Glucose-6-Phosphatase-Dehydrogenase activity as modulative association between Parkinson's disease and periodontitis.

The association between periodontitis (PD) and Parkinson's disease (PK) is discussed due to the inflammatory component of neurodegenerative processes. PK severity and affected areas were determined using the following neuropsychological tests: Unified Parkinson's Disease Rating Score (UPDRS) and Hoehn and Yahr; non-motoric symptoms by Non-Motor Symptoms Scale (NMSS), and cognitive involvement by Mini-Mental State Examination (MMSE). Neuroinflammation and the resulting Glucose-6-Phosphatase-Dehydrogenase (G6PD) dysfunction are part of the pathophysiology of PK. This study aimed to evaluate these associations in periodontal inflammation. Clinical data and saliva-, serum-, and RNA-biobank samples of 50 well-characterized diametric patients with PK and five age- and sex-matched neurologically healthy participants were analyzed for G6PD function, periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Campylobacter rectus, Fusobacterium nucleatum, and Filifactor alocis), monocyte chemoattractant protein (MCP) 1, and interleukin (IL) 1-beta. Regression analysis was used to identify associations between clinical and behavioral data, and t-tests were used to compare health and disease. Compared with PK, no pathogens and lower inflammatory markers (p < 0.001) were detectible in healthy saliva and serum, PK-severity/UPDRS interrelated with the occurrence of Prevotella intermedia in serum as well as IL1-beta levels in serum and saliva (p = 0.006, 0.019, 0.034), Hoehn and Yahr correlated with Porphyromonas gingivalis, Prevotella intermedia, RNA IL1-beta regulation, serum, and saliva IL1-beta levels, with p-values of 0.038, 0.011, 0.008, <0.001, and 0.010, while MMSE was associated with Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, serum MCP 1 levels, RNA IL1-beta regulation and G6PD serum activity (p = 0.036, 0.003, 0.045, <0.001, and 0.021). Cognitive and motor skills seem to be important as representative tests are associated with periodontal pathogens and oral/general inflammation, wherein G6PD-saliva dysfunction might be involved. Clinical trial registration: https://www.bfarm.de/DE/Das-BfArM/Aufgaben/Deutsches-Register-Klinischer-Studien/_node.html, identifier DRKS00005388.

Influence of Anti-Infective Periodontal Therapy on Subgingival Microbiota Evaluated by Chair-Side Test Compared to qPCR-A Clinical Follow-Up Study.

A chair-side test (CST) for five periodontal pathogens (Aggregatibacter actinomycetemcomitans, A.a.; Porphyromonas gingivalis, P.g.; Prevotella intermedia, P.i.; Treponema denticola, T.d.; Tannerella forsythia, T.f.) was compared with qPCR in a previous clinical study on 100 periodontitis patients at first diagnosis (T0). Following non-surgical treatment alone (SRP) or in combination with systemic or local antibiotics, 74 patients (57.4 ± 13.5 years) were again tested at the same sites from 14 to 24 months after T0. Bacterial elimination (%; compared to T0) was determined for each single species and compared between both test systems. In all patients, all five pathogens could not be fully eliminated regardless of therapy or test method. Tested with CST, the mean elimination ranged from 90% for SRP + Amoxicillin/Metronidazole to 59.13% for SRP only. The corresponding qPCR values were 30% and 29.6%. Only A.a. was eradicated in 100% by SRP + Amoxicillin/Metronidazole tested by CST, and it was 80% when qPCR was the test method. CST agreed with qPCR in 98.7% in the detection of A.a., and 74.3%, 78.4%, 73.0%, and 48.7% for P.g., P.i., T.d., and T.f., respectively. Neither conventional treatment nor the additional use of antibiotics-even with the correct indication-could completely eradicate the tested pathogens or prevent pocket reinfection.

Antibacterial Action, Substantivity and Anti-plaque Effect of Different Toothpaste Slurries - A Randomised Controlled Trial.

