Peri-implantitis in partially edentulous patients: association with inadequate plaque control

Objective: The aim of the present study was to describe some clinical periodontal features of partially edentulous patients referred for the treatment of peri‐implantitis. Material and methods: The 23 subjects involved in this study were selected from consecutive patients referred to the department of Periodontology Södra Älvsborgs Hospital, Borås, Sweden, for treatment of peri‐implantitis during 2006. The patients had clinical signs of peri‐implantitis around one or more dental implants (i.e.≥6 mm pockets, bleeding on pockets and/or pus and radiographic images of bone loss to≥3 threads of the implants) and remaining teeth in the same and/or opposite jaw. The following clinical variables were recorded: Plaque Index (PI), Gingival Bleeding Index (GBI) Probing Pocket Depth (PPD), Access/capability to oral hygiene at implant site (yes/no), Function Time. The patients were categorized in the following sub‐groups: Periodontitis/No periodontitis, Bone loss/No bone loss at teeth, Smoker/Non‐smokers. Results: Out of the 23 patients, the majority (13) had minimal bone loss at teeth and no current periodontitis; 5 had bone loss at teeth exceeding 1/3 of the length of the root but not current periodontitis and only 5 had current periodontitis. Six patients were smokers (i.e. smoking more than 10 cig/day). The site level analysis showed that only 17 (6%) of the 281 teeth present had ≥1 pocket of ≥6mm, compared to 58 (53%) of the total 109 implants (28 ITI^® and 81 Brånemark^®); 74% of the implants had no accessibility to proper oral hygiene. High proportion of implants with diagnosis of peri‐implantitis were associated with no accessibility/capability for appropriate oral hygiene measures, while accessibility/capability was rarely associated with peri‐implantitis. Indeed 48% of the implants presenting peri‐implantitis were those with no accessibility/capability for proper oral hygiene (65% positive predict value) with respect to 4% of the implants with accessibility/capability (82% negative predict value). Conclusion: The results of the study indicate that local factors such as accessibility for oral hygiene at the implant sites seems to be related to the presence or absence of peri‐implantitis. Peri‐implantitis was a frequent finding in subjects having signs of minimal loss of supporting bone around the remaining natural dentition and no signs of presence of periodontitis (i.e. presence of periodontal pockets of ≥6 mm at natural teeth). Only 6 of the examinated subjects were smokers. In view of these results we should like to stress the importance of giving proper oral hygiene instructions to the patients who are rehabilitated with dental implant and of proper prosthetic constructions that allow accessibility for oral hygiene around implants.     

Outcome of surgical treatment of peri-implantitis: results from a 2-year prospective clinical study in humans

Aim: The aim of the present study was to evaluate the outcome of a surgical procedure based on pocket elimination and bone re‐contouring for the treatment of peri‐implantitis. Material and methods: The 31 subjects involved in this study presented clinical signs of peri‐implantitis at one or more dental implants (i.e. ≥6 mm pockets, bleeding on probing and/or suppuration and radiographic evidence of ≥2 mm bone loss). The patients were treated with a surgical procedure based on pocket elimination and bone re‐contouring and plaque control before and following the surgery. At the time of surgery, the amount of bone loss at implants was recorded. Results: Two years following treatment, 15 (48%) subjects had no signs of peri‐implant disease; 24 patients (77%) had no implants with a probing pocket depth of ≥6 mm associated with bleeding and/or suppuration following probing. A total of 36 implants (42%) out of the 86 with initial diagnosis of peri‐implantitis presented peri‐implant disease despite treatment. The proportion of implants that became healthy following treatment was higher for those with minor initial bone loss (2–4 mm bone loss as assessed during surgery) compared with the implants with a bone loss of ≥5 mm (74% vs. 40%). Among the 18 implants with bone loss of ≥7 mm, seven were extracted. Between the 6‐month and the 2‐year examination, healthy implants following treatment tended to remain stable, while deepening of pockets was observed for those implants with residual pockets. Conclusion: The results of this study indicated that a surgical procedure based on pocket elimination and bone re‐contouring and plaque control before and following surgery was an effective therapy for treatment of peri‐implantitis for the majority of subjects and implants. However, complete disease resolution at the site level seems to depend on the initial bone loss at implants. Implants with no signs of peri‐implantitis following treatment tended to remain healthy during the 2‐year period, while a tendency for disease progression was observed for the implants that still showed signs of peri‐implant disease following treatment. To cite this article:
Serino G, Turri A. Outcome of surgical treatment of peri‐implantitis: results from a 2‐year prospective clinical study in humans.
Clin. Oral Impl. Res. 22 , 2011; 1214–1220.
doi: 10.1111/j.1600‐0501.2010.02098.x     

