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Abstract Background Periodontitis, a prevalent chronic inflammatory disease, offers insights into the broader landscape of chronic inflammatory conditions. The progression and treatment outcomes of periodontitis are closely related to the oral microbiota’s composition. Adjunctive systemic Amoxicillin 500 mg and Metronidazole 400 mg, often prescribed thrice daily for 7 days to enhance periodontal therapy’s efficacy, have lasting effects on the oral microbiome. However, the precise mechanism through which the oral microbiome influences clinical outcomes in periodontitis patients remains debated. This investigation explores the pivotal role of the oral microbiome's composition in mediating the outcomes of adjunctive systemic antibiotic treatment. Methods Subgingival plaque samples from 10 periodontally healthy and 163 periodontitis patients from a randomized clinical trial on periodontal therapy were analyzed. Patients received either adjunctive amoxicillin/metronidazole or a placebo after mechanical periodontal treatment. Microbial samples were collected at various intervals up to 26 months post-therapy. Using topic models, we identified microbial communities associated with normobiotic and dysbiotic states, validated with 86 external and 40 internal samples. Logistic regression models evaluated the association between these microbial communities and clinical periodontitis parameters. A Directed Acyclic Graph (DAG) determined the mediating role of oral microbiota in the causal path of antibiotic treatment effects on clinical outcomes. Results We identified clear distinctions between dysbiotic and normobiotic microbial communities, differentiating healthy from periodontitis subjects. Dysbiotic states consistently associated with below median %Pocket Probing Depth ≥ 5 mm (OR = 1.26, 95% CI [1.14–1.42]) and %Bleeding on Probing (OR = 1.09, 95% CI [1.00–1.18]). Factors like microbial response to treatment, smoking, and age were predictors of clinical attachment loss progression, whereas sex and antibiotic treatment were not. Further, we showed that the oral microbial treatment response plays a crucial role in the causal effect of antibiotic treatment on clinical treatment outcomes. Conclusions The shift towards a normobiotic subgingival microbiome, primarily induced by adjunctive antibiotics, underscores the potential for microbiome-targeted interventions to enhance therapeutic efficacy in chronic inflammatory conditions. This study reaffirms the importance of understanding the oral microbiome's role in periodontal health and paves the way for future research exploring personalized treatment strategies based on individual microbiome profiles. Video Abstract

Purpose Patients with periodontitis, who currently make up a large proportion of the adult population, show high interest in orthodontic therapy. It is therefore important to recognize and assess orthodontic treatment need in these patients. The index of orthodontic treatment (IOTN) is an established tool to determine malocclusions clinically and digitally.Materials and methods A semi-automatic IOTN-assessment using OnyxCeph3TM was performed on patients undergoing supportive periodontal therapy (SPT). Intra- and inter-rater reliability were investigated using intra-class-coefficient (ICC). Self-perceived aesthetic by patients and perception by the investigator according to the aesthetic component (AC) were compared to both each other and normative need, measured by the dental health component (DHC). Periodontitis stage and grade and the possibility of an orthodontic treatment were determined.Results The mean age of the 64 included patients in this study was 62.1 years (SD ± 8.6; min-max 45–81) at the time of the examination. Self-related AC was different to the investigator’s assessment (ICC: = 0.474; 95%-CI: [0.262, 0.643]). Normative treatment need compared to self-perceived treatment need resulted in poor reliability (ICC: = 0.098; 95%-CI: [−0.071, 0.298]). Comparison of IOTN between investigators showed moderate reliability for AC (ICC: = 0.618; 95%-CI: [0.331, 0.799]) and an excellent reliability for DHC (ICC: = 0.932; 95%-CI: [0.863, 0.967]). AC Intra-rater reliability was considered good (ICC: = 0.796; 95%-CI: [0.613, 0.898]). Orthodontic treatment was possible in 48 of the 64 patients.Conclusion Semi-automated IOTN-assessment showed satisfying inter- and intra-rater reliability, but patients’ self-perceived dental aesthetics differed from the dentist’s assessment as well as from the normative treatment need.

Objective: The current study explores whether there is a clinically relevant distinction in the measurement of marginal bone loss when comparing high-dose (HD) versus low-dose (LD) cone beam computed tomography (CBCT) protocols in small and large acquisition volumes. Material and Methods: CBCTs of four human cadaveric preparates were taken in HD and LD mode in two different fields of view 8 × 8 cm2 (LV) and 5 × 5 cm2 (SV). In total, 43 sites of 15 teeth were randomly chosen, and marginal bone loss was measured twice in all protocols at 43 sites of 15 teeth by one calibrated investigator. Bland-Altman plots and Lin’s concordance correlation coefficient (CCC) were calculated to assess the extent of agreement of the measurements. Additionally, the rater scored the certainty in each of the measurements. Results: For HD-CBCT CCC of measurements obtained using SV versus LV was 0.991. CCC of measurements obtained using SV versus LV of LD-CBCT was 0.963. Both CCC values indicated excellent agreement between the two volumes in both protocols. CCC also indicated high intramodality correlation between HD-CBCT and LD-CBCT independent of the acquisition volume (0.963 – 0.992). Bland-Altman plots also indicated no substantial differences. Results of certainty scoring showed significant differences (p = 0.004 (LV), p < 0.001(SV)) between the LD and HD-CBCT. Conclusions: Accuracy of measurements of bone loss shows no clinical noticeable effects depending on the CBCT volume in this ex vivo study. There appears to be no relevant advantage of SV over LV, neither in HD-CBCT nor in LD-CBCT and additionally no relevant advantage of HD versus LD in visualizing marginal bone loss.

The aim of this study was to investigate the influence of examiner experience on measurements of bone-loss using high-dose (HD) and low-dose (LD) CBCT. Three diagnosticians with varying levels of CBCT interpretation experience measured bone-loss from CBCT scans of three cadaveric heads at 30 sites, conducting measurements twice. Between the first and second measurements, diagnostician 2 and diagnostician 3 received training in LD-CBCT diagnostics. The diagnosticians also classified the certainty of their measurements using a three-grade scale. The accuracy of bone-loss measurements was assessed using the absolute difference between observed and clinical measurements and compared among diagnosticians with different experience levels for both HD and LD-CBCT. At baseline, there was a significant difference in measurement accuracy between diagnostician 1 and diagnostician 2, and between diagnostician 1 and diagnostician 3, but not between diagnostician 2 and diagnostician 3. Training improved the accuracy of both HD-CBCT and LD-CBCT measurements in diagnostician 2, and of LD-CBCT measurements in diagnostician 3. Regarding measurement certainty, there was a significant difference among diagnosticians before training. Training enhanced the certainty for diagnosticians 2 and 3, with a significant improvement noted only for diagnostician 3. Examiner experience level significantly impacts the accuracy and certainty of bone-loss measurements using HD- and LD-CBCT.

