Qualitative studies of patients' perceptions of loss of teeth, the edentulous state and prosthetic rehabilitation: a systematic review with meta-synthesis.

OBJECTIVE: To conduct a systematic review and meta-synthesis of qualitative studies addressing patients' perceptions of loss of teeth, edentulism and oral rehabilitation. BACKGROUND: Qualitative studies can complement quantitative studies by achieving deep understanding of patients' subjective experiences of losing teeth and coping with edentulism. They can also explore the perception that the benefits of prosthetic rehabilitation extend far beyond primary clinical treatment goals of restoration of oral function. MATERIALS AND METHODS: The major data bases were searched extensively for relevant qualitative and quantitative studies, followed by manual searching of the reference lists of included publications. Two authors independently read all abstracts. Relevant papers were retrieved in full-text and included or excluded according to a specially designed protocol. The included articles were then appraised and rated for quality: high, moderate or low. Articles of low quality were excluded. RESULTS: The database search yielded 36 abstracts of qualitative studies; manual search disclosed one further article. All were read in full-text by two independent authors: 28 were excluded. Of the remaining nine, two (assessed as of low quality) were excluded for further analysis. Meta-synthesis, based on seven studies, disclosed two major themes: loss of quality-of-life associated with losing teeth and restored quality-of-life after oral rehabilitation. CONCLUSIONS: In this relatively new field of research, there are few published papers. Nevertheless, the studies to date show that loss of teeth is associated not only with compromised oral function, but also loss of social status and diminished self-esteem. Oral rehabilitation has broad positive implications, restoring quality of life and self-worth.

Oral rehabilitation of tooth loss: a systematic review of quantitative studies of OHRQoL.

PURPOSE: This study aimed to review published quantitative studies for evidence regarding the influence of oral rehabilitation following total or partial tooth loss on self-perceived oral health-related quality of life (OHRQoL). MATERIALS AND METHODS: Three databases were searched using specified indexing terms. The reference lists of relevant publications were also searched manually. Quality of evidence was classified according to GRADE guidelines as high, moderate, low, or very low. RESULTS: The search yielded 2,138 titles and abstracts, 2,102 of which were of a quantitative study design. Based on pre-established criteria, the full-text versions of 322 articles were obtained. After data extraction and interpretation, 5 publications of high or moderate study quality remained. The results of these 5 studies showed positive effects of oral rehabilitation on OHRQoL. Two studies showed substantial improvements. CONCLUSIONS: This is a relatively new field of research; there are very few quantitative studies of how patients perceive OHRQoL following tooth loss and subsequent rehabilitation. While this review indicates that treatment has positive effects on quality of life, the scientific basis is insufficient to support general conclusions about the influence of various interventions on the OHRQoL of patients who have experienced total or partial tooth loss. To achieve a more comprehensive analysis, it is recommended that future studies be based on a combination of quantitative and qualitative methods, ie, questionnaires and semi-structured interviews. The follow-up period must also be appropriate for the specific intervention studied.

Treatment of adult patients with edentulous arches: a systematic review.

PURPOSE: This study aimed to evaluate the outcomes of treatment methods used to rehabilitate adult patients with maxillary and/or mandibular edentulism after at least 5 years of follow-up. The risks, adverse effects, and cost effectiveness of these methods were also evaluated. MATERIALS AND METHODS: Three databases as well as the reference lists of included publications were searched using specified indexing terms. Publications that met the inclusion criteria were read and interpreted using pre-established protocols. Quality of evidence was classified according to the GRADE system (high, moderate, low, or very low). RESULTS: The search yielded 2,130 titles and abstracts. Of these, the full-text versions of 488 publications were obtained. After data extraction and interpretation, 10 studies with moderate study quality of evidence and 1 study with low quality of evidence regarding outcomes, risks, and adverse effects remained. Three studies on the economic aspects of treatment were also included (1 with moderate quality and 2 with low quality). Low-quality evidence showed that the survival rate of implant-supported fixed prostheses is 95% after 5 years in patients with maxillary edentulism and 97% after 10 years in patients with mandibular edentulism. The survival rate of implant-supported overdentures is 93% after 5 years (low-quality evidence). In implant-supported fixed prostheses, 70 of every 1,000 implants are at risk of failing in the maxilla after 5 years and 17 of every 1,000 implants in the mandible are at risk after 10 years. Regarding economic aspects, the evidence was insufficient to provide reliable results. CONCLUSIONS: Due to the low quality of evidence found in the included studies, further research with a higher quality of evidence is recommended to better understand the outcomes of treatment for patients with maxillary and/or mandibular edentulism.

