Bristle splaying and its effect on pre-existing gingival recession-a 12-month randomized controlled trial.

OBJECTIVE: The link between bristle splaying and gingival recession is unclear. METHODS: In a 12-month, parallel group, randomized, controlled clinical trial, 110 systemically healthy participants with pre-existing gingival recessions (pre-GR) were assigned to brush their teeth with either a manual (MT) or a powered toothbrush (PT). Every 3 months, toothbrushes and brush heads were replaced. Wear was measured using the Bristle-Splaying-Index (BSI), matched between groups and correlated to the change of pre-GR. RESULTS: Data from 109 subjects (PT, 55; MT, 54) were analyzed. The overall mean BSI was found to be significantly lower (p < 0.001) in the PT group (median 5.5; second and third quartile 1.9-10.0) as compared to the MT group (21.5; 15.0-30.5). After 12 months, pre-GR decreased significantly in the PT group (∆0.2 ± 0.1 mm; p < 0.001) and remained stable in the MT group (∆0.1 ± 0.1 mm; p > 0.05). In the MT group, higher BSI values were associated with a higher risk for increasing or stable recession over 12 months: odds ratio (95 % CI) = 27.9 (1.7; 452.9); p = 0.019. CONCLUSION: After a mean using time of 3 months, the PT group demonstrated a lower BSI than the MT group, and the greater bristle splaying was associated with a higher risk of increased (or stable) GR in subjects using a MT but not a PT. CLINICAL RELEVANCE: Compared to a manual toothbrush, powered toothbrushes seem to be utilized with less force and can be considered safe to use in patients with pre-existing gingival recession.

The effectiveness of a dentifrice without sodium lauryl sulphate on dental plaque and gingivitis - a randomized controlled clinical trial.

OBJECTIVES: The purpose of the study was to evaluate the effect on dental plaque and gingivitis of a dentifrice without sodium lauryl sulphate (SLS) compared to two SLS-containing dentifrices. MATERIAL AND METHODS: For this double-blind, parallel study, 90 volunteers having moderate gingival inflammation (≥40%) were randomly divided among three groups: one group using non-SLS dentifrice containing enzymes, colostrum and low concentrations of zinc and two control groups each using different SLS-containing dentifrices. Dental plaque scores (Turesky modification of Quigley & Hein) and gingivitis scores (Bleeding On Marginal Probing) were assessed at baseline, after 2 and 4 weeks. RESULTS: Eighty-nine participants provided evaluable data. A slight decrease in gingivitis scores was observed for all groups over 4 weeks, which was statistically significant for the non-SLS group. Mean values for dental plaque scores did not show major differences over 4 weeks. For both parameters, no significant differences between groups could be observed at any time point. Patient appreciation was in favour of the SLS groups especially regarding the foaming effect. CONCLUSION: No significant differences could be observed with respect to the effect on plaque and gingivitis between SLS-containing and SLS-free dentifrice containing enzymes, colostrum and low concentration zinc. Patients enjoyed the duration of taste and the 'foaming effect' of SLS-containing dentifrices better.

The effectiveness of dentifrices without and with sodium lauryl sulfate on plaque, gingivitis and gingival abrasion--a randomized clinical trial.