PURPOSE: This single-center, clinically controlled, double-blinded, randomised, crossover study aimed to evaluate and compare the antibacterial effect, substantivity and patients' acceptance of three toothpaste slurries after a single application on established biofilms observed for 24 h. MATERIALS AND METHODS: Twenty-four participants started a test cycle after refraining from oral hygiene for 48 h, with a baseline plaque sample measuring biofilm vitality (in %; VF0) using vital fluorescence (VF). They were instructed to rinse for 1 min with either an amine fluoride, stannous chloride (ASC), an herbal (SBC) or a sodium fluoride (SFL) toothpaste prepared as slurries. Every two hours up to 12 and after 24 h, plaque samples were harvested (VF2-VF24%). Plaque-covered areas (PA in %) were evaluated after 24 h using digital photographs. Patients' acceptance was determined by visual analogue scale (VAS) questionnaire. RESULTS: All participants (16 women, 8 men; 27.5 ± 7.9 years) completed all cycles. Two hours after application (VF2), all toothpastes showed a statistically significant reduction in bacterial vitality (p < 0.05), maintained up to 12 h. ASC revealed statistically significantly lower vitality values compared to SBC at VF2, VF4, VF8, VF12 and VF24, and at VF4, VF12 and VF24 compared to SFL (p < 0.05), while SBC and SFL did not differ statistically significantly at any time point. The preferred toothpastes were SFL (18/24 participants) and ASC (15/24 participants). CONCLUSIONS: All toothpastes showed statistically significant anti-plaque effects on established plaque biofilm and a substantivity up to 24 h compared to their baseline, while ASC still presented a statistically significant effect after 12 and 24 h compared to SBC and SFL.

Clinical Evaluation of a New Electronic Periodontal Probe: A Randomized Controlled Clinical Trial.

Precise measurements of periodontal parameters (such as pocket depths: PPD, gingival margins: GM) are important for diagnosis of periodontal disease and its treatment. Most examiners use manual millimeter-scaled probes, dependent on adequate pressure and correct readouts. Electronic probes aim to objectify and facilitate the diagnostic process. This randomized controlled trial compared measurements of a standard manual (MP) with those of an electronic pressure-sensitive periodontal probe (EP) and its influence on patients' acceptance and practicability. In 20 patients (2436 measuring points) PPD and GM were measured either with MP or EP by professionals with different levels of experience: dentist (10 patients), 7th and 10th semester dental students (5 patients each). Time needed was measured in minutes and patients' subjective pain was evaluated by visual analogue scale. Differences were analyzed using the generalized estimating equations approach (GEE) and paired Wilcoxon tests. Mean PPD varied with ΔPPD 0.38 mm between both probes, which was significant (p < 0.001), but GM did not (ΔREC 0.07 mm, p = 0.197). There was a statistically significant correlation of both probes (Spearman's rho correlation coefficient GM: 0.674, PPD: 0.685). Differences can be considered robust (no deviation in either direction). The comparison of time needed and pain sensitivity did not result in statistically significant differences (p > 0.05).

Influence of Probiotics on the Salivary Microflora Oral Streptococci and Their Integration into Oral Biofilm.

Probiotics' ability to integrate into dental biofilms is not yet clarified. The aim of this trial was to detect probiotic bacteria from probiotic products in dental biofilm and saliva during and after intake. In this parallel, randomized clinical trial, 39 subjects wore customized appliances to build up intra-oral biofilms (72-h periods). The trial was divided into screening (S) to determine baseline biofilm flora, intervention (I), and wash out (WO). During I (28 days), subjects consumed a product containing (a) Enterococcus faecalis (b) Lactobacilluscasei, or (c) Lactobacillus rhamnosus GG. Probiotic bacteria and Streptococci spp. were detected in the biofilms and saliva of the 35 subjects that were included in the analysis. During I and WO, the ratio of probiotics in the biofilm was very low compared to total bacterial load, while saliva had slightly but not significantly higher values. No significant changes of probiotic bacteria (p > 0.05) were found at any visit during I or WO. The proportion of streptococci was significantly reduced (p < 0.05) during I and even lower in WO, compared to S. Probiotic bacteria could neither integrate nor persist in dental biofilm and saliva but did influence the growth of streptococci in biofilm and saliva.

