Prevalence, Etiology and Treatment of Peri-Implant Mucositis and Peri-Implantitis: A Survey of Periodontists in the United States

Impact of surface chemical treatment in surgical regenerative treatment of ligature-induced peri-implantitis: A canine study

BACKGROUND

Implant surface decontamination is a critical step in peri-implantitis treatment. The aim of this study was to assess the effect chemotherapeutic agents have on reosseointegration after treatment on ligature-inducted peri-implantitis.

METHODS

Six male canines had 36 implants placed and ligatures were placed around them for 28 weeks to establish peri-implantitis. The peri-implant defects were randomly treated by 1 of 3 methods: 0.12% chlorhexidine (CHX test group), 1.5% sodium hypochlorite (NaOCl test group), or saline (Control group). Sites treated with NaOCl and CHX were grafted with autogenous bone, and all sites then either received a collagen membrane or not. Histology sections were obtained at 6 months postsurgery to assess percentage of reosseointegration.

RESULTS

Thirty-five implants were analyzed (CHX: 13; NaOCl: 14; Control:8). NaOCl-treated sites demonstrated reosseointegration with direct bone-to-implant-contact on the previously contaminated surfaces (42% mean reosseointegration), which was significantly higher than Controls (p < 0.05). Correspondingly, clinical improvement was noted with a significant reduction in probing depth from 5.50 ± 1.24 mm at baseline to 4.46 ± 1.70 mm at 6-months postsurgery (p = 0.006). CHX-treated sites demonstrated a nonsignificant reosseointegration of 26% (p > 0.05); however, in the majority of cases, the new bone growth was at a distance from the implant surface without contact. Probing depths did not improve in the CHX group. The use of membrane did not influence reosseointegration or probing depths (all p > 0.05).

CONCLUSION

Titanium implants with peri-implantitis have the capacity to reosseointegrate following regenerative surgery. However, treatment response is contingent upon the chemotherapeutic agent selection. Additional chemical treatment with 1.5% NaOCl lead to the most favorable results in terms of changes in defect depth and percentage of reosseointegration as compared to CHX, which may hinder reosseointegration.

Periodontists and oral surgeons' peri-implantitis-related education, knowledge, attitudes, and professional behavior: A national survey

OBJECTIVES

Each year, approximately 5 million dental implants are placed in the United States and one out of three patients is likely to experience peri-implantitis (PI). The objectives were to compare the PI-related education, knowledge, attitudes, and professional behavior of periodontists and oral maxillofacial surgeons (OMS), and to explore relationships between these constructs of interest.

METHODS

A total of 389 periodontists and 161 OMS responded to a web-based survey. Descriptive and inferential statistical analyses (independent sample t-tests, chi-square tests, and correlational analyses) were conducted.

RESULTS

On average, periodontists reported a higher percentage of time spent in residency on implant surgery (21.02% vs. 7.27%; p < 0.001), better education about PI (5-point scale with 1 = not at all well: means: 2.86 vs. 2.59; p < 0.001), and better knowledge of risk factors (4.07 vs. 3.86; p < 0.001) than OMS. Periodontists argued that oral hygiene-related treatment (4.45 vs. 4.22; p = 0.001) and regeneration-focused treatments such as guided tissue regeneration (3.62 vs. 3.20; p < 0.001) contributed more to successfully treating PI and used these treatments more in their practices (4.86 vs. 4.56; p < 0.001/3.06 vs. 2.68; p < 0.001) than OMS. They also considered PI as a more serious problem than OMS (4.55 vs. 3.80; p < 0.001). The better the respondents' PI-related knowledge was, the more they considered PI as a serious problem (r = 0.19; p < 0.001). The more cases they treated per month, the more they considered PI as a serious problem (r = 0.19; p < 0.001).

CONCLUSIONS

The results of the present study highlight the lack of standardization in the specialty training of periodontists and OMS. Best practice guidelines for the diagnosis and treatment of PI are needed to optimize graduate education about this important topic.

Prevalence of Peri-Implant Mucositis, Peri-Implantitis and Associated Risk Indicators of Implants with and without Laser-Microgrooved Collar Surface: A Long-Term (≥20 Years) Retrospective Study

The aim of the current study was to retrospectively investigate the prevalence of peri-implant mucositis (PIM) and peri-implantitis (P) in a long-term follow-up (≥20 years) of implants with the same body design and body surface but different collar surfaces with laser-microtextured grooves (LMGSs) vs. no laser-microtextured grooves (no-LMGSs) in private practice patients. Furthermore, several patient-related, implant-related, site-, surgical-, and prosthesis-related potential disease risk factors were analyzed. A chart review of patients receiving at least one pair of implants (one with an LMGS and the other without LMGS) in the period 1993-2002 was used. Chi-square analysis was used to determine if a statistically significant difference between the investigated variables and PIM/P was present. Possible risk factors were statistically evaluated by a binary logistic regression analysis. A total of 362 patients with 901 implant-supported restorations (438 with LMGS and 463 no-LMGS) were included in the study. The cumulative survival rates of implants at 5, 10, 15, and 20 years were 98.1%, 97.4%, 95.4%, and 89.8%, respectively, for the LMGS group, and 93.2%, 91.6%, 89.5%, and 78.3% for the no-LMGS group. The difference was statistically significant at all timepoints (p < 0.05). In total, at the end of the follow-up period, 45.7% of patients and 39.8% of implants presented PIM, and 15.6% of patients and 14% of implants presented P. A total of 164 LMGS implants (37.4%) and 195 no-LMGS implants (42.1%) presented peri-implant mucositis, while 28 (6.3%) of LMGS implants and 98 (21.1%) no-LMGS implants demonstrated peri-implantitis. Differences between LMGS implants and no-LMGS implants were statistically significant (p < 0.05). The binary logistic regression identified collar surface, cigarette smoking, histories of treated periodontitis, and lack of peri-implant maintenance as risk factors for P. After at least 20 years of function in patients followed privately, LMGS implants compared to no-LMGS implants presented a statistically and significantly lower incidence of P. Implant collar surface, cigarette smoking, previously treated periodontitis, and lack of peri-implant maintenance are factors with significant association to P.

Predictive factors for the treatment success of peri-implantitis: a protocol for a prospective cohort study

INTRODUCTION

Peri-implantitis, a common biological complication of dental implant, has attracted considerable attention due to its increasing prevalence and limited treatment efficacy. Previous studies have reported several risk factors associated with the onset of peri-implantitis (eg, history of periodontitis, poor plaque control and smoking). However, inadequate data are available on the association between these risk factors and successful outcome after peri-implantitis therapy. This prospective cohort study aims to identify the local and systemic predictive factors for the treatment success of peri-implantitis.

METHODS AND ANALYSIS

A single-centre cohort study will be conducted by recruiting 275 patients diagnosed with peri-implantitis. Sociodemographic variables, healthy lifestyles and systemic disorders will be obtained using questionnaires. In addition, clinical and radiographic examinations will be conducted at baseline and follow-up visits. Treatment success is defined as no bleeding on probing on more than one point, no suppuration, no further marginal bone loss (≥0.5 mm) and probing pocket depth ≤5 mm at the 12-month follow-up interval. After adjustment for age, sex and socioeconomic status, potential prognostic factors related to treatment success will be identified using multivariable logistic regression models.

ETHICS AND DISSEMINATION

This cohort study in its current version (2.0, 15 July 2022) is in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of Stomatological Hospital, Southern Medical University (EC-CT-(2022)34). The publication will be on behalf of the study site.