OBJECTIVES: The aim of this study was to compare the efficacy of a dentifrice without sodium lauryl sulfate (SLS) to a dentifrice with SLS in young adults aged 18-34 years on gingivitis. MATERIAL AND METHODS: One hundred twenty participants (non-dental students) with a moderate gingival inflammation (bleeding on probing at 40-70 % of test sites) were included in this randomized controlled double blind clinical trial. According to randomization, participants had to brush their teeth either with dentifrice without SLS or with SLS for 8 weeks. The primary outcome was bleeding on marginal probing (BOMP). The secondary outcomes were plaque scores and gingival abrasion scores (GA) as well as a visual analogue scale (VAS) score at exit survey. Baseline and end differences were analysed by univariate analysis of covariance (ANCOVA) test, between group differences by independent t test and within groups by paired sample t test. RESULTS: BOMP improved within groups from on average 0.80 at baseline to 0.60 in the group without SLS and to 0.56 in the group with SLS. No statistical difference for BOMP, plaque and gingival abrasion was found between both groups. VAS scores for taste, freshness and foaming effect were significantly in favour of the SLS-containing dentifrice. CONCLUSION: The test dentifrice without SLS was as effective as a regular SLS dentifrice on gingival bleeding scores and plaque scores. There was no significant difference in the incidence of gingival abrasion. CLINICAL RELEVANCE: In patients diagnosed with gingivitis, a dentifrice without SLS seems to be equally effective compared to a dentifrice with SLS and did not demonstrate any significant difference in gingival abrasion. In patient with recurrent aphthous ulcers, the absence of SLS may even be beneficial. However, participants indicate that they appreciate the foaming effect of a dentifrice with SLS more.

[Prevention and Information for Patients Undergoing Periodontal Treatment: Potentials for Improvement from the Patients' Perspective]. / Prävention und Aufklärung im Rahmen der Parodontitisbehandlung: Verbesserungspotenziale aus Patientensicht.

2 334 patients from 29 dental practices took part in a written survey on their experiences with dental treatment in general as well as treatment of periodontal disease (response rate 80.8%). 72.6% of all participating patients fully agreed that they could recommend their dentist to their friends. 63.6% of patients undergoing treatment of periodontitis (N=328) rated this treatment as "excellent". However, for important aspects (prevention, patient information, treatment) potentials for improvement became obvious. 43.7% of patients treated for periodontitis were not completely satisfied with information on how this disease develops; 40.7% saw potentials for better information on preventive care (dental-hygiene, nutrition). An even higher percentage of patients actually not treated for periodontitis was interested in more information on prevention (51.4%). The results of the survey show that dentists should offer information and exercise on how to prevent periodontal desease more actively. There is a lack of research on the present state of affairs and potentials for improvement concerning treatment and prevention of periodontitis including the patients' perspective.

Comparison of triclosan and stannous fluoride dentifrices on parameters of gingival inflammation and plaque scores: a systematic review and meta-analysis.

OBJECTIVE: To systematically review the literature to compare the efficacy of triclosan (Tcs) and stannous fluoride (SnF) dentifrices on parameters of gingivitis and plaque scores. MATERIALS AND METHODS: Medline, EMBASE and Cochrane Central Register of Controlled Trials were searched up to March 2013 to identify appropriate studies. Studies regarding self-performed manual brushing by adults with a minimum 4 weeks of follow-up were included. Primary outcomes were parameters of gingivitis. Secondary outcome was plaque score. RESULTS: Of 55 publications, 11 met the eligibility criteria. Additionally, four unpublished papers were added after contacting the manufacturers of the leading brands. In total, 15 studies [10 medium term and five long term (>6 months)] were processed for data analysis. There was no difference in gingival index (or its modification) between the two types of dentifrice [DiffM-0.04, 95% confidence interval CI (-0.11; 0.04); P = 0.34]. The change in the average gingival bleeding score was significantly in favour of SnF [DiffM0.02, 95% CI (0.01; 0.02); P < 0.00001]. Plaque scores demonstrated a statistical significant difference in favour of Tcs, according to Quigley-Hein Plaque Index (Q&H PI; DiffM-0.29, 95% CI [-0.45; -0.13]; P = 0.0004), but there was no difference according to Rustogi Modified Navy Plaque Index (RMNPI) [DiffM-0.09, 95% CI (-0.01; 0.18); P = 0.07]. Long-term results supported these findings. CONCLUSIONS: In the context of inconclusive results for the primary outcome variable of gingival health, it can be concluded that there was a minor and most likely clinically insignificant difference between Tcs- and SnF-containing dentifrices. Meta-analysis of plaque score reduction was also inconclusive; whereas Tcs was more effective when assessed by the Q&H PI, it was not when scored with the RMNPI.

