Tord Berglundh

Definition and prevalence of peri-implant diseases.

OBJECTIVES The aim of the current review was to describe the prevalence of peri-implant diseases including peri-implant mucositis and peri-implantitis. MATERIAL AND METHODS A MEDLINE search (PubMed) until December 2007 was conducted and different keywords related to the prevalence of peri-implant diseases were used. Cross-sectional and longitudinal studies including > or =50 implant-treated subjects exhibiting a function time of > or =5 years were considered. RESULTS AND CONCLUSION The current review revealed that only a few studies provided data on the prevalence of peri-implant diseases. Cross-sectional studies on implant-treated subjects are rare and data from only two study samples were available. Peri-implant mucositis occurred in approximately 80% of the subjects and in 50% of the implants. Peri-implantitis was found in 28% and > or =56% of subjects and in 12% and 43% of implant sites.

Effectiveness of Implant Therapy Analyzed in a Swedish Population: Prevalence of Peri-implantitis

Peri-implantitis is an inflammatory disease affecting soft and hard tissues surrounding dental implants. As the global number of individuals that undergo restorative therapy through dental implants increases, peri-implantitis is considered as a major and growing problem in dentistry. A randomly selected sample of 588 patients who all had received implant-supported therapy 9 y earlier was clinically and radiographically examined. Prevalence of peri-implantitis was assessed and risk indicators were identified by multilevel regression analysis. Forty-five percent of all patients presented with peri-implantitis (bleeding on probing/suppuration and bone loss >0.5 mm). Moderate/severe peri-implantitis (bleeding on probing/suppuration and bone loss >2 mm) was diagnosed in 14.5%. Patients with periodontitis and with ≥4 implants, as well as implants of certain brands and prosthetic therapy delivered by general practitioners, exhibited higher odds ratios for moderate/severe peri-implantitis. Similarly, higher odds ratios were identified for implants installed in the mandible and with crown restoration margins positioned ≤1.5 mm from the crestal bone at baseline. It is suggested that peri-implantitis is a common condition and that several patient- and implant-related factors influence the risk for moderate/severe peri-implantitis (ClinicalTrials.gov NCT01825772).

Primary prevention of peri-implantitis: managing peri-implant mucositis

AIMS Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considered as a preventive measure for the onset of peri-implantitis. Therefore, the remit of this working group was to assess the prevalence of peri-implant diseases, as well as risks for peri-implant mucositis and to evaluate measures for the management of peri-implant mucositis. METHODS Discussions were informed by four systematic reviews on the current epidemiology of peri-implant diseases, on potential risks contributing to the development of peri-implant mucositis, and on the effect of patient and of professionally administered measures to manage peri-implant mucositis. This consensus report is based on the outcomes of these systematic reviews and on the expert opinion of the participants. RESULTS Key findings included: (i) meta-analysis estimated a weighted mean prevalence for peri-implant mucositis of 43% (CI: 32-54%) and for peri-implantitis of 22% (CI: 14-30%); (ii) bleeding on probing is considered as key clinical measure to distinguish between peri-implant health and disease; (iii) lack of regular supportive therapy in patients with peri-implant mucositis was associated with increased risk for onset of peri-implantitis; (iv) whereas plaque accumulation has been established as aetiological factor, smoking was identified as modifiable patient-related and excess cement as local risk indicator for the development of peri-implant mucositis; (v) patient-administered mechanical plaque control (with manual or powered toothbrushes) has been shown to be an effective preventive measure; (vi) professional intervention comprising oral hygiene instructions and mechanical debridement revealed a reduction in clinical signs of inflammation; (vii) adjunctive measures (antiseptics, local and systemic antibiotics, air-abrasive devices) were not found to improve the efficacy of professionally administered plaque removal in reducing clinical signs of inflammation. CONCLUSIONS Consensus was reached on recommendations for patients with dental implants and oral health care professionals with regard to the efficacy of measures to manage peri-implant mucositis. It was particularly emphasized that implant placement and prosthetic reconstructions need to allow proper personal cleaning, diagnosis by probing and professional plaque removal.

