Association, prediction, generalizability: Cross-center validity of predicting tooth loss in periodontitis patients.

OBJECTIVES: To predict patients' tooth loss during supportive periodontal therapy across four German university centers. METHODS: Tooth loss in 897 patients in four centers (Kiel (KI) n = 391; Greifswald (GW) n = 282; Heidelberg (HD) n = 175; Frankfurt/Main (F) n = 49) during supportive periodontal therapy (SPT) was assessed. Our outcome was annualized tooth loss per patient. Multivariable linear regression models were built on data of 75 % of patients from one center and used for predictions on the remaining 25 % of this center and 100 % of data from the other three centers. The prediction error was assessed as root-mean-squared-error (RMSE), i.e., the deviation of predicted from actually lost teeth per patient and year. RESULTS: Annualized tooth loss/patient differed significantly between centers (between median 0.00 (interquartile interval: 0.00, 0.17) in GW and 0.09 (0.00, 0.19) in F, p = 0.001). Age, smoking status and number of teeth before SPT were significantly associated with tooth loss (p < 0.03). Prediction within centers showed RMSE of 0.14-0.30, and cross-center RMSE was 0.15-0.31. Predictions were more accurate in F and KI than in HD and GW, while the center on which the model was trained had a less consistent impact. No model showed useful predictive values. CONCLUSION: While covariates were significantly associated with tooth loss in linear regression models, a clinically useful prediction was not possible with any of the models and generalizability was not given. Predictions were more accurate for certain centers. CLINICAL RELEVANCE: Association should not be confused with predictive value: Despite significant associations of covariates with tooth loss, none of our models was useful for prediction. Usually, model accuracy was even lower when tested across centers, indicating low generalizability.

Long-term tooth retention in periodontitis patients in four German university centres.

OBJECTIVES: In this retrospective study, we compared tooth loss between patients receiving periodontal therapy (PT) in four German university centres, stratified according to periodontal treatment phase. MATERIALS AND METHODS: Overall, 896 patients (Kiel (KI) n = 391; Greifswald (GW) n = 282; Heidelberg (HD) n = 174; Frankfurt a.M. (F) n = 49) were examined initially (T0), after active periodontal therapy (APT, T1) and after supportive periodontal therapy (SPT, T2). Descriptive analyses and multivariable negative binomial regression models were performed. RESULTS: Follow-up periods differed significantly between the centres, ranging between 6.7 ±â€¯3.0 (GW) and 18.2 ±â€¯5.5 (KI) years (p < 0.001). At T0, age, gender, smoking and diabetes showed notable regional distinctions (p < 0.001). However, the number of teeth per patient was similar (between 24.0 ±â€¯4.6 (F) and 24.5 ±â€¯4.1 (HD); p = 0.27). During PT, the number of extracted teeth differed significantly between centres, with greater differences during SPT (0.9 ±â€¯1.8 (GW) to 2.3 ±â€¯2.8 (KI), p < 0.001) compared to APT (0.4 ±â€¯0.9 (F) to 1.0 ±â€¯2.1 (KI), p = 0.02). Annual tooth loss during SPT remained low in all centres (between 0.10 ±â€¯0.14 (F) to 0.15 ±â€¯0.30 (HD), p < 0.001). CONCLUSION: Within the limitation of the study, PT leads to a low risk of tooth loss in all university centres irrespective of patients' baseline characteristics. CLINICAL RELEVANCE: Within the limitations of this retrospective investigation, long-term tooth retention seems to be feasible for most patients, as long as a systematic and structured treatment approach is applied.

Administration of systemic antibiotics during non-surgical periodontal therapy-a consensus report.

