT, whereas a positive correlation was observed at those sites treated with the regenerative approach.

Conclusion

Horizontal soft and hard tissue dimensions were similar among different treatment groups.

Implantoplasty: Carbide burs vs diamond sonic tips. An in vitro study

OBJECTIVES

Implantoplasty (IP) is a treatment option for peri-implantitis. Mechanical concerns were raised on fracture resistance of implants subjected to this procedure. This study aimed to compare two methods of IP in terms of implant wear and fracture resistance, and of surface topography.

MATERIAL AND METHODS

Eighteen cylindrical screw-shaped dental implants (4 mm diameter, 13 mm length) with an external hexagonal connection were used. IP was performed on the first 6-mm implant surface with a sequence of burs or diamond sonic tips, both followed by an Arkansas finishing. IP duration and implant weight variation were recorded. Micro-computed tomography (micro-CT) was used to evaluate material loss. Implant fracture resistance was assessed by static compression test. Surface topography analysis was performed with a stylus profilometer. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) was applied for implant surface morphology and elemental characterization.

RESULTS

Micro-CT showed less material loss in sonic compared to burs. No statistically significant difference was found between the mean fracture resistance values reached in bur and sonic, both followed by Arkansas, and with respect to control. IP performed with burs led to a smoother surface compared to sonic. Equivalent final surface roughness was found after Arkansas in both IP procedures. SEM-EDS showed a deburring effect associated to sonic and revealed carbon and aluminum peaks attributable to contamination with sonic diamond tips and Arkansas bur, respectively.

CONCLUSIONS

IP with sonic diamond tips was found to be more conservative in terms of structure loss. This could have a clinical relevance in case of narrow-diameter implants.

Effect of crown to implant ratio and implantoplasty on the fracture resistance of narrow dental implants with marginal bone loss: an in vitro study

Background

Peri-implantitis is a biological complication that affects soft and hard tissues around dental implants. Implantoplasty (IP) polishes the exposed implant surface, to decontaminate it and make it less prone to bacterial colonization. This study investigates whether a higher clinical crown-to-implant-ratio (CIR) reduces implant fracture resistance and whether implants are more fracture-prone after IP in the presence of 50% of bone loss.

Methods

Forty-eight narrow platform (3.5 mm) 15 mm long titanium dental implants with a rough surface and hexagonal external connection were placed in standardized bone-like resin casts leaving 7.5 mm exposed. Half were selected for IP. The IP and control groups were each divided into 3 subgroups with different clinical CIRs (2:1, 2.5:1 and 3:1). The implant wall width measurements were calculated using the software ImageJ v.1.51 through the analysis of plain x-ray examination of all the samples using standardized mounts. A fracture test was performed and scanning electron microscopy was used to evaluate maximum compression force (F_max) and implant fractures.

Results

IP significantly reduced the implant wall width (P < 0.001) in all reference points of each subgroup. F_max was significantly higher in the 2:1 subgroup (control = 1276.16 N ± 169.75; IP = 1211.70 N ± 281.64) compared with the 2.5:1 (control = 815.22 N ± 185.58, P < 0.001; IP = 621.68 N ± 186.28, P < 0.001) and the 3:1 subgroup (control = 606.55 N ± 111.48, P < 0.001; IP = 465.95 N ± 68.57, P < 0.001). Only the 2.5:1 subgroup showed a significant reduction (P = 0.037) of the F_max between the controls and the IP implants. Most fractures were located in the platform area. Only 5 implants with IP of the 2:1 CIR subgroup had a different fracture location (4 fractures in the implant body and 1 in the prosthetic screw).

Conclusions

IP significantly reduces the fracture resistance of implants with a 2.5:1 CIR. The results also suggest that the CIR seems to be a more relevant variable when considering the resistance to fracture of implants, since significant reductions were observed when unfavorable CIR subgroups (2.5:1 and 3:1 CIR) were compared with the 2:1 CIR samples.