Abstract Clinical photon-counting CT (PCCT) offers a spatial resolution of about 200 µm and might allow for acquisitions close to conventional dental CBCTs. In this study, the capabilities of this new system in comparison to dental CBCTs shall be evaluated. All 8 apical osteolysis identified in CBCT were identified by both readers in all three PCCT scan protocols. Mean visibility scores showed statistical significant differences for root canals(p = 0.0001), periodontal space(p = 0.0090), cortical(p = 0.0003) and spongious bone(p = 0.0293) in favor of high and medium dose PCCT acquisitions. Overall, both devices showed excellent image quality of all structures assessed. Interrater-agreement showed high values for all protocols in all structures. Bland–Altman plots revealed a high concordance of both modalities with the reference measurements. In vitro, ultra-high resolution PCCT can reliably identify different diagnostic entities and structures relevant for dental diagnostics similar to conventional dental CBCT with similar radiation dose. Acquisitions of five cadaveric heads were performed in an experimental CT-system containing an ultra-high resolution PC detector (0.25 mm pixel size in isocenter) as well as in a dental CBCT scanner. Acquisitions were performed using dose levels of 8.5 mGy, 38.0 mGy and 66.5 mGy (CTDI16cm) in case of PCCT and of 8.94 mGy (CTDI16cm) in case of CBCT. The quality of delineation of hard tissues, root-canals, periodontal-space as well as apical osteolysis was assessed by two readers. Mean visibility scores and interrater-agreement (overall agreement (%)) were calculated. Vertical bone loss (bl) and thickness (bt) of the buccal bone lamina of 15 lower incisors were measured and compared to reference measurements by ore microscopy and clinical probing.

Abstract Different cone beam computed tomography (CBCT) protocols have shown promising results for imaging furcation defects. This study evaluates the suitability of low-dose (LD)-CBCT for this purpose. Fifty-nine furcation defects of nine upper and 16 lower molars in six human cadavers were measured by a high-dose (HD)-CBCT protocol, a LD-CBCT protocol, and a surgical protocol. HD-CBCT and LD-CBCT measurements were made twice by two investigators and were compared with the intrasurgical measurements, which served as the reference. Furcation defect volumes generated from HD-CBCT and LD-CBCT imaging were segmented by one rater. Cohen’s kappa and intraclass correlation coefficient (ICC) values were calculated to determine intra- and interrater reliability. The level of significance was set at α = 0.05. In total, 59 furcation defects of nine upper and 16 lower human molars were assessed. Comparing CBCT furcation defect measurements with surgical measurements revealed a Cohen’s kappa of 0.5975 (HD-and LD-CBCT), indicating moderate agreement. All furcation defects identified by HD-CBCT were also detected by LD-CBCT by both raters, resulting in a Cohen’s kappa of 1. For interrater agreement, linear furcation defect measurements showed an ICC of 0.992 for HD-CBCT and 0.987 for LD-CBCT. The intrarater agreement was 0.994(r1)/0.992(r2) for HD-CBCT and 0.987(r1)/0.991(r2) for LD-CBCT. The intermodality agreement was 0.988(r1)/0.991(r2). Paired t-test showed no significant differences between HD-CBCT and LD-CBCT measurements. LD-CBCT is a precise and reliable method for detecting and measuring furcation defects in mandibular and maxillary molars in this experimental setting. It has the potential to improve treatment planning and treatment monitoring with a far lower radiation dose than conventional HD-CBCT.

Abstract The objective of this study was to investigate oral health-related quality of life (OHRQoL) in times of the COVID-19 pandemic and to examine a possible association to psychosocial factors like psychological stress and symptoms of depression and anxiety disorders. Secondary research questions were whether people changed oral hygiene regimens during the COVID-19 pandemic and to what extent dental symptoms existed and developed compared to pre-pandemic. For this cross-sectional study a survey has been conceptualized to determine OHRQoL, stress, depression and anxiety and their specific confounders in a German cohort. Validated questionnaires as OHIP-G14, PHQ-Stress and PHQ-4 have been implemented. Altogether 1178 participants completed the survey between May and August 2020. The overall OHIP-G14 sum score of 4.8 ± 7.5 indicated good OHRQoL. 21% of the participants (n = 248) reported toothache, 23% (n = 270) mucosal problems, 31% (n = 356) hypersensitivity of the teeth and 27% (n = 305) myofacial pain. The PHQ-Stress score (4.5 ± 3.5) demonstrated a mild severity of stress. Depression and anxiety level has been mild to moderate (PHQ-4 score: 2.4 ± 2.6). 38% of the participants stated subjectively greater emotional burden compared to pre-pandemic. Statistically significant differences exist for OHRQoL, stress, anxiety and depression levels between participants with greater, equal or less emotional burden compared to pre-pandemic. COVID-19 history and aggravated levels of depression, anxiety, and stress seem to associate with lower OHRQoL. Psychosocial consequences during pandemic times and their association to oral health should be further investigated.

