Tooth loss in aggressive periodontitis: Results 25 years after active periodontal therapy in a private practice.

AIM: To assess tooth loss in patients with aggressive periodontitis (AgP) 10-35 years after active periodontal therapy (APT) in a private practice and to detect possible factors influencing tooth loss. MATERIAL AND METHODS: In 100 patients with AgP, tooth loss was recorded over a median follow-up period of 25.5 years after APT, retrospectively. Patient- and tooth-level factors were assessed with a Cox frailty regression model. RESULTS: Of 2,380 teeth, 227 were lost during a median follow-up time of 25.5 years (2.3 ± 3.6 teeth/patient, range 0-17 teeth), resulting in a mean tooth loss rate of 0.09 teeth/patient/year. At patient-level, statistically significant factors for tooth loss were smoking (p = .039) and the baseline diagnosis generalized AgP (p < .001). Influencing factors at tooth-level were location in the maxilla (p = .003), baseline bone loss (p < .001), molars (p < .001) and premolars (p < .001) as well as abutment teeth (p = .009). CONCLUSION: Tooth loss occurred rarely in patients with AgP treated in a private practice over a long-time period. Annual tooth loss rates are comparable with those described in university settings. Smoking, generalized form of AgP, location/type of tooth, baseline bone loss and abutment status could be detected as factors impacting upon tooth loss.

Clinical validation of robot simulation of toothbrushing--comparative plaque removal efficacy.

BACKGROUND: Clinical validation of laboratory toothbrushing tests has important advantages. It was, therefore, the aim to demonstrate correlation of tooth cleaning efficiency of a new robot brushing simulation technique with clinical plaque removal. METHODS: Clinical programme: 27 subjects received dental cleaning prior to 3-day-plaque-regrowth-interval. Plaque was stained, photographically documented and scored using planimetrical index. Subjects brushed teeth 33-47 with three techniques (horizontal, rotating, vertical), each for 20s buccally and for 20s orally in 3 consecutive intervals. The force was calibrated, the brushing technique was video supported. Two different brushes were randomly assigned to the subject. Robot programme: Clinical brushing programmes were transfered to a 6-axis-robot. Artificial teeth 33-47 were covered with plaque-simulating substrate. All brushing techniques were repeated 7 times, results were scored according to clinical planimetry. All data underwent statistical analysis by t-test, U-test and multivariate analysis. RESULTS: The individual clinical cleaning patterns are well reproduced by the robot programmes. Differences in plaque removal are statistically significant for the two brushes, reproduced in clinical and robot data. Multivariate analysis confirms the higher cleaning efficiency for anterior teeth and for the buccal sites. CONCLUSIONS: The robot tooth brushing simulation programme showed good correlation with clinically standardized tooth brushing.This new robot brushing simulation programme can be used for rapid, reproducible laboratory testing of tooth cleaning.