AIM: The aim of this meta-review was to evaluate whether there is a meaningful clinical benefit regarding the use of systemic adjunctive antibiotics in the treatment of patients with periodontitis. Additionally, a consensus regarding possible recommendations for future administration of antibiotics should be reached. METHODS: A structured literature search was performed by two independent investigators focusing on systematic reviews (SR) covering adjunctive systemic antibiosis during non-surgical periodontal therapy. Additionally, recent randomized clinical trials (RCT, July 2015 to July 2017) were searched systematically to update the latest SR. Results were summarized and discussed in a plenary to reach a consensus. RESULTS: Mostly, systematic reviews and RCTs showed a significant positive effect of adjunctive systematic antibiosis compared to controls. These positive effects gain clinical relevance in patients with severe periodontal disease aged 55 years and younger. CONCLUSION: Systemic antibiotics as an adjunct to non-surgical periodontal therapy should be sensibly administered and restrictively used. Only certain groups of periodontitis patients show a significant and clinically relevant benefit after intake of systemic antibiosis during periodontal therapy. CLINICAL RELEVANCE: Avoiding antibiotic resistance and possible side effects on the human microbiome should be a focus of dentists and physicians. Thus, a sensible administration of antibiotics is mandatory. This manuscript suggests guidelines for a reasonable use.

Effect of Periodontal Treatment on HbA1c among Patients with Prediabetes.

Evidence is limited regarding whether periodontal treatment improves hemoglobin A1c (HbA1c) among people with prediabetes and periodontal disease, and it is unknown whether improvement of metabolic status persists >3 mo. In an exploratory post hoc analysis of the multicenter randomized controlled trial "Antibiotika und Parodontitis" (Antibiotics and Periodontitis)-a prospective, stratified, double-blind study-we assessed whether nonsurgical periodontal treatment with or without an adjunctive systemic antibiotic treatment affects HbA1c and high-sensitivity C-reactive protein (hsCRP) levels among periodontitis patients with normal HbA1c (≤5.7%, n = 218), prediabetes (5.7% < HbA1c < 6.5%, n = 101), or unknown diabetes (HbA1c ≥ 6.5%, n = 8) over a period of 27.5 mo. Nonsurgical periodontal treatment reduced mean pocket probing depth by >1 mm in both groups. In the normal HbA1c group, HbA1c values remained unchanged at 5.0% (95% CI, 4.9% to 6.1%) during the observation period. Among periodontitis patients with prediabetes, HbA1c decreased from 5.9% (95% CI, 5.9% to 6.0%) to 5.4% (95% CI, 5.3% to 5.5%) at 15.5 mo and increased to 5.6% (95% CI, 5.4% to 5.7%) after 27.5 mo. At 27.5 mo, 46% of periodontitis patients with prediabetes had normal HbA1c levels, whereas 47.9% remained unchanged and 6.3% progressed to diabetes. Median hsCRP values were reduced in the normal HbA1c and prediabetes groups from 1.2 and 1.4 mg/L to 0.7 and 0.7 mg/L, respectively. Nonsurgical periodontal treatment may improve blood glucose values among periodontitis patients with prediabetes (ClinicalTrials.gov NCT00707369).

Long-term tooth loss in periodontally compromised but treated patients according to the type of prosthodontic treatment. A retrospective study.

If prosthodontic treatment is considered after periodontal therapy, the questions arise i) does prosthodontic treatment affect the treatment outcome of the dentition in general and ii) which type of prosthesis is related to best treatment outcome of abutment teeth? Our goal was to compare long-term tooth loss after comprehensive periodontal therapy in patients with or without prosthodontic treatment. Ninety patients' charts with a total of 1937 teeth who had received comprehensive periodontal treatment 5-17 years ago by the same periodontist were retrospectively evaluated. Sixty-five patients received fixed dental prostheses (FDP; n = 29) and/or removable partial dentures anchored with clips (RPDC; n = 25) or double crowns (RPDD; n = 25). Twenty-five patients were also periodontally compromised but treated without prosthodontic treatment and served as a control group. A total of 317 teeth and 70 abutment teeth were lost during 9.7 ± 4.1 years of observation. Thereof, 273 teeth and 48 abutment teeth were lost due to periodontal reasons. Mean tooth loss amounted to 1.2 ± 1.5 (controls) and 4.4 ± 3.4 (partial dentures). Abutment tooth loss was 0.4 ± 1.1 (FDP), 1.0 ± 1.2 (RPDC) and 1.3 ± 1.0 (RPDD). Poisson regressions identified prosthodontic treatment, age, socio-economic status, diabetes mellitus, mean initial bone loss and aggressive periodontitis as factors significantly contributing to tooth loss. Age, diabetes and non-compliance contributed to abutment tooth loss. Not considering biomechanical factors, patients with prosthodontic reconstructions under long-term supportive periodontal therapy were at higher risk for further tooth loss than patients without prostheses. Not only the type of partial denture but also the patient-related risk factors were associated with abutment tooth loss.