TRIAL REGISTRATION NUMBER

ChiCTR2200066262.

Knowledge and attitude of dental students regarding etiology, diagnosis, and treatment of peri-implantitis

OBJECTIVE

The objective of this study was to assess the level of knowledge and attitude of dental students about the etiology, diagnosis, and management of peri-implantitis.

METHODS

An online cross-sectional study that targeted senior undergraduate dental students at the College of Dentistry was conducted. A closed-ended survey consisting of 28 questions was designed. Three sections were created: 1) participants' characteristics; 2) Knowledge of peri-implantitis etiology, risk factors, diagnosis, and complications; 3) The use of antibiotics in peri-implantitis, diagnosis, and treatment methods. SPSS version 22 (IBM Corp.) was used for data analysis. Counts and percentages were calculated for correct answers in each section.

RESULTS

A total of 267 dental students responded to the questionnaire. The majority of the participants (81.6%) were knowledgeable about peri-implantitis being an inflammatory reaction, and a lesser percentage (77.9%) knew that bacterial plaque is an etiologic factor for peri-implant diseases. 82.0% of the participants identified smoking as a risk factor, followed by periodontitis (80.5%). Regarding implant complications, 57.3% of the participants considered implant mobility as a definitive indication for implant removal. More than half of the participants reported using crater-like bone defects surrounding implants to diagnose peri-implantitis. The most commonly used antibiotic was amoxicillin (34.1%), followed by amoxicillin combined with metronidazole (26.9%).

CONCLUSION

Most participants had a basic understanding of the etiology and risk factors of peri-implantitis. On the other hand, more courses addressing peri-implantitis diagnosis are needed.

The Effectiveness of the Association of Chlorhexidine with Mechanical Treatment of Peri-Implant Mucositis

(1) Background: The aim of the study was to evaluate the benefit of combining chlorhexidine with the mechanical treatment of peri-implant mucositis. (2) Methods: Articles from 2016 to 2021 included in the PubMed and Scopus databases were analyzed, following the PICOS criteria and the randomized controlled study model that used chlorhexidine in various forms in the treatment of peri-mucositis. According to the established criteria, a limited number of studies were selected. These studies had as their criteria of evaluation for the effectiveness of chlorhexidine, plaque indices, bleeding indices and depth probing indices. Chlorhexidine has been used after mechanical debridement as a solution, with different concentrations of 0.06%/0.12%/0.2% alone or in a concentration of 0.03%, in combination with 0.05% cetylpyridinium chloride, as well as in the form of a gel with a concentration of 0.2%. (3) Results: The results were assessed to a placebo or other substances, and showed a significant reduction in the indices with a follow-up period ranging from 3 months to 1 year. (4) Conclusions: The association of chlorhexidine with the mechanical treatment of peri-implant mucositis has a role in reducing inflammation, although a complete remission was not obtained in all cases, and the results were not statistically significantly different from the use of other antiseptics.

A comparative evaluation of lasers and photodynamic therapy in the nonsurgical treatment of peri-implant diseases: A Bayesian network meta-analysis

PURPOSE

We conducted this Bayesian network meta-analysis (NMA) to evaluate the safety and efficacy of different lasers and PDT compared to conventional mechanical debridement (CMD) for peri-implant treatment.

METHODS

The Web of Science, Cochrane Library and PubMed databases were searched for randomized clinical trials (RCTs) assessing the clinical effectiveness of adjunctive PDT, different lasers, and CMD until January 1st, 2022. Clinical outcomes were the changes in pocket probing depth (PPD), marginal bone loss (MBL), and clinical attachment level (CAL).

RESULTS

Twenty-three studies, including 4 types of lasers, were included. Compared to that with CMD alone, PPD reduction was significantly more efficient in the diode laser (LD)+CMD groups (MD, 0.53; 95%CI, 0.13-0.93) and the PDT+CMD groups (MD, 0.83; 95%CI, 0.32-1.34) than in the CMD group in the follow-up period. Moreover, PDT+CMD treatment also showed a significantly better marginal bone level gain (MD, 0.32; 95%CI, 0.06-0.57). No significant effect on ΔCAL was observed among the different treatment strategies. Despite no differences in PPD reduction, MBL and CAL gains were found among the adjunctive laser treatment groups, PDT+CMD had the highest ranking probability of the most effective treatment in these clinical indices of periodontitis. The certainty of evidence for all outcomes was judged as very low to moderate.

CONCLUSIONS

Within the limits of this NMA, we found that adjunctive PDT achieved a small additional benefit on PPD reduction and MBL gain compared with CMD alone and had the highest probability of being ranked first on the changes in PPD, MBL and CAL. PDT+CMD may represent an alternative method for peri‑implant treatment. Further high-quality RCTs are needed to assess the influence of potential confounders on the efficacy of lasers and PDT.

In it together: Candida-bacterial oral biofilms and therapeutic strategies

Under natural environmental settings or in the human body, the majority of microorganisms exist in complex polymicrobial biofilms adhered to abiotic and biotic surfaces. These microorganisms exhibit symbiotic, mutualistic, synergistic, or antagonistic relationships with other species during biofilm colonization and development. These polymicrobial interactions are heterogeneous, complex and hard to control, thereby often yielding worse outcomes than monospecies infections. Concerning fungi, Candida spp., in particular, Candida albicans is often detected with various bacterial species in oral biofilms. These Candida-bacterial interactions may induce the transition of C. albicans from commensal to pathobiont or dysbiotic organism. Consequently, Candida-bacterial interactions are largely associated with various oral diseases, including dental caries, denture stomatitis, periodontitis, peri-implantitis, and oral cancer. Given the severity of oral diseases caused by cross-kingdom consortia that develop hard-to-remove and highly drug-resistant biofilms, fundamental research is warranted to strategically develop cost-effective and safe therapies to prevent and treat cross-kingdom interactions and subsequent biofilm development. While studies have shed some light, targeting fungal-involved polymicrobial biofilms has been limited. This mini-review outlines the key features of Candida-bacterial interactions and their impact on various oral diseases. In addition, current knowledge on therapeutic strategies to target Candida-bacterial polymicrobial biofilms is discussed.

Bone Augmentation for Implant Placement: Recent Advances

There are various advancements in biomaterials and methods for bone augmentation. This article aims to review the recent advances in bone augmentation for dental implants. Relevant articles on bone augmentation for dental implants were searched in PubMed/Medline, Scopus, Google Scholar, and Science Direct published in English literature published between January 1996 and March 2021. Relevant studies on bone grafts for dental implants were included and critically analyzed in this review. Various biomaterials can be used to augment bone for implant placement. Each graft procedure has advantages and disadvantages in each clinical application and needs to choose the graft material with a high success rate and less morbidity.

Fusobacterium nucleatum: The Opportunistic Pathogen of Periodontal and Peri-Implant Diseases

Peri-implant diseases are considered to be a chronic destructive inflammatory destruction/damage occurring in soft and hard peri-implant tissues during the patient’s perennial use after implant restoration and have attracted much attention because of their high incidence. Although most studies seem to suggest that the pathogenesis of peri-implant diseases is similar to that of periodontal diseases and that both begin with microbial infection, the specific mechanism of peri-implant diseases remains unclear. As an oral opportunistic pathogen, Fusobacterium nucleatum (F. nucleatum) has been demonstrated to be vital for the occurrence and development of many oral infectious diseases, especially periodontal diseases. More notably, the latest relevant studies suggest that F. nucleatum may contribute to the occurrence and development of peri-implant diseases. Considering the close connection between peri-implant diseases and periodontal diseases, a summary of the role of Fusobacterium nucleatum in periodontal diseases may provide more research directions and ideas for the peri-implantation mechanism. In this review, we summarize the effects of F. nucleatum on periodontal diseases by biofilm formation, host infection, and host response, and then we establish the relationship between periodontal and peri-implant diseases. Based on the above aspects, we discuss the importance and potential value of F. nucleatum in peri-implant diseases.

