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Background: The Bologna reform resulted in a drastic restructuring of pre‐clinical training courses at the University of Zurich. The aim of this study was to assess student pre‐clinical scaling/root planning skills after just 8.5 hours of manual training. Material and Methods: Three consecutive classes of dental students (n = 41; n = 34; n = 48) were tasked with removing lacquer concrement from the maxillary left canine on a typodont using Gracey and universal (Deppeler M23A) curettes. At baseline (prior to instruction), a timed five‐minute session of scaling/root planning was undertaken. The second scaling/root planning session was held immediately following training. Eight experienced dental hygienists and eight lay people served as positive and negative controls, using the same instruments and time limit, respectively. Instrumented teeth were collected, scanned and planimetrically analysed for the percentage of tooth surface cleaned. Statistical analyses were performed to assess the dental students' improvement after the training (Wilcoxon signed‐rank test) and to compare it to that of laypeople and dental hygienists (Kruskal–Wallis rank sum test followed by Conover's post hoc test). Results: At baseline, the dental students' mean scaling scores of the cleaned surfaces were not significantly different than those of laypeople (29.8%, 31.0%, 42% vs 27.9%). However, after 8.5 hours of manual training, the students' ability to clean the maxillary tooth improved significantly and they achieved mean removal values of 61.7%, 79.5% and 76% compared to the 67.4% (P < .001) of the experienced dental hygienists (Tables Tables  and). There were no statistically significant differences between the scores achieved by students after training and those achieved by experienced dental hygienists. Conclusion: A shortened pre‐clinical training time was sufficient for students to acquire the basic scaling/root planning skills needed in preparation for clinical training. Further research is needed to identify ways to help students consistently reach highest skill levels. [ABSTRACT FROM AUTHOR]

Aim To assess two contemporary rotary instrumenting systems subjectively and objectively in a pre-clinical student course setting. Methodology Undergraduate dental students ( n = 44) prepared mesiolingual canals of 3D-printed mandibular molar replicas (RepliDens, Zurich, Switzerland). The HyFlex and BioRace rotary systems, both previously unknown to the students, were used according to the manufacturers' guidelines after a short theoretical introduction. For comparison, a first-generation rotary system (ProFile .04), which the students knew from their previous education, was then used in a third RepliDens. Questionnaires were issued to note subjective experiences immediately after instrumentation. Objectively, time to instrument to size 40, .04 taper and shaping outcomes were analysed. Categorical data were compared using chi-square and Fisher's exact tests, numerical data according to goodness of fit to the normal distribution, P < 0.05. Results Subjectively, the students liked the file size and sequence designation in the BioRace system significantly ( P < 0.05) better than in the HyFlex counterpart, whilst they found better controllability with the HyFlex ( P < 0.05), and reported no difference in cutting efficiency. They preferred both systems to the ProFile. Objectively, canal transportation was significantly less with the HyFlex (and the ProFile) systems compared to BioRace ( P < 0.05). Both systems under investigation were statistically similar in terms of file fractures (nil), length control, and instrumentation time, which was considerably faster than with the ProFile control system. Conclusions HyFlex and BioRace had perceived and quantifiable strengths and weaknesses. Both systems were equally liked by the students and preferred over the ProFile first-generation rotary system. [ABSTRACT FROM AUTHOR]