ObjectivesThis comparative study aimed to evaluate intraoral digital photography (IODP) as assessment-tool for DMFT and number of implants (IMPL) compared to clinical diagnosis (CLIN) in an elderly population with high restorative status. Secondary research questions were whether an additional evaluation of panoramic radiographs (PAN-X) or raters' clinical experience influence the agreement.MethodsFifty patients (70.98±7.60 years) were enrolled for standardized CLIN and IODP. The clinical reference examiner and ten blinded raters evaluated the photographs without and with a PAN-X regarding DMFT and IMPL. CLIN were used as reference standard and differences to IODP and IODP-PAN-X findings were analysed descriptively. To assess intra-rater agreement, pairwise Gwet's AC1s of the three diagnostic methods CLIN, IODP and IODP+PAN-X were calculated.ResultsCompared to a DMFT of 22.10±3.75 (CLIN), blinded raters evaluated a DMFT of 21.54±3.40 (IODP) and 22.12±3.45 (IODP+PAN-X). Mean values for "Decayed" were 0.18±0.52 (CLIN), 0.45±0.46 (IODP) and 0.48±0.47 (IODP-PAN-X), while 11.02±5.97 (CLIN), 10.66±5.78 (IODP) and 10.93±5.91 (IODP+PAN-X) were determined for "Missing" and 10.90±5.61 (CLIN), 10.43±4.85 (IODP) and 10.71±5.11 (IODP+PAN-X) for "Filled". IMPL were 0.78±2.04 (CLIN), 0.58±1.43 (IODP), 0.78±2.04 (IODP+PAN-X). Gwet's AC1 using the mode of the blinded raters' assessment of "Decayed", "Missing" and IMPL compared to CLIN ranged from 0.81 to 0.89 (IODP) and 0.87 to 1.00 (IODP+PAN-X), while for "Filled" and DMFT they were 0.29 and 0.36 (IODP) as well as 0.33 and 0.36 (IODP+PAN-X), respectively. Clinical experience did not influence the agreement.ConclusionsAssessment of "Decayed", "Missing" and IMPL by IODP showed almost perfect agreement, whereas of "Filled" and DMFT revealed fair to moderate agreement with clinical findings. Additional PAN-X-evaluation increased agreement compared to IODP-diagnostics alone. IODP for the assessment of DMFT and IMPL might be a suitable method in large-scale epidemiological studies, considering high agreement in total values and miscellaneous agreement at patient-level.

The aim of this follow-up study was, to compare the effects of mechanical periodontal therapy with or without adjunctive amoxicillin and metronidazole on the subgingival microbiome of smokers with periodontitis using 16S rDNA amplicon next generation sequencing. Fifty-four periodontitis patients that smoke received either non-surgical periodontal therapy with adjunctive amoxicillin and metronidazole (n = 27) or with placebos (n = 27). Subgingival plaque samples were taken before and two months after therapy. Bacterial genomic DNA was isolated and the V4 hypervariable region of the bacterial 16S rRNA genes was amplified. Up to 96 libraries were normalized and pooled for Illumina MiSeq paired-end sequencing with almost fully overlapping 250 base pairs reads. Exact ribosomal sequence variants (RSVs) were inferred with DADA2. Microbial diversity and changes on the genus and RSV level were analyzed with non-parametric tests and a negative binomial regression model, respectively. Before therapy, the demographic, clinical, and microbial parameters were not significantly different between the placebo and antibiotic groups. Two months after the therapy, clinical parameters improved and there was a significantly increased dissimilarity of microbiomes between the two groups. In the antibiotic group, there was a significant reduction of genera classified as Porphyromonas, Tannerella, and Treponema, and 22 other genera also decreased significantly, while Selenomonas, Capnocytophaga, Actinomycetes, and five other genera significantly increased. In the placebo group, however, there was not a significant decrease in periodontal pathogens after therapy and only five other genera decreased, while Veillonella and nine other genera increased. We conclude that in periodontitis patients who smoke, microbial shifts occurred two months after periodontal therapy with either antibiotics or placebo, but genera including periodontal pathogens decreased significantly only with adjunctive antibiotics.

Empiric antibiotics are often used in combination with mechanical debridement to treat patients suffering from periodontitis and to eliminate disease-associated pathogens. Until now, only a few next generation sequencing 16S rDNA amplicon based publications with rather small sample sizes studied the effect of those interventions on the subgingival microbiome. Therefore, we studied subgingival samples of 89 patients with chronic periodontitis (solely non-smokers) before and two months after therapy. Forty-seven patients received mechanical periodontal therapy only, whereas 42 patients additionally received oral administered amoxicillin plus metronidazole (500 and 400 mg, respectively; 3x/day for 7 days). Samples were sequenced with Illumina MiSeq 300 base pairs paired end technology (V3 and V4 hypervariable regions of the 16S rDNA). Inter-group differences before and after therapy of clinical variables (percentage of sites with pocket depth ≥ 5mm, percentage of sites with bleeding on probing) and microbiome variables (diversity, richness, evenness, and dissimilarity) were calculated, a principal coordinate analysis (PCoA) was conducted, and differential abundance of agglomerated ribosomal sequence variants (aRSVs) classified on genus level was calculated using a negative binomial regression model. We found statistically noticeable decreased richness, and increased dissimilarity in the antibiotic, but not in the placebo group after therapy. The PCoA revealed a clear compositional separation of microbiomes after therapy in the antibiotic group, which could not be seen in the group receiving mechanical therapy only. This difference was even more pronounced on aRSV level. Here, adjunctive antibiotics were able to induce a microbiome shift by statistically noticeably reducing aRSVs belonging to genera containing disease-associated species, e.g., Porphyromonas, Tannerella, Treponema, and Aggregatibacter, and by noticeably increasing genera containing health-associated species. Mechanical therapy alone did not statistically noticeably affect any disease-associated taxa. Despite the difference in microbiome modulation both therapies improved the tested clinical parameters after two months. These results cast doubt on the relevance of the elimination and/or reduction of disease-associated taxa as a main goal of periodontal therapy.

Purpose: The subgingival area is only reached to a limited extent during home oral hygiene with the aids available to date. The question was investigated whether a newly developed, flattened cross-sectional design of interdental brushes (IDBs) can extend their subgingival reach. Materials and Methods: In part I, the passage-hole diameters (PHD) of IDBs of different sizes and side-bristle lengths, with circular and flattened cross-sections, were compared according to the ISO standard 16409/2016. In part II, handling of flattened IDBs was described based on a case report of a patient with generalised stage 4, grade C periodontitis with locally persistent pockets. Results: Depending on the brush's size, flattening of IDBs reduced the PHD by 1-18 intervals. IDBs with longer side bristles could thus be inserted into interdental spaces with equal force. This may increase the potential range of IDBs in the vertical dimension. Regular instruction and check-ups are necessary to enable correct handling, as the flattened brushes can only be used in two positions. The observations documented in the case report (duration: 1.5 years) showed that flattened IDBs were associated with reduced signs of inflammation (reduction of pocket depths from 6 to 3 mm, absence of bleeding on probing). Conclusion: IDBs with a flattened cross-sectional design have not been previously described in the literature. It was shown that flattening of IDBs leads to a size-dependent decrease in PHD. Based on a case report, it was hypothesised that the design change of the IDBs could be clinically relevant in the case of persistent deep pockets in narrow interdental spaces. However, this can only be verified or falsified by clinical studies. [ABSTRACT FROM AUTHOR]