Immediate functional loading of implants in single tooth replacement: a prospective clinical multicenter study

OBJECTIVES The aim of the present study was to evaluate the outcome of immediate functional loading of implants in single-tooth replacement using two different installation procedures. MATERIAL AND METHODS One hundred and fifty-one subjects, who required single-tooth rehabilitation in the area of 15-25 and 35-45, were enrolled in eight private clinics in Italy. The implant sites were randomly allocated to one of the following treatment groups. In the control group, in which a standard preparation procedure for implant placement and submerged healing of the implant was used, abutment connection and loading of the implants were performed 3 months after installation. In the test group 1, a standard preparation procedure for the implant placement and immediate functional loading of implant was carried out. In the test 2 group, however, a modified implant installation procedure (osteotome technique) was used followed by immediate functional loading of the implant. Clinical and radiographic examinations were performed at 3 and 12 months of follow-up at all sites. RESULTS Three implants (5.5%) from the test 2 group (osteotome preparation) and one (2%) from the test 1 group (conventional drill preparation) failed to integrate and were removed one and three months after implant installation. The mean marginal bone loss assessed at 12 months was 0.31 mm (test 1), 0.25 mm (test 2) and 0.38 mm (control) (no statistically significant differences were found between the three treatment groups.) CONCLUSION It is suggested that immediate functional loading of implants that are placed with a conventional installation technique and with sufficient primary stability may be considered as a valid treatment alternative in a single-tooth replacement.

Implant surface characteristics influence the outcome of treatment of peri-implantitis: an experimental study in dogs.

AIM To analyse the effect of surgical treatment of peri-implantitis without systemic antibiotics at different types of implants. MATERIAL AND METHODS Four implants representing four different implant systems - turned (Biomet 3i), TiOblast (Astra Tech AB), SLA (Straumann AG) and TiUnite (Nobel Biocare AB) were placed in the left side of the mandible in six dogs, 3 months after tooth extraction. Experimental peri-implantitis was initiated by placement of ligatures and plaque formation. The ligatures were removed when about 40-50% of the supporting bone was lost. Four weeks later, surgical therapy including mechanical cleaning of implant surfaces was performed. No systemic antibiotics or local chemical antimicrobial therapy were used. After 5 months, block biopsies were obtained and prepared for histological analysis. RESULTS Two of the TiUnite implants were lost after surgical therapy. Radiographic bone gain occurred at implants with turned, TiOblast and SLA surfaces, while at TiUnite implants additional bone loss was found after treatment. Resolution of peri-implantitis was achieved in tissues surrounding implants with turned and TiOblast surfaces. CONCLUSION Resolution of peri-implantitis following treatment without systemic or local antimicrobial therapy is possible but the outcome of treatment is influenced by implant surface characteristics.

Longevity of teeth and implants - a systematic review.

The objective of this systematic review was to describe the incidence of tooth and implant loss reported in long-term studies. Prospective longitudinal studies reporting on teeth or implants survival with a follow-up period of at least 10 years were considered. Papers were excluded if the drop out rate exceeded 30% or if <70% of the initial subject sample was examined at 10 years of follow-up. Seventy publications on teeth were identified as potentially relevant for the focussed question. The analysis of the abstracts yielded 37 studies eligible for full-text analysis. The inclusion criteria were met in 11 of the publications that included in all 3015 subjects. The initial search on implant studies generated 52 publications that possibly could be included. Following the evaluation of the abstracts and full-text analysis nine publications were found to fulfil the inclusion criteria. The nine studies included 476 subjects. The incidence of tooth loss among subjects with a follow-up period of 10-30 years varied from 1.3% to 5% in the majority of studies, while in two epidemiological studies on rural Chinese populations the incidences of tooth loss were 14% and 20%. The percentage of implants reported as lost during the follow-up period varied between 1% and 18%. In clinically well-maintained patients, the loss rate at teeth was lower than that at implant. Bone level changes appeared to be small at teeth as well as at implants in well-maintained patients. Comparisons of the longevity at teeth and dental implants are difficult due to heterogeneity among the studies.

