Purpose: To evaluate the use of hydrogen peroxide as an adjunct to ultrasonication (US) in biofilm removal and whether it can limit the spread of viable microorganisms in the aerosol. Materials and Methods: Multi-species biofilms were formed on dentin disks and titanium disks fixed on a plastic surface. After placing the specimens in a periodontal pocket model, an ultrasonic scaler was applied for 30 s, in part combined with 0.25% or 0.5% H2O2. After treatment, the remaining biofilm was analysed for bacterial counts (colony forming units [CFU]), biofilm quantity and metabolic activity. Further, the cytotoxic effect of hydrogen peroxide on periodontal ligament fibroblasts was assessed and the spread of bacteria in aerosol was quantified. Results: Ultrasonication reduced bacterial counts in biofilm, biofilm mass and metabolic activity on both dentin and titanium disks. Adjunctive use of 0.25% and 0.5% H2O2 more effectively reduced the viable bacteria in biofilm than ultrasonication alone; this was also found on both dentin and titanium. The different concentrations of H2O2 did not lead to corresponding differences in bacterial mass and metabolic activity. The spread of bacteria through aerosols was statistically significantly reduced when adjunctive H2O2 was used. However, a certain cytotoxic effect on periodontal ligament fibroblasts by H2O2 could not be ruled out. Conclusions: Irrigating with H2O2 during periodontal instrumentation with an ultrasonic scaler increases the reduction of viable bacteria within biofilms. It might limit bacterial spreading via aerosols. Schlagwörter: aerosol, biofilm, hydrogen peroxide, periodontal therapy

Objectives: To verify the effect of adjunctive enamel matrix derivative (EMD) in subgingival reinstrumentation during supportive periodontal therapy. Method and materials: Using a split-mouth design, residual periodontal pockets with probing depth (PD) of 5 to 8 mm in 13 patients were treated by subgingival reinstrumentation with (test teeth) and without (control teeth) EMD. At baseline and after 6 and 12 months the clinical variables PD, clinical attachment level (CAL), and bleeding on probing (BOP) were recorded. At the same appointments gingival crevicular fluid (GCF) was collected to analyze for interleukin (IL)-1β, matrix metalloproteinase (MMP)-8, IL-10, and transforming growth factor (TGF)-β. Results: Statistically significant improvements in PD, CAL, and BOP occurred in both groups. The reduction of PD was significantly higher in the test group than in the control group after 12 months (P = .005). The change of IL-1β within 12 months was significantly different between both groups (P = .019). No other significant differences were detected between both groups. Conclusion: The study suggests that subgingival reinstrumentation with adjunctive EMD could additionally reduce probing pocket depth and the need for periodontal surgery. (Quintessence Int 2021;52:506–513; doi: 10.3290/j.qi.b1044079) Schlagwörter: biomarkers, clinical variables, enamel matrix proteins, periodontitis, scaling and root planing

Purpose: To compare clinical outcomes and oral fluid biomarkers in gingivitis subjects using an electric toothbrush/irrigator combination (test) or a manual toothbrush alone (control) over 8 weeks. Materials and Methods: Subjects were randomly assigned to two groups of n = 30. In both groups, toothbrushing was performed twice daily at home and no additional interdental cleaning aids were allowed. Plaque Index (PLI), Gingival Index (GI), whole saliva (WS), and gingival crevicular fluid (GCF) samples were collected at weeks 2, 4, and 8. Results: Subjects’ mean age was 23 years and 52% were female. Overall baseline means were 1.31 for PLI, 1.07 for GI, and 34.9 for number of bleeding sites. At every follow-up visit, both groups differed statistically significantly (p < 0.001) from baseline for all clinical parameters. The test group demonstrated statistically significantly (p < 0.001) greater reductions in GI vs the control group by 18% at week 2, 17% at week 4 and 24% at week 8. The test group also demonstrated statistically significantly (p < 0.002) greater reductions in the number of bleeding sites vs the control group by 33% at week 2, 34% at week 4 and 43% at week 8. Between-group comparisons for both WS and GCF revealed numerical trends for decreased levels of interleukin (IL)-1β in GCF after 4 and 8 weeks, but these were not statistically significant. Conclusion: In subjects using the electric toothbrush/irrigator combination, increased clinical improvements may be found accompanied by similarly improved trends for oral fluid biomarkers such as IL-1β. Schlagwörter: gingival crevicular fluid, gingivitis, prevention, toothbrushing