Clinical evaluation of a newly developed chairside test to determine periodontal pathogens.

BACKGROUND: The subgingival microbiota as well as determination of markers such as associated pathogens is still in the focus of dental research. The aim of this controlled clinical trial was to determine clinical applicability of a newly developed chairside bacterial test (CST) for the most relevant periodontal pathogens. METHODS: Within 125 participants (100 with periodontitis, 25 healthy) two sulcus fluid samples each were collected and pooled for further analysis. Samples were analyzed with CST and results (positive signals for every pathogen/control) were visually detected by eye. As a reference quantitative polymerase chain reaction (qPCR) was performed. RESULTS: The detection limit of CST revealed 1.2 × 104 for Treponema denticola (T.d.) and Tannerella forsythia (T.f.), 2.5 × 104 for Porphyromonas gingivalis (P.g.), 5.3 × 103 for Prevotella intermedia (P.i.), and 5.8 × 104 for Aggregatibacter actinomycetemcomitans (A.a.). Based on this maximum potential of positive detections, the sensitivities of CST in reference to qPCR were: T.d. (91.3%); T.f. (86.3%); P.g. (83.8%); P.i. (85.7%), and A.a. (100%). In regard to the clinical diagnosis, the CST assay and the qPCR method reached a sensitivity of 87.82% and 94%, respectively. The specificity for both methods was 100%. CONCLUSION: This newly developed CST can detect five typical periodontal pathogens with a somewhat lower sensitivity towards qPCR that can be classified as "good."

Antibacterial Effect and Substantivity of Toothpaste Slurries In Vivo.

PURPOSE: This double-blind, clinical, cross-over study evaluated the antibacterial effect of three toothpastes (ASF, HTP and STP) and a chlorhexidine mouthrinse (0.2%; CHX; positive control) after a single application on established biofilm over a period of 24 h (substantivity). MATERIALS AND METHODS: Twenty-four subjects refrained from all oral hygiene measures for a period of 72 h. After 48 h, a baseline biofilm sample was taken and vitality of the biofilm flora was examined (baseline, VF0). Then they rinsed for 1 min with one of the randomly allocated, freshly prepared toothpaste slurries (ASF, HTP, STP) or CHX. Further biofilm samples were taken every second hour up to 14 h as well as 24 h after rinsing, and biofilm vitality was assessed (VF2-24). After a wash-out period of 4 days, a new test cycle was started. RESULTS: All subjects (18 female, 6 male) finished the four test cycles. At VF2, all products showed a statistically significant reduction in vitality compared to VF0 (p<0.05). CHX and ASF revealed the most pronounced effect (49% and 40% reduction), while the other toothpastes (HTP: 24%, STP: 11%) reached lower but still statistically significant effects. At each further time point CHX and ASF showed the lowest biofilm vitality. ASF demonstrated a significant antibacterial effect on dental biofilm over a 24-h period compared to baseline and superiority over both other toothpastes at time points VF2-VF14. CONCLUSION: ASF toothpaste showed a significant antibacterial action on biofilm and a high substantivity which was maintained up to 24 hours.

Patient self-care of periodontal pocket infections.

Treatment of periodontitis aims to control the infection caused by the periodontal pathogenic flora and includes mechanical debridement of root surfaces to disrupt the supragingival and subgingival biofilm. As periodontal pockets of ≤ 5 mm can be perform in a stable condition and may not need additional therapy, the ability and the willingness of the patient to perform good oral hygiene on a long-term basis are of utmost importance for ensuring long-term success of periodontal treatment. In this context, the aim of all home-care measures must be the optimal control of plaque biofilm in order to prevent or treat gingival inflammation as a primary stage of periodontitis. Despite the fact that toothbrushing and other mechanical cleaning practices are the most important elements for preventing periodontal diseases or their progression, other factors, including education, motivation, manual dexterity and compliance with professional recommendation, provision of time and socio-economic status, as well as risk factors, play a role. The present article provides an overview on the various possibilities for self-care of residual pockets in patients with periodontitis.