The efficacy of systemic antibiotics as an adjunct to surgical treatment of peri-implantitis: a systematic review

BACKGROUND

Microbial biofilm accumulation is the main cause of peri-implantitis. The majority of surgical peri-implantitis treatment protocols suggests adjunctive use of systemic antibiotics to target specific putative bacteria. The aim of this systematic review was to critically evaluate the adjunctive use of systemically administered antibiotics in surgical treatment of peri-implantitis by reviewing previously published systematic reviews and primary studies.

METHODS

A systematic literature search was conducted in four electronic databases (MEDLINE, The Cochrane Library, EMBASE, and Web of Science) for randomised controlled trials, cohort studies, case-control studies, and systematic reviews reporting surgical treatment of peri-implantitis with and without adjunctive systemically administered antibiotic therapy. The included systematic reviews and primary studies were qualitatively assessed using AMSTAR and GRADE, respectively. No restrictions were set for date of publication, journal, or language.

RESULTS

The literature search identified 681 papers. Only seven systematic reviews and two primary studies met the inclusion criteria. Four out of seven included systematic reviews concluded that no evidence exists for use of systemic antibiotics to improve the clinical outcomes in surgical treatment of peri-implantitis. One review did not estimate the level of evidence, one did not clearly state any beneficial effect, whereas one reported a limited adjunctive effect. Further, the two included primary studies did not show a long-term significant benefit of adjunctive use of systemically administrated antibiotics. However, one study reported a short-term adjunctive effect in patients with modified surface implants. Due to heterogeneity in study design, low number of included primary studies, and grade of bias, no meta-analysis was performed.

CONCLUSION

The use of systemically administered antibiotics as an adjunct to surgical interventions of peri-implantitis cannot be justified as a part of a standard treatment protocol. A pervasive problem is the lack of uniform diagnosis criteria for peri-implantitis, deficient information about patient characteristics, absence of high quality long-term randomised controlled trials, and authors' declaration on conflict of interest.

Peri-Implantitis: Application of a Protocol for the Regeneration of Deep Osseous Defects. A Retrospective Case Series

Background and aims: Peri-implantitis is a complex pathology, both in its diagnosis and in the identification of etiological causes. Although we have been studying more and more over the years to try to answer the many questions that remain regarding everything that circulates around this disease which affects implants, nothing has yet been taken as an official consensus regarding its surgical treatment. There are still many proposed protocols, each of which has been shown to have comforting results and promising prospects, but no total predictability. The aim of this case series is to assess the clinical outcomes of a mixed protocol for the regeneration of deep osseous defects. Materials and methods: The data and clinical records of 23 patients, with 29 implants affected by peri-implantitis treated surgically in private practice, were analyzed retrospectively. The method used for the surgical treatment was a mixed protocol of mechanical–chemical decontamination and bone regeneration with bovine xenograft. Results: All patients were followed for at least 2 years, averaging 28.9 months (a range of 24–38 months) with a reduction in the probing depth (PD) at one year from the initial 8.14 ± 1.156 mm to 3.72 ± 0.649 mm, and to 4.14 ± 1.093 mm at the final assessment. The differences between assessment time points were always statistically significant. The data regarding bleeding on probing (BoP) and suppuration also showed a statistically significant reduction at the final time point compared to the baseline. Only one patient, at 24 months, still showed BoP, suppuration, and a PD deeper than 5 mm, indicating a recurrence of the disease compared to the initial improvement of the PD (5 mm) at one year. Conclusions: In conclusion, within the limits of this retrospective analysis, it can be affirmed that this combined mechanical–chemical and regenerative decontamination therapy is effective in the treatment of peri-implantitis.

Peri-Implant Health and the Knowing-Doing Gap—A Digital Survey on Procedures and Therapies

Objectives: Peri-implant tissue maintenance and treatment is becoming a serious challenge in implantology. With increasing numbers of implants being placed, more cases of peri-implant mucositis and peri-implantitis is seen. A digital survey on peri-implant disease management was issued to experts in periodontology and implantology to identify the tools and procedures most commonly used today to treat peri-implant diseases and successfully manage peri-implant health. The primary aim was to assess whether there is consensus in the choice of treatment to manage peri-implant diseases and to prevent their recurrence once treated. The secondary aim was to obtain insight into future protocols and /or devices, and the research and development needed.

Materials and Methods: Participants in this digital survey were professionals specialising in periodontology, oral surgery, and implant dentistry. The questionnaire included both a series of closed- and open-ended questions. A total of 16 countries participated. The survey was sent by e-mail to 70 individuals, 66 received the survey and 37 of receivers responded, two of the participants were excluded due to insufficient filling of the survey. In the end 35 respondents completed the survey.

Results: Respondents agree that the efficacy of mechanical and chemical decontamination of implant surfaces needs to be improved and better documented. It is a common opinion that the current remedies, mostly adapted from periodontal practises, do not provide effective and reliable clinical outcomes when treating peri-implant ailments. There is a general agreement amongst experts that regularly scheduled (3–6-month intervals) maintenance treatments are essential for maintaining peri-implant health in patients experiencing implant complications. Respondents are also concerned about unnecessary use of systemic antibiotics for managing peri-implant health.

Conclusion: Regardless of agreements in parts, there was no observed consensus on the most effective treatment options for treating peri-implantitis. The experts all agree it is an urgent need for well-designed, long-term follow-up randomised and controlled clinical trials comparing interventions to provide an evidence-based strategy for peri-implant health management.

Risk factors, diagnosis and treatment of peri-implantitis: A cross-cultural comparison of U.S. and European periodontists' considerations

BACKGROUND

Peri-implantitis (PI) is a growing concern in the dental community worldwide. The study aimed to compare U.S. vs. European periodontists' considerations of risk factors, diagnostic criteria, and management of PI.

MATERIALS AND METHODS

393 periodontists from the U.S. and 100 periodontists from Europe (Germany, Greece, Netherlands) responded to anonymous surveys electronically or by mail.

RESULTS

Compared to U.S. periodontists, European respondents were younger, more likely to be female and placed fewer implants per month (9.12 vs. 13.90;p = 0.003). Poor oral hygiene, history of periodontitis, and smoking were considered as very important risk factors by both groups (rated >4 on 5-point scale). European periodontists rated poor oral hygiene (4.64 vs. 4.45;p = 0.005) and history of periodontitis (4.36 vs. 4.10;p = 0.006) as more important and implant surface (2.91 vs. 3.18;p = 0.023), occlusion (2.80 vs. 3.75;p<0.001) and presence of keratinized tissue (3.27 vs. 3.77;p<0.001) as less important than did U.S. periodontists. Both groups rated clinical probing, radiographic bone loss, and presence of bleeding and suppuration as rather important diagnostic criteria. They rated implant exposure/mucosal recession as relatively less important with U.S. periodontists giving higher importance ratings than European periodontists (3.99 vs. 3.54;p = 0.001). Both groups nearly always used patient education, plaque control and mechanical debridement when treating PI. U.S. periodontists were more likely to use antibiotics (3.88 vs. 3.07;p<0.001), lasers (2.11 vs. 1.68;p = 0.005), allograft (3.39 vs. 2.14;p<0.001) and regenerative approaches (3.57 vs. 2.56;p<0.001), but less likely to use resective surgery (3.09 vs. 3.53;p<0.001) than European periodontists.