Objectives: Teeth with combined endodontic-periodontal lesions (EPLs) have favorable to hopeless prognoses. The new classification system was developed by the World Workshop on the Classification of Periodontal and Peri-Implant Disease in 2017 and suitable epidemiologic data related to this new system are currently lacking. This study aims to contribute data about the prevalence of EPLs according to the new system. Method and materials: A total of 1,008 panoramic views taken in 2019 were analyzed, recording the presence of an EPL and other periodontic parameters. Radiographs of bad quality and of the same person were excluded. Additionally, the EPLs' radiographic patterns were rated by two raters according to their shape (j-shaped vs cone-shaped). Descriptive statistical methods as well as t tests for continuous and chi-squared tests for categorical variables were used. Results: Overall, 866 patients (with 18,963 teeth) were included. Prevalence of EPLs was 4.9% (n = 43) (patient-related)/0.4% (n = 71) (tooth-related). Mean age (62.3 years vs 51.5 years), mean maximal percentage of bone loss (60% vs 30%), and mean age-adjusted bone-loss index (1.0 vs 0.6) were considerably higher compared to patients without EPL. A total of 67 EPLs were found in patients with stage III/IV periodontitis and 4 in patients with stage II periodontitis. Conclusions: This is the first study showing prevalence of EPLs (4.9%/0.4%) according to the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Disease. Patients with EPLs have a substantially higher maximal percentage of bone loss and a higher age-adjusted bone-loss index at residual teeth, excluding teeth with EPLs. All patients have at least stage II periodontitis. [ABSTRACT FROM AUTHOR]

The majority of inflammatory periodontal diseases is caused by bacteria. Mechanical removal of bacterial deposits from the teeth by the patient (individual oral hygiene) and mechanical debridement by the dentist (professional tooth cleaning, antiinfective periodontal therapy, periodontal surgery) are effective in treatment of most cases of plaque-induced gingivitis and periodontitis. However, in particular risk patients (e.g. under elevated risk for bacterial endocarditis) periodontal procedures that cause transitory bacteremia require systemic antibiotic prophylaxis. Further, in severe cases of necrotising ulcerative gingivitis and periodontitis local therapy has to be supported by systemic antibiotics. In cases of aggressive and generalised severe chronic periodontitis that show subgingival infection with particular periodontal pathogens, especially by Actinobacillus actinomycetemcomitans, successful therapy requires systemic antibiotics adjunctively to mechanical antiinfective therapy. Therapy of persisting pockets during supportive periodontal therapy may additionally benefit from application of locally delivered antibiotic devices. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare the efficacy of guided tissue regeneration GTR) using two different biodegradable barriers (polylactide acetyltributyl citrate; polydioxanon) in three- and two-walled infrabony defects. The polydioxanon barrier is an experimental GTR membrane that consists of a continuous occlusive barrier with a layer of slings on the side that is meant to face the mucoperiosteal flap. Fifteen patients provided 15 pairs of similar contralateral periodontal defects: 12 predominantly two-walled and 18 predominantly three-walled infrabony defects. Each defect was randomly assigned to treatment with polylactide acetyltributyl citrate (control) or polydioxanon test) devices. At baseline, 6, 12, 18, and 24 months after surgery, clinical measurements were performed and standardized radiographs obtained (not at 18 months). Both treatments revealed a significant Gingival Index reduction, probing depth reduction, and vertical probing attachment level gain 24 months after surgery. Both treatments showed slight resorption of the crestal alveolar ridge after 24 months, which failed to reach statistical significance. A statistically significant bone gain within the infrabony pockets was measured for both treatment options 24 months postsurgical. Regarding Gingival Index and probing depth reduction as well as vertical probing attachment level and bone gain, there were neither statistically significant nor clinically relevant differences between test and control barriers. The use of both biodegradable barriers in GTR therapy may be recommended. [ABSTRACT FROM AUTHOR]

Periodontitis is characterized by chronic inflammation associated with alteration of the oral microbiota. In contrast to previous microbiome studies focusing a priori on comparison between extreme phenotypes, our study analyzed a random sample of 85 people. The aim of this study was to link microbial differences to disease's prevalence and severity. Using next generation sequencing of 16S rRNA amplicons and cluster analysis, we observed that the population can be divided into two major ecotypes: One mainly contained periodontal healthy/mild periodontitis individuals whereas the second ecotype showed a heterogeneous microbial distribution and clustered into three distinct sub-ecotypes. Those sub-ecotypes differed with respect to the frequency of diseased patients and displayed a gradual change in distinct subgingival microbiota that goes along with clinical disease symptoms. In ecotype 2, the subgroup with no clinical signs of disease was linked to an increase of F. nucleatum vincentii but also several other species, while only in "end-stage" dysbiosis classical red complex bacteria gained overweight. Therefore, the microbial disease ecotypes observed in our population can lead to an establishment of an early microbial risk profile for clinically healthy patients. [ABSTRACT FROM AUTHOR]

Background: To investigate the periodontal disease status in a multi-center cross-sectional study in Germany. Associations of dental, socio-economic, blood and biomedical variables with periodontal outcome parameters were evaluated. Methods: From 4 different centers N = 311 persons were included, drawn randomly from the registration offices. Maximal pocket depth (PD) was used as primary indicator for periodontitis. It was classified as: no/mild ≤3 mm, moderate 4-5 mm, severe ≥6 mm. Associations between socioeconomic (household income, education), lifestyle, and biomedical factors and PD or bleeding on probing (BOP) per site (“Yes”/”No”) was analyzed with logistic regression analysis. Results: Mean age of subjects was 46.4 (range 20-77) years. A significantly higher risk of deeper pockets for smokers (OR = 2.4, current vs. never smoker) or persons with higher BMI (OR = 1.6, BMI increase by 5) was found. Severity of periodontitis was significantly associated with caries lesions (p = 0.01), bridges (p < .0001), crowns (p < .0001), leukocytes (p = 0.04), HbA1c (p < .0001) and MCV (p = 0.04). PD was positively correlated with BOP. No significant associations with BOP were found in regression analysis. Conclusions: Earlier findings for BMI and smoking with severity of PD were confirmed. Dental variables might be influenced by potential confounding factors e.g. dental hygiene. For blood parameters interactions with unknown systemic diseases may exist. [ABSTRACT FROM AUTHOR]

The article describes a study which aims to test the hypothesis that teeth that are adequately endodontically treated build more periodontal bone loss than their contra-lateral counterpart without root canal filling (RCF) in relation to the restoration margin (RM) in periodontitis patients. Researchers examined 66 pairs of radiographed periodontitis patients. The study concluded that teeth with endodontic treatment did not have more bone loss than endodontically untreated teeth.