Resin Infiltration for Aesthetic Improvement of Mild to Moderate Fluorosis: A Six-month Follow-up Case Report.

PURPOSE: To determine whether fluorosed areas of teeth can be successfully treated with resin infiltration and whether the results are long lasting. MATERIALS AND METHODS: For the present case of mild to moderate dental fluorosis, the microinvasive resin infiltration technique was chosen, following suboptimal results of in-office vital tooth bleaching to improve the aesthetic appearance of the affected teeth. RESULTS: Six months after treatment, the white opaque and brown discolourations remain masked. CONCLUSION: This case report demonstrates that resin infiltration is an agreeable option for this type of tooth discolouration, rather than choosing more invasive, conventional procedures. More studies need to be completed to determine longer-term outcomes of the technique.

Confusion over live/dead stainings for the detection of vital microorganisms in oral biofilms--which stain is suitable?

BACKGROUND: There is confusion over the definition of the term "viability state(s)" of microorganisms. "Viability staining" or "vital staining techniques" are used to distinguish live from dead bacteria. These stainings, first established on planctonic bacteria, may have serious shortcomings when applied to multispecies biofilms. Results of staining techniques should be compared with appropriate microbiological data. DISCUSSION: Many terms describe "vitality states" of microorganisms, however, several of them are misleading. Authors define "viable" as "capable to grow". Accordingly, staining methods are substitutes, since no staining can prove viability.The reliability of a commercial "viability" staining assay (Molecular Probes) is discussed based on the corresponding product information sheet: (I) Staining principle; (II) Concentrations of bacteria; (III) Calculation of live/dead proportions in vitro. Results of the "viability" kit are dependent on the stains' concentration and on their relation to the number of bacteria in the test. Generally this staining system is not suitable for multispecies biofilms, thus incorrect statements have been published by users of this technique.To compare the results of the staining with bacterial parameters appropriate techniques should be selected. The assessment of Colony Forming Units is insufficient, rather the calculation of Plating Efficiency is necessary. Vital fluorescence staining with Fluorescein Diacetate and Ethidium Bromide seems to be the best proven and suitable method in biofilm research.Regarding the mutagenicity of staining components users should be aware that not only Ethidium Bromide might be harmful, but also a variety of other substances of which the toxicity and mutagenicity is not reported. SUMMARY: - The nomenclature regarding "viability" and "vitality" should be used carefully.- The manual of the commercial "viability" kit itself points out that the kit is not suitable for natural multispecies biofilm research, as supported by an array of literature.- Results obtained with various stains are influenced by the relationship between bacterial counts and the amount of stain used in the test. Corresponding vitality data are prone to artificial shifting.- As microbiological parameter the Plating Efficiency should be used for comparison.- Ethidium Bromide is mutagenic. Researchers should be aware that alternative staining compounds may also be or even are mutagenic.

Nonsurgical treatment of aggressive periodontitis with photodynamic therapy or systemic antibiotics. Three-month results of a randomized, prospective, controlled clinical study.