CONCLUSIONS

U.S. and European periodontists' considerations concerning risk factors, diagnosis and management of PI were evidence-based. Identified differences between the two groups can inform future educational efforts. This article is protected by copyright. All rights reserved.

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.

Dentists' preferences in implant maintenance and hygiene instruction

BACKGROUND

This study investigated the preferences of dentists in Australia in providing professional implant maintenance and implant-specific oral hygiene instructions (OHI).

METHODS

General dentists were surveyed online about their preferences in peri-implant diagnostics, maintenance provision, armamentarium used, and implant OHI techniques and frequency.

RESULTS

Most of the 303 respondents (96%) provided maintenance services; 87.6% reviewed implants regularly while 10.7% only performed diagnostics after detecting clinical signs/symptoms. Supragingival prosthesis cleaning was performed by 77.9% of respondents, 35.0% performed subgingival debridement, 41.9% treated peri-implant mucositis and 18.2% treated peri-implantitis. About 15% did not treat nor refer peri-implant disease, including significantly more non-implant providers and dentists without implant training. Maintenance armamentarium commonly included floss (76.3%), prophylaxis (73.9%), plastic curettes (43.3%) and stainless-steel ultrasonics (38.0%). Brushing (86.5%), flossing (73.9%) and interdental brush use (68.3%) were most commonly recommended. Implant OHI was repeated routinely by 57.4% of dentists who provided it. Dentists with greater implant training and experience were more likely to perform reviews and complex maintenance procedures.

CONCLUSIONS

Peri-implant diagnostics performed, treatments provided and armamentarium varied among dentists. Implant providers and those with higher levels of training had more preventative approaches to implant OHI. Possible shortcomings in disease management and OHI reinforcement were identified.

Diagnosis of Biofilm-Associated Peri-Implant Disease Using a Fluorescence-Based Approach

Dental implants have become a routine component of daily dental practice and the demand for dental implants is expected to increase significantly in the future. Despite the high success rates of dental implants, failures do occur, resulting in discomfort, rampant destruction of the oral health, or painful and costly surgical replacement of a failed implant. Peri-implant diseases are inflammatory conditions affecting the soft/hard tissues surrounding a functional dental implant. Plenty of experimental evidence indicates that the accumulation of dental plaque at the soft tissue-implant interface and the subsequent local inflammatory response seems to be key in the pathogenesis of the peri-implant mucositis. Such peri-implant-soft tissue interface is less effective than natural teeth in resisting bacterial invasion, enhancing vulnerability to subsequent peri-implant disease. Furthermore, in certain individuals, it will progress to peri-implantitis, resulting in alveolar bone loss and implant failure. Although early diagnosis and accurate identification of risk factors are extremely important to effectively prevent peri-implant diseases, current systematic reviews revealed that a uniform classification and diagnostic methodology for peri-implantitis are lacking. Recent progress on fluorescence-based technology enabled rapid diagnosis of the disease and effective removal of plaques. Here, we briefly review biofilm-associated peri-implant diseases and propose a fluorescence-based approach for more accurate and objective diagnoses. A fluorescence-based diagnosis tool through headlights combined with special-filtered dental loupes may serve as a hands-free solution for both precise diagnosis and effective removal of plaque-biofilms.

In vitro Interactions between Streptococcus intermedius and Streptococcus salivarius K12 on a Titanium Cylindrical Surface

Peri-implantitis is a steadily rising disease and is caused by oral bacterial pathogens able to form biofilm on implant surfaces and peri-implant tissues, making antibiotics treatment less effective. The use of commercial probiotics against oral pathogens could serve as an alternative to prevent biofilm formation. Streptococcus intermedius is one of the early colonizers of biofilm formation in dental implants. The aim of this study was to model the interaction between S. intermedius and Streptococcus salivarius strain K12, a probiotic bacterium producing bacteriocins. S. intermedius was co-cultured with S. salivarius K12 in an in vitro model simulating the biofilm formation in a dental implant composed by a titanium cylinder system. Biofilm formation rate was assessed by Real-Time PCR quantification of bacterial count and expression levels of luxS gene, used in response to cell density in the biofilm. Biofilm formation, bacteriocin production, luxS expression patterns were found to be already expressed within the first 12 h. More importantly, S. salivarius K12 was able to counter the biofilm formation in a titanium cylinder under the tested condition. In conclusion, our dental implant model may be useful for exploring probiotic-pathogen interaction to find an alternative to antibiotics for peri-implantitis treatment.

Repeated delivery of chlorhexidine chips for the treatment of peri-implantitis: A multicenter, randomized, comparative clinical trial

BACKGROUND

Peri-implantitis is a challenging condition to manage and is frequently treated using non-surgical debridement. The local delivery of antimicrobial agents has demonstrated benefit in mild to moderate cases of peri-implantitis. This study compared the safety and efficacy of chlorhexidine gluconate 2.5 mg chip (CHX chips) as an adjunctive treatment to subgingival debridement in patients afflicted with peri-implantitis.

METHODS

A multicenter, randomized, single-blind, two-arm, parallel Phase-3 study was conducted. Peri-implantitis patients with implant pocket depths (IPD) of 5-8 mm underwent subgingival implant surface debridement followed by repeated bi-weekly supragingival plaque removal and chlorhexidine chips application (ChxC group) for 12 weeks, or similar therapy but without application of ChxC (control group). All patients were followed for 24 weeks. Plaque and gingival indices were measured at every visit whereas IPD, recession, and bleeding on probing were assessed at 8, 12, 16, 24 week.

RESULTS

A total of 290 patients were included: 146 in the ChxC group and 144 in the control. At 24 weeks, a significant reduction in IPD (P = 0.01) was measured in the ChxC group (1.76 ± 1.13 mm) compared with the control group (1.54 ± 1.13 mm). IPD reduction of ≥2 mm was found in 59% and 47.2% of the implants in the ChxC and control groups, respectively (P = 0.03). Changes in gingival recession (0.29 ± 0.68 mm versus 0.15 ± 0.55 mm, P = 0.015) and relative attachment gain (1.47 ± 1.32 mm and 1.39 ± 1.27 mm, P = 0.0017) were significantly larger in the ChxC group. Patients in the ChxC group that were < 65 years exhibited significantly better responses (P < 0.02); likewise, non-smokers had similarly better response (P < 0.02). Both protocols were well tolerated, and no severe treatment-related adverse events were recorded throughout the study.

CONCLUSIONS

Patients with peri-implantitis that were treated with an intensive treatment protocol of bi-weekly supragingival plaque removal and local application of chlorhexidine chips had greater mean IPD reduction and greater percentile of sites with IPD reduction of ≥2 mm as compared with bi-weekly supra-gingival plaque removal.

Effect of implant cleaning on titanium particle dissolution and cytocompatibility

BACKGROUND

Peri-implantitis treatments are mainly based on protocols for teeth but have not shown favorable outcomes for implants. The potential role of titanium dissolution products in peri-implantitis necessitate the consideration of material properties in devising treatment protocols. We assessed implant cleaning interventions on (1) bacterial removal from Ti-bound biofilms, (2) Ti surface alterations and related Ti particle dissolution, and (3) cytocompatibility.

