Risk factors associated with the longevity of multi-rooted teeth. Long-term outcomes after active and supportive periodontal therapy.

AIM: To investigate risk factors for the loss of multi-rooted teeth (MRT) in subjects treated for periodontitis and enrolled in supportive periodontal therapy (SPT). MATERIAL AND METHODS: A total of 172 subjects were examined before (T0) and after active periodontal therapy (APT)(T1) and following a mean of 11.5 ± 5.2 (SD) years of SPT (T2). The association of risk factors with loss of MRT was analysed with multilevel logistic regression. The tooth was the unit of analysis. RESULTS: Furcation involvement (FI) = 1 before APT was not a risk factor for tooth loss compared with FI = 0 (p = 0.37). Between T0 and T2, MRT with FI = 2 (OR: 2.92, 95% CI: 1.68, 5.06, p = 0.0001) and FI = 3 (OR: 6.85, 95% CI: 3.40, 13.83, p < 0.0001) were at a significantly higher risk to be lost compared with those with FI = 0. During SPT, smokers lost significantly more MRT compared with non-smokers (OR: 2.37, 95% CI: 1.05, 5.35, p = 0.04). Non-smoking and compliant subjects with FI = 0/1 at T1 lost significantly less MRT during SPT compared with non-compliant smokers with FI = 2 (OR: 10.11, 95% CI: 2.91, 35.11, p < 0.0001) and FI = 3 (OR: 17.18, 95% CI: 4.98, 59.28, p < 0.0001) respectively. CONCLUSIONS: FI = 1 was not a risk factor for tooth loss compared with FI = 0. FI = 2/3, smoking and lack of compliance with regular SPT represented risk factors for the loss of MRT in subjects treated for periodontitis.

Peri-implantitis susceptibility as it relates to periodontal therapy and supportive care.

OBJECTIVE: To assess the long-term survival of implants inserted in periodontally susceptible patients and to investigate the influence of residual pockets on the incidence of peri-implantitis and implant loss. MATERIALS AND METHODS: For 70 patients, comprehensive periodontal treatment was followed by installation of 165 Straumann Dental implants. Subsequently, 58 patients entered a University supportive periodontal therapy (SPT) program and 12 had SPT in a private practice. The follow-up time ranged from 3 to 23 years (mean 7.9 years). Bleeding on probing (BOP), clinical attachment level (CAL), and peri-implant probing depths (PPD) were evaluated at baseline (T0), completion of active treatment (T1), and at follow-up (T2). Peri-implant bone levels were assessed on radiographs at T2. Patients were categorized as having implants not affected by peri-implantitis (non-PIP), or affected by peri-implantitis (PIP). RESULTS: From 165 implants inserted, six implants were lost, translating into a cumulative survival rate of 95.8%. Solid screw implants yielded significantly higher survival rates than the hollow cylinder and hollow screw implants (99.1% vs. 89.7%). Implants lost due to peri-implant infection were included in the PIP groups. When peri-implantitis (PPD ≥ 5 mm, BOP+) was analyzed, 22.2% of the implants and 38.6% of patients had one or more implants affected by peri-implantitis. Using the peri-implantitis definition (PPD ≥ 6 mm, BOP+), the prevalence was reduced to 8.8% and 17.1%, respectively. Moreover, all these implants demonstrated significant (≥ 2 mm) bone loss at T2. At T1, the non-PIP group had significantly (P = 0.011) fewer residual pockets (≥ 5 mm) per patient than the PIP group (1.9 vs. 4.1). At T2, the PIP group displayed an increased number of residual pockets compared to T1, whereas in the non-PIP group, the number remained similar to T1. At T2, mean PPD, mean CAL and BOP were significantly higher in the PIP group compared with the non-PIP group. The prevalence of peri-implantitis was lower in the group that was in a well organized SPT at the University. CONCLUSIONS: In periodontitis susceptible patients, residual pockets (PPD ≥ 5 mm) at the end of active periodontal therapy represent a significant risk for the development of peri-implantitis and implant loss. Moreover, patients in SPT developing re-infections are at greater risk for peri-implantitis and implant loss than periodontally stable patients.

Complication and failure rates of fixed dental prostheses in patients treated for periodontal disease.