The aim of this randomized, controlled clinical study was to compare the short-term effects of nonsurgical periodontal therapy with the additional administration of systemic antibiotics (AB) and the same therapy with additional photodynamic therapy (PDT) in the treatment of patients with aggressive periodontitis (AP). Thirty-six patients with AP received full-mouth nonsurgical periodontal treatment (SRP) and were then randomly divided into two groups of 18 subjects each. Group AB received amoxicillin and metronidazole three times a day for 7 days. Group PDT received two applications of PDT on the day of SRP as well as at follow-up after 7 days. The following clinical parameters were measured at baseline and 3 months after therapy: plaque index (PLI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). After 3 months, PD was significantly reduced in both groups (from 5.0±0.8 mm to 3.2±0.4 mm with AB, and 5.1±0.5 mm to 4.0±0.8 mm with PDT; both p<0.001), while AB revealed significantly lower values compared to PDT (p = 0.001). In both groups, GR was not significantly changed. CAL was significantly reduced in both groups (PDT: 5.7±0.8 mm to 4.7±1.1 mm; p=0.011; AB: 5.5±1.1 mm to 3.9±1.0 mm; p<0.001) and differed significantly between the groups (p=0.025). The number of residual pockets (PD ≥4 mm) and positive BOP was reduced by AB from 961 to 377, and by PDT from 628 to 394. Pockets with PD ≥7 mm were reduced by AB from 141 to 7, and by PDT from 137 to 61. After 3 months, both treatments led to statistically significant clinical improvements. The systemic administration of antibiotics, however, resulted in significantly higher reduction of PD and a lower number of deep pockets compared to PDT.

Randomized clinical trial of the efficacy, tolerability, and long-term color stability of two bleaching techniques: 18-month follow-up.

OBJECTIVE: To investigate the efficacy, tolerability, and long-term color stability of tooth whitening using two different bleaching techniques: an at-home tray technique (5.0% H2O2) and an over-the-counter strip technique (5.3% H2O2). METHOD AND MATERIALS: Thirty subjects were included in this two-cell, parallel, examiner-blinded, randomized clinical trial. Shade evaluations were performed with a value-oriented VITA shade guide. The null hypothesis was that there would be no differences between the groups and no improvements from baseline with regard to tooth shade. Bleaching sensitivity, gingival irritation, and patient acceptance were recorded on a visual analog scale (VAS). Scanning electron microscopy (SEM) was performed to detect any enamel surface changes. RESULTS: After bleaching, both treatments demonstrated significant improvements in tooth shade (P < .001 for both groups). At the 18-month recall, tooth shade remained significantly lighter than at baseline (P = .006 for tray group; P = .001 for strip group). However, a relapse of the tooth shade was observed compared with the immediate postbleaching result (P < .05). VAS data yielded no significant differences between groups regarding bleaching sensitivity and gingival irritation. None of the teeth studied showed detectable enamel surface changes. Patient acceptance was statistically significantly higher in the tray group compared with the strip group (P < .05). CONCLUSION: Both techniques demonstrated significant and comparable levels of tooth shade improvement after 2 weeks and 18 months. Each treatment caused similar, transient oral adverse effects.

Occurrence and causing stimuli of postoperative sensitivity in composite restorations.

Despite improvements in composite treatments over the past decade, postoperative sensitivity still remains a problem. Therefore, this clinical study evaluated the appearance of postoperative sensitivity after composite treatments and the stimuli that may have caused it. A total of 600 teeth in 231 patients was included in this study. All treatments were performed by dental students working under close supervision following standard procedures and using the bonding system Optibond FL and the nanofilled composite Ceram X. At baseline (visit 1), the restorations were grouped according to the following criteria: use of anesthesia, use of a rubber dam, indication for the restoration treatment, cavity class and clinical dimension of the cavity. After approximately two weeks (at visit 2), all the restorations were assessed and failure was defined if one of the following criteria occurred: a negative reaction to the vitality test, postoperative pain from masticatory forces or reported postoperative sensitivity by the patient. The reported postoperative sensitivity was specified with a visual analogue scale into hot/cold-sensitivity, sweet/soursensitivity, sharp/dull-sensitivity, spontaneous sensitivity and blistering/stinging-sensitivity. Failure was observed in 6% of the restorations. The statistical analysis showed that the clinical cavity depth turned out to be the only factor to have a significant influence on the appearance of postoperative sensitivity: caries profunda showed a four times higher risk of failure, while cavities with pulp exposure had a 14 times higher failure risk compared to restorations that were localized in the dentin. With regard to the type of sensitivity, no patients reported sensitivity to sweet/sour; most of them described their sensitivity as sharp/dull.