METHODS

Acid-etched Ti discs were inoculated with human peri-implant plaque biofilms and mechanical antimicrobial interventions were applied on the Ti-bound biofilms for 30 seconds each: (1) rotary nylon brush; (2) Ti brush; (3) water-jet on high and (4) low, and compared to sterile, untreated and Chlorhexidine-treated controls. We assessed colony forming units (CFU) counts, biofilm removal, surface changes via scanning electron microscopy (SEM) and atomic force microscopy (AFM), and Ti dissolution via light microscopy and Inductively-coupled Mass Spectrometry (ICP-MS). Biological effects of Ti particles and surfaces changes were assessed using NIH/3T3 fibroblasts and MG-63 osteoblastic cell lines, respectively.

RESULTS

Sequencing revealed that the human biofilm model supported a diverse biofilm including known peri-implant pathogens. WJ and Nylon brush were most effective in reducing CFU counts (P < 0.01 versus control), whereas Chlorhexidine was least effective; biofilm imaging results were confirmatory. Ti brushes led to visible streaks on the treated surfaces, reduced corrosion resistance and increased Ti dissolution over 30 days of material aging as compared to controls, which increase was amplified in the presence of bacteria (all P-val < 0.05). Ti particles exerted cytotoxic effects against fibroblasts, whereas surfaces altered by Ti brushes exhibited reduced osteoconductivity versus controls (P < 0.05).

CONCLUSIONS

Present findings support that mechanical treatment strategies selected for implant biofilm removal may lead to Ti dissolution. Ti dissolution should become an important consideration in the clinical selection of peri-implantitis treatments and a necessary criterion for the regulatory approval of instruments for implant hygiene.

An Update on Antimicrobial Peptides (AMPs) and Their Delivery Strategies for Wound Infections

Bacterial infections occur when wound healing fails to reach the final stage of healing, which is usually hindered by the presence of different pathogens. Different topical antimicrobial agents are used to inhibit bacterial growth due to antibiotic failure in reaching the infected site, which is accompanied very often by increased drug resistance and other side effects. In this review, we focus on antimicrobial peptides (AMPs), especially those with a high potential of efficacy against multidrug-resistant and biofilm-forming bacteria and fungi present in wound infections. Currently, different AMPs undergo preclinical and clinical phase to combat infection-related diseases. AMP dendrimers (AMPDs) have been mentioned as potent microbial agents. Various AMP delivery strategies that are used to combat infection and modulate the healing rate-such as polymers, scaffolds, films and wound dressings, and organic and inorganic nanoparticles-have been discussed as well. New technologies such as Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-associated protein (CRISPR-Cas) are taken into consideration as potential future tools for AMP delivery in skin therapy.

Management of Peri-Implant Diseases: A Survey of Australian Periodontists

BACKGROUND/AIM

This survey-based study aims to explore the clinical management protocols of followed by Australian periodontists in relation to peri-implant diseases.

MATERIALS AND METHODS

A five-part online questionnaire was developed and administered through email. Descriptive statistics were used for analysis, with the univariate associations between a categorical outcome and the variables evaluated using Pearson's Chi-squared test.

RESULTS

The survey yielded 99 responses, resulting in a response rate of 41.8%. Most participants were male and aged 35-44 years. More than a quarter of practitioners had been placing implants for 6-10 years and almost two-fifths of practitioners placed 1-10 implants per month. The estimated prevalence of peri-implant mucositis and peri-implantitis in the general Australian population was 47% and 21%, respectively. Practitioners reported using systemic antibiotics to manage peri-implant mucositis (7%) and (72%) peri-implantitis lesions, with a combination of amoxicillin and metronidazole. Most common treatment modalities were oral hygiene instructions, nonsurgical debridement and antimicrobial gel/rinse. Surgical debridement and systemic antibiotics were also often used for peri-implantitis treatment. Practitioners preferred a 3-month clinical follow-up and 6-month radiographic evaluation. Furthermore, three-quarters of practitioners rated their management as moderately effective, although upwards of nine-tenths expressed the need for further training and awareness.

CONCLUSION

This study confirms a significant use of empirical treatment modalities due to lack of standard therapeutic protocol. However, some approaches followed by the specialists may provide a basis to formulate a therapeutic protocol for peri-implant disease management.

Laser-assisted regenerative surgical therapy for peri-implantitis: A randomized controlled clinical trial

BACKGROUND

Different surgical approaches have been proposed to treat peri-implantitis defects with limited effectiveness and predictability. Laser has been proposed as an effective tool to assist in bacterial decontamination and modulating peri-implant tissue inflammation. The aim of this pilot clinical trial was to evaluate the adjunctive benefits of Er:YAG laser irradiation for regenerative surgical therapy of peri-implantitis-associated osseous defects.

METHODS

Twenty-four patients diagnosed with peri-implantitis with a radiographic infrabony defect were randomized into two groups. Both test and control groups received the following treatment: open flap mechanical debridement, supracrestal implantoplasty, bone grafting using a mixture of human allograft with demineralized bone matrix human allograft putty, and then covered with acellular dermal matrix membrane. The only difference in the test group was the adjunctive use of Er:YAG laser to modulate and remove inflammatory tissue as well as to decontaminate the implant surface. Clinical assessments, including pocket depth (PD), clinical attachment level (CAL), and gingival index (GI) were performed by calibrated masked examiners for up to 6 months following surgery. Standardized radiographs were also taken to evaluate linear bone gain and defect bone fill. Student t-tests were used to analyze those clinical parameters.

RESULTS

Both groups showed significant reductions in PD, GI, and CAL gain overtime. The test group demonstrated significantly higher PD reductions at the site level compared to the control group (2.65 ± 2.14 versus 1.85 ± 1.71 mm; test versus control, P = 0.014). There were no statistical differences found in CAL gain (1.90 ± 2.28 versus 1.47 ± 1.76 mm; test versus control), GI reduction (-1.14 ± 1.15 versus -1.04 ± 0.89; test versus control), radiographic linear bone gain (1.27 ± 1.14 versus 1.08 ± 1.04 mm; test versus control) or proportional defect size reduction (- 24.46 ± 19.00% versus -15.19 ± 23.56%; test versus control). There was a positive trend for test patients on PD reduction and CAL gain found in narrow infrabony defects. Major membrane exposure negatively impaired the overall treatment outcome of CAL gain (2.47 ± 1.84 versus 1.03 ± 1.48 mm; no/minor versus major exposure, P = 0.051) and PD reduction in the test group (-3.63 ± 2.11 versus -1.66 ± 1.26 mm, P = 0.049).

CONCLUSION

This pilot study indicated using laser irradiation during peri-implantitis regenerative therapy may aid in better probing PD reduction. Nonetheless, a larger sample size and longer follow-up is needed to confirm if Er:YAG laser irradiation provides additional clinical benefits for peri-implantitis regenerative therapy (Clinicaltrials.gov: NCT03127228).

The effect of adjuvant oral irrigation on self-administered oral care in the management of peri-implant mucositis: A randomized controlled clinical trial

OBJECTIVES

This single-blinded randomized clinical trial evaluated the effect of adjuvant oral irrigation in addition to self-administered oral care on prevalence and severity of peri-implant mucositis.