[Physiology of the oral cavity. Dermatologic aspects]. / Physiologie der Mundhöhle. Dermatologisch relevante Aspekte.

The oral cavity is the first part of the digestive tract and, thus, the natural entry of food and fluids into the body. Further, it is permanently colonized by bacteria as are all other body surfaces. Humans have two sets of teeth: the deciduous dentition with 20 teeth and the permanent dentition with 32 teeth. Our teeth are unique solid bodies which penetrate the lining surface of the mouth. Thus special defense mechanisms are required to prevent the invasion of microorganisms into connective tissue and bone through the gap between the tooth surface and the gingiva. The host response is observed clinically as inflammation (gingivitis). In the conflict of microbiological exposure and host response this defense mechanism will derail in some individuals early and in most individuals later in life. The host's line of defense will yield to the microorganisms and the body will destroy the connective tissue and bone of the periodontal structures as part of its struggle against bacteria. Halitosis may indicate a particular medical problem (e.g. periodontitis). Contrary to common belief, in most cases halitosis is not due to gastric problems but is caused primarily by bacteria of the oral cavity.

Influence of individual brightness and contrast adjustment on accuracy of radiographic measurements of infrabony defects.

OBJECTIVES: To assess the accuracy of radiographic measurements of infrabony defects and to compare the accuracy with and without individual digital adjustment of brightness and contrast. METHODS: In 41 periodontitis patients (19 females, 22 males; age range 23-73 years), 50 radiographs of 50 infrabony defects were obtained. All radiographs were digitized. Using a personal computer program, the linear distances between cemento-enamel junction (CEJ) and alveolar crest (AC) and between CEJ and bony defect (BD), and the depth of the infrabony defect (INFRA), were measured twice, according to the individual judgement of the radiographic examiner: (1) without digital adjustment (W) and (2) after use of contrast and brightness adjustment (A). Intrasurgical bone measurements served as the gold standard. The accuracy of measurements with or without digital adjustment was compared. RESULTS: Radiographic measurements underestimated the gold standard for CEJ-BD (W: 1.1 mm ± 1.8 mm, P < 0.001; A: 1.0 mm ± 1.9 mm, P = 0.001). Both CEJ-AC (W: 0.2 mm ± 2.5 mm; A: 0.5 mm ± 2.6 mm) and INFRA (W: -0.4 mm ± 2.4 mm; A: -0.6 mm ± 2.5 mm) measurements came close to the gold standard. Statistically significant differences between W and A regarding accuracy were not observed. CONCLUSIONS: The measurement tool used in this study provided high-accuracy measurements of periodontal bone loss in INFRA. Individual brightness and contrast adjustment failed to improve accuracy.

Elevation of collagen type I in fibroblast-keratinocyte cocultures emphasizes the decisive role of fibroblasts in the manifestation of the phenotype of cyclosporin A-induced gingival overgrowth.