Treatment of adult patients with partial edentulism: a systematic review.

PURPOSE: The purpose of this systematic review was to identify and critically appraise published studies of treatment methods used in general practice to rehabilitate adult patients with single tooth loss or partial edentulism, with special emphasis on outcomes reported after at least 5 years of follow-up. MATERIALS AND METHODS: Three databases were searched using specified indexing terms. Publications were included if the study design, research questions, and sample size satisfied pre-established criteria. Reference lists of relevant publications and systematic reviews were also searched. The quality of evidence was classified according to the GRADE system as high, moderate, low, or very low. RESULTS: The search yielded 7,675 titles, of which 1,130 were read in full text. A final total of 15 publications were deemed eligible for inclusion: 5 of moderate quality and 10 of low quality. The five studies of moderate quality were all related to implant-based treatment. The 5-year survival rates for implant-supported single crowns and prostheses were 91% and 94.7%, respectively (implant survival rates: 98.5% and 94.9%, respectively). The underlying scientific evidence was low in quality. No relevant publications were identified regarding the economic aspects of treatment. CONCLUSION: Due to the low scientific evidence of the included studies, it was not possible to compare various treatment methods used for rehabilitation of single tooth loss or partial edentulism.

Outcome of Brånemark Novum implant treatment in edentulous mandibles: a retrospective 5-year follow-up study.

BACKGROUND: A gradual progression from a two-stage surgical technique to a one-stage and even immediate surgical protocol has occurred during the last decade with most oral implant systems. However, every new approach must obviously be reported individually, with long-term results, in order to assess whether the changes have any real patient value. PURPOSE: The aim of the present report was to retrospectively review the 5-year outcome of patients treated with the Brånemark Novum (Nobel Biocare AB, Göteborg, Sweden) protocol. METHODS: The first 15 patients treated according to the Novum procedure in a private specialist clinic in Lovere, Italy, were followed-up with clinical, radiographic, and resonance frequency analyses. All the patients' fixed constructions had been in function for an average of 5 years. Parameters recorded were implant survival, prosthesis success, oral hygiene and mucosal health, marginal bone remodeling, type and frequency of complications, and patient's opinion of the treatment outcome. RESULTS: After 5 years, the cumulative survival rate for implants was 91%, and for inserted bridge constructions it was 87%. Very small changes in implant stability occurred during implant loading from 1 to 5 years. Oral health conditions were good; 87% of mucosal quadrants around the implants were free from signs of inflammation. Very small marginal bone height changes were observed at the implants during the examination period, and except for four implant losses reported, severe complications were few. All patients were satisfied with the functional outcome of their constructions, but two patients were not completely happy with the aesthetics of their bridgework as supplied. CONCLUSION: This report shows 5-year evidence of acceptably good results with the Brånemark Novum implant technique in edentulous mandibles, when using only three implants to support the fixed bridge construction, and as long as inserted implants become and remain osseointegrated.

A study on variances in multivariate analyses of oral implant outcome.

