A 10–year retrospective study of periodontal disease progression

The purpose of this study was to record the rate of periodontal disease progression over a 10-year period with respect to individual subject, age and tooth type. 283 subjects, who had undergone a full-mouth radiographic examination in 1974-76 and at that time were 25-70 years old, were randomly selected from a larger patient sample for a new radiographic examination in 1985-86. 201 subjects (71%) agreed to participate. For each respondent, tooth loss over the 10-year period was calculated. The radiographic bone height at the mesial and distal aspect of all teeth was assessed by measuring the distance between the cemento-enamel junction and the bone crest. Difference in periodontal bone height between the 2 examinations was calculated for each tooth site. The results revealed that the mean number of teeth lost over the 10-year period was 3.8 (SD 4.6). Tooth mortality, expressed as a % of the no. of teeth present at the initial examination, increased with age and varied between 2.9%-28.5%. In all age groups, molars had the highest and canines the lowest rate of tooth mortality. The frequency of subjects with loss of greater than 10 teeth was highest for the initially 45-year old individuals (20%). 7 individuals (3%) had become edentulous. The mean annual reduction of alveolar bone height varied between 0.07-0.14 mm in the age groups 25-65 years. The initially 70-year old subjects showed a statistically significant higher annual rate of bone loss (0.28 mm).(ABSTRACT TRUNCATED AT 250 WORDS)     

A 6-year study on the pattern of periodontal disease progression

Abstract. The present longitudinal radiographic investigation was designed to study the change in the alveolar bone height over 6 years in relation to tooth type, age and the presence of previous bone loss in a group of 142 subjects (age 18–67 years) who were not under systematic periodontal treatment. The subjects were examined radiographically at baseline, and after 2 and 6 years, and sites showing significant (≥ 1 mm) change in the alveolar bone height during 2 consecutive examinations were identified. 90.2% of all examined sites showed no bone loss during the 6 years, while 8.6% and 1.2% of the sites exhibited bone loss during one or both examination periods, respectively, 3 groups of subjects within the studied population were identified. Approximately 5% of the subjects had high rates of periodontal disease progression whilst ∼ 70% demonstrated very few or no sites with bone loss, and ∼ 25% had a moderate level of disease progression during the study period. The results also showed that the number of sites exhibiting alveolar bone loss during the study period varied with respect to tooth type, age of the patient and presence of bone loss at baseline. In addition, significantly different rates of bone loss were disclosed with relation to tooth type ( P <0.01), age ( P <0.0001) and initial bone loss ( P <0.01). It was concluded that periodontal disease progression occurs infrequently and may take the form of discrete or recurrent episodes of loss of periodontal support which can be influenced by the location of the site, age of the subject and previous periodontal disease experience.     

Oral rehabilitation with implant-supported fixed partial dentures in periodontitis-susceptible subjects. A 5-year prospective study

