Implant Surface Decontamination by Surgical Treatment of Periimplantitis: A Literature Review

Comprehensive treatment protocol for peri-implantitis: an up-to date narrative review of the literature

This narrative review describes up-to-date treatment options for peri-implantitis and proposes a treatment protocol and flowchart based on the current scientific evidence. Peri-implantitis treatment should be based on the phased treatment protocol for periodontitis, which is a continuous flow of decisions for extraction, nonsurgical and surgical treatments with step-by-step re-evaluation. The protocol's goals are to fulfill the success criteria for peri-implantitis treatment (probing depth of ≤5 mm, and absence of bleeding on probing, suppuration, and progressive bone loss) and to halt disease progression. Fixtures with peri-implantitis can initially be classified as failed or failing. A failed implant needs to be removed. In contrast, nonsurgical and surgical treatments can be applied to a failing implant. Nonsurgical treatment should be the initial treatment for failing implants; however, sole nonsurgical treatment was regarded as inefficient for peri-implantitis. Recent studies have found that the adjunctive use of antibiotics to nonsurgical debridement increased the success of nonsurgical treatment for peri-implantitis. Surgical treatments can be classified into resective, access, and reconstructive surgeries. The technique should be selected according to the patient's bone defect configuration, which relate to regenerative potential. Various combinations of decontamination methods (e.g., mechanical, chemical, and pharmacological approaches) are required to achieve absolute surface decontamination. Clinicians should select an appropriate surface decontamination strategy according to the purpose of surgery. After signs of disease disappear and its progression is halted through active peri-implantitis treatment, it is necessary to enroll patients into maintenance programs. Compliance of patients with the maintenance program reduces the recurrence of peri-implantitis and sustains clinical success after treatment. Maintenance visits should include professional plaque control and hygiene care reinforcement for patients, and their interval should be set according to individual peri-implantitis risk. Clinicians should remind that peri-implantitis treatment is not a single procedure, but rather a continuing cycle of treatment and re-evaluation.

Comparison of the efficacy of Er,Cr:YSGG laser on oral biofilm removal from implant surfaces with various application times for the treatment of peri-implantitis defects: ex vivo study

PURPOSE

The major struggle in peri-implantitis therapy is the availability of successful decontamination of the infected implant surface. The main hypothesis of this study was the Er,Cr: YSGG laser decontamination efficacy investigation on the infected implant surfaces with various peri-implantitis defects. The primary objective of this study was to decide the efficacy of Er,Cr:YSGG laser as a decontamination tool at various peri-implantitis simulating defects. The secondary objective was to compare the efficacy of the Er,Cr: YSGG laser on oral biofilm removal between two protocols the first protocol (4 cycles at 2.5 min) and the second protocol (5 cycles at 5 min) at various peri-implantitis simulating defects.

MATERIALS AND METHODS

A total of 3 subjects whose plaque biofilms formed in-vivo on twenty-four tested implants were divided into four tested groups. Two native implants were tested as controls.The in vitro defect model was computer-aided designed and printed into a 3D-printed model with various anulations in peri-implant infrabony defects, which were 15,30,60,and 90 degrees.

RESULTS

Both Er, Cr: YSGG decontamination protocols at 50 mJ (1.5 W/30 Hz), 50% air, and 40% water were effective at reducing the total implant surface area/ biofilm ratio (%), but the second protocol had a markedly greater reduction in the duration of application (5 cycles at 5 min) than did the first protocol (4 cycles at 2.5 min).

CONCLUSION

The Er, Cr: YSGG laser is an effective decontamination device in various peri-implantitis defects. The second protocol(5 cycles at 5 min) with greater application time and circles is more effective than the first one. The defect angulation influence the decontamination capability in peri-implantitis therapy.

CLINICAL RELEVANCE (SCIENTIFIC RATIONALE FOR STUDY)

Clinicians anticipate that the exploration of suitable therapeutic modalities for peri-implantitis therapy is limited by the obvious heterogeneity of the available evidence in the literature and need for a pre-clinical theoretical basis setup. The major challenges associated with peri-implantitis therapy include the successful decontamination of the infected implant surface, the absence of any damage to the treated implant surface with adequate surface roughness, and the biocompatibility of the implant surface, which allows osteoblastic cells to grow on the treated surface and is the key for successful re-osseointegration. Therefore, these are the expected empirical triads that need to be respected for successful peri-implantitis therapy. Failure of one of the triads represents a peri-implantitis therapeutic failure. The Er, Cr: YSGG laser is regarded as one of the expected devices for achieving the required triad.

TRIAL REGISTRATION

"Efficacy of Er,Cr YSGG Laser in Treatment of Peri-implantitis".

CLINICALTRIALS

gov ID NCT05137821. First Posted date: 30 -11-2021.

Evaluation of the effect of adjunctive diode laser application on peri-implant crevicular fluid biomarker levels: a randomized controlled trial

OBJECTIVES

To assess both the clinical and immunological effectiveness of diode laser therapy when used as an adjunct to non-surgical mechanical therapy in managing peri-implantitis.

MATERIALS AND METHODS

A cohort of 27 participants, comprising 21 females and 6 males, agreed to take part in this investigation. 37 dental implants with peri-implantitis diagnosis were randomly allocated to either the laser group (n = 19) or the control group (n = 18). Evaluation of peri-implant clinical parameters and collection peri-implant crevicular fluid (PICF) samples occurred at baseline, as well as at 3 and 6-month follow-up intervals. The level of various biomarkers (TWEAK, IL-1β, sclerostin, IL-17, RANKL, OPG and IL-10) within the PICF were quantified using enzyme-linked immunosorbent assay.

RESULTS

Significant time-dependent decreases in clinical and biochemical parameters were detected in both groups compared to the baseline. There were marked differences between the groups in terms of periodontal parameters, except probing depth, and IL-1β, IL-17, sclerostin levels in PICF at 3rd month follow-up. However, no statistically significant difference was detected at 6th month.

CONCLUSIONS

Diode laser seems to be a reliable tool as an adjunct for supporting the nonsurgical mechanical treatment during the early stages of peri-implantitis. Furthermore, the findings suggest that IL-17, sclerostin and IL-1β may serve as promising biomarkers for assessing efficacy of peri-implantitis treatment.