BACKGROUND: Elaborate studies have shown that interdependency exists between implants being placed in the same patient/jaw. Therefore, interdependency ought to be an important aspect to address, whenever performing statistical analyses of oral implant outcomes. A Jackknife method could be an option when conducting statistical evaluations of oral implant failure prognoses. PURPOSE: The aim of this study was to evaluate whether a statistical difference can be detected by using the Jackknife method in conjunction with life table analyses and/or a log rank test of four different combinations of jaw density and quantity. MATERIALS AND METHODS: Four multicenter studies were pooled and adjusted in order to create a research database consisting of 486 patients and 1,737 implants in preparation for the Jackknife resampling method. Combinations of jaw shapes and bone qualities were constructed to select at-risk patients. STATISTICAL METHODS: Life tables with confidence intervals were calculated and a log rank test was used to determine whether a statistical difference between the combinations could be established. RESULTS: Both statistical analyses, after the Jackknife resampling method, showed that patients with poor bone quality and resorbed jaws (combination IV) had a statistically higher risk of implant failure. CONCLUSION: By rearranging data using the Jackknife method, standardized statistical tests seem to work well even when the study population tested was affected by interdependency.

Outcome of oral implant treatment in partially edentulous jaws followed 20 years in clinical function.

BACKGROUND: Most long-term follow-up studies of implants in partially edentulous jaws present their outcomes as mean values of implant survival and follow-up time, and few address the fate of the remaining teeth. PURPOSE: The aim of this study was to investigate the results of oral implant treatment in partially edentulous jaws after 20 years, and simultaneously to assess what happens to teeth present at the time of implant placement. MATERIALS AND METHODS: Seventeen partially edentulous patients, of 27 originally treated individuals, were retrospectively reviewed after receiving implants from 1983 to 1985. The parameters studied were implant survival, prosthesis stability, marginal bone loss at teeth and implants, treatment complications, need for dental treatment, and patient's satisfaction with the outcome. RESULTS: The cumulative survival rate was 91%, when all 27 patients were assessed, that is, including the 10 dropouts. Of the 69 inserted and followed implants (Brånemark system; Nobel Biocare AB, Göteborg, Sweden), six failed (8.7%) during the 20-year period, four during the first decade, and the remaining two during the second. A majority (n=4) of the losses were due to implant fractures, two after 8 years, and two after 17 years. In all, 10 of the original fixed bridges being followed (n=24) remained in function during the entire investigation period, whereas 12 were exchanged for new constructions after an average of 7 years. The mean marginal bone loss at teeth was 0.7 mm, and at implants it was 1.0 mm. The major complication observed during the second decade was veneer material fractures, which occurred 14 times in six patients. Component loosening and abutment- and bridge-locking screw fractures were the second most common problems seen, indicating material/component fatigue. Most patients were satisfied with their treatment and many mentioned that they did not think of the constructions as anything but a part of their own body. CONCLUSION: Over the decades, treatment of partially edentulous jaws with turned titanium implants seems to function well and to provide patients with good support for fixed short-span bridge constructions.

Tissue alterations at implant-supported single-tooth replacements: a 1-year prospective clinical study.

OBJECTIVES: The aim of this prospective study was to evaluate dimensional alterations of the peri-implant tissues at single-tooth restorations from the time of implant placement to 1-year post-loading. MATERIAL AND METHODS: Eleven patients, aged 18-36 years, subjected to single-tooth replacements with implant-supported restorations (Brånemark implant system) in the maxillary anterior region were included in the analysis. The implant installation was performed as a two-stage procedure with a 6-month healing interval. Bone dimensions were determined by direct assessments immediately following implant placement and at abutment connection. The prosthetic restoration was placed approximately 1 month after abutment surgery. Radiographic and clinical examinations were performed at crown placement and at 1-year post-loading. Assessments of the soft tissues at the implant site and at the neighboring teeth were performed before and during implant placement, before abutment connection, after crown placement and at the 1-year follow-up examination. Mean values and standard deviations were calculated for each variable and interval, with the subject as the statistical unit. RESULTS: At the time of abutment connection, a mean loss of bone height at the facial and lingual aspect of the implant amounting to 0.7-1.3 mm (P < 0.05) was recorded, whereas no significant change was noted at proximal sites. A mean reduction of 0.4 mm of the labial bone thickness was observed between implant placement and the second-stage surgery. The radiographic bone-to-implant level showed a mean loss of 0.9 mm between abutment connection and crown placement (P<0.05) and a further 0.7 mm loss at 1 year (P < 0.05). The thickness of the labial mucosa was increased at crown placement followed by a slight remission at 1 year. During the corresponding interval, a mean apical displacement of the labial soft tissue margin of 0.6 mm had taken place (P < 0.05). A papilla fill of > or = 50% was observed at a frequency of 32% at crown placement and 86% at 1 year. CONCLUSIONS: The results demonstrated that following implant surgery remodeling takes place, which is manifested in diminished bone dimensions, both horizontally and vertically, at the facial aspect of the implant. The observed soft tissue alterations after the crown placement may affect the esthetic appeal of the restorative therapy.