BACKGROUND AND OBJECTIVE: Collagen type I elevation in cyclosporin A-induced gingival overgrowth supports evidence that gingival fibroblasts play a decisive role in the manifestation of the phenotype. To analyze the role of gingival fibroblasts under more in vivo-like conditions, we evaluated the effect of cyclosporin A on collagen type I gene and protein expression in gingival overgrowth-derived gingival fibroblasts established as cocultures with gingival keratinocytes as well as in matched gingival fibroblast monolayers. MATERIAL AND METHODS: Monolayers and cocultures of primary gingival fibroblasts were treated with cyclosporin A for 6 and 72 h. The expression of collagen type I mRNA was analyzed by quantitative real time polymerase chain reaction, while expression and secretion of collagen type I protein was analyzed by indirect immunofluorescence and western blotting. RESULTS: Compared with controls, significant elevation of collagen type I mRNA was restricted to cocultures after 6 and 72 h of treatment with cyclosporin A. In keratinocytes, collagen type I remained undetectable. In monolayers and cocultures, indirect immunofluorescence showed a slightly higher level of collagen type I protein in gingival fibroblasts in response to stimulation with cyclosporin A. Semiquantitative detection of collagen type I by western blotting demonstrated a nonsignificant increase for cell extracts in monolayers and cocultures. For secreted collagen type I, western blot analysis of the supernatants revealed elevated protein levels in cultures stimulated with cyclosporin A. Compared with the corresponding monolayers, the stimulatory effect of cyclosporin A on protein secretion was significant only in coculture. CONCLUSION: Our results indicate that collagen type I is a target of cyclosporin A and that gingival fibroblasts are decisive for the manifestation of the gingival overgrowth-phenotype. Furthermore, the results suggest that cocultures of gingival overgrowth-derived gingival fibroblasts and gingival keratinocytes permit analysis of cyclosporin A-induced effects under more in vivo-like conditions.

Differences in subgingival microflora of Korean and German periodontal patients.

PURPOSE: The goal of this study was to characterize the microbiological profile in samples of subgingival plaque taken from periodontal patients with different ethnic origin. METHODS: 178 patients (n=90 from South Korea and n=88 from Germany; age: 45.4 +/- 10.4 years) were diagnosed with severe generalized periodontitis. In all patients the deepest pocket of each quadrant was sampled for subgingival plaque. The four samples per patient were pooled and subsequently analysed with a 16s-RNA-gene probe test. RESULTS: Prevalence of Aggregatibacter actinomycetemcomitans was significantly higher in German patients (47.7%) compared to Korean patients (26.7%) (p < 0.01, chi(2)-test). For Tannerella forsythia and porphyromonas gingivalis, differences between Germans and Koreans were not as pronounced. A statistically significant difference could also be found for Treponema denticola (Germans: 95.5%, Koreans: 81.1%, p < 0.01, chi(2)-test). After logarithmic transformation, bacterial counts differed for all microorganisms under investigation between Germans and Koreans, even after using a General Linear Model/Analysis of Covariance (GLM/ANCOVA) to adjust for gender, age, smoking status, pocket probing depths (PPD) of sampled teeth, and gingival bleeding index (GBI). CONCLUSION: Depending on their ethnic origin, the microbiological profile of pooled subgingival plaque sample seems to differ significantly between patients of Caucasian and Asian ethnic origin.

Digital enhancement of radiographs for assessment of interproximal dental caries.

OBJECTIVES: Evaluation of a particular digital caries image-enhancing mode (filter) for its effect on the validity of measurements of caries lesion depth. METHODS: Standardized radiographs of 44 extracted teeth exhibiting interproximal caries lesions were obtained. Six radiographs were obtained of each tooth and digitized. Four radiographs were made using D-speed film with and without soft tissue scattering equivalent (STSE) at normal exposure time (0.32 s) and underexposed (0.16 s). Two were made using E-speed film with STSE normally (0.16 s) and underexposed (0.08 s). On each of the 264 radiographs, 4 independent examiners measured the central depth (CD) of 1 carious lesion per tooth both on the unchanged radiographic image and after use of the filter. Histometric CD assessments provided a gold standard for comparison with the radiographic measurements (validity). Repeated measures ANOVA was calculated for validity in relation to examiner, lesion type, filter, film type, exposure time and STSE. RESULTS: The lesion type was identified to statistically significantly influence the validity of CD measurements. Examiner in combination with defect type (P<0.001), filter (P = 0.017), exposure (P = 0.027) and film type (P = 0.044) had an additional albeit small effect. CONCLUSIONS: The lesion type significantly influenced the validity of CD measurements: enamel lesions were less underestimated than dentin lesions.