CLINICAL RELEVANCE

Based on these outcomes, clinicians may consider the application of adjunctive use of diode laser to non-surgical peri-implantitis treatment to achieve better clinical and immunological improvements than nonsurgical peri-implantitis therapy alone in just early healing period. However, it should be noted that there was no difference between the two methods in the long term.

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.

Management of Advanced Peri-Implantitis by Guided Bone Regeneration in Combination with Trabecular Metal Fixtures, Two Months after Removal of the Failed Implants: Two-Year Results of a Single-Cohort Clinical Study

Background: Implant replacement is among the treatment options for severe peri-implantitis. The aim of this single-cohort study was to evaluate the feasibility of replacing compromised implants affected by advanced peri-implantitis with new implants with a porous trabecular metal (TM) structure. Materials and Methods: Patients with one or more implants in the posterior region showing a defect depth >50% of implant length, measured from the residual crest, were consecutively included. Two months after implant removal, patients received a TM implant combined with a xenograft and a resorbable membrane. The implant stability quotient (ISQ) was measured at placement and re-assessed five months later (at uncovering), then after 6, 12, and 24 months of function. Marginal bone loss was radiographically evaluated. Results: Twenty consecutive cases were included. One patient dropped out due to COVID-19 infection, and nineteen cases were evaluated up to 24 months. At placement, the mean ISQ was 53.08 ± 13.65 (standard deviation), which increased significantly to 69.74 ± 9.01 after five months of healing (p < 0.001) and to 78.00 ± 7.29 after six months of loading (p < 0.001). Thereafter, the ISQ remained stable for up to 24 months (80.55 ± 4.73). All implants successfully osseointegrated and were restored as planned. After two years, the average marginal bone level change was -0.41 ± 0.38 mm (95% confidence interval -0.60, -0.21), which was limited yet significantly different from the baseline (p < 0.05). Conclusions: The treatment of advanced peri-implant defects using TM implants inserted two months after explantation in combination with guided bone regeneration may achieve successful outcomes up to two years follow-up, even in the presence of low primary stability.

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.

Peri-implantitis management by resective surgery combined with implantoplasty and Er:YAG laser irradiation, accompanied by free gingival graft: a case report

The optimal method for decontamination of implant surfaces for peri-implantitis treatment remains controversial. In recent years, erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and implantoplasty (IP) (i.e. mechanical modification of the implant) have been reported to be effective in decontaminating implant surfaces during the surgical treatment. Also, a lack of adequate keratinized mucosa (KM) around the implant is known to be associated with more plaque accumulation, tissue inflammation, attachment loss, and mucosal recession, increasing the risk of peri-implantitis. Therefore, free gingival graft (FGG) has been recommended for gaining adequate KM around the implant. However, the necessity of acquiring KM for the treatment of peri-implantitis using FGG remains unclear. In this report, we applied the apically positioned flap (APF) as resective surgery for peri-implantitis treatment in conjunction with IP and Er:YAG laser irradiation to polish/clean the implant surface. Furthermore, FGG was conducted simultaneously to create additional KM, which increased the tissue stability and contributed to the positive results. The two patients were 64 and 63 years old with a history of periodontitis. The removal of granulation tissue and debridement of contaminated implant surfaces were performed with Er:YAG laser irradiation post flap elevation and then modified smooth surfaces mechanically using IP. Er:YAG laser irradiation was also utilized to remove the titanium particles. In addition, we performed FGG to increase the width of KM as a vestibuloplasty. Peri-implant tissue inflammation and progressive bone resorption were not observed, and both patients maintained good oral hygiene conditions until the 1-year follow-up appointment. Bacterial analysis via high-throughput sequencing revealed proportional decreases in bacteria associated with periodontitis (Porphyromonas, Treponema, and Fusobacterium). To the best of our knowledge, this study is the first to describe peri-implantitis management and bacterial change before and after procedures by resective surgery combined with IP and Er:YAG laser irradiation for peri-implantitis treatment, accompanied by FGG for increasing KM around the implants.

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).

Implant Surface Topography Following Different Laser Treatments: An In Vitro Study

Background Although dental implants have demonstrated very high success rates, they are susceptible to complications such as peri-implantitis that can lead to failure. Methods Twenty implants with surfaces grit-blasted using hydroxyapatite and acid-etched were randomly divided into four groups (five in each group). Three groups were assigned to laser treatments: Group I (erbium, chromium-doped: yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser), Group II (650-nm diode laser), and Group III (808-nm diode), and one control group, Group IV. The surface roughness parameters (roughness average(Ra) and root mean square roughness(Rq)) were measured using a non-contact optical profilometer and scanning electron microscope to evaluate the surface topography after the laser treatments. Results Significant differences were observed between the laser groups regarding the surface roughness Ra (3.56±0.26, 3.45±0.19, 3.77±0.42, p_c=0.0004, p_e=0.0002, p_f=0.001) and Rq values (4.49±0.34, 4.35±0.26, 4.72±0.56, p_c=0.0007, p_e=0.0006, p_f=0.002) and the control group (2.81±0.10; 3.57±0.19). However, no significant difference was observed between the different laser treatment modalities. The scanning electron microscope images revealed some morphological changes on the implant surfaces following laser treatment, but no melted morphology was observed. Conclusions The application of Er,Cr:YSGG, 650-nm diode laser, and 808-nm diode did not show melting changes on implant topography. However, some increase in surface roughness was detected. Further studies are recommended to assess the effectiveness of these laser settings on bacterial reduction and osseointegration.