[Strips versus gel: a clinical comparison of two over-the-counter bleaching systems]. / Streifen versus Gel: Klinischer Vergleich zweier Over-the-Counter-Bleichsysteme.

The objective of this clinical, randomized, examiner-blinded split-mouth study was to compare the efficacy, the side effects and patients acceptance of two over-the-counter bleaching systems (strips versus gel) with respect to the bleaching times required to achieve six grades of whitening in human teeth. Tooth shades were documented by matching with the VITA shade guide, or dered according to value and assigned a numeric ranking from 1 to 16, lightest to darkest. Twenty-six adults participated in the study. Both treatments were applied twice daily according to the manufacturer's instructions. Efficacy and the PBI were measured by a dental examiner. Tooth hypersensitivity, gingival irritations as well as patients acceptance were recorded by a visual analog scale ranging from 0 to 10. In order to detect changes in the enamel surface due to treatment epoxy casts of the study teeth were analysed by SEM. A total of 20 volunteers completed the study. The subjects teeth treated with the strips-system exhibited a 6.0 +/- 0.0 mean shade scores improvement compared to baseline (53.7 cycles; 1610.3 min), and the subjects teeth treated with the gel-system exhibited a 3.3 +/- 1.4 mean shade scores improvement (64.6 cycles; 969.0 min). However, both treatments were able to whiten teeth statistically significantly compared to baseline. Side effects caused by the two systems were minimal and reversible. None of the teeth studied showed detectible enamel surface changes in the subsequent SEM analysis. Both methods were well accepted.

Four-year results of a prospective-controlled clinical study evaluating healing of intra-bony defects following treatment with an enamel matrix protein derivative alone or combined with a bioactive glass.

AIM: To evaluate the 4-year results following regenerative periodontal surgery at intra-bony defects with either a combination of an enamel matrix protein derivative (EMD) and a bioactive glass (BG) or with EMD alone. METHODS: Twenty-five patients with one deep intra-bony defect each were randomly treated with either an EMD+BG (test) or with EMD alone (control). Measurements were recorded at baseline, at 1 and at 4 years following therapy. The primary outcome variable was the clinical attachment level (CAL). RESULTS: The test group demonstrated a mean CAL change from 10.3+/-1.6 to 6.7+/-1.2 mm (p<0.001) and to 6.9+/-1.0 mm (p<0.001) at 1 and 4 years, respectively. No statistically significant differences were found between the 1- and 4-year results. The control group showed a mean CAL change from 10.4+/-1.6 to 6.7+/-1.1 mm (p<0.001) at 1 year and 7.0+/-0.9 mm (p<0.001) at 4 years. The CAL change between 1 and 4 years did not present statistically significant differences. In each of the two groups, four defects have lost 1 mm of the CAL gained at 1 year. A CAL gain of 1 mm compared with the 1-year results was measured in only one defect of the test group. Compared with baseline, a CAL gain of >/=3 mm was found at 4 years in 10 defects in both groups. Between the treatment groups, no statistically significant differences in any of the investigated parameters were observed at 1 and at 4 years. CONCLUSIONS: Within their limits, the present results indicate that the clinical improvements obtained with both regenerative modalities can be maintained over a period of 4 years.

Antibacterial effect of two toothpastes following a single brushing.