Objective To evaluate a novel device for its efficacy in removing experimental biofilm from root surfaces and its potential for concomitantly removing/roughening the surface substance. Methods and Materials A novel acrylic rotary device (biofilm remover, BR) was tested in vitro in three experiments: surface loss, surface roughness [positive controls: Perioset ( PS) and Proxoshape ( PR)] and biofilm removal [positive controls: ultrasonic ( US) and PS]. Surface loss/surface roughness was evaluated for dentin samples instrumented for three 20 s periods. The calcium removed during instrumentation was analysed after each interval and cumulatively, using atomic absorption spectrophotometry ( AAS). Surface roughness was measured using profilometric analysis. Biofilm removal was evaluated on dentin specimens coated with a 64.5 h 6-species in vitro formed biofilm, after one 20 s treatment. Surface loss was analysed using anova with Scheffé post hoc test, and surface roughness/biofilm removal was analysed using Mann-Whitney test (all P ≤ 0.05). Results Significantly less substance loss [μg (±1 SD)] was observed with the novel device at all time points, both interval and cumulative (1.0 (±0.5) versus 9.3 (±3.2) PS and 9.9 (±1.9) PR at 60 s). Surface roughness [μm (95% CI)] was significantly lower for BR than for PS and PR [0.00 (−0.01, 0.08) 0.20 (0.16, 0.27) and 0.21 (0.19, 0.24) at 60 s]. Significantly less biofilm bacteria remained after treatment with both BR 4.5 (−0.1, 16.2) and US 1.9 (−0.2, 14.3), compared to PS 52 (27.9, 82.1). Conclusions The novel biofilm remover was less damaging to dentin surfaces, while removing biofilm at least as effectively as devices used in this study. [ABSTRACT FROM AUTHOR]

Aim To monitor chlorine consumption from nonagitated aqueous sodium hypochlorite (NaOCl) solutions in human root canals using a recently developed assay, which can determine the order of magnitude of available chlorine in small volumes of liquid. Methodology The root canals of 80 extracted single-rooted human teeth were instrumented to ProTa-per Universal F4 and irrigated using 1% NaOCl. Subsequently, canals were irrigated with copious amounts of deionized water to rinse out the residual chlorine. Subsequently, the teeth were sealed externally and placed in a water bath of 37 °C. Root canals were filled with NaOCl of 1%, 2.75%, 5.5%, or distilled water for 1, 10, 100 or 1000 min (n = 5 teeth per solution and time). Consumption of chlorine was measured using paper points pre-impregnated with 15% potassium iodide. Colour change of the paper points was determined photo-electronically, assessing their red value after absorbing solutions from root canals. Measurements were compared to a standard series of NaOCl down to 0.001% (n = 5 paper points per concentration). Results Red values of the paper points inserted into the root canal were affected by initial NaOCl concentration and time (two-way ANOVA, P < 0.05). If NaOCl concentrations above 0.1% are considered to be clinically relevant, then 5.5% NaOCl retained its activity in the root canal for more than 100 min, whereas 1% NaOCl lost its activity between 10 and 100 min. Conclusions Nonagitated NaOCl solutions can remain biologically active in human root canals for extended time periods. [ABSTRACT FROM AUTHOR]

Lenherr P, Allgayer N, Weiger R, Filippi A, Attin T, Krastl G. Tooth discoloration induced by endodontic materials: a laboratory study. International Endodontic Journal, 45, 942-949, 2012. Abstract Aim To investigate the discoloration potential of endodontic materials using a bovine tooth model. Methodology Two hundred and 10 dentine-enamel cuboid blocks (10 × 10 × 3.5 mm) were prepared out of the middle thirds of bovine tooth crowns. Standardized cavities were prepared in the walls of the pulp chamber leaving 2 mm of enamel and dentine on the labial wall of the crown. The specimens were randomly assigned to 14 groups ( n = 15). Endodontic materials were placed into the cavities as follows: group A: empty, group B: blood, group C: calcium hydroxide, group D: ApexCal, group E: Ultracal XS, group F: Ledermix, group G: triple antibiotic paste (3Mix), group H: grey MTA(GMTA), group I: GMTA + blood, group J: white MTA (WMTA), group K: WMTA + blood, group L: Portland cement (PC), group M: PC + blood and group N: AH Plus. The cavities were sealed with composite and stored in water. Standardized colour measurement (VITA Easyshade compact) was performed at the following intervals: prior to (T0) and after placement of the filling (T1), 1 week (T2), 1 month (T3), 3 months (T4), 6 months (T5) and after 1 year (T6). Colour change (ΔE) values were calculated. A two-way analysis of variance was used to assess significant differences between the endodontic materials. The mean values of all groups were compared using the Tukey multiple comparison test (α = 0.05). Results Significant differences were detected amongst the experimental groups after 12 months ( P < 0.0001). The lowest colour change values were observed in the groups N (AH Plus, 3.2 ± 1.5), A (empty, 3.8 ± 1.4), L (PC, 4.1 ± 1.7), C (calcium hydroxide, 4.7 ± 1.5), E (Ultracal XS, 5.1 ± 1.9) and J (WMTA, 7.9 ± 6.7). The most discoloration was measured in groups G (3Mix, 66.2 ± 9.9) and F (Ledermix, 46.2 ± 11.6). PC showed the best colour stability amongst the Portland cement-based materials; however, when contaminated with blood (group M), a significantly higher ΔE value (13.6 ± 4.2) was detected ( P = 0.032). Conclusion Materials used in endodontics may stain teeth. Therefore, the choice of material should not rely solely on biological and functional criteria, but also take aesthetic considerations into account. [ABSTRACT FROM AUTHOR]