Background: The identification of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) serotypes may add some important information to the understanding of the pathogenetic background of severe periodontal infections. This study compared serotypes of A. actinomycetemcomitans in two groups of periodontal patients with different ethnic backgrounds. Methods: A total of 194 patients (96 Germans and 98 Koreans) with aggressive or severe chronic periodontitis participated in the study. Microbiologic analysis of pooled samples from subgingival plaque was performed by using a real-time polymerase chain reaction (PCR) test for A. actinomycetemcomitans. In patients who tested positive for A. actinomycetemcomitans, serotypes (a through f) were determined by nucleic acid-based methods. Results: The prevalence of patients who tested positive for A. actinomycetemcomitans with the real-time PCR was comparable in both groups (Germans: 27.0%; Koreans: 22.2%). In German patients, the serotypes detected most frequently were b (33.3%), c (25.0%), and a (20.8%), whereas in Korean patients, the serotype distribution was different, with serotypes c (61.9%) and d (19.0%) accounting for >80% of the complete serotype spectrum. Conclusion: Even if the percentage of patients who tested positive for A. actinomycetemcomitans was identical in patients with generalized aggressive and severe chronic periodontitis and different ethnic backgrounds, the distribution of A. actinomycetemcomitans serotypes may exhibit marked differences. [ABSTRACT FROM AUTHOR]

Objective: Evaluation of the 10-year results after GTR-therapy of infrabony defects using two bioabsorbable barriers in a randomized-controlled clinical trial. Material and Methods: In 15 patients with periodontitis, 15 pairs of infrabony defects were treated. For each patient, one defect received a polydioxanon (test: T) and the other received a polylactide acetyltributyl citrate (control: C) barrier by random assignment. At baseline, 12 and 120 ± 6 months after surgery, the clinical parameters and standardized radiographs were obtained. Results: Nine patients were available for the 120-month re-examinations. Twelve and 120 ± 6 months after therapy statistically significant ( p⩽0.004) vertical probing attachment level (PAL-V) gain was found in both groups (T12: 3.9 ± 1.6 mm; T120: 2.4 ± 1.8 mm; C12: 4.0 ± 1.1 mm; C120: 2.4 ± 1.7 mm). From 12 to 120 months both groups experienced PAL-V loss (T: 1.4 ± 1.5 mm, p=0.021; C: 1.6 ± 2.5 mm, p=0.09). After 120 month, two teeth were lost in the control group (one periapical lesion, and one due to unknown reason). The study failed to show statistically significant differences between both groups regarding PAL-V gain 120 months after surgery. Conclusions: PAL-V gain achieved after GTR therapy in infrabony defects using both bioabsorbable barriers was stable after 10 years in 15 of 22 defects (68%). [ABSTRACT FROM AUTHOR]

Background: A 10-year follow-up study was conducted to clinically evaluate the long-term results after guided tissue regeneration (GTR) therapy of infrabony defects using non-resorbable and bioabsorbable barriers. Methods: Twelve pairs of contralateral infrabony defects were treated in 12 subjects with advanced periodontitis. Within each subject, one defect received a non-resorbable barrier and the other received a bioabsorbable barrier by random assignment. Clinical parameters were obtained at baseline and at 12 and 120 ± 6 months after surgery. Results: Eight of 12 subjects were available for the examination at 120 ± 6 months. Twelve and 120 ± 6 months after GTR therapy statistically significant (P <0.05) vertical clinical attachment level ( CAL-V) gain was observed in both groups (3.4 ±1.0 mm and 1.5 ± 1.2 mm for the control group at 12 and 120 months, respectively, and 3.3 ± 1.6 mm and 3.5 ± 2.5 mm for the test group at 12 and 120 months, respectively). However, 120 ± 6 months after GTR therapy, three infrabony defects (two controls and one test) had lost >2 mm of the attachment that had been gained 12 months after GTR therapy, and a statistically significant mean CAL-V loss of 1.7 ± 1.3 mm was observed from 12 to 120 ± 6 months in the control group. One tooth in the control group was lost between 60 and 120 ± 6 months. The case series failed to show statistically significant differences between test and control regarding CAL-V gain 120 ± 6 months after surgery. Conclusion: CAL-V gain achieved 12 months after GTR therapy in infrabony defects using non-resorbable and bioabsorbable barriers was stable after 10 years in 12 of 16 defects. [ABSTRACT FROM AUTHOR]