PURPOSE: The aim of this double-blind, randomised cross-over study was to compare the antibacterial effect and the substantivity of two toothpaste formulations containing amine fluoride (AmF) or zinc chloride (ZnCl2). MATERIALS AND METHODS: After a professional tooth cleaning, 20 volunteers refrained from all oral mechanical hygiene measures for the subsequent 24 hours (day 0). Subsequently, a plaque sample was taken from three teeth and analysed for vitality of the plaque bacteria by means of the vital fluorescence technique (VF0; in %). After assessment of this baseline value the subjects had to brush their teeth for 2 minutes with 1.2 ml of the allocated toothpaste containing (a) 0.66% AmF or (b) 0.2% ZnCl2. For the following 8 hours no oral hygiene measures were allowed. After 4 and after 8 hours further plaque samples were analysed for biofilm vitality (VF4, VF8). During the following 3 days the volunteers had to brush twice daily for 2 minutes with the allocated toothpaste. On day 4, plaque index was assessed using the criteria of Quigley and Hein (Turesky modification). After a washout time of 9 days the next test cycle with the other toothpaste was started. RESULTS: Both toothpastes reduced the biofilm vitality significantly at VF4 and VF8 compared with VF0 (p < or =0.001). While after 8 hours the vitality values for the ZnCl2-toothpaste obtained significantly higher reductions (53%) than for the AmF-toothpaste (44%), results for plaque index were not significantly different (0.98 and 1.04 respectively). CONCLUSIONS: Both toothpastes showed a significant and prolonged antibacterial effect up to 8 hours with a benefit in favour of the ZnCl2 toothpaste.

Effect of in-office tooth bleaching on the microhardness of six dental esthetic restorative materials.

OBJECTIVES: The aim of this in vitro study was to evaluate the effect of the in-office bleaching technique on the microhardness of six dental esthetic restorative materials. METHODS: Four composite resins (a hybrid, a flowable, a micro-hybrid and a nano-hybrid), an ormocer and a ceramic were tested, after the use of an in-office bleaching product. Fourteen specimens of each composite and the ormocer were fabricated and randomly divided into two groups of seven samples each. One group was polished and the other group remained unpolished. For the ceramic, seven polished samples were fabricated. Two samples of each group were used as negative controls. The specimens were bleached for 15, 30 and 45min. Five Knoop microhardness measurements were made on each sample, for each of the following periods tested: before bleaching, after 15, 30 and 45min of bleaching, 24h and 1 month after the bleaching procedure. Data were analyzed by the repeated measures analysis of variance with three between factors and one within. RESULTS: The differences in the microhardness values between the bleached and the control samples for the composites and the ceramic, were not statistically significant (hybrid: p=0.264; flow: p=0.584; micro-hybrid: p=0.278; nano-hybrid: p=0.405; ceramic: p=0.819). For the ormocer, although bleaching did not have any significant effect on the unpolished samples (p=0.115), it caused an increase on microhardness of the polished samples. SIGNIFICANCE: Bleaching with 38% hydrogen peroxide does not reduce the microhardness of the restorative materials tested. Therefore, no replacement of restorations is required after bleaching.

Differences in efficacy of two commercial 0.2% chlorhexidine mouthrinse solutions: a 4-day plaque re-growth study.

BACKGROUND: The purpose of this clinical cross-over study was to examine the antibacterial and plaque-inhibiting properties of two chlorhexidine solutions compared with a negative control. MATERIAL AND METHODS: Twenty-one volunteers refrained from all oral hygiene measures, but rinsed instead twice daily with 10 ml of a conventional chlorhexidine solution (0.2%; CHX), a chlorhexidine solution with anti-discolouration system (ADS) (0.2%, alcohol-free chlorhexidine solution (CSP)) or a placebo solution (Pla). Plaque index (PI), plaque area (PA) and bacterial vitality were assessed after 24 h (PI1, vital flora (VF)1) and 96 h (PI2; VF2, PA). After a 10-day wash-out period, a new test cycle was started. RESULTS: Results for Pla were 0.94, 1.59, 27.4 (PI1, PI2, PA) and 79% and 72% (VF1 and VF2). CSP significantly reduced the parameter PI1, PI2 and PA to 0.67 (p=0.012), 1.0 and 15.7 (p<0.001). VF1 and VF2 (63% and 53%) were not significantly affected. The corresponding figures of CHX were 0.42, 0.43, 6.77, 33 and 16%, which were all significantly lower (all p<0.001). On comparing the two chlorhexidine solutions, CHX showed significantly higher reductions of all parameters. CONCLUSION: The results suggest that the 0.2% alcohol-containing solution showed superiority in inhibiting plaque re-growth and reducing bacterial vitality compared with the solution with ADS.