Summary In the following case series, we report on six cases of erosive worn dentitions (75 posterior teeth), which have been reconstructed using a template-based technique with direct composite resin restorations and already examined after 3 years in service. In all patients either one or both tooth arches were completely restored using direct resin composite restorations. A wax-up-based template was used to avoid freehand build-up techniques and to ensure optimal anatomy and function. All patients were re-assessed after a mean service time of 5·5 years (mean 67 ± 4 months) using United States Public Health Service criteria. The overall quality of the restorations was good with predominantly 'alpha' and 'bravo' scores, respectively. However, the restorations showed some deterioration with respect to marginal quality, marginal discoloration, surface texture and anatomy as compared to the 3-year investigation. The marginal impairments could be resolved by polishing. It is concluded that this non-invasive technique provides a possible treatment option at least for the displayed observation period of 5·5 years. [ABSTRACT FROM AUTHOR]

Aim: To compare the use of interdental brushes to a periodontal probe in assessing marginal bleeding, in natural gingivitis. Materials and methods: Sixty-four consecutive volunteers presenting with gingival inflammation were recruited at their semiannual recall appointments for this study. All had ≥50% papillary height and no pocketing that exceeded 4 mm. Contra-lateral quadrants (1 & 3 or 2 & 4) were randomly tested for bleeding with one pass-through with an interdental brush or with a periodontal probe inserted 2 mm into the gingival sulcus. The presence or absence of both bleeding and plaque were then recorded. Correlation coefficients were calculated for the interdental brushes and the periodontal probe, and the plaque and bleeding scores. Results: The periodontal probe and the interdental brushes showed mean average bleeding scores of 47.39% and 45.74% respectively. The correlation coefficient for the two methods was 0.73 (P < 0.0001). No correlation between plaque and bleeding was found. Conclusions: Interdental brushes can be considered a valid alternative to a periodontal probe in assessing marginal bleeding in gingivitis patients. An interdental brush, sized correctly for each interdental space, is easy to handle, atraumatic to the papillae and will allow gingivitis patients to monitor their own progress, while at the same time performing a beneficial oral hygiene procedure and removing any interdental plaque present. [ABSTRACT FROM AUTHOR]