Ebselen restores peri-implantitis-induced osteogenic inhibition via suppressing BMSCs ferroptosis

It is hard to reconstruct bone defects in peri-implantitis due to osteogenesis inhibited by excessive ROS. Ferroptosis, a recently identified regulated cell death characterized by iron- and reactive oxygen species- (ROS-) dependent lipid peroxidation, provides us with a new explanation. Our study aims to explore whether ferroptosis is involved in peri-implantitis-inhibited osteogenesis and confirm ebselen, an antioxidant with glutathione peroxidase (GPx)-like activity, could inhibit ferroptosis and promote osteogenesis in peri-implantitis. In this study, we used LPS to mimic the microenvironment of peri-implantitis. The osteogenic differentiation of bone-marrow-derived mesenchymal stem cells (BMSCs) was assessed by alkaline phosphatase (ALP), Alizarin Red S, and mRNA and protein expression of osteogenic-related markers. Ferroptosis index analysis included iron metabolism, ROS production, lipid peroxidation and mitochondrial morphological changes. Iron overload, reduced antioxidant capability, excessive ROS, lipid peroxidation and the characteristic mitochondrial morphological changes of ferroptosis were observed in LPS-treated BMSCs, and adding Ferrostatin-1 (Fer-1) restored the inhibitory effect of ferroptosis on osteogenic differentiation of BMSCs. Furthermore, ebselen ameliorated LPS-induced ferroptosis and osteogenic inhibition, which was reversed by erastin. Our results demonstrated that ferroptosis is involved in osteogenic inhibition in peri-implantitis and ebselen could attenuate osteogenic dysfunction of BMSCs via inhibiting ferroptosis.

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.

Effect of Er,Cr:YSGG laser with a side-firing tip on decontamination of titanium disc surface: an in vitro and in vivo study

PURPOSE

To evaluate the effectiveness of an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser with side-firing tip in decontamination of titanium (Ti) disc.

METHODS

In the first test series, 29 Ti-discs were contaminated with Staphylococcus aureus and treated as follows: positive control (no treatment); Perioflow; Laser A (0.75 W, 100 Hz), Laser B (1.5 W, 30 Hz); Laser C (no radiation, 60% water); and Laser D (no radiation, 50% water). For bacterial quantification, colony forming units (CFU, vital cells only) and quantitative PCR (qPCR, vital and devital cells) were performed. In a second test series, 92 Ti-discs were used, contaminated with in vivo-grown biofilm and treated as follows: positive control (no treatment); Perioflow; Laser E (1.5 W, 30 Hz), and Laser F (no radiation, 50% water). Considering the different and unknown culture conditions, quantification of bacteria was performed by broad-spectrum bacterial qPCR only. Based on the assumption that all cells of an organism contain an equivalent complement of genetic information, genome equivalent (GE) determination ensured the detection of the different intact and semi-intact genomes, regardless of type of bacterial species and vitality, circumvent the inherent bias of cultures.

RESULTS

The GE values were significantly reduced by all interventions in both test series, compared to the positive control group (p < 0.001). In the first test series with S. aureus as model organism, Perioflow yielded a lower GE than the Laser groups A-D (all p < 0.025). The number of CFUs was significantly reduced in the intervention groups compared to the positive control (p < 0.001), except for Laser A (p = 0.157) and Laser D (p = 0.393). In the second test series, none of the pairwise comparisons of the intervention conditions showed a significant difference (Perioflow vs. Laser E: p = 0.732; Perioflow vs. Laser F: p = 0.590; Laser E vs. Laser F: p = 0.379).

CONCLUSION

The Er,Cr:YSGG laser with side-firing tip and Perioflow were equally capable of effectively decontaminating a Ti-disc surface. It is assumed that the bacterial reduction was largely due to the mechanical effect of the air and water stream.

Hard and soft tissue regeneration of severe peri-implantitis defects with the laser-assisted peri-implant defect regeneration technique: 3-year results

PURPOSE

This retrospective cohort study evaluates the regeneration of severe peri-implantitis deficiencies treated with the laser-assisted peri-implant defect regeneration (LAPIDER) approach within a 3-year follow-up.

METHODS

Twenty-four implants with severe peri-implantitis in 18 patients were treated according to the LAPIDER technique. In contrast to classic techniques for reconstructive peri-implantitis surgery with a marginal incision, a buccal split-flap preparation avoiding papillae separation was used. After a coronal flap elevation and a laser-assisted peri-implant defect cleaning, connective tissue and autogenous bone grafting was performed. Primary outcomes were the changes of the marginal bone levels (MBL) and the buccal bone thickness. Secondary outcomes included implant survival, peri-implant probing depths (PPD), bleeding on probing (BOP), recession, width of keratinized mucosa (KMW), thickness of keratinized mucosa (KMT), soft tissue esthetics (PES), and implant success.

RESULTS

MBL improved interproximal by 3.10 ± 2.02 mm (p < 0.001), buccal by 3.49 ± 2.89 mm (p < 0.001), and lingual by 1.46 ± 1.98 mm (p = 0.003); buccal bone thickness by 0.55 ± 0.60 mm (p = 0.005), and 1.01 ± 1.25 mm (p = 0.001) at 1 and 3 mm below reference level. Two implants were removed; 22 implants were still in function at a mean follow-up of 36 months. PPD changed from 5.05 ± 1.39 to 3.08 ± 0.71 mm (p < 0.001); recession was reduced from 2.07 ± 1.70 to 0.91 ± 1.13 mm (p = 0.001); KMW increased from 2.91 ± 1.81 to 4.18 ± 1.67 mm (p = 0.006); KMT improved from 1.73 ± 0.50 to 2.44 ± 0.43 mm (p < 0.001); PES changed from 7.7 ± 2.8 to 10.7 ± 1.9 (p < 0.001). 45.8% to 54.2% of the implants met the criteria of implant success.

CONCLUSIONS

The favorable results document the proof of principle for the regeneration of severe peri-implant hard and soft tissue deficiencies by the LAPIDER treatment approach.

Photo/mechanical and physical implant surface decontamination approaches in conjunction with surgical peri-implantitis treatment: A systematic review

AIM

To evaluate the efficacy of adjunctive/alternative photo/mechanical and physical implant-surface decontamination approaches compared to standard instrumentation in conjunction with surgical peri-implantitis treatment.

MATERIALS AND METHODS

Randomized controlled clinical trials (RCTs) and controlled clinical trials investigating the efficacy of adjunctive or alternative photo/mechanical/physical measures for implant surface decontamination in conjunction with surgical peri-implantitis treatment without (PICOS 1) or with (PICOS 2) additional decontamination methods performed in test and control groups with changing inflammation parameters were covered. Changes in bleeding scores (i.e., bleeding index, or bleeding on probing [BOP]), suppuration, and probing depth (PD) were considered the primary outcomes.