The infrabony defect and its determinants.

BACKGROUND AND OBJECTIVE: The purpose of this study was to assess the defect width of infrabony defects in a cross-sectional study and to evaluate whether the defect width is a function of defect depth. MATERIAL AND METHODS: Complete sets of intra-oral radiographs of patients with severe periodontitis, which exhibited at least one infrabony defect, were digitised and evaluated. The following parameters were measured: depth and width of the infrabony defect, defect angle, and width of the interdental spaces. RESULTS: Fifty-one patients (26 women), ranging from 21 to 73 yr of age (48.5 +/- 13.4 yr), contributed a total of 1272 teeth with 135 infrabony defects (10.6%). Seventeen infrabony defects were located at sites without a neighboring tooth. Infrabony defects were statistically more prevalent in the mandible (n = 82) than in the maxilla (p = 0.013), and more prevalent at mesial sites (n = 92) than at distal sites (p < 0.001). At infrabony defects, the width of interdental spaces at the most coronal extension of the alveolar crest could be measured only at sites with neigboring teeth 2.67 +/- 0.78 mm (range: 1.19-5.70 mm). Analysis failed to reveal a statistically significant difference between defect width at sites with (2.64 +/- 0.82 mm) and sites without (2.76 +/- 0.70 mm) a neighboring tooth. Multilevel regression analysis revealed narrow defect angles to be related to deep infrabony defects, whereas width of the interdental space and distal location were related to wide defects. CONCLUSION: Defect angle depended on defect depth and defect width was not different at sites with or without a neighboring tooth. Even in severe periodontitis, infrabony defects are found only at a minority of teeth.

Periodontal therapy in siblings with Papillon-Lefèvre syndrome and tinea capitis: a report of two cases.

OBJECTIVE: Report of clinical and microbiological periodontal findings before and 6 months after treatment of two siblings with Papillon-Lefèvre syndrome (PLS) and tinea capitis. METHODS: Two brothers, RG 3 years and NG 5 years of age, were referred for treatment due to premature mobility of their deciduous teeth. Probing depths (PPD), attachment levels (PAL-V), and furcation involvements were examined clinically. Panoramic radiographs were taken. Subgingival plaque samples within the deepest pocket of each tooth were taken and analysed by real-time polymerase chain reaction (PCR) for Actinobacillus actinomycetemcomitans (AA), Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Fusobacterium nucleatum, and Prevotella intermedia. One-stage full-mouth scaling and extraction of hopeless teeth were performed under general anaesthesia, followed by systemic amoxicillin and metronidazole for 7 days. Clinical and microbiological analyses were performed 6 months after treatment. RESULTS: Before treatment, both siblings had exhibited PPD of up to 13 mm, Class III furcation defects at four teeth, and marginal suppuration. AA was detected in both patients and at all teeth at levels ranging from 3.0 x 10(2) to 5.1 x 10(6). Both patients exhibited palmar and plantar hyperkeratosis. Seven teeth were extracted from RG, and nine from NG. Six months after treatment, PPD had been reduced to

Novel mutations in the cathepsin C gene in patients with pre-pubertal aggressive periodontitis and Papillon-Lefèvre syndrome.

Aggressive periodontitis (AP) in pre-pubertal children is often associated with genetic disorders like Papillon-Lefèvre syndrome (PLS). PLS is caused by mutations in the cathepsin C (CTSC) gene. We report a novel CTSC mutation (c.566-572del) in an otherwise healthy AP child and two novel compound heterozygous mutations (c.947T>G, c.1268G>C) in a PLS patient. We conclude that at least a subset of pre-pubertal AP is due to CTSC mutations and therefore may be an allelic variant of PLS.

Effect of dose reduction in digital dental panoramic radiography on image quality.