Effect of an Er,Cr:YSGG Laser on the Surface of Implants: A Descriptive Comparative Study of 3 Different Tips and Pulse Energies

Peri-implant diseases are one of the main complications of dental implants. There are no well-established guidelines regarding laser parameters for implant decontamination. The aim was to compare two different settings of irradiation of the Er,Cr:YSGG laser on dental implants regarding surface alterations and determine the best settings for less damage on the surface. An in vitro study was performed and 30 areas of dental implants were irradiated with two different regimes of energy per pulse 50 and 84 mJ (1.5 W/30 Hz and 2.5 W/30 Hz). A total of 30 sites of implants were irradiated with three different tips (10 surfaces per tip): conical (RTF3-17 mm), side firing (SFT8-18 mm) and cylindrical (MGG6-6 mm). The following descriptive classification on surface damage was employed: no damage (class A), minimal effects (class B), metal fall with melting (class C), and destruction with carbonization (class D). The assessment was made through a descriptive scanning electron microscope (SEM) analysis. Side firing and conical tips at 50 mJ were classified as class A. Side firing at 84 mJ and cylindrical tips 50 mJ and 84 mJ were classified as class B. Finally, class C defects were found in the areas where the conical tip was used at 84 mJ. Side firing and conical tips at 50 mJ do not seem to damage the implant surface.

Does implantoplasty affect the failure strength of narrow and regular diameter implants? A laboratory study

Objective

To assess whether the impact of implantoplasty (IP) on the maximum implant failure strength depends on implant type/design, diameter, or material.

Methods

Fourteen implants each of different type/design [bone (BL) and tissue level (TL)], diameter [narrow (3.3 mm) and regular (4.1 mm)], and material [titanium grade IV (Ti) and titanium-zirconium alloy (TiZr)] of one company were used. Half of the implants were subjected to IP in a computerized torn. All implants were subjected to dynamic loading prior to loading until failure to simulate regular mastication. Multiple linear regression analyses were performed with maximum implant failure strength as dependent variable and IP, implant type/design, diameter, and material as predictors.

Results

Implants subjected to IP and TL implants showed statistically significant reduced implant failure strength irrespective of the diameter compared with implants without IP and BL implants, respectively. Implant material had a significant impact for TL implants and for regular diameter implants, with TiZr being stronger than Ti. During dynamic loading, 1 narrow Ti TL implant without IP, 4 narrow Ti TL implants subjected to IP, and 1 narrow TiZr TL implant subjected to IP were fractured.

Conclusion

IP significantly reduced the maximum implant failure strength, irrespective implant type/design, diameter, or material, but the maximum implant failure strength of regular diameter implants and of narrow BL implants remained high.

Clinical Relevance

IP seems to have no clinically relevant impact on the majority of cases, except from those of single narrow Ti TL implants, which may have an increased risk for mechanical complications. This should be considered for peri-implantitis treatment planning (e.g., communication of potential complications to the patient), but also in the planning of implant installation (e.g., choosing TiZr instead of Ti for narrow implants).

Fracture resistance after implantoplasty in three implant-abutment connection designs

Background

To assess the effect of implantoplasty and implant-abutment design on the fracture resistance and macroscopic morphology of narrow-diameter (3.5 mm) dental implants.

Material and Methods

Screw-shaped titanium dental implants (n = 48) were studied in vitro. Three groups (n = 16) were established, based on implant-abutment connection type: external hexagon, internal hexagon and conical. Eight implants from each group were subjected to an implantoplasty procedure; the remaining 8 implants served as controls. Implant wall thickness was recorded. All samples were subjected to a static strength test.

Results

The mean wall thickness reductions varied between 106.46 and 153.75 µm. The mean fracture strengths for the control and test groups were, respectively, 1211.90±89.95 N and 873.11±92.37 N in the external hexagon implants; 918.41±97.19 N and 661.29±58.03 N in the internal hexagon implants; and 1058.67±114.05 N and 747.32±90.05 N in the conical connection implants. Implant wall thickness and fracture resistance (P < 0.001) showed a positive correlation. Fracture strength was influenced by both implantoplasty (P < 0.001) and connection type (P < 0.001).

Conclusions

Implantoplasty in diameter-reduced implants decreases implant wall thickness and fracture resistance, and varies depending on the implant-abutment connection. Internal hexagon and conical connection implants seem to be more prone to fracture after implantoplasty.

Key words:Dental implants, narrow diameter, implant connection, peri-implantitis, implantoplasty, fracture strength.