Oral Diseases (2011) , 508-514 The aim of this study was to evaluate the erosive/abrasive enamel wear after contact with orange juices modified with different dietary supplements. A total of 96 bovine enamel samples were prepared and allocated to eight groups (1-8; n = 12). Samples were eroded (120 s) in 200 ml of the following eight solutions: 1: water (control), 2: orange juice, 3: water + calcium effervescent tablet, 4: orange juice + calcium effervescent tablet, 5: water + 0.75 g acid/base regulating powder (Probase), 6: water + 0.375 g Probase, 7: orange juice + 0.75 g Probase and 8: orange juice + 0.375 g Probase. After erosion, the samples were brushed with 40 brushing strokes (load 2.5 N). Enamel wear was measured using surface profilometry after 20 and 40 cycles of erosion/abrasion respectively. Highest mean enamel wear (±SD) after 20 and 40 cycles of erosion/abrasion was observed for the unmodified orange juice (group 2) (0.605 ± 0.240 μm; 1.375 ± 0.496 μm respectively). The enamel wear in all other groups (3-8) was significantly lower (P < 0.0001 respectively) with no significant difference within these groups and compared with water (control). Erosive/abrasive enamel wear induces by orange juice and tooth brushing could be reduced significantly by modification with free available dietary supplements. [ABSTRACT FROM AUTHOR]

Int J Dent Hygiene , 2011; 60-67 DOI: 10.1111/j.1601-5037.2009.00437.x Hofer D, Meier A, Sener B, Guggenheim B, Attin T, Schmidlin PR. Biofilm reduction and staining potential of a 0.05% chlorhexidine rinse containing essential oils. To assess the biofilm reduction and discolouration potential of a new 0.05% chlorhexidine (CHX) digluconate solution, containing additional essential oil and alcohol components, compared with that of standard control CHX solutions (0.05% and 0.2% CHX). The potential to reduce total viable counts of growing mixed microbial populations was examined using the Zurich biofilm model. Biofilms were created on sterile pellicle-coated hydroxyapatite discs and exposed to test substances at different time points. After 64.5 h, mean colony-forming units and SDs were determined. Colour change measurements using light reflection analysis were carried out on saliva preconditioned bovine dentin and enamel samples, as well as on composite and glass ceramic restorative materials, after successive immersions in a standardized tea brew and the CHX solutions. The test solution was able to reduce biofilm formation by 3 log steps compared with a negative (water) control. This was significantly less effective than the standard control CHX solutions, which reduced viable counts by 6 log steps. Both the test and control solutions exhibited staining on all surfaces. Staining was most pronounced on dentin, followed by enamel and to a significantly lesser degree on the restorative materials. Furthermore, the staining caused by the test solution on these restorative materials was generally lower than that caused by the control solutions. The test solution exhibited an antimicrobial activity. The composition, however, seems to hamper its effectiveness. Accordingly, it produced statistically significant, although by trend less, staining on restorative materials. [ABSTRACT FROM AUTHOR]

Sahrmann P, Puhan MA, Attin T, Schmidlin PR. Systematic review on the effect of rinsing with povidone-iodine during nonsurgical periodontal therapy. J Periodont Res 2010;.doi: 10.1111/j.1600-0765.2009.01232.x. © 2009 The Authors. Journal compilation © 2009 Blackwell Munksgaard Background and Objective: The existing literature is inconsistent regarding whether there is any additional effect of povidone-iodine (PVP-iodine) as an adjunctive to scaling and root planing, and, if there is an effect, what its size is. Therefore, the aim of this study was to assess the additional effect of PVP-iodine as an adjunct to scaling and root planing compared with water, saline or no rinse in the treatment of chronic periodontitis. Material and methods: An electronic literature search of the databases PubMed, EMBASE and the Cochrane Central Library, and a handsearch, were performed (up to November 2008). Two reviewers independently identified and selected screened abstracts for possible inclusion, and assessed randomized, controlled clinical trials comparing the additional benefit of PVP-iodine with water, saline rinsing or no rinsing in the nonsurgical periodontal therapy of patients with chronic periodontitis. A fixed-effects meta-analysis was conducted in the absence of statistically significant heterogeneity. Results: A small, but statistically significant additional beneficial effect of the adjunctive use of PVP-iodine with enhanced probing pocket depth reductions of 0.28 mm (95% confidence interval: 0.08 to 0.48, p = 0.007) was found. There was no significant heterogeneity between studies ( I2 = 0%). However, most of the studies included in the meta-analysis were of low quality, and the treatment modalities showed various differences such as the use of PVP-iodine at different concentrations and application modalities. Nevertheless, single-rooted teeth, in particular, showed an additional benefit after scaling and root planing with PVP-iodine, particularly when the treatment was repeated during the healing stage. Conclusion: The adjunctive use of PVP-iodine during scaling and root planing may increase the clinical pocket depth reduction, although the clinical significance is small to moderate. [ABSTRACT FROM AUTHOR]