OBJECTIVES: To investigate the effect of dose reduction in digital panoramic radiography on subjective image quality and diagnostic performance. METHODS: Two digital panoramic radiographs were obtained with the Orthophos DS(Sirona, Bensheim, Germany) of patients (n=100) receiving dental care. The first image was taken at the standard exposure setting. For the second image the tube current was reduced by between 48 and 53%, 63 and 69%, 75 and 80% and 80 and 81% respectively. Ten observers rated both images for 21 specific anatomical details and 30 pathological findings. RESULTS: All radiographs taken at reduced mA levels had a significantly inferior score (P<0.01) for anatomical details. There was no difference in the scores for pathological findings. CONCLUSION: Radiographs obtained at reduced mA had inferior subjective image quality, but there was no difference in diagnostic performance. Thus, a reduction in tube current of approximately 50% is recommended. In certain circumstances such as follow-up radiographic examinations, a reduction of up to 65% should be considered.

Reliability of assessing interproximal bone loss by digital radiography: intrabony defects.

AIM: The aim of the present study was to assess the reproducibility and validity of linear measurements of interproximal bone loss in intrabony defects on digitized radiographic images after application of different filters and magnifications. METHODS: Immediately before surgery 50 radiographs of 50 periodontally diseased teeth exhibiting interproximal intrabony defects were obtained by a standardized technique in 50 patients. Intrasurgically the distances from the cementoenamel-junction (CEJ) to the alveolar crest (AC) and from the CEJ to the deepest extension of the bony defect (BD) were assessed. All radiographs were digitized by a flatbed scanner (resolution: 600x1200 dpi). Using the FRIACOM-soft ware, the linear distances CEJ to AC and CEJ to BD were measured at 50 intrabony defects on digitized but unchanged radiographic images and also after use of 2 different basic image processing modes (filters: enhancement of grey level differences, spreading of grey values) with 7-fold and 14-fold magnification by 2 different examiners. RESULTS: Repeated measures MANOVA revealed reproducibility of the measurement of the distance CEJ to AC to be significantly influenced by examiner (p=0.027) and filter in combination with the height of 2 wall component of the intrabony defect (p=0.066). For the distance CEJ to BD filters had significant influence on reproducibility in correlation with vertical angulation difference (p=0.001). On the average in this study radiographic measurements tended to overestimate the amount of bone loss as assessed by intrasurgical measurements (CEJ-AC: 0.74-1.91 mm; CEJ-DB: -0.04-0.77 mm). Validity of measurement of the distance CEJ-AC was shown to be significantly influenced by the depth of the intrabony defect (p<0.003). Validity of the distance CEJ-BD was significantly influenced by intrasurgically assessed bone loss (p=0.029), horizontal angulation (p=0.066). Filters influenced the validity only in combination with examiner (p<0.001). CONCLUSIONS: In this study, the chosen digital manipulations (filters: spreading, structure) of radiographic images failed to result in statistically significantly more reproducible or valid measurements of interproximal bone loss within intrabony defects when compared to the digitized but unchanged images. All radiographic assessments on the digitized images except for use of enhancement of grey level differences (structure) came close to the intrasurgical gold standard.

Combined mechanical and antibiotic periodontal therapy in a case of Papillon-Lefèvre syndrome.