Purpose: The topical fluoride treatment of teeth can lead to a formation of CaF2-like material, which is considered to play a significant role in caries prevention. Different types of fluoride sources are applied. The aim of this study was to analyse the in vitro fluoridation effect of the lesser known organic fluoride compound nicomethanol hydrofluoride (NH) regarding fluoride accumulation and morphological changes on dental enamel surfaces. Materials and Methods: The fluoridation effect was investigated by scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDX) after treatment with fluoride solutions at a concentration of 1350 ppm F - and a pH value of 5.5. NH was tested against inorganic sodium fluoride (NaF) as reference. Fluoridation was done on pellicle-free and pellicle-covered enamel. Results: Formation of globular CaF2-like material was observed for both fluoride types. However, NH led to considerably higher calcium fluoride accumulation on the enamel surface as shown by both EDX and SEM. The globule diameters varied between 0.2 and 0.8 µm. Cross-sectional analysis revealed that the globular precipitates lay directly on the enamel surface; only the very surface-near volume was affected. No statistically significant difference of the fluoridation effect was measured with vs without saliva pre-treatment. Conclusion: The experiments showed a 6 times greater F - surface uptake on dental enamel with NH compared to sodium fluoride, thus suggesting an important role of NH during remineralization phases, fostering equilibrium between de- and remineralization. Schlagwörter: amine fluorides, calcium fluoride precipitation, enamel, energy dispersive x-ray analysis, scanning electron microscopy

Purpose: Systemic inflammation is characteristic for the pathogenesis of Alzheimer’s disease (AD) and is responsible for the accumulation of its disease-specific Tau-protein and β-amyloid plaques. Studies focusing on an association with periodontitis showed worse periodontal conditions in patients with dementia, but until now, no study has investigated the differences between AD and other forms of dementia (noAD/DEM). Expecting severe periodontal disease in AD, the aim of this pilot-study was to compare the periodontal and dental status in patients with either AD or noAD/DEM. Materials and Methods: Twenty patients recently diagnosed with AD and 20 with noAD/DEM between the ages of 50 and 70 years were recruited at the Department of Neurology, University Hospital, Münster, Germany and clinically examined at the Department of Periodontology, School of Dental Medicine, Münster, Germany. Neuropsychological testing, levels of Tau-protein and β-amyloid in serum and liquor were used to distinguish between both groups. Dental and periodontal parameters such as clinical attachment loss (CAL), probing pocket depth (PPD), bleeding-on-probing (BOP), radiographic bone loss, full-mouth plaque score (FMPS), and missing and restored teeth were recorded. Results: Periodontitis was diagnosed in all patients. Patients with AD presented mean BOP of 54.7 ± 31.1% and radiographic bone loss of 42.5 ± 25.3%; the mean BOP of those with noAD/DEM was 52.0 ± 23.7% and radiographic bone loss was 40.9 ± 32.3%. There was also no statistically significant difference regarding other periodontal and dental parameters. Conclusions: Both patients with AD and noAD/DEM had periodontal disease. Consequently, patients with all forms of dementia (AD/other) need special dental care to improve periodontal and oral health. Schlagwörter: Alzheimer’s disease, dementia, dental care, oral health, periodontal disease

Purpose: Grape-seed extract (GSE) contains polyphenols that readily adhere to proteins and modify the acquired enamel pellicle (AEP). The first step in biofilm formation is bacterial adhesion to the AEP-covered enamel. The aim of this in vitro study was to test whether AEP modification with GSE, fluoride (F-), or their combination (GSE+F-) modulates bacterial adhesion, biofilm metabolism and composition, or cariogenic demineralisation of the enamel. Materials and Methods: The study comprised 3 parts: 1) single-strain Streptococcus gordonii species, 2) a five-species biofilm model, or 3) biofilm (re-)formation using the five-species biofilm model after removal of initial biofilm with toothbrushing. Human whole-mouth stimulated saliva was used to form an AEP on human enamel specimens. The AEP was incubated in water (control), or modified with GSE, F-, or GSE+F-. Bacterial adhesion, biofilm diversity, metabolic activity, biofilm mass, and cariogenic demineralisation (surface hardness) of enamel were assessed after incubation in bacterial broths after 4 h or 22 h. Differences between groups were analysed with one-way ANOVA and post-hoc Bonferroni tests. Results: GSE and GSE+F- statistically significantly decreased single-strain S. gordonii adhesion, but had no relevant influence when the five-species biofilm model was used. In the biofilm (re-)formation model, GSE reduced bacterial adhesion compared to GSE+F-, while F- caused less cariogenic demineralisation than was found in the control group. Conclusion: AEP modified with GSE retards S. gordonii adhesion, but it does not influence the formation, metabolism and composition of a cariogenic multi-species biofilm. Schlagwörter: biofilms, caries, dental pellicle, enamel, fluoride, grape-seed extract, pellicle modification

Probiotika sind lebende Mikroorganismen, die, in entsprechender Menge appliziert, einen gesundheitlichen Nutzen bewirken. Sie stammen häufig aus dem humanen Gastrointestinaltrakt, aber auch aus Speichel oder Nahrungsmitteln. In Bezug auf eine Anwendung bei oralen Erkrankungen ist wichtig, dass Probiotika oralpathogene Bakterien inhibieren sowie sich an orale Gewebe (Epithel, Zahnhartsubstanzen) anlagern können. Anwendung in der Zahnmedizin finden vor allem Lactobacillus-reuteri- Stämme. Sie können Entzündungszeichen einer Gingivitis vermindern und hemmen offensichtlich die Biofilmneubildung. Im Rahmen einer adjunktiven Anwendung bei der Parodontitistherapie wird vor allem die Zahl der Sites mit Sondierungswerten ≥ 5 mm verstärkt reduziert. Bei periimplantär Erkrankten hingegen besteht kein zusätzlicher Nutzen durch Probiotika. Schlagwörter: Parodontale Therapie, Probiotika, Gingivitis, Parodontitis, Mukositis, Periimplantitis