Objective: To assess tooth-related factors contributing to tooth loss over a period of 10 years after completion of active periodontal therapy (APT). Material and Methods: All patients who had received APT by the same experienced periodontist, 10 years before beginning the research, were recruited until 100 patients were re-examined. Examinations included, at the patient level: test for interleukin-1 polymorphism, compliance to supportive periodontal therapy (SPT), mean plaque scores during SPT; at the tooth level: assessment of baseline bone loss (type, amount), tooth type, furcation status and abutment status. Logistic multilevel regression was performed for statistical analysis. Results: Hundred patients with 2301 teeth at the baseline (completion of APT) were retrospectively examined. One hundred fifty-five teeth were lost over 10 years after APT. Logistic multilevel regression identified high plaque scores, irregular attendance of SPT and age as patient-related factors significantly accounting for tooth loss. Tooth-related factors significantly contributing to tooth loss were baseline bone loss, furcation involvement and use as an abutment tooth. However, in patients with regular SPT, 93% of teeth with 60–80% bone loss at the baseline, survived 10 years. Conclusion: The following tooth-related risk factors for tooth loss were identified: baseline bone loss, furcation involvement, and use as an abutment tooth. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the effect of tooth related and patient related factors on the success of non-surgical and surgical periodontal therapy. In 41 patients (22 female) with untreated and/or recurrent periodontitis, no therapy, scaling and root planing (SRP), or access flap (AF) were assigned according to probing pocket depth (PPD). PPD and vertical relative attachment level (RAL-V) were obtained initially, 3 and 6 months after therapy. Baseline data were compared according to therapy, jaw, tooth type, and site. Factors influencing clinical parameters were identified using multilevel analyses. Baseline PPDs were deeper interproximally, in the maxilla and at premolars compared to buccal/oral sites, mandibular, and anterior teeth. At 6 months, PPD reduction and RAL-V gain were significantly greater at sites receiving SRP and AF as compared to untreated sites ( p < 0.001). PPD reduction and RAL-V gain were significantly less ( p < 0.005) in smokers as compared to nosmokers and at interproximal sites ( p < 0.0001) as compared to buccal/oral sites. RAL-V gain was less in aggressive periodontitis, and PPD reduction was less in the maxilla ( p < 0.001). In sites with greater bone loss and infrabony defects, a poorer response was observed regarding RAL-V gain or PPD reduction, respectively. The conclusions of the study are the following: (1) Nonsurgical and surgical periodontal therapies are effective in single-rooted teeth; (2) severe interproximal bone loss and infrabony defects deteriorate clinical results; and (3) there seem to be more defect-associated (tooth, site) factors influencing treatment outcome than patient-associated factors. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical and microbiological effects of a combined mechanic-antibiotic periodontal therapy in subjects that were tested positive for subgingival Actinobacillus actinomycetemcomitans (A.a.). Methods: The postoperative follow-up ranged from 12-115 months (average 39.2 months). This follow-up study analyzed the data of 53 subjects (37 females) aged from 16-59 years, who underwent systemic periodontal therapy with adjunctive systemic antibiotics between 1992-2001 and had their last re-examination including microbiological analysis done in 2003. The antibiotic regime was either amoxicillin/metronidazole or ciprofloxacine/metronidazole. During this study, A.a. was detected with two gene probe tests (IAI PadoTest 45 and DMDx/PathoTek) and cultivation on TSBV agar plates. The clinical situation was characterized with the help of pocket probing depths and subsequent categorization into three different groups (≤ 4 mm, 5-6 mm and ≥ 7 mm). Results: After therapy, A.a. was detected with IAI PadoTest 4.5 in a magnitude between 3.0 x 10³ up to 2.06 x 105 counts per specimen in 9 out of 53 subjects. Only two subjects tested positive for A.a. with the DMDx/PathoTek-assays and the agar cultivation. The clinical situation improved significantly in all subjects after systemic periodontal therapy. The treatment results remained stable during the course of the postoperative follow-up. Concerning the clinical data, no differences were found between the subjects that were tested positive and negative for A.a in the postoperative period. [ABSTRACT FROM AUTHOR]

Background: The aim of this 10-year follow-up was to evaluate the long-term results after guided tissue regeneration (GTR) therapy of Class II furcation defects using non-resorbable and bioabsorbable barriers clinically. Methods: In nine patients with advanced periodontitis, nine pairs of contralateral Class II furcation defects were treated. Within each patient, one defect received a non-resorbable expanded polytetrafluoroethylene barrier (ePTFE; C) and the other a bioabsorbable (polyglactin 910; T) barrier by random assignment. At baseline and 12 and 120 ± 6 months after surgery, clinical parameters were obtained. Results: Twelve and 120 months after GTR therapy, statistically significant (P<0.05) horizontal clinical attachment level (CAL-H) gain was observed in both groups (C12: 1.9 ± 0.5 mm; C120: 1.1 ± 1.3 mm; T12: 1.9 ± 0.8 mm; T120; 1.7 ± 1.4 mm). However, one patient with furcations that had been assessed as Class I 12 months after GTR therapy had lost two teeth after 10 years, and another patient had lost more than 2 mm CAL-H at one furcation from 12 to 120 ± 6 months post-surgery 10 years after implantation of an ePTFE barrier. Horizontal bone sounding revealed similar bone gain in both groups 120 ± 6 months post-surgery (C120: 0.8 ± 1.0 mm; T120: 1.1 ± 1.1 mm). Conclusions: CAL-H gain achieved after GTR therapy in Class II furcations was stable after 10 years in 15 of 18 defects (83%). The study failed to show a statistically significant difference in stability of CAL-H gain between group C and T 10 years after GTR therapy. [ABSTRACT FROM AUTHOR]

Purpose: To assess the accuracy of linear measurements of bone loss within infrabony defects on digitized radiographs after digital filtering particularly designed to image periodontal bone loss. Methods: Before surgery, 50 standardized radiographs of 50 infrabony defects were obtained. Intrasurgically the distances from the cementoenamel-junction (CEJ) to the alveolar crest (AC), from the CEJ to the bottom of the bony defect (BD), and the depth of the infrabony component (INFRA) were assessed. All radiographs were digitized and the distances CEJ-AC, CEJ-BD, and INFRA were measured on digitized but unchanged radiographs and after use of the filter. Results: There was a small overestimation of CEJ-AC (0.35-0.68 mm) and underestimation of CEJ-BD (0.84-1.12 mm) and INFRA (0.66-0.76 mm). Accuracy of measurement of the distance CEJ-AC was influenced by vertical angulation difference (P= 0.047) and the intrasurgical CEJ-AC (P= 0.003). Accuracy of CEJ-BD was influenced by intrasurgically assessed bone loss (P= 0.012). Accuracy of INFRA was influenced by individual patient, intrasurgically assessed INFRA (P< 0.001), and filter (P= 0.018). [ABSTRACT FROM AUTHOR]