Influence of volumetric shrinkage and curing light intensity on proximal contact tightness of class II resin composite restorations: in vitro study.

BACKGROUND: Proximal contact tightness of class II resin composite restorations is influenced by a myriad of factors. Previous studies investigated the role of matrix band type and thickness, consistency of resin composite, and technique of placement. However, the effect of volumetric shrinkage of resin and intensity of curing light has yet to be determined. Thus, the aim of this study was to identify the influence of these factors on the proximal contact tightness when restoring class II cavity preparations in vitro. METHODS: Sixty artificial molars were restored with either a low-shrinkage (Filtek Silorane, 3M ESPE) or a conventional (Z100, 3M ESPE) composite and polymerized with low-intensity (Smartlite IQ2, Dentsply) or high-intensity light curing units (Demi(TM), Kerr). Proximal contact tightness was measured using the Tooth Pressure Meter. Data were statistically analyzed using one-way analysis of variance and Tukey post hoc test. RESULTS: Use of low-shrinkage composite (Filtek Silorane) resulted in significantly tighter proximal contacts compared to the use of conventional composite (Z100) when cured with the same polymerization unit (p<0.001). Moreover, the low-intensity curing unit (IQ2) resulted in significantly tighter contacts than the high-intensity unit when material is constant (p<0.001). CONCLUSIONS: Low-shrinkage resin composite and low curing light intensity is associated with tighter proximal contact values.

Creating tight proximal contacts for MOD resin composite restorations.

OBJECTIVE: The purpose of this study was to compare proximal contact tightness (PCT) of MOD resin composite restorations placed with different matricing protocols. METHODS: Forty-five ivorine lower right first molars with standardized MOD cavities were equally divided into three groups according to the restoration protocol. Group 1: Sectional matrix (Standard matrix, Palodent, Dentsply) secured with a wedge (Premier Dental Products Co.) and separation ring (BiTine I, Palodent, Dentsply, York, PA, USA) was used to restore the mesial surface first and then removed and repeated for the distal surface. Group 2: Identical to group 1, but separation rings were placed at both the mesial and distal sides (BiTine I+II, Palodent) prior to restoration. Mesial surface was restored followed by distal. Group 3: Walser matrix (O-form, Dr. Walser Dental GmbH) was used. Following composite resin restoration, PCT was measured using the tooth pressure meter. Data were analyzed using analysis of variance and a Tukey post hoc test (p<0.05). RESULTS: PCT values for mesial contacts were 2.99 ± 0.47N for group 1, 4.57 ± 0.36N for group 2, and 3.03 ± 0.79N for group 3. For the distal contacts, the values were 4.46 ± 0.44N for group 1, 5.12 ± 0.13N for group 2, and 0.76 ± 0.77N for group 3. Significantly tighter contacts were obtained for mesial and distal contacts for group 2 compared to groups 1 and 3 (p<0.05). For groups 1 and 3, mesial contacts were not significantly different (p=0.993), while distal contacts for group 1 were significantly tighter (p<0.001). CONCLUSION: Within the limitations of this study, tighter contacts can be obtained when sectional matrices and separation rings are applied to both proximal surfaces prior to placement of the resin composite in MOD cavities.

Oral Mesenchymal Stem/Progenitor Cells: The Immunomodulatory Masters.

Oral mesenchymal stem/progenitor cells (MSCs) are renowned in the field of tissue engineering/regeneration for their multilineage differentiation potential and easy acquisition. These cells encompass the periodontal ligament stem/progenitor cells (PDLSCs), the dental pulp stem/progenitor cells (DPSCs), the stem/progenitor cells from human exfoliated deciduous teeth (SHED), the gingival mesenchymal stem/progenitor cells (GMSCs), the stem/progenitor cells from the apical papilla (SCAP), the dental follicle stem/progenitor cells (DFSCs), the bone marrow mesenchymal stem/progenitor cells (BM-MSCs) from the alveolar bone proper, and the human periapical cyst-mesenchymal stem cells (hPCy-MSCs). Apart from their remarkable regenerative potential, oral MSCs possess the capacity to interact with an inflammatory microenvironment. Although inflammation might affect the properties of oral MSCs, they could inversely exert a multitude of immunological actions to the local inflammatory microenvironment. The present review discusses the current understanding about the immunomodulatory role of oral MSCs both in periodontitis and systemic diseases, their "double-edged sword" uniqueness in inflammatory regulation, their affection of the immune system, and the underlying mechanisms, involving oral MSC-derived extracellular vesicles.