Single implants and buccal bone grafts in the anterior maxilla: measurements of buccal crestal contours in a 6-year prospective clinical study.

BACKGROUND: Patients provided with buccal bone grafts seem to lose a substantial part of the graft in the short term. PURPOSE: To measure long-term changes in buccal and proximal tissue volumes after local bone grafting and single implant treatment. MATERIALS AND METHODS: Eight of 10 originally treated male patients were followed up for 6 years after treatment with buccal bone grafts in the central incisor region. After a healing time of 6 months, a two-stage implant surgery procedure was performed followed by single crown placement. Clinical photographs and impressions were taken prior to the surgical interventions and after crown placement and at first and fifth annual checkups. The photographs were analyzed with regard to papilla regeneration by means of a clinical papilla index. The models were used to measure the clinical length of teeth and tooth movements adjacent to the implants. Changes in buccal crest volume during the study period were measured by means of optical scanning of obtained study models. RESULTS: Papillae volume increased significantly (p<.05) during the first year, thereafter showing a slow further increase during the 4 following years. Three of the patients (38%) presented small movements of their adjacent central incisor in a vertical or palatal direction of less than 1 mm during the follow-up period. All patients showed resorption during the first year after grafting (p<.01), in which three patients (38%) had lost basically all of increased volume at second surgery. After abutment or crown placement, all patients showed an increased volume (p<.01), followed by an average reduction during the first year, reaching a significant level in the apical part of the crest (p<.05). Thereafter, a relatively stable average situation was observed during the following 4 years, with individual variations, however. CONCLUSION: Local bone grafting seems to create sufficient bone volume for implant placement after 6 months, but individual variations in resorption pattern make the grafting procedure unpredictable for long-term prognosis. Instead, the abutment and the crown seem to play a more important role for building up and maintaining the buccal contour in the coronal part of the crest long term.

Prevalence of subjects with progressive bone loss at implants.

AIM: The aim of the present study was to assess the prevalence of subjects with progressive bone loss at implants with a function time of at least 5 years. MATERIAL AND METHODS: Radiographs of 1346 patients who had attended annual follow-up visits at the Brånemark Clinic, Public Dental Services, Gothenburg, Sweden were retrieved. Six hundred and sixty-two subjects fulfilled the inclusion criteria. Thus, they all had been provided with implant-supported (Brånemark System) Nobel BioCare, Gothenburg, Sweden) fixed partial or complete dentures or single-tooth replacements with a documented function time in radiographs of at least 5 years. Implants that demonstrated progressive bone loss to a level of > or =3 threads of an implant were detected. The number of subjects who exhibited one or more implants with progressive bone loss to the threshold level was recorded. RESULTS: Twenty-eight percent of 662 included subjects had one or more implants with progressive bone loss. A logistic regression analysis revealed that the individuals in this group carried a significantly larger number of implants than the subjects in whom no implants with progressive loss were detected (6 vs. 4.8). Furthermore, >30% of the subjects in the group with progressive bone loss had > or =3 identified implants and that about 33% of all such implants in this group exhibited extensive bone loss. Out of the total 3413 implants included in the study, 423 implants (12.4%) demonstrated progressive bone loss. CONCLUSION: It is suggested that the prevalence of progressive bone loss at implants assessed from subject-based data is higher than that evaluated from implant-based data.

Evaluation of patient and implant characteristics as potential prognostic factors for oral implant failures.