BACKGROUND: Papillon Lefèvre syndrome (PLS) is a rare entity and, as such, it is almost impossible to evaluate an effective therapy in a randomized controlled study. The amount of success reported after therapy for prepubertal periodontitis (PP) in PLS is highly variable from case to case. The goal of this case report is to evaluate the effects of a combined mechanical and antibiotic periodontal therapy regimen in the management of PLS. METHODS: A male patient was diagnosed as suffering from PP associated with PLS at the age of 7 years. He showed hyperkeratosis of the palms and soles, as well as advanced periodontal disease already affecting permanent teeth with maximal probing depth and vertical attachment loss of 12 mm and 11 mm, respectively. Subgingival debridement was performed with simultaneous administration of oral 250 mg amoxicillin 3 times daily and 250 mg metronidazole twice daily for one week. Clinical parameters were assessed and subgingival plaque was collected from all teeth prior to therapy and 7 and 26 months after treatment. Selective cultures for A. actinomycetemcomitans were incubated for each individual tooth and DNA probe analysis was performed for various periodontal pathogens. RESULTS: Prior to combined mechanical and antibiotic treatment, all teeth but one harbored Actinobacillus actinomycetemcomitans subgingivally. However, at 7 and 26 months after therapy A. actinomycetemcomitans could be detected neither by culture nor by DNA probes. Clinical parameters improved markedly and teeth erupting after therapy did not exhibit attachment loss of more than 1.5 mm during the observation period. CONCLUSIONS: Eradication (suppression beneath detection levels) of A. actinomycetemcomitans seems to play a significant role in the successful treatment of localized prepubertal periodontitis in PLS.

Reproducibility of peri-implant probing using a force-controlled probe.

The aim of the present study was to evaluate the reproducibility of probing depth (PD) and vertical attachment level (PAL-V) measurements at endosseous implants. Twenty partially edentulous patients who had received 44 Frialit-2 and 30 Astra implants between 1994 and 1996 were examined. At all teeth and implants, clinical parameters (GI, PlI, PD, PAL-V) were measured at 6 sites using the flexible plastic version of the universal explorer TPS probe. At the implants and at teeth that were in similar locations compared to the implants, PD and PAL-V measurements were repeated. For each of the 20 probes that had been used for clinical examination of the 20 patients, the probing force was assessed using a precision balance. As a measure of intraexaminer reproducibility, the following standard deviations of single PD and PAL-V measurements were calculated: Frialit-2: 0.71/0.74 mm; Astra: 0.72/0.75 mm; tooth: 0.59/0.57 mm (PD/PAL-V). Stepwise multiple regression analysis revealed implant/tooth position and GI to influence PD and PAL-V measurement error (P<0.001). At anterior teeth, a lower variability was observed than at posterior teeth (P<0.001). PD and PAL-V measurement error were higher at implants than at teeth and influenced by patients. The respective models explained 13% and 17% of the variability of the dependent variable (PD/PAL-V), respectively. Intraexaminer variability of PD and PAL-V measurements at implants tended to be higher than at teeth. Multivariate analysis of variance revealed probe and probe holder to statistically significantly (P<0.001) influence probing force. However, the differences in probing force between the various probe heads were very small. They reached a maximum of 0.054 N between probe 3 and 14 and may be looked upon as clinically irrelevant.

Adverse health effects related to mercury exposure from dental amalgam fillings: toxicological or psychological causes?

BACKGROUND: Possible adverse health effects due to mercury released by amalgam fillings have been discussed in several studies of patients who attribute various symptoms to the effects of amalgam fillings. No systematic relation of specific symptoms to increased mercury levels could be established in any of these studies. Thus, a psychosomatic aetiology of the complaints should be considered and psychological factors contributing to their aetiology should be identified. METHODS: A screening questionnaire was used to identify subjects who were convinced that their health had already been affected seriously by their amalgam fillings (N = 40). These amalgam sensitive subjects were compared to amalgam non-sensitive subjects (N = 43). All participants were subjected to dental, general health, toxicological and psychological examinations. RESULTS: The two groups did not differ with respect to the number of amalgam fillings, amalgam surfaces or mercury levels assessed in blood, urine or saliva. However, amalgam sensitive subjects had significantly higher symptom scores both in a screening instrument for medically unexplained somatic symptoms (SOMS) and in the SCL-90-R Somatization scale. Additionally, more subjects from this group (50% versus 4.7%) had severe somatization syndromes. With respect to psychological risk factors, amalgam sensitive subjects had a self-concept of being weak and unable to tolerate stress, more cognitions of environmental threat, and increased habitual anxiety. These psychological factors were significantly correlated with the number and intensity of the reported somatic symptoms. CONCLUSIONS: While our results do not support an organic explanation of the reported symptoms, they are well in accord with the notion of a psychological aetiology of the reported symptoms and complaints. The findings suggest that self-diagnosed 'amalgam illness' is a label for a general tendency toward somatization.