[Patient evaluation of dental care. Results of a written patient survey in dental practices]. / Wie bewerten Patienten ihre zahnärztliche Versorgung? Ergebnisse einer schriftlichen Befragung von Patienten bei niedergelassenen Zahnärzten.

1,317 patients from 18 dentists took part in a written survey on patient evaluation of dental care. General satisfaction was high, but patients were critical concerning some aspects of dental care. On average, the aspects rated most often with "excellent" were hygiene in the practice, the possibility to get through to the practice on the telephone and quick service in case of urgent health problems. Most critical evaluations (on average) were given for waiting times, costs of the dental treatment for the patient and the range of magazines and written information in the waiting room. The highest statistical correlation to overall satisfaction (willingness to recommend this doctor to friends) showed the patients' assessments concerning the questions whether the doctor was listening to them and took enough time, as well as the result of the dental treatment from the patients' point of view. Differences of the survey results between practices were high. On average, patients of female dentists were more satisfied than patients of their male colleagues. Patients younger than 50 years and male patients were less satisfied than older patients and female patients. The patient surveys give important clues for quality management in the participating dental practices. The results of a patient survey should be evaluated against the background of the individual situation of the practice.

The efficacy of interdental brushes on plaque and parameters of periodontal inflammation: a systematic review.

AIM: The aim of the study was to asses the effect of the use of interdental brushes (IDB) in patients as an adjunct to toothbrushing compared with toothbrushing alone or other interdental oral hygiene devices on plaque and the clinical parameters of periodontal inflammation. MATERIAL AND METHODS: MEDLINE-PubMed and the Cochrane Central register of controlled trials (CENTRAL) were searched through November 2007 to identify appropriate studies. Clinical parameters of periodontal inflammation such as plaque, gingivitis, bleeding and pockets were selected as outcome variables. RESULTS: Independent screening of the titles and abstracts of 218 MEDLINE-PubMed and 116 Cochrane papers resulted in nine publications that met the eligibility criteria. Mean values and standard deviations were collected by data extraction. Descriptive comparisons are presented for brushing alone or brushing and woodsticks; meta-analyses were also performed for the floss comparison. CONCLUSION: As an adjunct to brushing, the IDB removes more dental plaque than brushing alone. Studies showed a positive significant difference using IDB with respect to the plaque scores, bleeding scores and probing pocket depth. The majority of the studies presented a positive significant difference in the plaque index when using the IDB compared with floss.

A clinical study on interdental separation techniques.