BACKGROUND: Comparatively few studies with at least 5 years of follow-up are available that describe the use of implants in prosthetic rehabilitation of partially edentulous patients. Randomized, controlled clinical studies that evaluated the effect of different surface designs of screw-shaped implants on the outcome of treatment are also sparse. OBJECTIVE: To determine, in a prospective randomized, controlled clinical trial, the outcome of restorative therapy in periodontitis-susceptible patients who, following basic periodontal therapy, had been restored with implants with either a machined- or a rough-surface topography. MATERIAL AND METHODS: Fifty-one subjects (mean age, 59.5 years), 20 males and 31 females who, following treatment of moderate-to-advanced chronic periodontitis, required implant therapy for prosthetic rehabilitation were recruited. Seventeen of the patients were current smokers. Following the active treatment, all subjects were included in an individually designed maintenance program. A total of 56 fixed partial dentures (FPDs) and a total of 149 screw-shaped, and self-tapping implants (Astra Tech implants) -- 83 in the maxilla and 66 in the mandible -- were installed in a two-stage procedure. Each patient received a minimum of two implants and by randomization every second implant that was installed had been designed with a machined surface and the remaining with a roughened Tioblast surface. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographical examinations were performed following FPD connection and once a year during a 5-year follow-up period. The analysis of peri-implant bone-level alterations was performed on subject, FPD and implant levels. RESULTS: Four patients and four FPDs were lost to the 5 years of monitoring. One implant (machined surface) did not properly integrate (early failure), and was removed at the time of abutment connection. Three implants were lost during function and a further eight implants could not be accounted for at the 5-year follow-up examination. The overall failure rate at 5 years was 5.9% (subject level), 5.3% (FPD level) and 2.7% (implant level). Radiographic signs of loss of osseointegration were not found at any of the implants during the 5-year observation period. During the first year in function there was on average 0.33 (SD, 0.61) mm loss of peri-implant marginal bone on the subject and FPD levels and 0.31 (0.81) mm on the implant level. During the subsequent 4 years, the peri-implant bone-level alterations were small. The calculated annual change in peri-implant bone level was -0.02 (0.15) on subject and FPD levels and -0.03 (0.20) on the implant level. Thus, the mean total bone-level change over the 5-year interval amounted to 0.41 mm on all three levels of analysis. In the interval between baseline and 5 years, the machined and the Tioblast implants lost on average 0.33 and 0.48 mm, respectively (p>0.05). CONCLUSION: The present randomized, controlled clinical trial that included partially edentulous periodontitis-susceptible subjects demonstrated that bone loss (i) during the first year of function as well as annually thereafter was small and (ii) did not vary between implants with machined- or rough-surface designs.     

Minimum periodontal bone loss in dentally-aware adults A 10-year prospective study

Abstract A prospective study was performed on periodontal bone height changes over 10 years in dentally aware subjects. 94 subjects, aged 20–60 year, were radiographically examined by means of full mouth surveys at baseline in 1982 and 10 years later. The periodontal bone height evaluated by means of a computerized method was expressed as % of the root length. The mean of all measurements in the individual constituted the bone height value. The mean (SEM) periodontal bone height was 82.8% (0.64) at baseline and 82.0% (0.61) at follow-up. Although small, the periodontal bone height reduction over the 10 year period was statistically significant (p<0.05). The reduction in periodontal bone height over time ranged from 0.4% (0.87) for subjects aged 30–39 years to 1.3% (0.80) for subjects aged 60–69 year. Only 15% of the subjects exhibited a bone loss >5 % and none >10%. It is concluded that the rate of periodontal bone height reduction in dentally aware subjects is low. In the vast majority of these subjects, the 10 year bone loss may be considered clinically negligible.     

Mineral status of skeleton and advanced periodontal disease

Abstract Studies of the effect of general bone loss on periodontal condition and on development of periodontal pockets suggest that there is no clear correlation between periodontal health or number of teeth and the general mineral status of the skeleton. In some reports, however, deep periodontal pockets have been correlated with good mineral status in the jawbones and skeleton. The purpose of this study of 227 healthy postmenopausal women aged 48 to 56 years was to determine whether advanced alveolar bone loss, diagnosed by panoramic radiographs, and periodontal probing depths or number of remaining teeth were correlated with the bone mineral status of the skeleton and cortical bone in the mandible. The results suggest that individuals with high mineral values in the skeleton seem to retain their teeth with deep periodontal pockets more easily than those with osteoporosis. This finding may especially motivate treatment of persons suffering from advanced periodontal disease but having good mineral status.     