Aim To evaluate whether passive ultrasonic irrigation (PUI) of 2.5% NaOCl would dissolve necrotic pulp tissue from simulated accessory root canals (SACs) better than passive placement of the irrigant, when temperature was equilibrated between the two treatments. Methodology Transparent root canal models ( n = 6) were made from epoxy resin. SACs of 0.2 mm diameter were placed at defined angles and positions in the mid-canal and apical area. SACs were filled with necrotic bovine pulp tissue. PUI was performed five times for 1 min each with irrigant replenishment after every minute. Main canal temperature was measured after each minute, and a digital photograph was taken. In control experiments, mock treatments were performed with the same set-up without activation of the file using heated NaOCl to mimic the temperature created by PUI. Experiments were repeated five times. Digital photographs were analysed for the distance of dissolved tissue into the SACs in mm. Overall comparison (sum of dissolved tissue from all five accessory canals) between treatments was performed using paired t-test. Differences between SAC angulation and position after PUI were investigated usinganova/Bonferroni (alpha < 0.05). Results Passive ultrasonic irrigation caused a rise in irrigant temperature in the main canal to 53.5 ± 2.7 °C after the fifth minute. PUI dissolved a total of 6.4 ± 2.1 mm, mock treatment controlled for heat: 1.4 ± 0.6 mm ( P < 0.05). No significant influence of SAC position or angulation was found. Conclusions Passive ultrasonic irrigation promotes positive tissue-dissolving effects beyond a rise in irrigant temperature. [ABSTRACT FROM AUTHOR]

The study aimed to compare the dentine wear of primary and permanent human and bovine teeth because of erosion/abrasion and evaluate if bovine dentine is an appropriate substitute for human dentine in further erosion/abrasions tests. Dentine samples from deciduous molars and human third molars as well as from calves’ and cattle’s lower incisors were prepared and baseline surface profiles were recorded. Each day all samples were demineralized in 1% citric acid, tooth brushed with 100 brushing strokes with toothpaste slurry and stored in artificial saliva for the rest of the day. This cycle was run for 20 days. Afterwards, new surface profiles were recorded and dentine wear was calculated by a customized computer program. Dentine wear because of erosion/abrasion was not statistically, significantly different for human third molars and cattle’s lower incisors ( P = 0·7002). The dentine wear because of erosion/abrasion of deciduous molars and calves’ lower incisors was significantly different ( P < 0·0000). No statistically significant difference in the dentine wear of human third molars and cattle’s lower incisors was observed, so that the use of cattle’s lower incisors as substitute for adult human teeth for further investigations in erosion/abrasion studies could be accepted. [ABSTRACT FROM AUTHOR]

Aim To evaluate the hypothesis that food-borne viable Enterococcus faecalis cells could enter the root canal space via coronal leakage. Methodology In a simulated oral environment under mastication the capacity of a calcium sulphate-based temporary filling material (Cavit W) to prevent leakage of E. faecalis from a cheese through the endodontic access cavity into the pulp chamber was assessed. Standardized class I access cavities were prepared in human maxillary molars. These were filled with Cavit of either 2 or 4 mm thickness ( n = 16, each). Empty access cavities served as positive, teeth filled with a light-curing composite material acted as negative controls ( n = 8, each). A cheese containing viable E. faecalis cells was placed on the occlusal aspects of test and control teeth, which were subsequently subjected to 680 mastication loads per day for 1 week in a masticator device perfused with artificial saliva at 37 °C. Leakage of E. faecalis from the cheese into the pulp chamber was assessed by culture on a kanamycin aesculin azide agar and compared between groups using Fisher's exact test. Results All of the positive controls showed pure growth of E. faecalis. In addition, one of the negative control teeth leaked. The 4 mm application of Cavit prevented leakage of E. faecalis significantly better than the corresponding 2 mm application: 1 of 16 specimens compared with 6 of 16 specimens had leakage, respectively ( P < 0.05). Conclusions The current results substantiate the suspicion that food-derived microbiota could enter the necrotic root canal system via microleakage. [ABSTRACT FROM AUTHOR]