Lack of Clinical Benefit of Implantoplasty to Improve Implant Survival Rate

The objective of this study was to compare postsurgical outcomes of resective treatment for peri-implantitis with and without implant surface modification (implantoplasty [IP]). This was accomplished by a retrospective analysis with data from patients with ≥1 implant who were surgically treated for peri-implantitis by resective therapy. Patients were divided into 2 groups regarding treatment approach: IP (test) and no IP (control). Retrospective data were obtained after implant placement (T0) and the day of peri-implantitis surgical treatment (T1). Patients were then recalled (≥1 y after T1) for clinical and radiographic examination (T2). The findings were conclusive. A total of 41 patients (68 implants; mean ± SD follow-up, 41.6 ± 24.4 mo) were included in this study. The survival rate at the implant level was 90% in the test group and 81.6% in the control group ( P > 0.05). Multilevel regression analysis showed that the probability of implant failure was influenced by marginal bone loss (MBL) at T1 and not surgical modality. For example, peri-implantitis defects ≥50% and 25% to 50% MBL were 18.6 and 8.86 times more likely to lose the implant, respectively, when compared with <25% MBL. Nonetheless, MBL changes were similar in the test and control groups ( P = 0.592). Similarly, changes in bleeding on probing, probing pocket depth, and suppuration at T2 did not differ between groups ( P > 0.05). Multilevel regression analysis indicated that clinical improvement of these parameters was influenced by the number of supportive peri-implant therapy visits ( P < 0.01). The results demonstrate little difference between the procedures. Regardless of the implant surface modification (IP) being performed or not, the survival rate of implants treated for peri-implantitis was primarily influenced by the amount of bone loss at the time of treatment. Other clinical parameters (MBL, probing pocket depth, bleeding on probing, suppuration) were influenced by the frequency of supportive peri-implant therapy visits and not by the IP procedure (ClinicalTrials.gov NCT04259840).

Biofilm Formation on Dental Implant Surface Treated by Implantoplasty: An In Situ Study

Peri-implantitis is a biofilm-related disease whose characteristics are peri-implant tissues inflammation and bone resorption. Some clinical trials report beneficial effects after implantoplasty, namely the surgical smoothening of the implant surface, but there is a lack of data about the development of the bacterial biofilm on those smoothened surfaces. The aim of this study is to evaluate how implantoplasty influences biofilm formation. Three implants with moderately rough surfaces (control) and three implants treated with implantoplasty (test) were set on a tray reproducing the supra- and sub-gingival environment. One volunteer wore this tray for five days. Every 24 h, plaque coverage was measured and, at the end of the period of observartion, the implant surfaces were analyzed using scanning electron microscopy and confocal laser scanning microscopy. The proportion of implant surface covered with plaque was 65% (SD = 7.07) of the control implants and 16% (SD = 0) of the test implants. Untreated surfaces showed mature, complex biofilm structures with wide morphological diversity, and treated surfaces did not show the formation of mature biofilm structures. This study supports the efficacy of implantoplasty in reducing plaque adhesion and influencing biofilm formation. These results can be considered a preliminary proof of concept, but they may encourage further studies about the effects of implantoplasty on biofilm formation.

Experimental implantoplasty outcomes correlate with fibroblast growth in vitro

BACKGROUND

Implantoplasty is an option in peri-implantitis treatment, but little is known about the effect on the soft tissue. The aim of the study was to characterize surface roughness following experimental implantoplasty and to examine its effect on human fibroblast growth and secretion of selected proteins.

METHODS

Titanium grade IV coins were mechanically treated with six different rotating bur sequences; diamond burs or carbide burs alone, or followed by either Arkansas stone bur or silicone burs. Machined and rough-surface sandblasted, acid-etched (SLA) coins were used as control. The surface topography was characterized by scanning electron microscope and profilometer. Human gingival fibroblasts from two donors were cultured on the coins to quantify the effect on cell morphology, growth, and protein secretion by confocal microscopy and multiplex immunoassay.

RESULTS

All surface roughness parameters were lower for the surfaces treated with experimental implantoplasty than for the SLA surface, and the sequence of carbide burs followed by silicone burs rendered the least rough surface of the test groups. The implantoplasty procedures changed the elemental composition of the titanium surface. High surface roughness showed a weak to moderate negative correlation to fibroblast growth, but induced a higher secretion of VEGF, IL-6 and MCP-3 to the cell medium compared to the least rough surfaces of the test groups. At day 30 fibronectin levels were higher in the SLA group.

CONCLUSIONS

The surface roughness following implantoplasty demonstrated a weak to moderate negative correlation with the growth of fibroblasts. The addition of Arkansas stone and silicon burs to the experimental implantoplasty bur protocol rendered an initial increase in fibroblast growth. Implantoplasty altered the elemental composition of the titanium surface, and had an effect on the fibroblast cytokine secretion and fibronectin levels.