Effect of two antimicrobial agents on early in situ biofilm formation.

OBJECTIVES: The aim of this observer-blind, controlled, three-cell cross-over study was to evaluate the influence of an amine fluoride/stannous fluoride (Meridol, 250 ppm; ASF) and a chlorhexidine mouthrinse (CHX; Chlorhexamed forte, 0.2%) compared with water on in situ biofilm growth. MATERIAL AND METHODS: After a professional toothcleaning seven volunteers had to wear a special acrylic appliance, in which six specimens each were inserted to allow the build-up of intra-oral biofilms. The volunteers had to rinse twice daily for 1 min. with 10 ml of the allocated mouthrinse. After 48 h of wearing, the specimens with the adhering biofilms were removed from the splints and stained with two fluorescent dyes, which selectively stain vital bacteria green and dead bacteria red. Under the confocal laser scanning microscope biofilm thickness (BT) was evaluated. To examine bacterial vitality (BV%) the biofilms were scanned (1 microm sections) and digital images were made. An image analysis program was used to calculate the mean BV as well as the BV of the single sections. After a wash-out period of 14 days a new test cycle was started. RESULTS: The use of CHX and ASF resulted in a BT of 8.4+/-4.4 mum and 15.7+/-9.9 compared with 76.7+/-29.4 mum using water. The mean vitality (in %) was reduced from 66.1+/-20.4 to 23.3+/-11.6 and 23.9+/-12.4 using CHX and ASF, respectively. Both active solutions reduced BT and BV significantly compared with water (p<0.001). Differences between the two active solutions were not significant (p>0.05). CONCLUSION: Both mouthrinses showed antibacterial and plaque-reducing properties against the in situ biofilm. The study design enables the examination of an undisturbed oral biofilm and for the first time shows the influence of antibacterial components applied under clinical conditions regarding biofilm formation.

Healing of human intrabony defects following regenerative periodontal therapy with an enamel matrix protein derivative alone or combined with a bioactive glass. A controlled clinical study.

AIM: The purpose of the present study was to compare clinically the treatment of deep intrabony defects with a combination of an enamel matrix protein derivative (EMD) and a bioactive glass (BG) to EMD alone. METHODS: Thirty patients (16 females and 14 males) suffering from advanced marginal periodontitis were included in this prospective, controlled parallel design multicenter study. In each of the patients, one intrabony defect was randomly treated with either EMD+BG (test) or with EMD alone (control). Clinical measurements were recorded at baseline and at 1 year following therapy. RESULTS: No differences in any of the investigated parameters were observed at baseline between the two groups. Healing was uneventful in all patients. At 1 year after therapy, the test group showed a reduction in mean probing depth (PD) from 8.5+/-1.1 to 4.4+/-1.2 mm (p<0.001) and a change in mean clinical attachment level (CAL) from 10.4+/-1.5 to 7.1+/-1.5 mm (p<0.0001). In the control group, the mean PD was reduced from 8.5+/-1.5 to 4.0+/-1.6 mm (p<0.001) and the mean CAL changed from 10.2+/-2.1 to 6.3+/-2.2 mm (p<0.01). In the test group, 12 sites (80%) gained at least 3 mm or more of CAL, whereas in the control group a CAL gain of 3 mm or more was measured at 13 sites (87%). No statistically significant differences in terms of PD reduction and CAL gain were found between the test and the control treatment. CONCLUSIONS: Within the limits of the present study it can be concluded that: (i) at 1 year after surgery, both therapies resulted in significant PD reductions and CAL gains, and (ii) the combination of EMD+BG does not seem to additionally improve the clinical results.