Effectiveness of Implant Therapy Analyzed in a Swedish Population Early and Late Implant Loss

Treatment outcomes in implant dentistry have been mainly assessed as implant survival rates in small, selected patient groups of specialist or university clinical settings. This study reports on loss of dental implants assessed in a large and randomly selected patient sample. The results were aimed at representing evaluation of effectiveness of implant dentistry. Using the national data register of the Swedish Social Insurance Agency, 4,716 patients were randomly selected. All had been provided with implant-supported restorative therapy in 2003. Patient files of 2,765 patients (11,311 implants) were collected from more than 800 clinicians. Information on patients, treatment procedures, and outcomes related to the implant-supported restorative therapy was extracted from the files. In total, 596 of the 2,765 subjects, provided with 2,367 implants, attended a clinical examination 9 y after therapy. Implant loss that occurred prior to connection of the supraconstruction was scored as an early implant loss, while later occurring loss was considered late implant loss. Early implant loss occurred in 4.4% of patients (1.4% of implants), while 4.2% of the patients who were examined 9 y after therapy presented with late implant loss (2.0% of implants). Overall, 7.6% of the patients had lost at least 1 implant. Multilevel analysis revealed higher odds ratios for early implant loss among smokers and patients with an initial diagnosis of periodontitis. Implants shorter than 10 mm and representing certain brands also showed higher odds ratios for early implant loss. Implant brand also influenced late implant loss. Implant loss is not an uncommon event, and patient and implant characteristics influence outcomes (ClinicalTrials.gov NCT01825772).

Effects of different implant surfaces and designs on marginal bone‐level alterations: a review

OBJECTIVE The purpose of this review was to evaluate the effect of different implant surfaces and designs on marginal bone-level (MBL) alterations. MATERIAL AND METHODS A MEDLINE search (PubMed) was performed to identify clinical, prospective and controlled studies using a sufficient sample size (>10 subjects) and with a follow-up time of > or =3 years. RESULTS Ten publications fulfilled the inclusion criteria. Two studies evaluated the influence of implant surface characteristics and two studies reported on the effect of implant design on MBL changes. Six publications analyzed the combined effect of different implant surfaces and designs on MBL alterations. As revealed from available studies, there is no evidence that modified surfaces are superior to non-modified implant surfaces in marginal bone preservation. One study reported on significantly improved MBL preservation for implants with a conical and micro-threaded marginal collar than implants with a cylindrical and non-threaded marginal portion after 3 years in function. No implant system was found to be superior in marginal bone preservation.

Severity and pattern of peri-implantitis-associated bone loss

OBJECTIVE The purpose of the present study was to describe the severity and pattern of peri-implantitis-associated bone loss. MATERIAL AND METHODS Intra-oral radiographs from 182 subjects were analysed. Bone-level measurements were performed in 419 implants with a history of bone loss. All radiographs obtained in the interval from the 1-year follow-up to the end-point examination (5-23 years) were analysed. The amount of bone loss that occurred from 1 year after prosthesis insertion was assessed and the pattern of bone loss was evaluated. RESULTS The average bone loss after the first year of function was 1.68 mm and 32% of the implants demonstrated bone loss > or =2 mm. The multilevel model revealed that the bone loss showed a non-linear pattern and that the rate of bone loss increased over time. The model also revealed that the pattern of peri-implantitis associated bone loss was similar within the same subject. CONCLUSION It is suggested that peri-implantitis-associated bone loss varies between subjects and is, in most cases, characterized by a non-linear progression, with the rate of loss increasing over time.

Composition of Human Peri-implantitis and Periodontitis Lesions

The aim of the present study was to examine differences in cellular characteristics of human peri-implantitis and periodontitis lesions. Two groups of patients were included: 40 patients with generalized severe chronic periodontitis and 40 patients presenting with severe peri-implantitis. Soft tissue biopsies were obtained from diseased sites (probing pocket depth ≥ 7 mm with bleeding on probing) and prepared for histologic and immunohistochemical analysis. In contrast to periodontitis samples, peri-implantitis lesions were more than twice as large and contained significantly larger area proportions, numbers, and densities of CD138-, CD68-, and MPO-positive cells than periodontitis lesions. Peri-implantitis lesions also extended to a position that was apical of the pocket epithelium and not surrounded by noninfiltrated connective tissue. They further presented with significantly larger densities of vascular structures in the connective tissue area lateral to the infiltrated connective tissue than within the infiltrate. This study suggests that peri-implantitis and periodontitis lesions exhibit critical histopathologic differences, which contribute to the understanding of dissimilarities in onset and progression between the 2 diseases.