Long‐Term Effect of Surface Roughness and Patients' Factors on Crestal Bone Loss at Dental Implants. A Systematic Review and Meta‐Analysis

Publications from 2011 to 2015 were selected to evaluate effect of implant surface roughness on long‐term bone loss as surrogate for peri‐implantitis risk. 87 out of 2,566 papers reported the mean bone loss after at least 5 years of function. Estimation of the proportion of implants with bone loss above 1, 2, and 3 mm as well as analysis the effect of implant surface roughness, smoking, and history of periodontitis was performed. By means of the provided statistical information of bone loss (mean and standard deviation) the prevalence of implants with bone loss ranging from 1 to 3 mm was estimated. The bone loss was used as a surrogate parameter for “peri‐implantitis” given the fact that “peri‐implantitis” prevalence was not reported in most studies or when reported, the diagnostic criteria were unclear or of dubious quality. The outcome of this review suggests that peri‐implant bone loss around minimally rough implant systems was statistically significant less in comparison to the moderately rough and rough implant systems. No statistically significant difference was observed between moderately rough and rough implant systems. The studies that compared implants with comparable design and different surface roughness, showed less average peri‐implant bone loss around the less rough surfaces in the meta‐analysis. However, due to the heterogeneity of the papers and the multifactorial cause for bone loss, the impact of surface roughness alone seems rather limited and of minimal clinical importance. Irrespective of surface topography or implant brand, the average weighted implant survival rate was 97.3% after 5 years or more of loading. If considering 3 mm bone loss after at least 5 years to represent the presence of “peri‐implantitis,” less than 5% of the implants were affected. The meta‐analysis indicated that periodontal history and smoking habits yielded more bone loss.     

Peri-implantitis: from diagnosis to therapeutics

Peri‐implantitis is an infection of the tissue around an implant, resulting in the loss of supporting bone. Risk factors for peri‐implantitis consist of a history of periodontitis, dental plaque, poor oral hygiene, smoking, alcohol consumption and diabetes. A clinical diagnosis indicates inflammatory signs including bleeding on probing with or without suppuration and a peri‐implant pocket depth ≥5 mm. A radiograph shows images of marginal bone loss ≥2 mm. A differential diagnosis of peri‐implant mucositis, occlusal overload, retrograde peri‐implantitis and inflammatory implant periapical lesions suggests the appropriate treatment in each case. The non‐surgical treatment of peri‐implantitis, including a mechanical treatment alone or combined with antiseptics or antibiotics can improve clinical parameters in the short term but residual defects may still persist. Surgical treatment such as guided bone regeneration results in a gain of clinical attachment level and bone reconstruction in the long term. The limited effect of laser‐assisted therapy needs to be further evaluated. The concept of prevention based on early detection and regular maintenance plays a principal role in reducing the occurrence of peri‐implantitis.     