PURPOSE: The purpose of this study was to evaluate patient, implant, and treatment characteristics to identify possible prognostic factors for implant failure. MATERIALS AND METHODS: Out of a database with different dental implant treatment protocols, a research database of 1 randomly selected implant per patient was created. The database consisted of 487 implants. Of these, 80 were withdrawn, 36 failed, and 371 remained successful during a 5-year follow-up period. Potential risk factors were evaluated by chi-square tests and post hoc analyses. RESULTS: Significant or strongly significant differences were found regarding implant failures as a result of jawbone quality, jaw shape, implant length, treatment protocol, and combinations of jawbone-related characteristics. Responsible clinics and number of implants supporting the restoration were factors that could not be associated with implant failure. DISCUSSION: Implant failures in this study were more often seen when negative patient-related factors were present. Approximately 65% of the patients with a combination of the 2 most negative bone-related factors (jawbone quality 4 and jaw shape D or E) experienced implant failure. However, only 3% of the patients had this combination. Implant length, the only implant-related factor evaluated, was also significantly correlated with the success rate, but implant length could also be regarded as a result of the jawbone volume available. Another negative patient-related factor was the treatment protocol; however, in most cases this was also indirectly or partly related to the status of the jawbone available for implant placement. CONCLUSION: Patient selection appears to be of importance for increasing implant success rates.

Histopathological observations of human periimplantitis lesions.

OBJECTIVE: The aim of the present study was to analyze some characteristics of advanced and progressive periimplantitis lesions in man. MATERIAL AND METHODS: Soft tissue biopsies were obtained from 12 implants in six patients. The implants had been in function between 4 and 21 years and were, with one exception, located in the maxilla. The radiographic examination performed prior to biopsy revealed that all sites exhibited advanced bone loss. Further, clinical signs of severe inflammation, such as suppuration, swelling and/or fistula formation were detected in the majority of sites and seven of the 12 implants were found to be mobile at biopsy. Each biopsy was following fixation embedded in epoxy resin and sections were prepared for histometric and morphometric analysis. RESULTS AND CONCLUSION: It was demonstrated (i). that all soft tissue units harbored large inflammatory cell infiltrates (ICT) that extended to a position apical of a pocket epithelium and (ii). that about 60% of the lesions were occupied by inflammatory cells, among which plasma cells dominated. Numerous amounts of PMN cells occurred not only in the pocket epithelium and adjacent connective tissue areas, but were also present in peri-vascular compartments in more central areas of the ICT.

Measurements of buccal tissue volumes at single-implant restorations after local bone grafting in maxillas: a 3-year clinical prospective study case series.

PURPOSE: The purpose of this study was to measure changes in buccal and proximal tissue volumes after local bone grafting and single-implant treatment. MATERIALS AND METHODS: Ten patients were provided with buccal bone grafts 6 months prior to implant treatment in central upper incisor regions. Following a healing time of 6 months, abutments and single-implant crowns were installed and followed up for 2 years. Clinical photographs and impressions were taken prior to the surgical intervention as well as after crown placement and at first and second annual checkups. The photographs and study models were analyzed with regard to papilla regeneration and changes in buccal crest volume during the study period by means of a clinical papilla index and optical scanning of study models. RESULTS: All bone grafts healed without problems. A significant reduction of the buccal crest volume (-50%, p <.01) was observed in the grafted area before abutment connection. However, a significant increase of tissue volume (+100%, p <.05) was noticed at the subsequent crown placement, followed by a second but slow reduction of the volume during the following 2 years of function. The interdental papillae increased significantly (p <.05) in volume during the first year, almost completely filling up the embrasure areas after 2 years. CONCLUSIONS: It may be concluded that local bone grafting seems to be a valuable protocol to create sufficient bone volume for implant placement. However, significant resorption of the graft may be present, which reduces the impact of grafting on the esthetic outcome. Instead, placement of the abutment cylinder and the crown seems to play a more important role for reestablishing the tissue volume at the implant-supported single crowns.

Peri-implant bone alterations in relation to inter-unit distances. A 3-year retrospective study.