MATERIAL & METHODS

After randomization, patients suffering from peri-implant mucositis were assigned to the following: Group 1 (control) received oral hygiene instruction following a standardized protocol, including a sub- and supramucosal mechanical debridement. Group 2 and 3 additionally were instructed to use an oral irrigator with either water or 0.06% CHX solution. One implant per patient was considered for examination. Clinical examinations included Probing Depth, Bleeding on Probing (BOP-positive sites), and Modified Plaque and Gingival Index. A surrogate variable (mucositis severity score) was applied measuring severity of disease. Statistical analysis included linear regression models and sensitivity analysis.

RESULTS

Sixty periodontally healthy patients were examined for presence and severity of peri-implant mucositis. 70% of all patients reached complete resolution of disease after 12 weeks. The prevalence of peri-implant mucositis after 12 weeks was 50% in group 1, 35% in group 2, and 5% in group 3. Average BOP-positive sites were reduced in all groups after 12 weeks (mean change from baseline: group 1: -1.5; group 2: -1.8; group 3: -2.3).

CONCLUSION

Within the limits of the study, adjuvant use of an oral irrigator with 0.06% CHX in addition to mechanical biofilm removal and oral hygiene instruction can reduce the presence and severity of peri-implant mucositis after 12 weeks.

Reosseointegration after the surgical treatment of induced peri-implantitis: systematic review on current evidence and translation from the animal to the human model

INTRODUCTION

The aim of this study was to review the histologic evidence of reosseointegration and related influencing factors in experimental induced peri-implantitis.

EVIDENCE ACQUISITION

An electronic search was performed on Medline for animal studies that included a histometric evaluation of the amount of regenerated bone in contact with an implant surface. Questions raised in the study focused on the role of implant surfaces, bone regeneration and decontamination treatments in achieving reosseointegration. A detailed electronic search was then conducted on MEDLINE (PubMed) up to July 2017.

EVIDENCE SYNTHESIS

One hundred and one articles were selected as abstract, thirty-seven articles assessed as full-text and sixteen finally included in the study. Reported measurements of reosseointegration varied significantly in the study, from 0 to 3.37 mm. There is histological evidence that reosseointegration can occur after treatment of ligature-induced peri-implantitis. However regenerated bone in contact with bone is generally restricted to the most apical portion of the peri-implant defect.

CONCLUSIONS

Animal studies of induced peri-implantitis seem to indicate that rough surfaces can enhance reosseointegration as compared to smooth surfaces. With regard to bone regeneration techniques and materials, submerged healing and barrier membranes have shown a positive effect on reosseointegration. No evidence exists, however, about the specific role of different bone substitutes and their ability to improve bone formation. Growth factors have been shown to improve reosseointegration in animal models, though additional study is required to confirm the data. Several decontamination treatments have been shown to promote reosseointegration compared to control; however no specific procedure has proven superior to others in achieving reosseointegration.

Mechanism of Action of Surface Immobilized Antimicrobial Peptides Against Pseudomonas aeruginosa

Bacterial colonization and biofilm development on medical devices can lead to infection. Antimicrobial peptide-coated surfaces may prevent such infections. Melimine and Mel4 are chimeric cationic peptides showing broad-spectrum antimicrobial activity once attached to biomaterials and are highly biocompatible in animal models and have been tested in Phase I and II/III human clinical trials. These peptides were covalently attached to glass using an azidobenzoic acid linker. Peptide attachment was confirmed using X-ray photoelectron spectroscopy and amino acid analysis. Mel4 when bound to glass was able to adopt a more ordered structure in the presence of bacterial membrane mimetic lipids. The ability of surface bound peptides to neutralize endotoxin was measured along with their interactions with the bacterial cytoplasmic membrane which were analyzed using DiSC(3)-5 and Sytox green, Syto-9, and PI dyes with fluorescence microscopy. Leakage of ATP and nucleic acids from cells were determined by analyzing the surrounding fluid. Attachment of the peptides resulted in increases in the percentage of nitrogen by 3.0% and 2.4%, and amino acid concentrations to 0.237 nmole and 0.298 nmole per coverslip on melimine and Mel4 coated surfaces, respectively. The immobilized peptides bound lipopolysaccharide and disrupted the cytoplasmic membrane potential of Pseudomonas aeruginosa within 15 min. Membrane depolarization was associated with a reduction in bacterial viability by 82% and 63% for coatings melimine and Mel4, respectively (p < 0.001). Disruption of membrane potential was followed by leakage of ATP from melimine (1.5 ± 0.4 nM) or Mel4 (1.3 ± 0.2 nM) coated surfaces compared to uncoated glass after 2 h (p < 0.001). Sytox green influx started after 3 h incubation with either peptide. Melimine coatings yielded 59% and Mel4 gave 36% PI stained cells after 4 h. Release of the larger molecules (DNA/RNA) commenced after 4 h for melimine (1.8 ± 0.9 times more than control; p = 0.008) and after 6 h with Mel4 (2.1 ± 0.2 times more than control; p < 0.001). The mechanism of action of surface bound melimine and Mel4 was similar to that of the peptides in solution, however, their immobilization resulted in much slower (approximately 30 times) kinetics.

Peri-implant health, peri-implant mucositis, and peri-implantitis: Case definitions and diagnostic considerations

The objective of this review is to identify case definitions and clinical criteria of peri-implant healthy tissues, peri-implant mucositis, and peri-implantitis. The case definitions were constructed based on a review of the evidence applicable for diagnostic considerations. In summary, the diagnostic definition of peri-implant health is based on the following criteria: 1) absence of peri-implant signs of soft tissue inflammation (redness, swelling, profuse bleeding on probing), and 2) the absence of further additional bone loss following initial healing. The diagnostic definition of peri-implant mucositis is based on following criteria: 1) presence of peri-implant signs of inflammation (redness, swelling, line or drop of bleeding within 30 seconds following probing), combined with 2) no additional bone loss following initial healing. The clinical definition of peri-implantitis is based on following criteria: 1) presence of peri-implant signs of inflammation, 2) radiographic evidence of bone loss following initial healing, and 3) increasing probing depth as compared to probing depth values collected after placement of the prosthetic reconstruction. In the absence of previous radiographs, radiographic bone level ≥3 mm in combination with BOP and probing depths ≥6 mm is indicative of peri-implantitis.

Pyrosequencing of the subgingival microbiome in peri-implantitis after non-surgical mechanical debridement therapy

BACKGROUND AND OBJECTIVES

Peri-implantitis remains a challenge for dental implant therapy, and the prognosis of non-surgical therapy for peri-implantitis is unsatisfactory. In order to reveal the impact of non-surgical mechanical debridement therapy on microbial communities, we investigated the subgingival microbial communities of healthy implants and implants with peri-implantitis, both before and after the therapy.

MATERIAL AND METHODS

Subgingival plaques were collected from patients with healthy dental implants (HC; n = 10) and from patients with peri-implantitis (n = 13) before and after non-surgical mechanical debridement therapy. The treatment was conducted using curettes for submucosal debridement followed by irrigation with 0.2% (w/v) chlorhexidine, with re-examination 1 month later. 16S rRNA pyrosequencing was used to analyze the subgingival microbiome, and co-occurrence networks were adopted to explore the interactions between pathogens in the microbial communities.

RESULTS

A total of 506 955 high-quality reads were generated, and 2222 operational taxonomic units were finally detected using a 97% similarity cutoff, with a mean of 249 ± 69 per sample. The peri-implantitis sites harbored similar microbial communities before and after the treatment, as demonstrated by the microbial diversity, relative abundance, and prevalence of bacteria. Most importantly, the microbial community structures were stable before and after non-surgical therapy based on the microbial diversity and bacterial composition, as well as the interactions between key pathogens, including Enterobacteriaceae, Selenomonas sputigena, Parvimonas, Eubacterium infirmum, Campylobacter gracilis, Tannerella forsythia, and Fusobacterium, which were measured using a co-occurrence network analysis. Periodontal pathogens were also detected in subgingival plaque after the treatment. Distinct microbial communities were found between the healthy and peri-implantitis sites.