Immunohistochemical characteristics of inflammatory lesions at implants

Objective: The aim of the present investigation was to study some immunohistochemical features of peri‐implant mucositis and peri‐implantitis lesions. Materials and methods: Two groups of subjects (Groups A and B) were included. Group A consisted of 10 partially edentulous subjects (eight females and two males; 45–72 years of age) who had been restored with implants (Brånemark System^®, Nobel Biocare AB, Göteborg, Sweden). The implants had been in function between 2 and 5 years. In each subject, one implant site demonstrating signs of peri‐implant mucositis, i.e. soft tissue inflammation but no bone loss, was selected. The site was anaesthetized and a soft tissue biopsy was collected. In Group B, six subjects were included. They had been restored with implants (Brånemark System^®, Nobel Biocare AB, Göteborg, Sweden) between 5 and 11 years prior to the current study. In each individual ≥ 1 implant site exhibited signs of peri‐implantitis and was selected for biopsy. All sites of peri‐implantitis had (i) a history of continuous marginal bone loss (assessed in radiographs), (ii) clinical symptoms of soft tissue inflammation (bleeding on probing and suppuration) but (iii) no implant mobility. From each selected peri‐implantitis site a 4 × 4 mm large soft tissue biopsy was obtained. All specimens were snap frozen and prepared for immunohistochemical analysis regarding the proportions of cells positive for the CD3, CD4, CD8, CD19 and elastase markers. Results: Peri‐implantitis lesions were considerably larger and contained significantly greater proportions of B cells (CD19⁺) and elastase‐positive cells than mucositis lesions. Peri‐implantitis sites, in contrast to sites with mucositis, consistently displayed elastase‐positive cells in the central portions of the infiltrate. Conclusion: It is suggested that peri‐implantitis lesions exhibit properties that are different from mucositis lesions.     

Prevalence and Predictive Factors for Peri‐Implant Disease and Implant Failure: A Cross‐Sectional Analysis

Background: Long‐term studies worldwide indicate that peri‐implant inflammation is a frequent finding and that the prevalence of peri‐implantitis correlates with loading time. Implant loss, although less frequent, has serious oral health and economic consequences. An understanding of predictive factors for peri‐implant disease and implant loss would help providers and patients make informed decisions. Methods: A cross‐sectional study was performed on 96 patients with 225 implants that were placed between 1998 and 2003. Implant placement data were collected from patient records, and patients presented for a clinical and radiographic follow‐up examination. Implant status and periodontal status were determined, the data were analyzed to determine the prevalence of peri‐implant disease or implant loss, and a predictive model was tested. Results: The mean follow‐up time for the patients was 10.9 years. The implant survival rate was 91.6%. Peri‐implant mucositis was found in 33% of the implants and 48% of the patients, and peri‐implantitis occurred in 16% of the implants and 26% of the patients. Individuals with peri‐implantitis were twice as likely to report a problem with an implant as individuals with healthy implants. Peri‐implantitis is associated with younger ages and diabetes at the time of placement and with periodontal status at the time of follow‐up. Implant loss is associated with diabetes, immediate placement, and larger‐diameter implants. Conclusions: One in four patients and one in six implants have peri‐implantitis after 11 years. The data suggest that periodontal and diabetes status of the patient may be useful for predicting implant outcomes.     

A Novel Rat Model of Polymicrobial Peri‐Implantitis: A Preliminary Study

Background: Peri‐implantitis is a complex polymicrobial biofilm‐induced inflammatory osteolytic gingival infection that results in orofacial implant failures. To the best knowledge of the authors, there are no preclinical in vivo studies in implant dentistry that have investigated the inflammatory response to known microbial biofilms observed in humans. The aim of this study is to develop a novel peri‐implant rat model using an established model of polymicrobial periodontitis. Methods: Wistar rats were used for the study of experimental peri‐implantitis. One month after extraction of maxillary first molars, a titanium mini‐implant was inserted. Two months after implant healing, implants were uncovered, and abutment fixing was done using cyanoacrylate to prevent abutment loosening. Rats were separated into two groups (group A: polymicrobial‐infected and group B: sham‐infected). One week after healing of abutments, rats were infected with Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia for 12 weeks. Bacterial colonization, bone resorption, and implant inflammation were evaluated by polymerase chain reaction (PCR), microcomputed tomography, and histology, respectively. Results: Three rats with four implants in the infection group and two rats with three implants in the sham‐infection group were analyzed. PCR analysis revealed presence of bacterial genomic DNA, and infection elicited significant immunoglobulin (Ig)G and IgM antibody responses, indicating bacterial colonization/infection around implants. Infection induced an enhanced mean distance from implant platform to the first bone‐to‐implant contact, extensive peri‐implantitis with advanced bone resorption, and extensive inflammation with granulation tissue and polymorphonuclear leukocytes. Conclusions: To the best knowledge of the authors, this is the first study to develop a novel rat model of polymicrobial peri‐implantitis. With modifications to improve implant retention it could offer significant advantages for studies of initiation and progression of peri‐implantitis.     