RESULTS

Six articles describing five original RCTs were eligible for analysis. Based on two RCTs, the adjunctive/alternative use of air polishing with glycine or erythritol powder did not improve BOP reduction compared to standard instrumentation (PICOS 1). Based on one RCT, alternative use of titanium brushes resulted in significantly higher BOP reduction compared to either air polishing or standard instrumentation (PICOS 1). During reconstructive therapy and as an adjunct to implantoplasty, use of a titanium brush did not have any benefit on the BOP and mean PD reductions compared to the control group (i.e., implantoplasty + mechanical and chemical implant surface decontamination; one RCT; PICOS 2). Use of the Er:YAG laser resulted in significantly higher PD reduction after 6 months (one RCT), whereas no difference between the test and respective controls could be detected after 1 and 2 years (one RCT). Additionally, the use of the Er:YAG laser was not associated with improved BOP reductions over respective controls (two RCTs; PICOS 2).

CONCLUSIONS

Owing to the limited available data, clinical efficacy of photo/mechanical and physical implant surface decontamination in conjunction with surgical peri-implantitis therapy is inconclusive. However, titanium brushes may be beneficial in reducing signs of inflammation.

An Experimental Anodized Titanium Surface for Transgingival Dental Implant Elements-Preliminary Report

The characteristics such as microtopography, physical and chemical properties influence the behavior of an implant in a soft tissue. Anodization-as a potent method of titanium alloy surface modification-of the transgingival abutment or healing screw, has achieved some improvement. One of the possible surface treatment method is low-pressure radiofrequency oxygen plasma treatment. The aim of the study was to evaluate the chemical properties and cytocompatibility of the experimental surface. Titanium discs made of grade-23 titanium alloy (Ti-6Al-4V) anodized (A sample) with different voltage parameters (28, 67, 78, and 98 V) were included in the study. Half of the samples regarded as the "S" group were additionally treated with low-pressure radiofrequency oxygen plasma treatment. The surfaces were characterized using scanning electron microscopy, X-ray spectroscopy and Raman spectroscopy, and electrochemically investigated via a corrosion test. Furthermore, two cell lines were used, including the CHO-compatible reference line and a primary human fibroblast line for the MTT assay; direct (contact) cytotoxicity of the materials was tested with the cells, and the growth of fibroblasts on the surfaces of the different materials was tested. The morphology of the "S"-treated samples did not differ from the morphology of only-anodized samples. However, the oxygen concentration on the surface in that group slightly increased by about 1% as a result of post-trial treatment. The highest corrosion resistance was observed for both A-78 V and S-78 V samples. The cytotoxicity assay revealed no changes in cell morphology or vitality. The MTT test proved comparable culture viability among all groups; however, the "S" samples showed statistically significantly higher fibroblast proliferation and adhesion scores compared to the "A" samples. Through the in vitro study, the low-pressure radiofrequency oxygen plasma treatment of the anodized Ti-6Al-4V alloy presented itself as an auspicious option in the field of transgingival element surface modification of implants.

Antimicrobial efficiency and cytocompatibility of different decontamination methods on titanium and zirconium surfaces

OBJECTIVES

The purpose of this study was to investigate the efficiency of different implant-decontamination methods regarding biofilm modification and potential cytotoxic effects. Therefore, the amount of biofilm reduction, cytocompatibility, and elementary surface alterations were evaluated after decontamination of titanium and zirconium surfaces.

MATERIAL AND METHODS

Titanium and zirconium disks were contaminated with a newly developed high-adherence biofilm consisting of six microbial species. Decontaminations were performed using titanium curette, stainless steel ultrasonic scaler (US), glycine (GPAP) and erythritol (EPAP) powder air-polishing, Er:YAG laser, 1% chlorhexidine (CHX), 10% povidone-iodine (PVI), 14% doxycycline (doxy), and 0.95% NaOCl solution. Microbiologic analysis was done using real-time qPCR. For assessment of cytocompatibility, a multiplex assay for the detection of cytotoxicity, viability, and apoptosis on human gingival fibroblasts was performed. X-ray photoelectron spectroscopy (XPS) was used to evaluate chemical alterations on implant surfaces.

RESULTS

Compared with untreated control disks, only GPAP, EPAP, US, and Er:YAG laser significantly reduced rRNA counts (activity) on titanium and zirconium (p < .01), whereas NaOCl decreased rRNA count on titanium (p < .01). Genome count (bacterial presence) was significantly reduced by GPAP, EPAP, and US on zirconium only (p < .05). X-ray photoelectron spectroscopy analyses revealed relevant re-exposure of implant surface elements after GPAP, EPAP, and US treatment on both materials, however, not after Er:YAG laser application. Cytocompatibility was impaired by CHX, PVI, doxy, and NaOCl. CHX and PVI resulted in the lowest viability and doxy in the highest apoptosis.

CONCLUSIONS

Within the limits of this in vitro study, air-polishing methods and ultrasonic device resulted in effective biofilm inactivation with surface re-exposure and favorable cytocompatibility on titanium and zirconium. Chemical agents, when applied on implant surfaces, may cause potential cytotoxic effects.

Surface decontamination protocols for surgical treatment of peri-implantitis: A systematic review with meta-analysis

OBJECTIVE

To answer the following PICO question: "In patients requiring surgical treatment of peri-implantitis (P), is any implant surface decontamination protocol (I) superior to others (C) in terms of clinical and radiographic parameters (O)?"

METHODS

Randomized clinical trials (RCTs) comparing two or more decontamination protocols as part of the surgical treatment of peri-implantitis were included. Two authors independently searched for eligible studies, screened titles and abstracts, did full-text analysis, extracted data, and performed the risk-of-bias assessment. Whenever possible, results were summarized through random effects meta-analyses.