CONCLUSION

Our results demonstrate that non-surgical mechanical debridement therapy did not significantly affect the subgingival microbial communities in peri-implantitis, and the stable microbial networks created via interactions among pathogens may be responsible for the poor prognosis of peri-implantitis treatment.

Peri-implant health, peri-implant mucositis, and peri-implantitis: Case definitions and diagnostic considerations

The objective of this review is to identify case definitions and clinical criteria of peri-implant healthy tissues, peri-implant mucositis, and peri-implantitis. The case definitions were constructed based on a review of the evidence applicable for diagnostic considerations. In summary, the diagnostic definition of peri-implant health is based on the following criteria: 1) absence of peri-implant signs of soft tissue inflammation (redness, swelling, profuse bleeding on probing), and 2) the absence of further additional bone loss following initial healing. The diagnostic definition of peri-implant mucositis is based on following criteria: 1) presence of peri-implant signs of inflammation (redness, swelling, line or drop of bleeding within 30 seconds following probing), combined with 2) no additional bone loss following initial healing. The clinical definition of peri-implantitis is based on following criteria: 1) presence of peri-implant signs of inflammation, 2) radiographic evidence of bone loss following initial healing, and 3) increasing probing depth as compared to probing depth values collected after placement of the prosthetic reconstruction. In the absence of previous radiographs, radiographic bone level ≥3 mm in combination with BOP and probing depths ≥6 mm is indicative of peri-implantitis.

Host response and peri-implantitis

Considering the absence of predictable and effective therapeutic interventions for the treatment of peri-implantitis, scientific evidence concerning the host response profile around dental implants could be important for providing in the future a wider preventive and/or therapeutic window for this peri-implant lesion, indicating biomarkers that provide quantifiable measure of response to peri-implant therapy. Moreover, a better knowledge of pattern of host osteo-immunoinflammatory modulation in the presence of peri-implantitis could either benefit the early diagnostic of the disease or to cooperate to prognostic information related to the status of the peri-implant breakdown. Finally, new evidences concerning the host profile of modulators of inflammation and of osseous tissue metabolism around dental implants could explain the individual susceptibility for developing peri-implant lesions, identifying individuals or sites with increased risk for peri-implantitis. The focus of this chapter was, based on a systematically searched and critically reviewed literature, summarizing the existing knowledge in the scientific research concerning the host osteo-immunoinflammatory response to the microbiological challenge related to periimplantitis.

Peri-implantitis and extracellular matrix antibodies: A case-control study

OBJECTIVE

The aim of this case-control study was to compare patients with a healthy peri-implant environment and patients affected by peri-implantitis, evaluating the occurrence of antibodies to extracellular matrix (ECM) molecules. The authors hypothesized the presence of ECM autoantibodies in serum of peri-implantitis patients.

MATERIALS AND METHODS

Patients were divided into two groups: one with dental implants with a diagnosis of peri-implantitis and one control group with implants classified as being "healthy." Enzyme-linked immunosorbent assay was performed on patients' sera to detect human antibodies to type I, III, IV, and V collagens, laminin, and fibronectin. Fisher exact test was performed to evaluate statistical association, with a significant P < 0.05.

RESULTS

Forty-two patients were enrolled in this study, 27 females (64.28%) and 15 males (35.72%) with a mean age of 53 ± 29.69 years (age range 32-74). The presence of antibodies to CIII was recorded in 6/21 (28.57%) patients of test group, compared to just 2/21 (9.52%) for the control group, showing a statistically significant difference (P < 0.05). Other antibodies tested were found to be not statistically significant or absent.

CONCLUSIONS

Within the limitations of this study, it can be concluded that further studies, with larger sample and different design, are necessary to address the research purpose, evaluating possible associations between anti-ECM antibodies and peri-implantitis.

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.

Nonsurgical Treatment of Peri-implantitis Without Eliminating Granulation Tissue: A 3-Year Study

OBJECTIVES

The purpose of this study was to evaluate a nonsurgical approach toward peri-implantitis by means of mechanical debridement and local detoxification leaving granulation tissue into the peri-implant pockets.

MATERIALS AND METHODS

An analysis was performed on the outcomes of 2 nonsurgical protocols: mechanical debridement plus chemical detoxification with 0.2% chlorhexidine and chlortetracycline hydrochloride (test), and mechanical debridement alone (control). Measures were collected at baseline, 3, 24, and 36 months after treatment.

RESULTS

Seventy-five implants with peri-implantitis were included. At a 36-month evaluation, mean pocket probing depth was 3.15 ± 0.32 mm for the test group and 5.97 ± 0.90 mm for the control group, the difference being significant. An improvement of marginal bone level was recorded for the test group, whether the control group showed a further marginal bone loss. Treatment success was 100% in the test group and 31.4% in the control group.

CONCLUSION

Nonsurgical implant debridement alone seemed not efficient in the treatment of peri-implantitis. Further longitudinal studies are required to evaluate the efficacy of mechanical debridement with chemical detoxification and removal of granulation tissues against mechanical debridement with chemical detoxification alone.

Doxycycline Release of Dental Implants With Nanotube Surface, Coated With Poly Lactic-Co-Glycolic Acid for Extended pH-controlled Drug Delivery

When dental implants become infected, the progression of the disease is rapid. Commercially available dental implant surfaces can be easily contaminated, resulting in rapid progression of peri-mucositis and peri-implantitis. The aim of this study was to evaluate, in vitro, the pattern of doxycycline release from by dental implants with titanium nanotube surface (DINS) at different pHs to examine novel drug loading and chemical coating techniques. Nine DINS were loaded with doxycycline and subsequently coated with polylactic-co-glycolic acid (PLGA). High-performance liquid chromatography (HPLC) was used to measure the amounts of released doxycycline in a 30-day period. Cytotoxicity of the DINS was evaluated by an assay using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT). The results showed that the experimental DINS coated with doxycycline and PLGA showed a mean drug release during the experimental period for the groups: pH 7.4 (8.39 μg/mL), pH 6.4 (8.63 μg/mL). The pH 5.4 (15.18 μl/mL) doxycycline release from DINS was faster at pH 5.4 than those at pHs 6.4 and 7.4 (P = .0031 and .0034, respectively). This new surface treatment of dental implants with titanium nanotubes and subsequent drug loading demonstrated biocompatibility and sustained doxycycline release over a 30-day period. Additional studies are needed in order to adopt a stable drug release at neutral pH environment while warranting a constant drug release in an acidic pH environment.

Longitudinal study on risk indicators for peri-implantitis using survival-time analysis

PURPOSE

The purpose of this study was to evaluate the incidence of peri-implantitis and to identify potential associated risk indicators.

METHODS

This longitudinal study included 477 patients treated with 1420 implants. Medical and dental histories were evaluated in all patients. The location, size, connection type, surgical protocol, use of prosthesis splinting and fixation type were evaluated for each implant. In peri-implant evaluation, minimum keratinized tissue width around implants, peri-implant probing depths, peri-implant bleeding and peri-implant suppuration were assessed. Bone resorption around implants was evaluated with intraoral radiographs at baseline and at follow-up examinations. The study endpoint was peri-implantitis, which was defined as the presence of bleeding on probing and/or suppuration with bone resorption >1mm, in accordance with previous studies. Data were analyzed with mixed-effects Cox models.