10‐Year Survival and Success Rates of 511 Titanium Implants with a Sandblasted and Acid‐Etched Surface: A Retrospective Study in 303 Partially Edentulous Patients

Purpose: This retrospective study assessed the 10‐year outcomes of titanium implants with a sandblasted and acid‐etched (SLA) surface in a large cohort of partially edentulous patients. Materials and Methods: Records of patients treated with SLA implants between May 1997 and January 2001 were screened. Eligible patients were contacted and invited to undergo a clinical and radiologic examination. Each implant was classified according to strict success criteria. Results: Three hundred three patients with 511 SLA implants were available for the examination. The mean age of the patients at implant surgery was 48 years. Over the 10‐year period, no implant fracture was noted, whereas six implants (1.2%) were lost. Two implants (0.4%) showed signs of suppuration at the 10‐year examination, whereas seven implants had a history of peri‐implantitis (1.4%) during the 10‐year period, but presented with healthy peri‐implant soft tissues at examination. The remaining 496 implants fulfilled the success criteria. The mean Plaque Index was 0.65 (±0.64), the mean Sulcus Bleeding Index 1.32 (±0.57), the mean Probing Depth 3.27 mm (±1.06), and the mean distance from the implant shoulder to the mucosal margin value ?0.42 mm (±1.27). The radiologic mean distance from the implant shoulder to the first bone‐to‐implant contact was 3.32 mm (±0.73). Conclusion: The present retrospective analysis resulted in a 10‐year implant survival rate of 98.8% and a success rate of 97.0%. In addition, the prevalence of peri‐implantitis in this large cohort of orally healthy patients was low with 1.8% during the 10‐year period.     

Periodontal and peri‐implant diseases: identical or fraternal infections?

Peri‐implant diseases (peri‐implantitis and peri‐implant mucositis) are bacterially driven infections. Peri‐implantitis leads to aggressive bone resorption and eventual loss of the implant. Traditionally, peri‐implantitis was regarded as microbially similar to periodontitis, and translocation of periodontal pathogens into the peri‐implant crevice was considered as a critical factor in disease causation. However, evidence is emerging to suggest that the peri‐implant and periodontal ecosystems differ in many important ways. The purpose of this review is to examine the evidence supporting microbial congruence and discordance in these two communities. Current evidence suggests that osseointegrated implants truly create unique microenvironments that force microbial adaptation and selection. Further studies that revisit the “microbial reservoir” hypothesis and identify species that play an etiologic role in peri‐implant disease and examine their transmission from teeth are needed.     

Initial and long‐term crestal bone responses to modern dental implants

Successful osseointegration is the result of a controlled foreign body reaction to dental implants. Osseointegrated implants have demonstrated excellent long‐term survivability, although they may be subject to limited marginal bone loss. Marginal bone loss during the first few years after implant placement seldom represents disease, but is instead the result of an adaptive bone response to surgical trauma and implant loading. It is not uncommon for implants with early marginal bone loss to enter a long‐lasting state of bone stability. Extensive bone resorption after the first year is generally due to an exacerbation of adverse body reactions caused by non‐optimal implant components, adverse surgery or prosthodontics and/or compromised patient factors. Disease in the form of peri‐implantitis is a late complication that affects some implants with suppuration and rapid loss of crestal bone, and is probably caused by bacterial pathogens and immunological reactions. Unfortunately, the literature is not consistent with respect to the type or magnitude of clinical implant problems, including how they are defined and diagnosed. If the peri‐implantitis diagnosis is confined to cases with infection, suppuration and significant bone loss, the frequency of the disease is relatively low, which is in sharp contrast to the frequencies reported with unrealistic definitions of peri‐implantitis. We suggest that when modern implants are placed by properly trained individuals, only 1–2% of implants show true peri‐implantitis during follow‐up periods of 10 years or more. Peri‐implantitis must be separated from the initial and self‐limiting marginal bone loss.     