The aim of the present retrospective study was to evaluate longitudinal alterations in radiographic bone topography at proximal sites of three-unit implant-supported fixed partial prostheses during the first 3 years after bridge installation, in relation to vertical and horizontal inter-unit distances. The subjects were partially dentate patients who had received implant-supported fixed partial prostheses during the year 1995 at the Brånemark Clinic, Göteborg, Sweden. For inclusion in the study, the patient had to have a three-unit bridge construction supported by three implants in the posterior area of the jaw. Twenty-eight patients having 35 screw-retained prostheses on Brånemark standard implants fulfilled the inclusion criteria. Radiographs obtained at bridge installation and at 1- and 3-year follow-ups were assessed for implant positions, contact point level, bone level at implants and adjacent tooth and mid-proximal bone crest level. The data were analysed with respect to two proximal units: tooth/implant units (n=35) and implant/implant units (n=70). Multiple regression analyses were used to evaluate the influence of various factors on the peri-implant and periodontal bone level changes during the 3 years of follow-up. At the tooth/implant units, the mean bone loss over the 3 years was 0.5 mm at the implant and 0.4 mm at the tooth. Multiple regression analysis failed to identify significant explanatory factors for the peri-implant/periodontal bone level changes at the tooth/implant units (R2=0.28). At the implant/implant units, the peri-implant bone loss was 0.6-0.7 mm and was significantly influenced by the vertical inter-implant distance (P<0.01), the difference in bone level at baseline between two neighbouring implants (P<0.001) and the bone level changes at the opposed implant surface (P<0.001) (R2=0.49). Furthermore, the magnitude of apical displacement of the inter-implant bone crest level during the 3 years of follow-up was negatively associated with the horizontal inter-implant distance (P<0.05). The results of the study demonstrated that both vertical and horizontal differences in implant positions might influence bone alterations in the inter-implant area during the first 3 years of loading, while the data failed to show corresponding relationships for the bone changes at the proximal area between the implant and the neighbouring tooth.

Some soft tissue characteristics at implant abutments with different surface topography. A study in humans.

BACKGROUND: : If an implant with a rough surface is exposed to the oral cavity, it may accumulate greater amounts of plaque than a smooth surface, which may lead to severe problems with mucositis and peri-implantitis. The purpose of the present paper was to investigate the early inflammatory response to mucosa-penetrating abutments prepared with varying surface roughness. METHODS: : Nine patients had all five of their original abutments exchanged to test abutments for a 4-week period. The test abutments were prepared with five different roughnesses. The surface roughness was measured with an optical profilometer. At the end of the test period, clinical evaluation was performed; the health of the surrounding mucosa, the amount of accumulated plaque and marginal bleeding were registered. One biopsy was taken from each test abutment. Qualitative and quantitative histological evaluations were performed. RESULTS: : There was a statistically significant difference between patients regarding the amount of accumulated plaque on the abutment surfaces and inflammatory cells, but no difference between the surface modifications in relation to plaque accumulation or number of inflammatory cells. CONCLUSION: : No relation was found between inflammatory response and abutment surface roughness after an evaluation time of 4 weeks in a human test model.

Statistical outcome of random versus selected withdrawal of dental implants.

PURPOSE: When performing clinical trials, missing data from withdrawn patients should be evaluated differently, depending on the reason for the withdrawal of the patients. The question is, if a certain type of patient drops out, will that affect the result? Could a randomly selected sample of a study population be used for analyses instead of evaluating each and every patient? The purpose of this study was to answer these questions. MATERIALS AND METHODS: Detailed information on 1,738 implants in 487 patients was pooled together in a new database and used for statistical evaluations. Random or selected withdrawals were pulled from the database. Chi-squared tests were used for significance tests, and lifetables were used for survival analysis. RESULTS: There was a difference in the outcome depending on whether the withdrawals were randomly chosen or selected. Random withdrawals could represent, in this study, as much as 50% of the included patients without changing the statistical results. If selected withdrawals were based on which jaw was treated, the statistical outcome did change, but it did not change if withdrawals were based on gender or age. CONCLUSION: Evaluation of reasons for withdrawals and withdrawn patient characteristics are of utmost importance when evaluating clinical trials. A randomly selected sample of the entire population could, however, be expected to give the same statistical value as the entire group, if the original material were large enough. Therefore, the use of study samples may more easily enable clinicians to do follow-up investigations.