RESULTS

Peri-implantitis occurred in 15.3% of patients and 9.2% of implants. The overall 5- and 10-year cumulative implant survival rates were 0.95 (95% confidence interval [CI]: 0.93-0.96) and 0.83 (95% CI: 0.8-0.87), respectively. Age (hazard ratio [HR]=0.94, 95% CI: 0.90-0.98, p<0.01), plaque control record >20% (HR=2.61, 95% CI: 1.02-6.67, p=0.04), maxillary placement (HR=1.90, 95% CI: 1.11-3.23, p=0.02) and number of occlusal supports (HR=0.87, 95% CI: 0.77-0.99, p=0.03) were significantly correlated with peri-implantitis development.

CONCLUSIONS

Within the limitations of this longitudinal study on risk indicators for peri-implantitis, age, inadequate plaque control, insertion in the maxilla and less occlusal support of natural teeth correlated with peri-implantitis development.

A Review of the Epithelial Cell Rests of Malassez on the Bicentennial of Their Description

The epithelial cell rests of Malassez (ERM) were first described in 1817, yet their significance has remained an enigma for more than 200 years. Given their embryological origins and persistence in adult periodontal tissue, recent research has investigated whether the ERM could be useful as stem cells to regenerate tissues lost as a consequence of periodontitis. The objective of this review is to describe results of studies that have vigorously investigated the functional capabilities of ERM, particularly with regard to periodontal ligament homeostasis and prevention of dentoalveolar ankylosis. The significance of the ERM relative to evolution of the dental attachment apparatus will be examined. The current status of use of ERM as stem cells for dental tissue engineering and in other applications will be reviewed.

Experience with bruxism in the everyday oral implantology practice in the Netherlands: a qualitative study

Objective

To explore how bruxism is dealt with by accredited oral implantologists within daily clinical practice.

Materials and methods

Nine semi-structured interviews of oral implantologists practicing in non-academic clinical practices in the Netherlands were performed, and thematic analysis was conducted using a framework-based approach.

Results

Oral implant treatments in bruxing patients were a generally well-accepted practice. Complications were often expected, with most being of minor impact. Contradictive attitudes emerged on the topic of bruxism being an etiologic factor for peri-implant bone loss and loss of osseointegration. Views on the ideal treatment plan varied, though the importance of the superstructure’s occlusion and articulation features was repeatedly pointed at. Similarly, views on protective splints varied, regarding their necessity and material choice. Bruxism was diagnosed mainly by clinical examination, alongside with patient anamnesis and clinician’s intuition. There was little attention for awake bruxism.

Discussion

Bruxism was generally not considered a contraindication for implantological treatments by accredited oral implantologists. Views on the interaction between bruxism and bone loss/loss of osseointegration varied, as did views on the ideal treatment plan.

Conclusions

There is a need for better understanding of the extent to which, and under which circumstances, sleep and/or awake bruxism can be seen as causal factors for the occurrence of oral implant complications.

Comparing the Antimicrobial In Vitro Efficacy of Amoxicillin/Metronidazole against Azithromycin-A Systematic Review

On account of its proven clinical efficacy, the combination of systemically administered amoxicillin and metronidazole is frequently adjuncted to non-operative periodontal therapy and well documented. Potential drawbacks of this regimen, e.g., side effects and problems with the compliance, led to an ongoing search for alternatives. Azithromycin, an antibiotic extensively used in general medicine, has recently found its niche in periodontal therapy as well. This systematic review aimed to analyze the in vitro antimicrobial efficacy of amoxicillin plus metronidazole versus azithromycin. For this purpose, a systematic literature search was performed, and studies published up to 29 March 2018 referenced in Medline, Embase, Cochrane, and Biosis were independently screened by two authors. An additional hand search was performed and studies focusing on the evaluation of in vitro antimicrobial efficacy of amoxicillin + metronidazole or azithromycin on bacteria from the subgingival biofilm were included. English and German language research reports were considered. From 71 identified articles, only three articles were eligible for inclusion. These studies showed heterogeneity in terms of analytical methods and strains explored. However, all studies used multispecies biofilm models for analysis of the antimicrobial activity. Unanimously, studies reported on more pronounced antimicrobial effects when applying the combination of amoxicillin + metronidazole, compared to azithromycin. Based on the few studies available, the combination of amoxicillin + metronidazole seemed to display higher antimicrobial efficacy in vitro than azithromycin.

Engineered chimeric peptides with antimicrobial and titanium-binding functions to inhibit biofilm formation on Ti implants

Titanium (Ti) implants have been commonly used in oral medicine. However, despite their widespread clinical application, these implants are susceptible to failure induced by microbial infection due to bacterial biofilm formation. Immobilization of chimeric peptides with antibacterial properties on the Ti surface may be a promising antimicrobial approach to inhibit biofilm formation. Here, chimeric peptides were designed by connecting three sequences (hBD-3-1/2/3) derived from human β-defensin-3 (hBD-3) with Ti-binding peptide-l (TBP-l: RKLPDAGPMHTW) via a triple glycine (G) linker to modify Ti surfaces. Using X-ray photoelectron spectroscopy (XPS), the properties of individual domains of the chimeric peptides were evaluated for their binding activity toward the Ti surface. The antimicrobial and anti-biofilm efficacy of the peptides against initial settlers, Streptococcus oralis (S. oralis), Streptococcus gordonii (S. gordonii) and Streptococcus sanguinis (S. sanguinis), was evaluated with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Transmission electron microscopy (TEM) and real-time quantitative PCR (qRT-PCR) were used to study cell membrane changes and the underlying antimicrobial mechanism. Compared with the other two peptides, TBP-1-GGG-hBD3-3 presented stronger antibacterial activity and remained stable in saliva and serum. Therefore, it was chosen as the best candidate to modify Ti surfaces in this study. This peptide inhibited the growth of initial streptococci and biofilm formation on Ti surfaces with no cytotoxicity to MC3T3-E1 cells. Disruption of the integrity of bacterial membranes and decreased expression of adhesion protein genes from S. gordonii revealed aspects of the antibacterial mechanism of TBP-1-GGG-hBD3-3. We conclude that engineered chimeric peptides with antimicrobial activity provide a potential solution for inhibiting biofilm formation on Ti surfaces to reduce or prevent the occurrence of peri-implant diseases.

Silicon Nitride (Si3N4) Implants: The Future of Dental Implantology?

For decades titanium has been the preferred material for dental implant fabrication, with mechanical and biological performance resulting in high clinical success rates. These have been further enhanced by incremental development of surface modifications aimed at improving speed and degree of osseointegration and resulting in enhanced clinical treatment options and outcomes. However, increasing demand for metal-free dental restorations has also led to the development of ceramic-based dental implants, such as zirconia. In orthopedics, alternative biomaterials, such as polyetheretherketone or silicon nitride, have been used for implant applications. The latter is potentially of particular interest for oral use as it has been shown to have antibacterial properties. In this article we aim to shed light on this particular biomaterial as a future promising candidate for dental implantology applications, addressing basic specifications required for any dental implant material. In view of available preclinical data, silicon nitride seems to have the essential characteristics to be a candidate for dental implants material. This novel ceramic has a surface with potentially antimicrobial properties, and if this is confirmed in future research, it could be of great interest for oral use.