Long-term results of guided tissue regeneration therapy with non-resorbable and bioabsorbable barriers. I. Class II furcations.

BACKGROUND: The aim of this 5-year follow-up study was to clinically and radiographically evaluate the long-term results after guided tissue regeneration (GTR) therapy of Class II furcation defects using non-resorbable and bioabsorbable barriers. METHODS: Nine pairs of contralateral Class II furcation defects were treated in 9 patients with advanced periodontitis. Within each patient, one defect received a non-resorbable (expanded polytetrafluoroethylene [ePTFE]; control, C) barrier and the other a bioabsorbable (polyglactin 910; test, T) barrier by random assignment. At baseline, 6, and 60 +/- 3 months after surgery, clinical parameters and standardized radiographs were obtained. Gain of bone density within furcation areas was assessed using subtraction radiography. RESULTS: Six and 60 months after GTR therapy, statistically significant (P <0.05) horizontal attachment (CAL-H) gain was observed in both groups (C6: 1.7 +/- 0.8 mm; C60: 1.6 +/- 1.2 mm; T6: 2.0 +/- 0.7 mm; T60: 2.2 +/- 0.9 mm). However, 1 furcation assessed as Class I six months after GTR therapy with a bioabsorbable barrier had progressed to Class III after 5 years, and in another patient, 5 years after placement of an ePTFE barrier, 1 furcation had lost all the CAL-H gain that had been observed at 6 months. Subtraction analysis revealed similar area gain in both groups 6 and 60 months postsurgically (C6: 0.3 +/- 0.5; C60 1.0 +/- 1.7; T6: 0.4 +/- 0.4; T60: 1.1 +/- 1.7). CONCLUSIONS: CAL-H gain achieved after GTR therapy in Class II furcations was stable after 5 years in 16 of 18 defects. The study failed to show a statistically significant difference in stability of CAL-H gain between control and test groups 5 years after GTR therapy.

Radiographic defect depth and width for prognosis and description of periodontal healing of infrabony defects.

BACKGROUND: The aims of the present study were to evaluate 1) defect depth and width as a prognostic factor and 2) change in defect width as a describing parameter of periodontal healing in infrabony defects treated by regenerative therapy after 6 and 24 months. METHODS: In 24 patients with advanced periodontitis, 39 infrabony defects were treated by guided tissue regeneration (GTR) using expanded polytetrafluoroethylene (ePTFE) (n = 7) or bioabsorbable barriers (n = 32). Clinical parameters were assessed and 39 standardized radiographs (in triplicate) were taken before and 6 and 24 months after surgery. Using a computer-assisted analysis, the depth, width, and angle of the bony defects were measured. RESULTS: Statistically significant vertical clinical attachment gains (CAL-V: 3.15 +/- 1.63 mm to 3.31 +/- 1.65 mm; P<0.001) and bony fill (1.30 +/- 2.53 mm; P<0.01 to 1.54 +/- 2.70 mm; P<0.005) were observed 6 and 24 months postsurgically. In a multilevel regression analysis CAL-V gain was predicted by baseline CAL-V (P <0.0001), actual smoking (P <0.05), and age (P <0.1). Bony fill could be predicted by baseline height of the infrabony component (P<0.0001), gingival index at baseline (P<0.05), and actual smoking (P <0.01). In narrow (<26 degrees) and deep (> or = 3 mm) infrabony defects bony fill was more pronounced than in wide and shallow defects (P <0.05). CONCLUSIONS: Improvement achieved by guided tissue regeneration in infrabony defects can be maintained up to 24 months after surgery. Narrow and deep infrabony defects respond radiographically and to some extent clinically more favorably to GTR therapy than wide and shallow defects. However, depth of the infrabony component was a stronger prognostic parameter than defect angle. Actual smoking impairs the results of GTR therapy in infrabony defects.