Radiographic Analysis of a Transalveolar Sinus‐Lift Technique: A Multipractice Retrospective Study With a Mean Follow‐Up of 5 Years

Background: Various sinus‐lift techniques have been described in the literature. The aim of this retrospective study is to evaluate the efficacy of a transalveolar sinus‐lift technique in terms of implant survival, marginal bone loss, and complications. Methods: A total of 538 patient records were examined, and after applying exclusion and inclusion criteria, a sample of patients was included with a mean follow‐up of 5 years. Implants with a smooth or tapered surface were considered. Therefore, only sinus lifts with inorganic bovine bone matrix or demineralized bone matrix were included, and 1,536 periapical radiographs were analyzed. Outcome measures were implant success, implant failure (peri‐implantitis and loss of osseointegration), marginal bone resorption, and biologic complications (membrane perforations, sinusitis, and intraoperative and/or postoperative hemorrhage). Periapical radiographs were evaluated before surgery, post‐surgery, and after 6 months and 1, 3, and 5 years. We analyzed the residual crestal bone height under the sinus, the amount (mm) of height increase after surgery, and values of implant marginal bone resorption for considered follow‐ups. Results: Two hundred eighty‐two (282) patients were excluded. Therefore, 256 patients treated with the transalveolar sinus‐lift technique were included. A total of 376 dental implants and 323 sinus lifts were analyzed. The overall rates of implant success and failure were 94.9% and 5.1%, respectively. The mean bone loss around implants was 1.98 mm (mean follow‐up of 5 years). Patients treated with inorganic bovine bone matrix showed a better implant success rate (P = 0.03) than did patients treated with demineralized human matrix. Three Schneiderian membrane perforations occurred in the 323 sinus lifts. In these cases, the surgeon performed another surgical operation after 3 months. Postoperative complications were peri‐implantitis (six cases) and osseointegration losses (13 cases). Conclusions: The transalveolar sinus‐lift technique was a safe, minimally invasive technique with an implant success rate comparable to traditional implantology. The implant success rate was positively affected by the low‐resorption graft material, and a low bone‐resorption rate around implants was found.     

Occurrence of peri‐implant diseases and risk indicators at the patient and implant levels: A multilevel cross‐sectional study

Background : High prevalence rates of peri‐implant diseases have been reported; however, the lack of standardization of definition criteria has lead to variations in the observed estimates. In addition, scarce data are available concerning patient and implant related factors associated to peri‐implantitis. The aim of this study was to determine the prevalence of peri‐implant diseases and their risk indicators at the patient and implant levels. Methods : One hundred forty‐seven patients with 490 dental implants were included. Dental implants were clinically and radiographically evaluated to determine their peri‐implant conditions. Patient‐related conditions and implant and prosthetic‐related factors were recorded. Multivariable Poisson regression was fitted and prevalence ratios (PR) were reported. Results : 85.3% of implants (95%CI 80.2 to 90.4) had mucositis and 9.2% (95%CI 4.7 to 13.7) had peri‐implantitis. 80.9% (95%CI 73.8 to 86.8), and 19.1% (95%CI 12.6 to 25.5) of patients had mucositis and peri‐implantitis. At the patient level, it was observed an increased probability of peri‐implantitis in individuals with pocket depths ≥6 mm (PR = 2.47) and with ≥4 implants (PR = 1.96). Smoking increased the probability of peri‐implantitis by three times (PR = 3.49). The final multilevel Poisson regression model at the implant level indicated that platform switching reduced the probability of peri‐implantitis (PR = 0.18) and implants in function for ≥5 years increased this probability (PR = 2.11). The final model including patient and implant level indicators demonstrated that higher time of function (PR = 2.76) and smoking (PR = 6.59) were associated with peri‐implantitis. C onclusion : Peri‐implant diseases are highly prevalent in the studied sample, and factors associated with the occurrence of peri‐implantitis were presence of pockets ≥6 mm, smoking, time of function, and type of platform.     