The effect of interdental separation of a special separation ring and wooden wedge was investigated. In a split-mouth design, 27 patients were randomly assigned to one of two groups (W or S). In 11 patients, an interdental wooden wedge (Hawe-Neos) was placed (group W), and in 16 patients, a separation ring (Composi-Tight Gold) was placed at the contact between teeth 4/5 and 5/6. Simultaneously, in both groups, a wooden wedge, combined with a separation ring (Composi-Tight Gold), was placed on the contact between teeth 4/5 and 5/6 (reference group W+S). To measure proximal contact tightness, frictional forces were recorded at the removal of a 0.05 mm thick metal matrix band inserted between adjacent teeth. Contact tightness was measured at contacts 4 and 5 and at 5 and 6 in the third and fourth quadrant using the Tooth Pressure Meter prior to applying separation devices (TO) five minutes after application (T1) and five minutes after removal of the devices (T2). The effect of separation was determined by calculating the differences between contact tightness before application and contact tightness with the devices in situ (T1-T0). Interdental recovery was calculated by the difference in contact tightness before application and after removal of the devices (T2-T0). To assess the presence of statistically significant differences between these measurement times, paired t-tests were applied. With each patient, either a comparison between W and W+S or S and W+S was made. For both W versus W+S and S versus W+S, paired t-tests were applied to compare differences (T1-T0 and T2-T0) between the separation devices. Within a patient, groups W and S could not be compared, therefore, to compare separation achieved between these two devices, unpaired t-tests were used. The increase in contact tightness measured at contact 4 and 5 for group W (0.98 +/- 0.26 N) was statistically significantly less compared to the increase in group S (5.48 +/- 0.88 N) (p < 0.001) or group W+S (4.62 +/- 0.68 N) (p = 0.02). No significant differences were found between groups S and W+S (p = 0.77). For all groups, five minutes after removal of the devices, the contact tightness at contact 4 and 5 and at contact 5 and 6 were still significantly weaker compared to the tightness at baseline (p < 0.02). When separation is required for restorative procedures, such as at placement of a Class II resin composite restoration, special separation rings may be more useful than wooden wedges.

A randomized clinical trial on proximal contacts of posterior composites.

OBJECTIVE: The objective of this study was to investigate clinical changes in proximal contact strength inserting Class II composite resin restorations according to one of three randomly assigned protocols. MATERIALS AND METHODS: Seventy-one Class II restorations (MO/DO) were placed by two calibrated operators. Restorations were randomly assigned to one of three groups: one using a circumferential and two a sectional matrix system with separation rings. Proximal contacts were measured by one independent observer with a Tooth Pressure Meter immediately before treatment, and directly after finishing the restoration. RESULTS: Compared to the situation before treatment groups with a sectional matrix system resulted in a statistical significant stronger mean proximal contact strengths (p<0.05), whereas the use of a circumferential matrix system with hand-instrument resulted in a lower proximal contact strength (p<0.05). CONCLUSION: Class II posterior composite resin restorations placed with a combination of sectional matrices and separation rings resulted in a stronger proximal contact than when a circumferential matrix system was used.

In vitro-cleaning efficacy of interdental brushes with different stiffness and different diameter.

PURPOSE: The aim of this study was to evaluate the cleaning efficacy of interdental brushes with different stiffnesses, e.g. soft and hard interdental brushes with identical brush diameter. MATERIALS AND METHODS: Cylindrical soft and hard interdental brushes with diameters of 2,3 and 5 mm each were tested. Sixteen extracted human molars were fixed in split cast models to simulate eight interdental spaces. After coating the teeth with a dye to simulate plaque, digital photographs were taken from the proximal surfaces in a highly standardised set-up. The teeth were repositioned and the proximal surfaces were cleaned in a standardised manner. Post-brushing digital photographs were taken as before. After digital subtraction, the cleaned area was measured by pixel count and the relative cleaning efficacy was calculated. RESULTS: The cleaning efficacy values of soft and hard interdental brushes of corresponding size in extra-small, small, medium and large interdental spaces as well as overall showed no statistically significant difference. In small, medium and large interdental spaces, increasing brush diameters resulted in higher cleaning efficacy; these differences were statistically significant. Irregular values were seen in extra-small interdental spaces. CONCLUSION: Both hard and soft interdental brushes cleaned the proximal tooth surfaces effectively. The filament stiffness had no statistically significant influence on the cleaning efficacy.

The effect of various model parameters on enamel caries lesions in a dose-response model in situ.