RESULTS

Twenty-two manuscripts reporting on 16 RCTs were included, testing mechanical, chemical and physical decontamination protocols. All of them resulted in an improvement in clinical parameters; however, the superiority of specific protocols over others is mainly based on single RCTs. The use of titanium brushes and implantoplasty showed favorable results as single decontamination methods. Meta-analyses indicated a lack of added effect of Er:Yag laser on probing pocket depth (PPD) reduction (n = 2, WMD = -0.24 mm, 95% confidence interval [CI] [-1.10; 0.63], p = .59); while systemic antimicrobials (amoxicillin or azithromycin) showed an added effect on treatment success ([PPD ≤5 mm, no bleeding or suppuration, no progressive bone loss]; n = 2, RR = 1.84, 95% CI [1.17;2.91], p = .008), but not in terms of PPD reduction (n = 2, WMD = 0.93 mm, 95% CI [-0.69; 2.55], p = .26), even if with substantial heterogeneity.

CONCLUSIONS

No single decontamination method demonstrated clear evidence of superiority compared to the others. Systemic antibiotics, but not Er:Yag laser, may provide short-term clinical benefits in terms of treatment success (CRD42020182303).

Are Mini Dental Implants Suitable for Support of Crowns or Small Bridges in the Mandibular Incisor Region? A 5-year Longitudinal Study

PURPOSE

It has not been previously studied whether 1-piece category 1 narrow dental implants (≤2.5 mm wide) can successfully support crowns or small bridges. The purpose of this study was to evaluate the long-term benefits of the fixed-type mini dental implants (MDIs) for replacement of mandibular incisors.

MATERIALS AND METHODS

In a prospective cohort study, fixed-type 1-piece MDIs, replacing single or multiple mandibular incisors, supporting metal-ceramic single crowns (unsplinted group), or splinted crowns/small bridges (splinted group) were observed over the period of 5 years. The primary predictor was the splinting status. The primary outcome variables were peri-implant marginal bone level (MBL) change, success, and survival rates (assessed as per Pisa Consensus Conference). The secondary outcomes were dental patient-reported outcome measures (dPROMs) and oral hygiene assessment. Descriptive statistics, Chi-squared test, t-test, Mann-Whitney and Wilcoxon tests, Kaplan-Meier survival analysis, log-rank (Mantel-Cox) comparison, Cox proportional hazard analyses adjusting for number of implants, Spearman correlation, and repeated measures were used for data analysis.

RESULTS

From 44 participants (mean age 56.02 ± 5.72 years), 40 completed the 5-year study: 23 in the splinted and 17 in unsplinted group. Three subjects did not respond, while 1 MDI failed (third year) in the unsplinted group. Mean MBL change in both groups was small; however, it increased over time (-0.22 ± 0.38 mm after 1 year; -0.54 ± 0.56 mm after 5 years; P < .05). After 5 years mean MBL change was -0.59 ± 0.71 mm in the unsplinted and -0.50 ± 0.41 mm in the splinted group (P > .05). Survival analysis revealed no significant difference between the unsplinted (85.7% success, 4.8% failures, and 9.5% satisfactory survivals) and splinted group (93.4% success and 6.6% satisfactory survivals) (P > .05). The group affiliation (unsplinted vs splinted) and number of implants were not significant predictors of MDI failure or survival rates (P > .05). Significant improvement in dPROMs after rehabilitation remained unchanged over 5 years (P > .05). Modified plaque index significantly increased over time, correlating with the MBL loss.

CONCLUSION

MDIs supporting crowns and/or small bridges in the mandibular incisor region showed small rates of marginal bone loss, acceptable success, and survival rates and improved dPROMs over a 5-year observation period.

Non-surgical mechanical therapy of peri-implantitis with or without repeated adjunctive diode laser application. A 6-month double-blinded randomized clinical trial

Objectives

The objective of this study is to investigate the outcomes following non‐surgical therapy of peri‐implantitis (PI) with or without adjunctive diode laser application.

Materials and methods

A double‐blinded randomized controlled clinical trial was carried out in 25 subjects with 25 implants diagnosed with PI. Following curettage of granulation tissue, test implants (T) were treated with adjunctive application of a diode laser for 90 s (settings: 810 nm, 2.5 W, 50 Hz, 10 ms), while at control implants (C) non‐activated adjunctive diode laser was applied. The entire treatment procedure was performed at days 0 (i.e., baseline), 7 and 14. The primary outcome measure was change in mean pocket probing depth (PPD). Clinical and microbiological outcomes, as well as host‐derived inflammatory markers were evaluated at baseline, 3 and 6 months, while radiographic outcomes were assessed at baseline and at the 6‐month follow‐up.

Results

No statistically significant differences with respect to baseline patient characteristic were observed. After 6 months, both test and control implants yielded statistically significant PPD changes compared with baseline (T: 1.28 and C: 1.47 mm) but without statistically significant difference between groups (p = .381). No statistically significant changes in peri‐implant marginal bone levels were detected (p = .936). No statistically significant differences between test and control implants were observed with respect to microbiological and host‐derived parameters (p > .05). At the 6‐month follow‐up, treatment success was observed in 41.7% (n = 5) of test and 46.2% (n = 6) of control patients, respectively (p = .821).

Conclusion

Repeated adjunctive application of diode laser in the non‐surgical management of PI failed to provide significant benefits compared with mechanical instrumentation alone.

Evaluation of Viability and Cell Proliferation in Bone and Gingival on Dental Implant Fixtures with Active Sandblasted and Sandblasted Surfaces by the Cytotoxicity Test Method

In recent years, the technology of dental implants has advanced a lot and this has become one of the main reasons for dentists to refer to implants immediately after tooth extraction. Evaluation of cell survival in implantology studies to determine cell sensitivity determines the outcome of treatment. This study aimed to investigate the bone integration properties as well as the cytotoxicity between the implant surface and the jaw bone. In this study, cytotoxicity test was used to evaluate the toxicity and viability of sandblasted large grit acid etched, and sandblasted large grit acid etched active surfaces in 3A brand dental implants with G292 osteoblastic cells and human gingival fibroblasts cells are discussed. This operation was performed using a laboratory incubator of the German company MEMMERT for 24 hours, by neubauer lam cells counting for one hundred thousand cultured cells in each test at a temperature of 37 °C, a pressure of 1 atmosphere and 90% humidity. Based on the scanning electron microscopy images and the cytotoxicity test results, it can be seen that the bone graft of the implant, with the sandblasted large grit acid etched active surface treatment, is much better and also one week faster than the implant with the sandblasted large grit acid etched one. However, the viability of the implant with the sandblasted large grit acid etched active surface treatment for both G292 osteoblastic cells and human gingival fibroblasts cells samples was equal to 98.4% and 97.3%, respectively, and is lower than the sandblasted large grit acid etched surface treatment. The results show that the viability of the sandblasted large grit acid etched implant is about 1.5 to 2% higher than the sandblasted large grit acid etched active one, but the surface integrity of sandblasted large grit acid etched active is better than sandblasted large grit acid etched in all samples, and the treatment process is reduced by one week.