Microbiologic diagnostics at titanium implants.

BACKGROUND: The microbiota found at periimplant lesions have been shown to contain putative periodontal pathogens as well as opportunistic species such as Staphylococcus spp, enterics, and Candida spp. Therefore, a microbiologic diagnosis may be of value as guidance before treatment of such lesions. PURPOSE: The aim of this study was to evaluate the prevalence of some putative pathogens associated with long-term followed-up cases using two different microbiologic procedures. MATERIALS AND METHODS: Fifteen subjects contributed with plaque samples from teeth and implants; these were analyzed with respect to 18 putative periimplant pathogens using cultural methods and a deoxyribonucleic acid DNA-DNA hybridization technique. RESULTS: The number of individuals positive for the analyzed pathogens was similar in samples taken from teeth and implants when analyzed with the DNA-DNA hybridization technique. When comparing detection frequency by culture procedure and by "checkerboard" technique at implants, the number of individuals positive for these species was lower with the traditional culture technique than with the checkerboard analyses. Using a higher cutoff point (> or = 4) with the checkerboard technique, the number of positive individuals was generally lower than that found with the culture technique. When comparing the techniques on an implant site level, the prevalence obtained by culture was lower for all analyzed species. If the specific species were present in the samples analyzed by the checkerboard technique, they were present only in every second sample analyzed with the culture technique. The high specificity values showed that if the checkerboard technique did not detect any Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, or Fusobacterium nucleatum, the bacteria were also undetectable by the culture technique. The two methods therefore did not overlap but did supplement each other. CONCLUSIONS: Based on the current results it is recommended that the technique used when analyzing microbiota around titanium implants should be a combination of the two protocols mentioned as they seem to give the most comprehensive outcome when used together.

Outcome of implant therapy in relation to experienced loss of periodontal bone support: a retrospective 5- year study.

PURPOSE: The aim of this retrospective study was to analyse bone level alterations over a 5-year period at implants in the maxillary posterior segments in patients with varying experience of periodontal bone loss in the natural dentition before implant placement. MATERIALS AND METHODS: 97 partially dentate patients with a total of 346 Brånemark oral implants in the maxillary posterior segments were included. By assessing the degree of radiographic marginal bone loss in the remaining natural dentition at time of the implant therapy, an age-related bone loss score (ArB-score) was calculated for description of the patient's experience of periodontal destruction. The two end quartiles of the distribution of the subjects with regard to the ArB-score were defined as Non-Perio subjects and Perio subjects, respectively. The primary outcome variables were implant losses (implant failures) and radiographic peri-implant bone loss over the 5-year observation period. RESULTS: A total of 18 implants were lost during the 5 years, resulting in an overall failure rate of 5.2%. The corresponding failure rate was 3.3% for the Non-Perio and 8.0% for the Perio patients. The peri-implant bone loss from the time of abutment connection to 5 years averaged 1.8 mm (SD 0.7). Of the patients, 34% showed a mean bone loss of > 2 mm and 39% of all implants had experienced a bone loss of 2 mm at the 5-year examination. The Non-Perio and Perio patients showed a mean bone loss of 1.7 mm (0.8) and 2.2 mm (0.8), respectively. Multiple regression analysis revealed a statistically significant relationship between the ArB-score and the peri-implant bone level change from abutment connection to 5 years (P < 0.05). In all, 64% of Perio patients had a mean peri-implant bone loss of > 2 mm from the time of abutment connection, compared to 24% for the Non-Perio patients (P < 0.01). The percentage of implants showing 2 mm of bone loss between abutment connection and 5 years was 62% and 44% in the Perio and Non-Perio groups, respectively (P = 0.055). CONCLUSION: The results indicate that longitudinal bone loss around implants is correlated to previous experience of loss of periodontal bone support and that periodontitis susceptible subjects may show an increased implant failure rate.