Electrospun Bioresorbable Membrane Eluting Chlorhexidine for Dental Implants

To prevent the uncontrolled development of a pathogenic biofilm around a dental implant, an antimicrobial drug-release electrospun membrane, set up between the implant and the gingival tissue, was developed by taking several technical, industrial and regulatory specifications into account. The membrane formulation is made of a blend of poly(l-lactic–co–gycolic acid) (PLGA, 85:15) and poly(l-lactic acide–co–ɛ-caprolactone) (PLC, 70:30) copolymers with chlorhexidine diacetate (CHX) complexed with β-cyclodextrin (CD). The amount of residual solvent, the mechanical properties and the drug release kinetics were tuned by the copolymers’ ratio, between 30% and 100% of PLC, and a CHX loading up to 20% w/w. The membranes were sterilized by γ-irradiation without significant property changes. The fiber′s diameter was between 600 nm and 3 µm, depending on the membrane composition and the electrospinning parameters. CHX was released in vitro over 10 days and the bacterial inhibitory concentration, 80 µg·mL⁻¹, was reached within eight days. The optimal membrane, PGLA/PLC/CHX-CD (60%/40%/4%), exhibited a breaking strain of 50%, allowing its safe handling. This membrane and a membrane without CHX-CD were implanted subcutaneous in a rat model. The cell penetration remained low. The next step will be to increase the porosity of the membrane to improve the dynamic cell penetration and tissue remodeling.

Management of peri-implantitis - A contemporary synopsis

Prevalence of peri-implant complication is expected to be on the rise with the increased number of implants being placed. Depending on the degree of osseous involvement, the clinician needs to decide if the treatment goal is to arrest the disease progression, regeneration or explantation and replacement. Host's medical status, defect configuration, aesthetic outcome, ability to access for plaque control post-treatment, and the patient's wishes are key factors to consider. The purpose of this review is to provide a contemporary synopsis on the management of peri-implantitis with emphasis on explantation. Guidance on the identification of factors/situations where salvaging an implant may be less favourable is discussed and the various techniques to remove a fractured, or peri-implantitis-affected non-mobile implant are described.

Is Peri-Implantitis Curable?

Peri-implant mucositis and peri-implantitis are clinically associated with inflammation of soft tissue around implants; however, peri-implantitis is associated with radiographic bone loss. Recently a new classification scheme-peri-implant health, peri-implant mucositis, peri-implantitis, and peri-implant soft-tissue and hard-tissue deficiencies-was introduced. Although various clinical interventions to treat peri-implant diseases have been suggested, early diagnosis and treatment is the key to successful outcomes. Clinicians can select nonsurgical or surgical techniques according to the clinical parameters present, although surgical intervention seems to be more effective in treating peri-implantitis. The best approach to treat peri-implantitis remains controversial.

Two to six-year disease resolution and marginal bone stability rates of a modified resective-implantoplasty therapy in 32 peri-implantitis cases

BACKGROUND

Different nonsurgical, antibacterial, surgical, and regenerative approaches to treat peri-implantitis have been proposed, but there is no an actual "gold" standard treatment showing the most favorable results to counteract peri-implantitis effects.

PURPOSE

To evaluate radiographically and clinically the disease resolution and peri-implant marginal bone stability rates of peri-implantitis cases treated through a combined resective-implantoplasty therapy in a moderate to long-term period.

MATERIALS AND METHODS

Records of patients diagnosed with peri-implantitis and treated through the same protocol applying a combined resective-implantoplasty therapy with minimum 2-year follow-up were screened. Eligible patients were contacted and asked to undergo clinical and radiologic examination. Progressive marginal bone loss, bleeding on probing, suppuration, implant mobility, and implant fracture were considered to establish the disease resolution rate and peri-implant bone stability of the treated implants.

RESULTS

Twenty-three patients with 32 treated implants fulfilled the inclusion criteria. Over the 2 to 6-year follow-up, (mean time: 3.4 ± 1.5 years), the disease resolution rate was 83% (patient level) and 87% (implant level). Four implants (13%) were lost or removed due to continuous MBL and osseointegration failure. At follow-up, peri-implant marginal bone remained stable with no further bone loss in 87% of the treated implants. BOP was absent in 89.3% (implant level), suppuration was resolved in all cases, and no pain or implant fracture was reported.

CONCLUSION

Implantoplasty treated cases showed high disease resolution rate and peri-implant marginal bone stability. This surgical antibiofilm strategy can counteract peri-implantitis progression providing an adequate environment for implant function and longevity over a moderate to long-term period.