Implant-supported single-tooth restorations: a 5-year prospective study

BACKGROUND: Comparatively few studies are available reporting at least 5 years of follow-up data of implant-supported single-tooth replacements. OBJECTIVE: To evaluate prospectively the 5-year outcome of implant-supported single-tooth prosthetic restorations. MATERIAL AND METHODS: Forty subjects (mean age 41 years), 23 males and 17 females, who required single-tooth prosthetic replacement for a missing tooth were recruited. A total of 45 self-tapping implants (Astra Tech ST-implants)--40 in the maxilla and five in the mandible--were installed in a two-stage procedure. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographic examinations were performed at the completion of the prosthetic treatment and once a year during a 5-year follow-up period. The analysis of peri-implant bone level alteration was performed on subject and implant levels and by the use of analysis of variance and binary logistic regression. RESULTS: Three patients were lost during the 5 years of follow-up. One implant was lost after 2.5 years in function and another four implants could not be accounted for at the 5-year follow-up examination. The overall failure rate at 5 years was 2.6% (subject level) and 2.3% (implant level). The mean loss of marginal bone at the implants during the first year in function was 0.06 mm (SD 0.67) on the subject level and 0.02 mm (0.65) on the implant level. During the subsequent 4 years the annual change in peri-implant bone level amounted to -0.02 mm (0.22) on both subject and implant levels. Thus, the mean total bone level change over the 5-year interval was -0.14 mm (1.04) on subject level and -0.11 mm (1.00) on the implant level of analysis (p>0.05). The frequency of implants with a 5-year bone loss of > or =1 mm was 13%. Approximately 50% of the implants demonstrated no bone loss. CONCLUSION: The present clinical trial on single-tooth replacements with the Astra Tech implant system demonstrated that the bone loss during the first year of function as well as annually thereafter was small.     

Disease progression in periodontally treated and untreated patients--a retrospective study

BACKGROUND, AIMS: The aim of this retrospective study was to assess the effect of regular supportive periodontal treatment on disease progression in patients with moderate to advanced periodontitis. METHOD: We compared radiographic change of interdental bone level and number of teeth at 2 time points in 3 patient groups (mean age 46 years): group A, periodontally untreated patients (n= 14) who dropped out during initial therapy; group B, non-compliant patients (n=26), who discontinued supportive periodontal therapy after ca. 2 years of maintenance; group C, compliant patients (n=27), who regularly attended the maintenance program for 7 years. Periodontal treatment was performed as scaling and root planing or flap surgery in groups B and C. All 3 groups were re-examined ca. 7 years after the initial examination. RESULTS: Patients in group A lost 3.8 teeth (0.5 teeth/year), those in group B 3.2 (0.4 teeth/year), and in group C, patients lost 2.0 teeth (0.2 teeth/year). About half of the patients lost no teeth (group A 43%, B 42%, C 55%), and only 17 subjects lost more than 3. At the 2nd examination, an increase in interdental bone was found only in group C (+0.13 mm), while groups A and B lost 0.57 mm and 0.31 mm of alveolar bone level, respectively (p<0.05 group C versus A and B). CONCLUSIONS: Systematic periodontal treatment stops interdental bone loss and decreases the rate of tooth loss in most cases. Periodontal surgery without regular follow-up care cannot prevent further periodontal destruction, but it can delay it.     

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

Abstract: 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.     

Retrospective study of teeth with a poor prognosis following non-surgical periodontal treatment

Aim: The aim of this retrospective study was to assess teeth with a poor prognosis and the proximal periodontium of adjacent teeth, and to identify the risk factors associated with the loss of teeth with a poor prognosis following non-surgical periodontal treatment.
Material and Methods: Teeth with a poor prognosis ( n =113), teeth adjacent to those of poor prognosis ( n =105) and non-adjacent teeth ( n =51) were evaluated in 25 non-smoking patients who had received supportive periodontal treatment for 5–16 years following non-surgical periodontal treatment at a university hospital.
Results: Probing pocket depth (PPD), percentage of alveolar bone loss, presence of tooth mobility and bleeding on probing in all teeth improved significantly after treatment. Logistic regression analysis showed that loss of teeth with a poor prognosis depended on the initial deepest PPD, tooth mobility and multi-rooted tooth.
Conclusions: Teeth with a poor prognosis did not affect the proximal periodontium of the adjacent teeth, and progression of periodontal disease in these teeth and adjacent teeth can be prevented by non-surgical periodontal treatment in non-smokers. The risk factors for loss of teeth with a poor prognosis were the initial deepest PPD, tooth mobility and multi-rooted tooth.     