Mechanical removal of biofilm on titanium discs: An in vitro study

The objective of this in vitro study was to evaluate surface cleanness and cytocompatibility following mechanical instrumentation of biofilm-contaminated titanium surfaces. Titanium discs (non-modified [Ti(s)] and shot-blasted surfaces [Ti(r)]) contaminated with Streptococcus gordonii were instrumented using four different techniques: (i) gauze soaked in saline (GS), (ii) ultra-sonic device (US), (iii) rotating nickel-titanium brush (TiB), or (iv) air-polishing device (AP). Non-contaminated, untreated titanium disks were used as controls (C). Residual deposits and cytocompatibility for osteoblast-like cells were evaluated using scanning electron microscopy, immunofluorescence, and reverse transcriptase polymerase chain reaction. While the number of residual bacteria on Ti(s) discs was close to 0 in all treatment groups, significantly higher mean numbers of residual bacteria were observed on Ti(r) discs for GS (152.7 ± 75.7) and TiB (33.5 ± 22.2) than for US (0) and AP (0). Instrumentation with US resulted in deposition of foreign material (mean area% of foreign material: 3.0 ± 3.6% and 10.8 ± 9.6% for Ti(s) and Ti(r) discs, respectively). AP was the most effective decontamination procedure in reducing bacteria without depositing residual foreign material on Ti(r) discs. TiB and AP were superior methods in restoring cytocompatibility, although no method of mechanical decontamination resulted in pristine levels of cytocompatibility.

Erythritol air polishing in the surgical treatment of peri-implantitis: A randomized controlled trial

Objectives

To compare erythritol air polishing with implant surface cleansing using saline during the surgical treatment of peri‐implantitis.

Material and Methods

During a resective surgical intervention, implant surfaces were randomly treated with either air polishing (test group n = 26 patients/53 implants) or saline‐soaked cotton gauzes (control group n = 31 patients/ 40 implants). Primary outcome was change in mean bleeding on probing (BoP) from baseline to 12 months follow‐up. Secondary outcomes were changes in mean suppuration on probing (SoP), plaque score (Plq), probing pocket depth (PPD), marginal bone loss (MBL), periodontal full‐mouth scores (PFMS), and levels of 8 classical periodontal pathogens. Clinical and radiographical parameters were analyzed using multilevel regression analyses. Microbiological outcomes were analyzed using the Mann–Whitney U test.

Results

No differences between the test and control group were found for BoP over 12 months of follow‐up, nor for the secondary parameters Plq, PPD, and MBL. Between both groups, a significant difference was found for the levels of SoP (p = 0.035). No significant effect on microbiological levels was found. A total number of 6 implants were lost in the test group and 10 in the control group. At 1‐year follow‐up, a successful treatment outcome (PPD<5 mm, max 1 out of 6 sites BoP, no suppuration and no progressive bone loss >0.5 mm) was achieved for a total of 18 implants (19.2%).

Conclusions

Erythritol air polishing as implant surface cleansing method was not more effective than saline during resective surgical treatment of peri‐implantitis in terms of clinical, radiographical, and microbiological parameters. Both therapies resulted in low treatment success.

Trial registry: https://www.trialregister.nl/ Identifier: NL8621.

The Use of a Diode Laser for Removal of Microorganisms from the Surfaces of Zirconia and Porcelain Applied to Superstructure Dental Implants

The aim of this paper was to study the effectiveness of a diode laser (LD) for removal of microorganisms isolated from porcelain and zirconia crown surfaces used in implantoprosthetics in order to minimize infections around dental implants. In order to optimize biocidal efficacy of the process (at the same time, avoiding increasing the surface roughness during decontamination) the effects of diode laser doses were investigated. The irradiation was performed with a diode laser at the wavelength of λ = 810 nm in three variants with a different number of repetitions (1 × 15 s, 2 × 15 s, 3 × 15 s). The quantitative microbial contamination of the surface of teeth, porcelain and zirconia crowns assessment was made using the culture-dependent method. The identification of microorganisms took place using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and next-generation sequencing (NGS) methods. The studies of the surface morphology and roughness were carried out by means of the optical profilometry, scanning electron microscopy (SEM) and optical microscopy with the C1 confocal attachment. The most important conclusion from the research is the fact that the laser operation, regardless of the exposure time, effectively eliminates the microorganisms from the surfaces used for dental implant rebuilding and does not have a destructive effect on the tested material.

The Effects of Three Chlorhexidine-Based Mouthwashes on Human Osteoblast-Like SaOS-2 Cells. An In Vitro Study

Several decontamination methods for removing biofilm from implant surfaces during surgical peri-implantitis treatment have been reported, including the intraoperative usage of chlorhexidine (CHX)-based antiseptics. There is a lack of information on possible adverse effects on bone healing. The study aimed to examine the impact of three CHX-based mouthwashes on osteoblast-like cells (SaOS-2) in vitro. Cells were cultured for three days in 96-well binding plates. Each well was randomly treated for either 30, 60 or 120 s with 0.05% CHX combined with 0.05% cetylpyridinium chloride (CPC), 0.1% CHX, 0.2% CHX or sterile saline (NaCl) as control. Cell viability, cytotoxicity and apoptosis were assessed at day 0, 3 and 6. Cell viability resulted in being higher in the control group at all time points. At day 0, the CHX 0.2 group showed significantly higher cytotoxicity values compared to CHX 0.1 (30 s), CHX + CPC (30 s, 60 s and 120 s) and control (60 s and 120 s), while no significant differences were identified between CHX + CPC and both CHX 0.1 and NaCl groups. All test mouthwashes were found to induce apoptosis to a lower extent compared to control. Results indicate that 0.2% CHX presented the highest cytotoxic effect. Therefore, its intraoperative use should be carefully considered.