Clinical follow-up of unilateral, fixed dental prosthesis on maxillary implants

Aims/Background: The aims of the present study were to evaluate (1) the success rate of unilateral maxillary fixed dental prosthesis (FDPs) on implants in patients at a periodontal clinic referred for periodontal treatment, (2) the prevalence of varying mechanical and biological complications and (3) effects of potential risk factors on the success rate. Material and methods: Fifty consecutive patients were invited to participate in a follow‐up. The patients had received FDPs on implants between November 2000 and December 2003 after treatment to achieve optimal peridontal health, and the FDPs had been in function for at least 3 years. A questionnaire was sent to the patients before the follow‐up examination. Forty‐six patients with 116 implants were examined. The follow‐up comprised clinical and radiographic examinations and evaluations of treatment outcome. Results: Before implant treatment, 13% of the teeth were extracted; of these, 80% were extracted due to periodontal disease. No implants had been lost before implant loading. One implant in one patient fractured after 3 years of functional loading and three implants in another patient after 6.5 years. The most frequent mechanical complications were veneer fractures and loose bridge screws. Patients with peri‐implant mucositis had significantly more bleeding on probing around teeth and implants. Patients with peri‐implantitis at the follow‐up had more deep periodontal pockets around their remaining teeth compared with individuals without peri‐implantitis, but these differences were not significant. Smokers had significantly fewer teeth, more periodontal pockets ≥4 mm and a tendency towards greater marginal bone loss at the follow‐up, compared with non‐smokers. Conclusion: In the short term, overloading and bruxism seem more hazardous for implant treatment, compared with a history of periodontitis. To cite this article:
Wahlström M, Sagulin G‐B, Jansson LE. Clinical follow‐up of unilateral, fixed dental prosthesis on maxillary implants
Clin. Oral Impl. Res. 21 , 2010; 1294–1300.
doi: 10.1111/j.1600‐0501.2010.01948.x     

Implant Patient Compliance Varies by Periodontal Treatment History

Background: This retrospective study aims to assess compliance to supportive periodontal therapy (SPT) among patients treated with dental implants with different periodontitis histories and the possible influence of their compliance on peri‐implant marginal bone level. Methods: Dental records of 106 patients treated with at least one dental implant were reviewed. A single operator who did not provide care to the patients recorded the following during the first year of implant function (first year of follow‐up), during the first 5 years of follow‐up, and during the entire follow‐up duration: 1) number of recalls; 2) compliance, calculated from registered attendance; 3) periodontal disease history; 4) peri‐implant radiographic bone level from most recent examination; and 5) clinical parameters including probing depth and bleeding on probing. Clinical and radiographic parameters were assessed at site level and analyzed for possible associations among them and with demographic parameters. Results: Collected data were based on 156 implants with an average of 6.5 ± 3.4 years (range: 1 to 13 years) in function. Patients with periodontitis history demonstrated greater compliance than patients without periodontitis history during the two longer follow‐up times. Over time, the majority of patients demonstrated partial compliance (71% to 80% of patients). Peri‐implant bone level averaged 0.9 ± 1.1 mm, without significant association with compliance level; however, positive periodontitis history and more years in function were significantly associated with greater peri‐implant bone loss. Conclusions: Patients with implants partially comply with scheduled SPT, regardless of periodontitis history. Patients who had received periodontal treatment demonstrated better compliance than those without prior periodontal therapy experiences.     

General genetic and acquired risk factors,and prevalence of peri‐implant diseases – Consensus report of working group 1

For decades, oral implants have been used successfully for the replacement of missing teeth. Nevertheless, peri‐implant diseases have become an increasingly important issue in daily practice. In this working group, the prevalence of peri‐implant mucositis and peri‐implantitis, as well as different general risk factors and their impact on the onset and progression of peri‐implant diseases, were discussed based on reviews reflecting the current state of evidence. The influence of smoking on the peri‐implant bone‐healing process and its association with peri‐implantitis has been explored in the current literature, demonstrating that smoking is an important risk indicator for the development of peri‐implantitis and implant loss. Compared with non‐smokers, smokers have a higher potential for pathological peri‐implant bone loss, which is also influenced by poor oral hygiene. Despite the fact that a growing number of genetic polymorphisms have been identified and related to periodontal diseases, there are still no genetic patterns that could act as adjuncts to clinical diagnostics in order to identify patients at higher risk of peri‐implant diseases. Long‐term medications, such as bisphosphonate therapy (> 3 years), may have an impact on implant loss. A higher incidence of implant failure was reported in patients using selective serotonin reuptake inhibitors in anti‐depression therapy. Alcoholism (defined as more than 5 units a day) has been associated with implant loss in retrospective and case–control studies, as well as in animal studies.     