OBJECTIVES: to evaluate the biological and technical complication rates of fixed dental prostheses (FDP) with end abutments or cantilever extensions on teeth (FDP-tt/cFDP-tt) on implants (FDP-ii/cFDP-ii) and tooth-implant-supported (FDP-ti/cFDP-ti) in patients treated for chronic periodontitis. MATERIAL AND METHODS: from a cohort of 392 patients treated between 1978 and 2002 by graduate students, 199 were re-examined in 2005. Of these, 84 patients had received ceramo-metal FDPs (six groups). RESULTS: at the re-evaluation, the mean age of the patients was 62 years (36.2-83.4). One hundred and seventy-five FDPs were seated (82 FDP-tt, 9 FDP-ii, 20 FDP-ti, 39 cFDP-tt, 15 cFDP-ii, 10 cFDP-ti). The mean observation time was 11.3 years; 21 FDPs were lost, and 46 technical and 50 biological complications occurred. Chances for the survival of the three groups of FDPs with end abutments were very high (risk for failure 2.8%, 0%, 5.6%). The probability to remain without complications and/or failure was 70.3%, 88.9% and 74.7% in FDPs with end abutments, but 49.8-25% only in FDPs with extensions at 10 years. CONCLUSIONS: in patients treated for chronic periodontitis and provided with ceramo-metal FDPs, high survival rates, especially for FDPs with end abutments, can be expected. The incidence rates of any negative events were increased drastically in the three groups with extension cFDPs (tt, ii, ti). Strategic decisions in the choice of a particular FDP design and the choice of teeth/implants as abutments appear to influence the risks for complications to be expected with fixed reconstruction. If possible, extensions on tooth abutments should be avoided or used only after a cautious clinical evaluation of all options.

Complication and failure rates in patients treated for chronic periodontitis and restored with single crowns on teeth and/or implants.

OBJECTIVES: To assess the biological and technical complication rates of single crowns on vital teeth (SC-V), endodontically treated teeth without post and core (SC-E), with a cast post and core (SC-PC) and on implants (SC-I). MATERIAL AND METHODS: From 392 patients with chronic periodontitis treated and documented by graduate students during the period from 1978 to 2002, 199 were reexamined during 2005 for this retrospective cohort study, and 64 of these patients were treated with SCs. Statistical analysis included Kaplan-Meier survival functions and event rates per 100 years of object-time. Poisson regression was used to compare the four groups of crowns with respect to the incidence rate ratio of failures, and failures and complications combined over 10 years and the entire observation period. RESULTS: Forty-one (64%) female and 23 (36%) male patients participated in the reexamination. At the time of seating the crowns, the mean patient age was 46.8 (range 24-66.3) years. One hundred and sixty-eight single unit crowns were incorporated. Their mean follow-up time was 11.8 (range 0.8-26.4) years. During the time of observation, 22 biological and 11 technical complications occurred; 19 SC were lost. The chance for SC-V (56) to remain free of any failure or complication was 89.3% (95% confidence interval [CI] 76.1-95.4) after 10 years, 85.8% (95% CI 66-94.5) for SC-E (34), 75.9% for SC-PC (39), (95% CI 58.8-86.7) and 66.2% (95% CI 45.1-80.7) for SC-I (39). Over 10 years, 95% of SC-I remained free of failure and demonstrated a cumulative incidence of failure or complication of 34%. Compared with SC-E, SC-I were 3.5 times more likely to yield failures or complications and SC-PC failed 1.7 times more frequently than did SC-E. SC-V had the lowest rate of failures or complications over the 10 years. CONCLUSIONS: While SCs on vital teeth have the best prognosis, those on endodontically treated teeth have a slightly poorer prognosis over 10 years. Crowns on teeth with post and cores and implant-supported SCs displayed the highest incidence of failures and complications.

Failures and complications in patients with birth defects restored with fixed dental prostheses and single crowns on teeth and/or implants.