Background: Topical application of active substances offers an additional option in periodontal therapy. The aim of this study was to examine the influence of the administration of a novel, biodegradable 14% doxycycline gel on microbiological findings, in connection with scaling and root planing. Methods: One hundred ten patients in three centers (Frankfurt and Heidelberg, Germany; Nijmegen, The Netherlands) with moderate to advanced periodontitis were evaluated in this randomized, double-masked, split-mouth clinical trial. In each patient, three test teeth were randomly assigned to one of three treatment modalities: 1) scaling and root planing (SRP) alone; 2) SRP with subgingival placebo gel (VEH); or 3) SRP and 14% doxycycline gel (DOX). Subgingival plague samples were analyzed at baseline and 3 and 6 months after therapy for Actinobacillus actinomycetemcomitans (A.a.), Tannerella forsythensis (T.f.), Porphyromonas gingivalis (P.g.), and Treponema denticola (T.d.) using a RNA probe. Samples from 10 patients were tested for resistance against doxycycline, amoxicillin/clavulanic acid, cefoxitin, clindamycin, and metronidazole using agar diffusion testing. Results: The largest decrease in pathogens was found after 3 months, with the most pronounced differences between DOX and SRP (P<0.05). At 6 months, pathogens were still reduced markedly in all groups. Treatment results were consolidated for VEH and DOX, with a slight deterioration for SRP (DOX versus SRP: P<0.001). Resistance was observed to amoxycillin/clavulanic acid, cefoxitin, clindamycin, and metronidazole (four isolates) but not to doxycycline. Conclusion: The addition of subgingival instillation of a 14% doxycycline gel resulted in pronounced reduction of periodontal pathogens after 3 months and stabilizing results up to 6 months after therapy. Resistance to doxycycline was not induced. [ABSTRACT FROM AUTHOR]

Background: The aim of this 5-year randomized controlled clinical trial was to evaluate the bag-term results after guided tissue regeneration (GTR) therapy of infrabony defects using two bioabsorbable barriers. Methods: Fifteen pairs of contra lateral infrabony defects in 15 patients with moderate to severe periodontitis were treated. Each patient received one polydioxanon (test: T) and one polylactide acetyltributyl citrate (control: C) barrier by random assignment. At baseline, 12, and 60 ± 3 months after surgery clinical parameters and standardized radiographs were obtained. Vertical bone levels (PBL-V) were measured during surgery and 60 ±3 months later by transgingival bone sounding. Results: Thirteen patients were available for the 60-month examinations. Twelve and 60 ± 3 months after GTR, statistically significant (P ≤0.001) vertical attachment (CAL-V) gain was found in both groups (T12: 3.5 ± 1.5 mm; T60: 2.2 ± 1.8 mm; C12: 4.0 ± 0.9 mm; C60: 2.4 ± 1.0 mm). However, from 12 to 60 months after therapy both groups experienced significant CAL-V loss (P <0.05|: two defects in the test group and three in the control group had CAL-V loss >2 mm compared lo the 12-month reexamination. Twelve and 60 ± 3 months after surgery, statistically significant (P <0.05) radiographic bony fill was found in both groups (T12: 1.2& plusmn; 1.3 mm; T60: 1.5 ± 2.2 mm, C12: 0.9 ± 1.4 mm; C60; 1.0 ± 1.6 mm). Further, 60 months after surgery significant (P <0.05) PBL-V gain was found in both groups (test 1.8 ± 2.3 mm; control: 2.2 ± 1.6 mm). The study failed to show statistically significant differences between test and control regarding CAL-V and PBL-V gain 60 months after surgery. Conclusion: CAL-V gain achieved after GTR therapy in infrabony defects using both bioabsorbable barriers was stable after 5 years in 21 of 26 defects (81%). [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to evaluate defect width and two different definitions of defect depth as prognostic factors of periodontal healing in infrabony defects treated by regenerative therapy 6 and 24 months after surgery. Methods: In 32 patients with moderate to advanced periodontitis, 50 infrabony defects were treated by the guided tissue regeneration (GTR) technique using non-resorbable or bioabsorbable barriers. Clinical parameters were assessed, and 50 triplets of standardized radiographs were taken before surgery and 6 and 24 months after surgery. Using a computer-assisted analysis, the distances cemento-enamel junction (CEJ) to alveolar crest (AC), CEJ to bony defect (BD), horizontal projection of the most coronal extension of the bony wall to the root surface to BD, width, and angle of the bony defects were measured. Depth of the bony defect was 1) calculated as CEJ-BD minus CEJ-AC (INFRA1) and 2) measured as horizontal projection of the most coronal extension of the bony wall to the root surface to BD (INFRA2). Results: Whereas statistically significant vertical clinical attachment level gains (CAL-V: 3.36 +/- 1.59 mm/ 3.41 +/- 1.72 mm; P < 0.001) could be found both 6 and 24 months after surgery, bony fill (0.70 +/- 2.52 mm; P = 0.056/1.21 +/- 2.55 mm; P < 0.005) was significant 24 months post-surgically only. In a multilevel regression analysis, CAL-V gain was predicted by bioabsorbable membrane (P = 0.005), baseline probing depths (PD) (P < 0.001), and actual smoking (P < 0.05). Bony fill could be predicted by baseline depth of the infrabony component as determined by INFRA2 (P < 0.05), angulation of bony defect (P < 0.005), and gingival index at baseline (P < 0.001). In narrow (< 37 degrees) and deep (> or = 4 mm) infrabony defects, bony fill was more pronounced than in wide and shallow defects (P < 0.001). Conclusions: Improvement achieved by GTR in infrabony defects can be maintained up to 24 months after surgery. Narrow and deep infrabony defects respond radiographically and are to some extent clinically more favorable to GTR therapy than are wide and shallow defects. The infrabony component of bony defects, as determined by the distance from the most coronal extension of the lateral bony wall to BD (INFRA2), is a better predictor of bony fill than that determined by AC-BD (INFRA1). [ABSTRACT FROM AUTHOR]