OBJECTIVES: The aim of this exploratory double-blinded, randomized, cross-over, in situ study was to compare the effects of various model parameters ('intervention', 'brushing', 'position') on enamel caries lesions in a dose-response model. METHODS: In each of four experimental legs of four weeks 16 participants wore intraoral mandibular appliances with four 'plaque-retaining' and four 'easily cleanable' positioned pre-demineralized bovine enamel specimens in the vestibular flanges mimicking proximal and buccal surfaces, respectively (n=512). The four randomly allocated interventions (either application only or brushing) included the following dentifrices: AlF3 1360ppmF(-)+chlorhexidine 0.05% (Lacalut aktiv, LA1360), NaF 1,450ppmF(-)(Blend-a-Med ProExpert), NaF 500ppm F(-) and 0ppm F(-) as negative control (NC) (both experimental, based on Blend-a-Med ProExpert). RESULTS: Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after the in situ period using transversal microradiography. Significant differences for ΔΔZ [adjusted mean (95% CI))] were found between NC, NaF500 and LA1360for both 'plaque-retaining' [-1830 (-2371;1289); -986 (-1530;442); -2 (-548;544)vol%×µm] as well as 'easily cleanable' specimens [-399 (-682; -116); -391 (-672; -110); -16 (-302;270)vol%×µm]. Values for NaF1450 revealed a similar dose-response as LA1360.Values for LA1360 and NaF1450 did not differ significantly (p>0.05; ANCOVA). CONCLUSION/CLINICAL SIGNIFICANCE: The design of the present in situ study was able to reveal a fluoride dose-response to hamper further demineralization of enamel specimens for 'easily cleanable' and 'plaque-retaining' sites being brushed or not. Particularly 'plaque-retaining' sites seem to be recommendable for measuring potential anticaries efficacy in situ.

Socioeconomic inequality and caries: a systematic review and meta-analysis.

Dental caries is the most prevalent disease worldwide, with the majority of caries lesions being concentrated in few, often disadvantaged social groups. We aimed to systematically assess current evidence for the association between socioeconomic position (SEP) and caries. We included studies investigating the association between social position (determined by own or parental educational or occupational background, or income) and caries prevalence, experience, or incidence. Risk of bias was assessed using the Newcastle-Ottawa Scale for observational studies. Reported differences between the lowest and highest SEP were assessed and data not missing at random imputed. Random-effects inverse-generic meta-analyses were performed, and subgroup and meta-regression analyses were used to control for possible confounding. Publication bias was assessed via funnel plot analysis and the Egger test. From 5539 screened records, 155 studies with mostly low or moderate quality evaluating a total of 329,798 individuals were included. Studies used various designs, SEP measures, and outcome parameters. Eighty-three studies found at least one measure of caries to be significantly higher in low-SEP compared with high-SEP individuals, while only 3 studies found the opposite. The odds of having any caries lesions or caries experience (decayed missing filled teeth [DMFT]/dmft > 0) were significantly greater in those with low own or parental educational or occupational background or income (between odds ratio [95% confidence interval] = 1.21 [1.03-1.41] and 1.48 [1.34-1.63]. The association between low educational background and having DMFT/dmft > 0 was significantly increased in highly developed countries (R (2) = 1.32 [0.53-2.13]. Publication bias was present but did not significantly affect our estimates. Due to risk of bias in included studies, the available evidence was graded as low or very low. Low SEP is associated with a higher risk of having caries lesions or experience. This association might be stronger in developed countries. Established diagnostic and treatment concepts might not account for the unequal distribution of caries (registered with PROSPERO [CRD42013005947]).

Gliding capacity of different dental flosses.

BACKGROUND: One of the major concerns with the use of dental floss is the passage of the proximal contact, which might be influenced by the material characteristics of the floss. The aim of this study was to compare the gliding capacities of different flosses with major differences in structure and experimental behavior in vivo. METHODS: In a clinical, single-blind, crossover study of 27 subjects, the forces necessary for passing all 14 proximal contacts between the first premolars were measured using 2 polytetrafluoroethylene (PTFE)-based flosses, 2 nylon-based flosses, and 1 nylon-based tape. The flosses were fixed in a special holder with strain gauges, which allowed registration of the maximum forces at insertion into and removal from the interdental area. RESULTS: In most contacts, the PTFE flosses needed less force compared to the nylon flosses. The range between the flosses was higher in the mandible compared to the maxilla and increased from the mesially located contacts to the more distally located contacts. The nylon tape required higher forces at insertion for all maxillary contacts. All other flosses proved to be equivalent at these contacts. CONCLUSIONS: PTFE flosses are superior to nylon flosses in terms of passing stronger proximal contacts in both directions. Due to gliding differences between different types of floss, the selection of a floss has the potential of compensating intra- and interindividual variation in contact strengths.