OBJECTIVES: To assess retrospectively, over at least 5 years, the incidences of technical and biological complications and failures in young adult patients with birth defects affecting the formation of teeth. MATERIAL AND METHODS: All insurance cases with a birth defect that had crowns and fixed dental prostheses (FDPs) inserted more than 5 years ago were contacted and asked to participate in a reexamination. RESULTS: The median age of the patients was 19.3 years (range 16.6-24.7 years) when prosthetic treatment was initiated. Over the median observation period of 15.7 years (range 7.4-24.9 years) and considering the treatment needs at the reexamination, 19 out of 33 patients (58%) with reconstructions on teeth remained free from all failures or complications. From the patients with FDPs and single unit crowns (SCs) on implants followed over a median observation period of 8 years (range 4.6-15.3 years), eight out of 17% or 47% needed a retreatment or repair at some point due to a failure or a complication. From the three groups of patients, the cases with amelogenesis/dentinogenesis imperfecta demonstrated the highest failure and complication rates. In the cases with cleft lip, alveolus and palate (CLAP) or hypodontia/oligodontia, 71% of the SCs and 73% of the FDPs on teeth (FDP T) remained complication free over a median observation period of about 16 years. Sixty-two percent of the SCs and 64% of the FDPs on implants remained complication free over 8 years. Complications occurred earlier with implant-supported reconstructions. CONCLUSIONS: Because healthy, pristine teeth can be left unprepared, implant-supported SCs and FDPs are the treatment choice in young adults with birth defects resulting in tooth agenesis and in whom the edentulous spaces cannot be closed by means of orthodontic therapy. However, the trend for earlier and more frequent complications with implant-supported reconstructions in young adults, expecting many years of function with the reconstructions, has to be weighed against the benefits of keeping teeth unprepared. In cases with CLAP in which anatomical conditions render implant placement difficult and in which teeth adjacent to the cleft require esthetic corrections, the conventional FDP T still remains the treatment of choice.

Cumulative costs for the prosthetic reconstructions and maintenance in young adult patients with birth defects affecting the formation of teeth.

OBJECTIVES: To assess retrospectively the cumulative costs for the long-term oral rehabilitation of patients with birth defects affecting the development of teeth. METHODS: Patients with birth defects who had received fixed reconstructions on teeth and/or implants > or =5 years ago were asked to participate in a comprehensive clinical, radiographic and economic evaluation. RESULTS: From the 45 patients included, 18 were cases with a cleft lip and palate, five had amelogenesis/dentinogenesis imperfecta and 22 were cases with hypodontia/oligodontia. The initial costs for the first oral rehabilitation (before the age of 20) had been covered by the Swiss Insurance for Disability. The costs for the initial rehabilitation of the 45 cases amounted to 407,584 CHF (39% for laboratory fees). Linear regression analyses for the initial treatment costs per replaced tooth revealed the formula 731 CHF+(811 CHF x units) on teeth and 3369 CHF+(1183 CHF x units) for reconstructions on implants (P<.001). Fifty-eight percent of the patients with tooth-supported reconstructions remained free from failures/complications (median observation 15.7 years). Forty-seven percent of the patients with implant-supported reconstructions remained free from failures/complications (median observation 8 years). The long-term cumulative treatment costs for implant cases, however, were not statistically significantly different compared with cases reconstructed with tooth-supported fixed reconstructions. Twenty-seven percent of the initial treatment costs were needed to cover supportive periodontal therapy as well as the treatment of technical/biological complications and failures. CONCLUSION: Insurance companies should accept to cover implant-supported reconstructions because there is no need to prepare healthy teeth, fewer tooth units need to be replaced and the cumulative long-term costs seem to be similar compared with cases restored on teeth.

Transalveolar maxillary sinus floor elevation using osteotomes with or without grafting material. Part II: Radiographic tissue remodeling.