Background: With the help of so-called controlled release delivery systems, the half-life period of locally administered antibiotics in gingival crevicular fluid (OCF) can be extended significantly. The aim of this study was to characterize the delivery profile of a new one-component 14% doxycycline free amine gel for local application. Pharmacokinetics of doxycycline (DOXY) were analyzed in GCF, saliva, and serum. Methods: Twenty patients with persisting or recurring pockets (probing depths ≥5 mm and bleeding on probing) after mechanical treatment (surgical or non-surgical) took part in the study. In each patient 1 periodontal defect was treated with DOXY gel. Samples of GCF saliva, and serum were obtained before application of DOXY gel; 15 minutes after application; at 2 and 5 hours; and at 1, 2, 3, 4, 7, 9, and 11 days after application. Separation and quantitative measurement of DOXY was performed with high performance liquid chromatography and UV detection at λ = 260 nm. Results: Coefficients of variation were lower than 2% (intraassay) and 4% (interassay), respectively. For concentrations between 50 to 1000 µg/ml, we found a linear relationship between expected and measured DOXY values (linear coefficient of correlation: r = 0.998). Within the first 5 hours after application, concentration of DOXY in GCF (maximum after 15 minutes 19.97 ± 5.85 mg/ml) and saliva (maximum after 15 minutes 17.83 ± 2.84 mg/ml) was similar. Then concentration fell to a lower level (28.90 ± 19.44 µg/ml) compared to GCF (577.41 ± 127.34 µg/ml) after 3 days. Up to 10 days after application, the concentration of DOXY in GCF was 34.24 µg/ml. With the exception of 1 patient, all serum samples were DOXY-negative. Conclusions: 1) After subgingival application of biodegradable 14% doxycycline gel, mean doxycycline levels in GCF that exceeded 16 µg/ml could be maintained for at least 12 days. Thus, the antimicrobial agent may be classified as a controlled release device. 2) The antibiotic effect was limited mainly to the subgingival sites of application of the doxycycline gel. 3) The doxycycline gel possesses the pharmacokinetic and clinical properties to deliver efficacious levels of antibiotics to the periodontal pocket and to maintain these levels for at least 1 week without the need of further drug retention by a periodontal dressing. [ABSTRACT FROM AUTHOR]

Background: The aim of this 5-year follow-up case series was to clinically and radiographically evaluate the long-term results after guided tissue regeneration (GTR) therapy of infrabony defects using nonresorbable and bioabsorbable barriers. Methods: In 12 patients with advanced chronic periodontitis 12 pairs of contralateral infrabony defects were treated. Within each patient one defect received a non-resorbable (expanded polytetrafluoroethylene [ePTFE]; control: C) and the other a bioabsorbable (polyglactin 910; test: T) barrier by random assignment. At baseline and at 6 and 60 ± 3 months after surgery clinical parameters and standardized radiographs were obtained. Gain of bone density within infrabony defects was assessed using subtraction radiography. Results; Eight of 12 patients were available for the 60-month reexaminations. Six and 60 ±3 months after GTR therapy statistically significant

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to compare the effects of guided tissue regeneration (GTR) using 2 different bioabsorbable barriers (control: polylactide acetyltributyl citrate; test: polydioxanon). The polydioxanon barrier is an experimental membrane for GTR therapy that consists of a continuous occlusive barrier that has a layer of slings on the side that is meant to face the mucoperiosteal flap.Methods: In 21 patients with 22 pairs of similar contralateral defects (30 intrabony and 14 Class II furcation lesions), each defect was randomly assigned for treatment with either control (c) or test (t) devices. At baseline and 12 months after surgery, clinical measurements, plaque index (PI) gingival index (GI), probing depth (PD), and vertical and horizontal clinical attachment loss (CAL-V; CAL-H) and standardized radiographs were obtained.Results: Barrier exposure was commonly observed in both groups. Four weeks after surgery 61% of all barriers were exposed to some extent. However, both treatments revealed a significant GI reduction (P <0.005), PD reduction (-3.08 +/- 2.29 mm [t]; -3.52 +/- 2.67 mm [c]; P <0.001) and CAL-V gain (2.44 +/- 2.29 mm [t], 2.80 mm +/- 2.21 [c]; P <0.001) 12 months after surgery in all defects. Within the intrabony defects significant bony fill (2.03 +/- 1.70 mm [t]; 1.91 +/- 1.20 mm [c]; P = 0.001), and within the furcations a significant but small CAL-H gain (0.79 +/- 0.68 mm [t]; 1.13 +/- 1.44 mm [c]; P <0.05), was observed.Conclusions: Regarding GI and PD reduction as well as CAL-V and CAL-H gain, this study failed to reveal statistically significant or clinically relevant differences between test and control 12 months postsurgically. Thus, the use of both bioabsorbable barriers in GTR therapy may be recommended. [ABSTRACT FROM AUTHOR]

THE AIM OF THIS STUDY WAS TO investigate the reliability of the assessment of clinical furcation parameters (horizontal attachment levels [CAL-H], class of furcation invasion). Replicate measurements of CAL-H and furcation class were performed within 14 days in 420 molars of 105 patients with advanced periodontitis using a Nabers- (n = 50), a TPS- (n = 30) and a PCPUNC15-probe (n = 25). Validity of clinical assessments was assessed by intrasurgical measurements. The standard deviation of single measurements (s) was calculated as a measure of the reproducibility of CAL-H measurements and weighted kappa-coefficients (kw) to estimate the agreement of furcation class assessments. The s ranged from 0.55 to 1.13 mm (Nabers), 0.55 to 1.02 mm (TPS), and 0.58 to 1.11 mm (PCPUNC15). For all probes, a statistically significantly smaller measurement error was observed in buccal and lingual sites than in mesiolingual and distolingual furcations (P < 0.005). The kw ranged from 0.59 to 0.89 (Nabers), 0.50 to 0.80 (TPS), and 0.53 to 0.72 (PCPUNC15). Multiple linear regression analysis identified distolingual location, probing depth (PD) and CAL-H as factors influencing the variability of CAL-H measurements. Whereas there was no statistically significant difference between pre- and intrasurgical CAL-H measurements using the Nabers probe, the TPS and PCPUNC15 probe underestimated CAL-H for distolingual furcations (P < 0.025). Using the Nabers probe, no asymmetries between pre- and intrasurgically obtained class of furcation involvement were revealed, while the TPS and PCPUNC15 probe underestimated furcation degrees (P < 0.1). Multiple linear regression analysis identified distolingual location and height of furcation, as well as PD, vertical attachment level (CAL-V) and type of probe, as factors influencing the validity of CAL-H measurements. Clinical diagnosis of furcation lesions using the 3 mm incrementally marked Nabers probe provides reproducible and valid information about furcation invasion. [ABSTRACT FROM AUTHOR]