Association of Preventive Maintenance Therapy Compliance and Peri‐Implant Diseases: A Cross‐Sectional Study

Background: This study aims to investigate association between peri‐implant maintenance therapy (PIMT) and the frequency of peri‐implant diseases and to further identify factors that contribute to failure of PIMT compliance. Methods: A cross‐sectional study on patients who were healthy and partially edentulous was conducted. They were grouped in the following categories according to PIMT compliance: 1) regular compliers (RC) (≥2 PIMT/year); 2) erratic compliers (EC) (<2 PIMT/year); and 3) non‐compliers (NC) (no PIMT). Radiographic and clinical analyses were carried out including probing depth (PD), plaque index (PI), bleeding on probing (BOP), mucosal redness (MR), suppuration (SUP), keratinized mucosa dimension, and marginal bone loss. A multiple logistic regression model was estimated at implant and patient level to obtain adjusted odds ratios (ORs) and to control possible confounding effects among variables. Results: Overall, 206 implants in 115 patients fulfilled inclusion criteria. At patient level, it was shown that association between compliance and peri‐implant condition was statistically significant (P = 0.04). Compliance was associated with 86% fewer conditions of peri‐implantitis. The probability of PIMT compliance was substantially associated with frequency of peri‐implantitis (OR = 0.13, P = 0.01). Patients with a history of periodontal disease multiplied their probability of being EC (versus NC) 4.23 times with respect to not having a history of periodontal disease (P = 0.02). Moreover, light smokers significantly resulted to be NC compared with RC (P = 0.04) and EC (P = 0.02). Nevertheless, mucositis was not found to be statistically associated with level of compliance. In addition, PD, PI, BOP, MR, and SUP varied significantly according to PIMT compliance and peri‐implant condition. Conclusions: Peri‐implant maintenance compliance ≥2 PIMT/year seems to be crucial to prevent peri‐implantitis in healthy patients. Furthermore, history of periodontal disease and disease severity, as well as its extent and a smoking habit, appear to be factors that influence the compliance risk profile (NCT02789306).     

Early intervention of peri‐implantitis and periodontitis using a mouse model

1 Background

Peri‐implantitis is an inflammatory response to bacterial biofilm resulting in bone loss and can ultimately lead to implant failure. Because of the lack of predictable treatments available, a thorough understanding of peri‐implantitis's pathogenesis is essential. The objective of this study is to evaluate and compare the response of acute induced peri‐implantitis and periodontitis lesions after insult removal.

2 Methods

Implants were placed in one‐month‐old C57BL/6J male mice eight weeks post extraction of their left maxillary molars. Once osseointegrated, ligatures were placed around the implants and contralateral second molars of the experimental groups. Controls did not receive ligatures. After one week, half of the ligatures were removed, creating the ligature‐retained and ligature‐removed groups. Mice were sacrificed at two time points, 5 and 14 days, from ligature removal. The specimens were analyzed via micro‐computed tomography and histology.

3 Results

By 5 and 14 days after ligature removal, the periodontitis group experienced significant bone gain, whereas the peri‐implantitis group did not. Histologically, all implant groups exhibited higher levels of cellular infiltrate than any of the tooth groups. Osteoclast numbers increased in peri‐implantitis and periodontitis ligature‐retained groups and decreased following insult removal. Collagen was overall more disorganized in peri‐implantitis than periodontitis for all groups. Peri‐implantitis experimental groups revealed greater matrix metalloproteinase‐8 and NF‐kB levels than periodontitis.

4 Conclusions

Implants respond slower and less favorably to insult removal than teeth. Future research is needed to characterize detailed peri‐implantitis disease pathophysiology.     