Purpose: During biofilm formation, bacterial species do not attach directly onto the enamel surface, but rather onto the salivary pellicle. Salivary pellicle modification with casein and mucin can hinder erosive demineralisation of the enamel, but it should also not promote bacterial adhesion. The aim of our study was to assess whether salivary pellicle modification with casein, or mucin, or a mixture of both proteins (casein and mucin) influence bacterial adhesion, biofilm diversity, metabolism and composition, or enamel demineralisation, after incubation in: (a) a single bacterial model; (b) a five-species biofilm model; or (c) biofilm reformation using the five-species biofilm model after removal of initial biofilm with toothbrushing. Materials and Methods: Enamel specimens were prepared from human molars. Whole-mouth stimulated human saliva was used for pellicle formation. Four pellicle modification groups were established: control (non-modified pellicle); casein – modified with 0.5% casein; mucin – modified with 0.5% mucin; casein and mucin – modified with 0.5% casein and 0.5% mucin. Bacterial adhesion, biofilm diversity, metabolic activity, biofilm mass, and demineralisation (surface hardness) of enamel were assessed after incubation in bacterial broths after 6 h or 24 h. Results: After 24 h incubation in the five-species biofilm model, the mucin group presented significantly lower biofilm mass than the control (p = 0.028) and the casein and mucin (p = 0.030) groups. No other differences between the groups were observed in any of the other experimental procedures. Conclusion: Pellicle modification with casein and mucin does not promote in vitro bacterial biofilm formation. Schlagwörter: biofilms, casein, demineralisation, enamel, mucin, salivary pellicle, salivary pellicle modification

Purpose: To analyze in vitro new formulations with Citrox and chlorhexidine digluconate (CHX) regarding their antibacterial activity against planktonic bacteria and their potential to inhibit biofilm formation or to act on existing biofilms. Materials and Methods: Five oral health care products with 0.05%–0.5% CHX formulations (four rinses and one gel) were compared with Citrox preparations and additive-free CHX solutions. The minimal inhibitory concentrations (MIC) were determined against 13 oral bacteria associated with caries or periodontitis. Further, the activity on retarding biofilm formation and on existing biofilms was analyzed; both a 'cariogenic' (5 species) and a 'periodontal' (12 species) biofilm were included. Results: The MIC values did not differ between the CHX mouthrinse/gel formulations and the respective additive-free CHX solutions. Citrox was active against selected periodontopathogens (e.g. Porphyromonas gingivalis). The CHX formulations more effectively retarded biofilm formation than did solutions with the same concentration of CHX but without additives. The anti-biofilm activities depended on the CHX concentration in the formulations. Both CHX solutions and formulations (rinse and gel) were only slightly active on an already formed biofilm. Citrox did not exert any anti-biofilm effect. Conclusion: The present in vitro data support the anti-biofilm activity of the novel CHX, Citrox, poly-L-lysine and xylitol oral health-care formulations. Further studies are warranted to confirm the present findings in various clinical settings. Schlagwörter: biofilm, caries, chlorhexidine digluconate, mouthrinse, periodontitis

Purpose: The rationale of using platelet-rich plasma (PRP) in reconstructive periodontal surgery is to amplify or accelerate the wound healing through the growth factors contained in platelets. On the other hand, bacterial colonisation of membranes may negatively affect the healing process. The aim of this study was to evaluate bacterial contamination of non-bio-resorbable membranes (ePTFE) used for regenerative periodontal therapy of intrabony defects and the clinical attachment level (CAL) gain with or without PRP. Materials and Methods: Seventeen patients were treated with a natural bone mineral (NBM) and guided tissue regeneration (GTR) with an ePTFE membrane (NBM + GTR group; ie, control group), while in another 17 patients PRP was additionally applied (NBM + PRP + GTR group; ie, test group). Furthermore, the retrieved membranes were analysed for the presence of periodontopathogens and data were related to the gain of clinical attachment. In addition, the in vitro sensitivity of selected microbes to PRP was checked by using agar diffusion test. Results: Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were not detected in the PRP group whereas in the controls A. actinomycetemcomitans was detected in five patients (p = 0.022) and P. gingivalis in two cases (difference not statistically significant, p = 0.242). Detection of A. actinomycetemcomitans was not associated with less CAL gain. If the samples were positively tested for Prevotella intermedia/nigrescens and/or P. gingivalis, the CAL gains were lower compared with the negative samples (p = 0.002). PRP did not show any inhibitory effect on bacterial growth in vitro. Conclusion: Within their limits, the present results appear to suggest that the presence of P. intermedia/nigrescens and/or P. gingivalis at the regenerated site may negatively influence the clinical outcomes. However, the potential influence of PRP on bacterial colonisation and the impact on the clinical outcome is still unclear and remains to be elucidated. Schlagwörter: guided tissue regeneration, natural bone mineral, periodontitis, periodontopathogens, platelet-rich plasma