OBJECTIVES: To evaluate the pattern of tissue remodeling after maxillary sinus floor elevation using the transalveolar osteotome technique with or without utilizing grafting materials. METHODS: During the period of 2000-2005, 252 Straumann dental implants were inserted using the transalveolar sinus floor elevation technique in a group of 181 patients. For 88 or 35% of those implants, deproteinized bovine bone mineral with a particle size of 0.25-1 mm was used as the grafting material, but for the remaining 164 implants, no grafting material was utilized. Periapical radiographs were obtained with a paralleling technique and digitized. Two investigators, who were blinded to whether grafting material was used or not, subsequently evaluated the pattern of tissue remodeling. RESULTS: The mean residual bone height was 7.5 mm (SD 2.2 mm), ranging from 2 to 12.7 mm. The mean residual bone height for implants placed with grafting material (6.4 mm) was significantly less compared with the implants installed without grafting material (8.1 mm). The implants penetrated on average 3.1 mm (SD 1.7 mm) into the sinus cavity. The measured mean radiographic bone gain using the transalveolar technique without grafting material was significantly less, 1.7 mm (SD 2 mm) compared with a mean bone gain of 4.1 mm (SD 2.4 mm), when grafting material was used. Furthermore, the probability of gaining 2 mm or more of new bone was 39.1% when no grafting material was used. The probability increased to 77.9% when the implants were installed with grafting material. CONCLUSION: When the transalveolar sinus floor elevation was performed without utilizing grafting material, only a moderate gain of new bone could be detected mesial and distal to the implants. On the other hand, when grafting material was used, a substantial gain of new bone was usually seen on the radiographs.

Influence of residual pockets on progression of periodontitis and tooth loss: results after 11 years of maintenance.

BACKGROUND: Limited evidence exists on the significance of residual probing pocket depth (PPD) as a predictive parameter for periodontal disease progression and tooth loss. AIM: The aim of this study was to investigate the influence of residual PPD >or=5 mm and bleeding on probing (BOP) after active periodontal therapy (APT) on the progression of periodontitis and tooth loss. MATERIAL AND METHODS: In this retrospective cohort, 172 patients were examined after APT and supportive periodontal therapy (SPT) for 3-27 years (mean 11.3 years). Analyses were conducted using information at site, tooth and patient levels. The association of risk factors with tooth loss and progression of periodontitis was investigated using multilevel logistic regression analysis. RESULTS: The number of residual PPD increased during SPT. Compared with PPDor=7 mm 37.9 and 64.2, respectively. At patient level, heavy smoking, initial diagnosis, duration of SPT and PPD>or=6 mm were risk factors for disease progression, while PPD>or=6 mm and BOP>or=30% represented a risk for tooth loss. CONCLUSION: Residual PPD>or=6 mm represent an incomplete periodontal treatment outcome and require further therapy.

Influence of interleukin-1 gene polymorphism on the outcome of supportive periodontal therapy explored by a multi-factorial periodontal risk assessment model (PRA).

BACKGROUND: Multi-factorial risk models have been proposed to enhance the ability to predict risk for the progression of treated chronic periodontitis. AIMS: to study if the outcomes of supportive periodontal therapy (SPT) based on a multi-factorial periodontal risk assessment are influenced by IL-1 gene polymorphism (IP) status. MATERIAL AND METHODS: Information about the IP and smoking status, clinical periodontal conditions and age related bone level measurements were used to calculate a peridontal risk assessment model (PRA). The surface area of this diagram was calculated for 224 subjects who had participated in an SPT program over four years. Baseline and 4-year follow-up data were studied in relation to the IP status. RESULTS: Positive IP tests were obtained for 80/224 (35.7%) of the subjects. At baseline the mean PRA for the IP positive group was 79.9 units, which at year four had increased to 81.3 units (mean diff: 1.4 units, S.D.+/-16.5, p<0.45, 95% CI: 2.3 to 5.1). At baseline and year four the mean PRA for the IP negative group was 44.2 and 38.6 units, respectively. This difference was statistically significant (mean diff: 5.6, S.D.+/-16.1, p<0.001, 95% CI: 3.0 to 8.3). Independent t-tests confirmed that the IP status was significantly associated with a less favorable change in PRA over the four-year period (PRA difference: 7.04, t=3.01, p<0.003, 95% CI: 2.4 to 11.65). Bleeding on probing, and probing depth values alone did not differ between positive and negative IP status. Regression analysis demonstrated that the best-fit model for change in PRA included bleeding on probing at baseline, IP status, proportional alveolar bone loss in relation to the age, and gender. CONCLUSION: The PRA allowed the assessment of the outcomes of SPT therapy. Subjects with positive IP did not respond to individualized SPT as favorably as did IP negative subjects.