Influence of rubber-dam on the reconstruction of proximal contacts with adhesive tooth-colored restorations.

PURPOSE: To clinically measure the influence of rubber-dam on the proximal contact strength after its reconstruction with tooth-colored restorations. MATERIALS AND METHODS: The frictional forces during the removal of a metal strip from the proximal contact area were taken as measure for the proximal contact strengths of 46 restorations (35 ceramic inlays, 11 direct composite restorations). The teeth were separated with a rubber-dam and wedged thoroughly during the complete reconstruction procedure according to the multiple wedging technique. The proximal contact strengths were measured immediately before and immediately after removing the rubber-dam. RESULTS: The contact strengths were statistically significantly lower immediately after the removal of the rubber-dam (1.07+/-0.82N) compared to the situation with the rubber-dam (1.99+/-1.21N). The amount of the reduction after removing the rubber-dam was statistically significantly higher between the second premolar and the first molar (1.45+/-1.06N) compared to the contacts between the canines and the first premolar (0.32+/-0.44N) and the first and second premolar (0.59+/-0.77N). No influence of the restorative material, the use and localization of retainers, localization of the restoration, or number of teeth under the rubber-dam was detectable. CONCLUSION: Rubber-dam is recommended for adhesive restorations as it is helpful for achieving good adhesion between the tooth and restorative materials. Nevertheless, the application of rubber-dam seems to be a factor which complicates the reconstruction of adequate proximal contacts.

Effect of intrapulpal pressure simulation in vitro on shear bond strengths and hybrid layer formation.

PURPOSE: To test the hypothesis that simulation of an intrapulpal pressure during the application of dentin bonding systems influences hybrid layer formation in vitro. MATERIALS AND METHODS: 180 teeth and three different bonding agents were used for shear bond strength measurements and for confocal laser scanning microscopy studies on the dentin-composite interface. The bonding agents (30 teeth each material) were applied without (90 teeth, Group A) and with intrapulpal pressure simulation of 34 cm H20 with water (90 teeth, Group B). 45 specimens from each group were sheared in a testing machine, and 45 teeth from each group were used for CLSM studies after labeling the primer components of the bonding agents with a fluorescent dye. RESULTS: After simulation of pulpal pressure the bond strengths decreased significantly in all groups (Syntac [without/with]: 16.0 +/- 4.5/8.0 +/- 3.7, P= 0.001; Gluma: 13.3 +/- 4.6/8.4 +/- 4.4, P= 0.008; Prime & Bond NT: 14.8 +/- 5.8/8.7 +/- 5.7, P= 0.007; n = 15 each; U-tests). There were no significant differences between the hybrid layer thickness without/with simulation of pulpal pressure (Syntac: 3.6 +/- 0.6/4.1 + 1.2, P= 0.35; Gluma: 3.5 +/- 0.6/3.7 + 0.9, P= 0.49; Prime & Bond NT: 3.5 +/- 0.9/3.8 + 0.8, P= 0.44; n = 15 each; U-tests). In the case of simulation of an intrapulpal pressure, CLSM examination revealed a distinctly shallower penetration of the adhesives into dentin compared to the samples treated without intrapulpal pressure.

Comparison of the safety and efficacy of an oscillating/rotating battery-powered toothbrush and a standard manual toothbrush.