Peri-Implantitis Regenerative Therapy: A Review

Simple Summary

Regenerative therapies are one of the options to treat peri-implantitis diseases that cause peri-implant bone loss. This review reports classic and current literature to describe the available knowledge on regenerative peri-implant techniques.

Abstract

The surgical techniques available to clinicians to treat peri-implant diseases can be divided into resective and regenerative. Peri-implant diseases are inflammatory conditions affecting the soft and hard tissues around dental implants. Despite the large number of investigations aimed at identifying the best approach to treat these conditions, there is still no universally recognized protocol to solve these complications successfully and predictably. This review will focus on the regenerative treatment of peri-implant osseous defects in order to provide some evidence that can aid clinicians in the approach to peri-implant disease treatment.

Treatment of Periimplantitis with Electrolytic Cleaning versus Mechanical and Electrolytic Cleaning: 18-Month Results from a Randomized Controlled Clinical Trial

Aim of the study: This RCT assesses patients’ 18-month clinical outcomes after the regenerative therapy of periimplantitis lesions using either an electrolytic method (EC) to remove biofilms or a combination of powder spray and an electrolytic method (PEC). Materials and Methods: Twenty-four patients (24 implants) suffering from periimplantitis were randomly treated by EC or PEC followed by augmentation and submerged healing. Probing pocket depth (PPD), Bleeding on Probing (BoP), suppuration, and standardized radiographs were assessed before surgery (T0), 6 months after augmentation (T1), and 6 (T2) and 12 (T3) months after the replacement of the restoration. Results: The mean PPD changed from 5.8 ± 1.6 mm (T0) to 3.1 ± 1.4 mm (T3). While BoP and suppuration at T0 were 100%, BoP decreased at T2 to 36.8% and at T3 to 35.3%. Suppuration was found to be at a level of 10.6% at T2 and 11.8% at T3. The radiologic bone level measured from the implant shoulder to the first visible bone to the implant contact was 4.9 ± 1.9 mm at mesial sites and 4.4 ± 2.2 mm at distal sites at T0 and 1.7 ± 1.7 mm and 1.5 ± 17 mm at T3. Conclusions: Significant radiographic bone fill and the improvement of clinical parameters were demonstrated 18 months after therapy.

Reconstructive treatment of peri-implantitis infrabony defects of various configurations: 5-year survival and success

Aim

To present the 5 years outcomes of a reconstructive surgical protocol for peri‐implantitis defects with different morphologies, by means of deproteinized bovine bone mineral with 10% collagen (DBBMC).

Material and Methods

The original population of this case series consisted of 75 patients with one crater‐like defect and probing depth (PD) ≥6 mm. After flap elevation, defects were assigned to one characteristic class and treated by means of DBBMC. Following healing, patients were enrolled in an individualized supportive periodontal/peri‐implant (SPT) program.

Results

Fifty‐one patients reached the 5 years examination, as 11 patients were lost to follow‐up and 13 implants were removed. Overall treatment success was registered in 29 patients (45.3%). Mean PD and BOP significantly decreased at one year and remained stable for the rest of observation period. No correlation was found between implant survival rate and defect configuration (p = 0.213). Patients, who did not fully adhere to the SPT, experienced more complications and implant loss than those who regularly attended recall appointments (p = 0.009).

Conclusions

The proposed reconstructive treatment resulted in a high 5 years implant survival rate in patients who fully adhered to SPT. The resolution of the peri‐implantitis defect does not seem significantly associated with the defect configuration at the time of treatment.

Factors Influencing Marginal Bone Loss around Dental Implants: A Narrative Review

Implant supported dental prostheses are increasingly used in dental practice. The aim of this narrative review is to present the influence of transmucosal surface of prosthetic abutment and implant on peri-implant tissue. The article describes causes of bone loss around the dental implant. Moreover, properties of different materials are compared and discussed. The advantages, disadvantages, and biomechanical concept of different implant-abutment connections are presented. The location of connections in relation to the bone level and the influence of microgap between the abutment and implant are described. Additionally, the implant abutments for cemented and screwed prosthetic restorations are compared. The influence of implant and abutment surface at the transmucosal level on peri-implant soft tissue is discussed. Finally, the biological aspect of abutment-implant connection is analyzed.

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.

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.

Dental Implants Surface in vitro Decontamination Protocols

Objective  The number of patients rehabilitated with dental implants has contributed to increased incidence of peri-implant diseases. Due to complex and difficult treatment, peri-implantitis is a challenge and an efficient clinical protocol is not yet established. Aim of this study was to evaluate the efficacy of two protocols for in vitro decontamination of dental implants surface.

Materials and Methods  Twenty titanium implants (BioHE-Bioconect) were used. Implants were divided into five groups ( n = 4). NC group (negative control): sterile implants; PC group (positive control): biofilm contaminated implants; S group: biofilm contaminated implants, brushed with sterile saline; SB group: biofilm contaminated implants, brushed with sterile saline and treated with air-powder abrasive system with sodium bicarbonate (1 minute); and antimicrobial photodynamic therapy (aPDT) group: biofilm contaminated implants, brushed with sterile saline and treated with antimicrobial photodynamic therapy (red laser + toluidine blue O). The implants were contaminated in vitro with subgingival biofilm and distributed in groups PC, S, SB, and aPDT. Each group received the respective decontamination treatment, except groups NC and PC. Then, all implants were placed in tubes containing culture medium for later sowing and counting of colony-forming units (CFUs).

Statistical Analysis  One-way analysis of variance and Tukey tests were performed, at 5% significance level.

Results  Significantly fewer CFUs were observed in the aPDT group (19.38 × 10 ⁵ ) when compared with groups SB (26.88 × 10 ⁵ ), S (47.75 × 10 ⁵ ), and PC (59.88 × 10 ⁵ ) ( p < 0.01). Both the aPDT and SB groups were statistically different from the NC group ( p < 0.01).