Peri-implant health around screw-shaped c.p. titanium machined implants in partially edentulous patients with or without ongoing periodontitis

Abstract: The relationship between periodontitis and peri‐implantitis remains a matter of debate. The present study compared, “within” randomly chosen partially edentulous patients (n=84 subjects, 97 jaws), the marginal bone loss around teeth and implants during 5 years (range 3 to 11 years) following the first year of bone remodelling. The patients had all been rehabilitated by means of screw‐shape c.p. titanium implants with a machined surface (Brånemark system^®). During the 5 years observation interval, periodontal parameters (marginal bone and attachment loss, the latter for teeth only) were collected together with data on confounding factors (smoking, oral hygiene, tooth loss). Marginal bone loss was measured through long‐cone intra‐oral radiographs. The mean “interval” bone loss was significantly (P=0.0001) higher around teeth (0.48±0.95 mm) than around implants (0.09±0.28 mm). The corresponding data for the “worst” performing tooth (0.99±1.25 mm) and implant (0.19±0.32 mm) per subject showed the same tendency. Neither attachment nor bone loss around teeth correlated with marginal bone loss around implants. This study indicated that the rate of bone loss around screw‐shape c.p. titanium implants with a machined surface (Brånemark system^® implants) was not influenced by the progression rate of periodontal destruction around the remaining teeth within the same jaw.     

Analysis of cathepsin-K activity at tooth and dental implant sites and the potential of this enzyme in reflecting alveolar bone loss

Background: Cathepsin‐K is an enzyme involved in bone metabolism which may make this feature important for both natural teeth and dental implants. The aims of the present study are to comparatively analyze the gingival crevicular fluid (GCF)/peri‐implant sulcus fluid (PISF) cathepsin‐K levels of natural teeth and dental implants, and to assess the potential relationship between this biochemical parameter and alveolar bone loss around natural teeth and dental implants. Methods: Probing depth, bleeding on probing, gingival index, and plaque index clinical parameters were assessed, and GCF/PISF samples were obtained from natural teeth/dental implants presenting with either clinical health, gingivitis/peri‐implant mucositis, or chronic periodontitis/peri‐implantitis. Cathepsin‐K activity levels of 42 GCF samples and 54 PISF samples were determined, and marginal bone loss (MBL) measures were calculated from digitalized standardized intraoral periapical radiographs obtained from natural teeth and dental implants by using cemento‐enamel junction and the actual distance between two consecutive threads of the dental implant as reference points for natural teeth and dental implants, respectively. Results: Comparing the natural teeth group with dental implant group with regard to MBL measure, cathepsin‐K activity, and GCF/PISF volume revealed no significant differences. In both natural teeth and dental implant groups, despite higher MBL measures, cathepsin‐K activity, and GCF/PISF volumes with the presence of inflammation, it was the presence of alveolar bone loss that lead to significantly higher values for these parameters. Conclusion: We suggest cathepsin‐K as a biochemical parameter for monitoring periodontal/peri‐implant alveolar bone loss.     

Clinical Outcomes of Using Lasers for Peri‐Implantitis Surface Detoxification: A Systematic Review and Meta‐Analysis

The aim of this systematic review is to compare the clinical outcomes of lasers with other commonly applied detoxification methods for treating peri‐implantitis. An electronic search of four databases and a hand search of peer‐reviewed journals for relevant articles were conducted. Comparative human clinical trials and case series with ≥6 months of follow‐up in ≥10 patients with peri‐implantitis treated with lasers were included. Additionally, animal studies applying lasers for treating peri‐implantitis were also included. The included studies had to report probing depth (PD) reduction after the therapy. Results: Seven human prospective clinical trials and two animal studies were included. In four and three human studies, lasers were accompanied with surgical and non‐surgical treatments, respectively. The meta‐analyses showed an overall weighted mean difference of 0.00 mm (95% confidence interval = ?0.18 to 0.19 mm) PD reduction between the laser and conventional treatment groups (P = 0.98) for non‐surgical intervention. In animal studies, laser‐treated rough‐surface implants had a higher percentage of bone‐to‐implant contact than smooth‐surface implants. In a short‐term follow‐up, lasers resulted in similar PD reduction when compared with conventional implant surface decontamination methods.