成年人牙周附着状况十年纵向研究

目的 观察口腔卫生条件较差的我国农村地区成年人牙周病的自然发展过程,分析牙周病进展速率与发达国家地区人群的区别。方法 在1984年对587名受检者进行的口腔状况调查的基础上,1994年由相同的检查人员随访复查了440人,其中398人仍有牙列,对其所有存留牙的牙齿松动度及牙周附着丧失、牙周袋深度等情况作了复查,分析牙周病的进展特点。结果 各年龄组受检者在10年后复查时,均有平均2mm以上的牙周附着丧失。下颌切牙和上颌磨牙的牙周病进展速率较其他牙齿为重。成年人的平均牙周附着丧失率在各年龄组之间差异无显著性。受检人群与其他口腔卫生习惯和口腔保健条件均较好的发达国家人群相比,牙周附着丧失情况基本相似。结论 与发达国家人群相比,牙周附着状况未显著不同;各年龄组相互之间,牙周病发展速率亦未见显著不同。提示人类牙周病发展可能是人类自身内在因素起决定性作用。     

Clinical, microbiological and immunological characteristics of subjects with "refractory" periodontal disease

The aim of the present study was to analyze the relationship between attachment loss and clinical, microbiological, and immunological parameters in a group of 21 human subjects exhibiting poor response to previous periodontal therapy. All had been treated with periodontal surgery, tetracycline, and subsequent maintenance recalls to periodontists who, upon detection of disease progression, referred the subjects to our clinic. In our clinic, each subject received oral hygiene instruction and a thorough subgingival scaling and root planing utilizing as many appointments as necessary. Clinical indices, including gingival index, bleeding on probing, suppuration, plaque index, pocket depth, and duplicate measurements of attachment level from an acrylic stent, were collected at monthly intervals. Probing measurements were performed using the Florida Probe. When significant attachment loss (0.8-1.2 mm) was detected in at least 1 site, a bacterial sample was taken from that site and from a comparably deep, but non-progressing, control site. Microbial samples were enumerated by darkfield microscopy, on selective and non-selective media, and by predominant cultivable technique. Blood samples were also collected to determine antibody levels against potential pathogens. There was no difference in the amount of plaque present in sites gaining or losing attachment, but losing sites exhibited more bleeding and suppuration. 20 of the 21 subjects were tested; of these, 17 exhibited elevated serum antibody against one or more of the following microorganisms: Actinobacillus actinomycetemcomitans, Bacteroides, gingivalis, and Eikenella corrodens. However, few, if any, of the "classical" pathogens were detected in the plaque samples obtained at the time progressive disease was diagnosed. The only exception was Streptococcus intermedius, which occurred in slightly higher numbers in active sites.     

Clinical outcome of Screw Vent implants. A 7-year prospective follow-up study

The clinical results of 85 Screw Vent implants are described with respect to 7-year success, including radiographically detectable bone loss, survival and prosthetic quality. The 1-year results of the same material have been reported previously (De Bruyn et al. 1992). Implants were considered as successful when they were meeting with the success criteria proposed by the European Academy for Periodontology. From the 85 implants originally installed, 16 failed during the 7-year interval (18.8%), 6 were unaccounted for (7%), 21 (24.7%) did not meet the success criteria yet survived and 42 implants (49.4%) were successful. The success rate was 65.2% for the mandibular and 43.5% for the maxillary implants. Implant failures were irrespective of implant length, smoking habits, prosthetic quality or oral hygiene level. From 24 patients with a corresponding number of 60 implants, radiographs were available for bone loss analysis. The mean bone loss after 7 years was 2.92 mm (range -0.5 to 6.3) 18 out of 60 examined implants (30%) showed unacceptable radiological bone loss beyond the critical value of 2.7 mm. Implant material analysis and histomorphometric analysis of a retrieved implant are discussed. In the present clinical study, the Screw Vent implant system does not meet the success criteria proposed by the European Academy for Periodontology. The ongoing bone loss increases the risk for future implant failures and peri-implant disease.