Conclusion  Proposed protocols, using air-powder abrasive system with sodium bicarbonate and aPDT, showed to be efficacious in the decontamination of dental implants surface in vitro .

Induced Experimental Periimplantitis and Periodontitis: What are the Differences in the Inflammatory Response ?

This preliminary study investigates the differences between experimental periodontitis and periimplantitis in a dog model, with a focus on the histopathology, the inflammatory responses and specific immunoregulatory activities, driven by Th1/Th2 positive cells. Twelve dental implants were inserted into the edentulated posterior mandibles of six Beagle dogs and were given twelve weeks time for osseointegration. Experimental periimplantitis and periodontitis (first mandible molar) was then induced using cotton-floss ligatures. Twelve weeks later, alveolar bones were quantitated by cone beam-computer tomography. Histopathological analysis of the inflamed gingiva and of the periodontal tissues was performed by light microscopy, and the Th1/ Th2 cell populations were investigated by flow cytometry. Periimplantitis as well as periodontitis were both found to be associated with pronounced bone resorption effects, both to a similar degree vertically, but with a differential bone resorption pattern mesio-distally, and with a significantly higher and consistent bone resorption result in periimplantitis; however, with a higher variance of bone resorption in periodontitis. The histological appearances of the inflammatory tissues were identical. The percentages of Th1/ Th2 cells in the inflamed gingival tissues of both experimental periimplantitis and periodontitis were also found to be similar. Experimental periodontitis and periimplantitis in the dog model show essentially the same cellular pathology of inflammation. However, bone resorption was found to be significantly higher in periimplantitis; the histopathological changes in the periodontal tissues were similar in both groups, but showed a higher inter-individual variation in periodontitis, and appeared more uniform in periimplantitis. This preliminary study indicates that more focused experimental in-vivo inflammation models need to be developed to better simulate the human pathology in the two different diseases, and in order to have a valuable tool to investigate more specifically how novel treatments/prevention approaches may heal the differential adverse effects on bone tissue and on periodontium in periodontitis and in periimplantitis.

Repeated Exposure of Nanostructured Titanium to Osteoblasts with Respect to Peri-Implantitis

Titanium offers excellent biocompatibility and extraordinary mechanical properties. As a result, it is used as a material for dental implants. Implants infected by peri-implantitis can be cleaned for successful re-osseointegration. Optimal surface properties, such as roughness and wettability, have a significant impact on cell adhesion. The aim of this study was to evaluate the adhesion and proliferation of osteoblasts on the surface of repeatedly cleaned nanostructured titanium samples. Human osteoblast-like cells MG-63 were seeded on nanostructured titanium specimens manufactured from rods produced by the equal channel angular pressing. For surface characterization, roughness and wettability were measured. Cell adhesion after 2 h as well as cell proliferation after 48 h from plating was assessed. We have found that this repeated cleaning of titanium surface reduced cell adhesion as well as proliferation. These events depend on interplay of surface properties, such as wettability, roughness and topography. It is difficult to distinguish which factors are responsible for these events and further investigations will be required. However, even after the several rounds of repeated cleaning, there was a certain rate of adhesion and proliferation recorded. Therefore the attempts to save failing implants by using in situ cleaning are promising.

Influence of In-Situ Electrochemical Oxidation on Implant Surface and Colonizing Microorganisms Evaluated by Scanning Electron Microscopy

Peri-implantitis is a worldwide increasing health problem, caused by infection of tissue and bone around an implant by biofilm-forming microorganisms. Effects of peri-implantitis treatment using mechanical debridement, air particle abrasion and electrochemical disinfection on implant surface integrity were compared. Dental implants covered with bacterial biofilm were cleaned using mechanical debridement and air particle abrasion. In addition, implants were disinfected using a novel electrochemical technique based on an array of boron-doped diamond (BDD) coated electrodes. Following treatment and preparation, the implants were inspected by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Mechanical debridement led to changes in surface topography destroying the manufacturer's medium-rough surface by scratch formation. Air particle abrasion led to accumulation of the abrasive used on the implant surface. With both treatment options, appearance of bacteria and yeasts was not affected. In contrast, electrochemical disinfection did not cause alterations of the implant surface but resulted in distorted microbial cells. Electrochemical disinfection of implant surfaces using BDD electrodes may constitute a promising treatment option for cleaning dental implant surfaces without negatively affecting materials and surface properties.

The Effect of Er,Cr:YSGG and Diode Laser Applications on Dental Implant Surfaces Contaminated with Acinetobacter Baumannii and Pseudomonas Aeruginosa

Treatment of peri-implantitis through several implant surface decontamination techniques have been reported, however, some of them can negatively alter the implant surface or enhance more bacterial resistance. The aim of this in vitro study was to evaluate implant surface decontamination by means of Er,Cr:YSGG and diode lasers. Fifty micro-textured (MTX) dental implants were contaminated with Acinetobacter baumannii (n = 25) and with Pseudomonas aeruginosa (n = 25). All implants were then divided into five groups for the decontamination procedure. In group I (GI), decontamination was done with an Er,Cr:YSGG laser (2780 nm), while in group II (GII) decontamination was performed using photodynamic therapy (a 650 nm diode laser). In Group III (GIII) decontamination was performed with photodynamic therapy (an 808 nm diode laser), and in group IV (GIV) decontamination was performed with 0.12% chlorhexidine. Group V (GV) was the control group with no decontamination. After decontamination, colony forming units (CFU) were counted and implants were prepared for SEM analysis. A significant difference (p < 0.001) was observed for GI compared to the other groups, and also for GIV compared to both GII and GIII. The Er,Cr:YSGG laser (GI) showed the best results in decontaminating the implant surface. Chlorhexidine (GIV), proved to be better in decontaminating the implant surface than photodynamic therapy GII and diode laser GIII. No significant difference was found between group GII and GIII. The SEM analysis showed no significant change in the implant surface topography. The results of this study suggest that the Er,Cr:YSGG laser can be considered as an effective technique for reducing bacteria contamination on implant surfaces.