PURPOSE: To compare the cleaning efficacy of a battery-powered toothbrush with an oscillating/rotating action (Dr. Best Powerclean) and a standard flat-trimmed manual toothbrush (Elmex super 39) in a single-blind, cross-over clinical study. MATERIALS AND METHODS: 78 healthy subjects took part in the study. Subjects were asked to abstain from all oral hygiene procedures for 48 hours, after which hard and soft oral tissues were examined. Plaque was then scored using the Turesky modification of the Quigley-Hein Index, and subjects were instructed to brush their teeth for a total time of 1 minute with either one or the other brush, according to a predetermined randomization schedule. Immediately after brushing, plaque was scored again and hard and soft tissues were re-examined. All plaque scoring was carried out by the same investigator who was blind with respect to the brushes used. Subjects were instructed to continue with their usual oral care routine throughout the study period. They were scheduled to return after 12-14 days, having again abstained from all oral hygiene for 48 hours prior to the visit, in order to repeat the evaluation sequence but brushing with the alternative brush. Prior to analysis of the results, data from the two phases of the study were combined. RESULTS: Both toothbrushes were found to be safe as used in the study. Using the non-parametric Wilcoxon test for paired samples, whole mouth plaque scores were found to be reduced significantly from 2.04 +/- 0.60 to 1.57 +/- 0.51 by the Powerclean toothbrush (P < 0.001), and from 1.99 +/- 0.65 to 1.27 +/- 0.52 by the manual toothbrush (P < 0.001). At approximal surfaces, the plaque scores were also significantly reduced from 2.14 +/- 0.0.59 to 1.69 +/- 0.50 for the Powerclean (P < 0.001), and from 2.08 +/- 0.64 to 1.40 +/- 0.57 for the manual toothbrush (P < 0.001). A comparison of the two brushes revealed that the manual toothbrush removed significantly more plaque than the Powerclean, both for the whole mouth and approximal surfaces (P < 0.001). The Powerclean reduced whole mouth plaque by 23.2 +/- 11.5% compared to 37.8 +/- 14.0% for the manual toothbrush and approximal plaque by 20.9 +/- 10.6% and 34.9 +/- 14.0%, respectively. It is concluded that the Dr. Best Powerclean toothbrush is not as effective as a standard flat-trimmed manual toothbrush.

Clinical evaluation of the efficacy of a battery-powered toothbrush. results from two independent studies.

PURPOSE: To compare the clinical efficacy with respect to plaque removal of a battery-operated power toothbrush (Dr. Johns Spin Brush Classic) with two manual toothbrushes, a standard ADA flat trim reference brush and the Oral-B CrossAction toothbrush. MATERIALS AND METHODS: Efficacy was evaluated in two independent studies using a randomized, single-use, cross-over design. Healthy adult subjects from a general population brushed their teeth for a timed 1 min and plaque was scored before and after brushing was completed. In Study 1 (Spin Brush vs. ADA toothbrush), plaque was scored using the modified Quigley and Hein Plaque Index, while in Study 2 (Spin Brush vs. CrossAction) plaque was scored using the Modified Navy Plaque Index. In addition, a hard and soft tissue examination was carried out before and after brushing to allow evaluation of safety. RESULTS: In Study 1, both the ADA toothbrush and the Spin Brush significantly reduced levels of whole mouth and approximal plaque (P < 0.0005); however, the Spin Brush was not significantly more effective than the manual brush. Relative plaque reduction for the whole mouth was 35.6 +/- 16.0% for the Spin Brush compared to 38.9 +/- 14.9% for the manual toothbrush (P < 0.047), and, for the approximal surfaces, 32.7 +/- 14.6% and 36.3 +/- 13.7%, respectively (P = 0.024). In Study 2, both toothbrushes significantly reduced plaque levels (P < 0.0001), but, as for Study 1, the CrossAction manual toothbrush was more effective than the Spin Brush. For whole mouth, marginal and approximal sites, respectively, the Spin Brush reduced plaque by 54.3%, 43.5% and 62.0%, compared with 58.6%, 47.5% and 67.1% for the CrossAction toothbrush. The difference in favor of the CrossAction brush was statistically significant (P < 0.0005) for all areas.