The study aimed at determining hydrogen peroxide recovery in saliva during use of different home bleaching products by smokers and non-smokers. Peroxide recovery was evaluated with respect to the safe level reported in the literature. Determination of peroxide levels in saliva was performed with peroxidase, phenol and 4-aminoantipyrin in a photometric method. Four different bleaching regimens were used by 10 smokers and 10 non-smokers: Whitestrips, Vivastyle (tray-based) and two paint-on products (Crest Night Effects, Colgate Simply White). Whole saliva was collected and total amount of peroxide (mg) released during the 60 min bleaching period was determined: Colgate Simply White: 2.67 +/-0.88 (non-smokers); 2.66 +/- 1.17 (smokers); Crest Night Effects: 0.23 +/- 0.13 (non-smokers); 0.25 +/-0.16 (smokers); Vivastyle: 2.47 +/- 0.82 (non-smokers), 2.44 +/- 1.31 (smokers); Whitestrips: 1.39 +/- 0.62 (non-smokers), 2.02 +/- 1.86 (smokers). In terms of amount of peroxide kg(-1) body weight the bleaching systems led to a single exposure of 0.004-0.046 mg kg(-1), which is distinctly less than safe daily dose of 0.26 mg kg(-1) day(-1), if calculated for a small person (58 kg). The criterion smoker versus non-smokers had no influence on peroxide levels in the oral cavity. Conclusion: Smoking did not appear to impact the anti-oxidant defence capacity of the oral cavity with respect to degrading peroxides released from bleaching products. Significantly lower amounts of peroxides were detected in saliva during application of the paint-on product Crest Nights Effects compared with the other bleaching systems. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The aims of this study were to (1) investigate prevalence and severity of erosive tooth wear among kindergarten children and (2) determine the relationship between dental erosion and dietary intake, oral hygiene behaviour, systemic diseases and salivary concentration of calcium and phosphate. MATERIALS AND METHODS: A sample of 463 children (2-7 years old) from 21 kindergartens were examined under standardized conditions by a calibrated examiner. Dental erosion of primary and permanent teeth was recorded using a scoring system based on O'Sullivan Index [Eur J Paediatr Dent 2 (2000) 69]. Data on the rate and frequency of dietary intake, systemic diseases and oral hygiene behaviour were obtained from a questionnaire completed by the parents. Unstimulated saliva samples of 355 children were analysed for calcium and phosphate concentration by colorimetric assessment. Descriptive statistics and multiple regression analysis were applied to the data. RESULTS: Prevalence of erosion amounted to 32% and increased with increasing age of the children. Dentine erosion affecting at least one tooth could be observed in 13.2% of the children. The most affected teeth were the primary maxillary first and second incisors (15.5-25%) followed by the canines (10.5-12%) and molars (1-5%). Erosions on primary mandibular teeth were as follows: incisors: 1.5-3%, canines: 5.5-6% and molars: 3.5-5%. Erosions of the primary first and second molars were mostly seen on the occlusal surfaces (75.9%) involving enamel or enamel-dentine but not the pulp. In primary first and second incisors and canines, erosive lesions were often located incisally (51.2%) or affected multiple surfaces (28.9%). None of the permanent incisors (n = 93) or first molars (n=139) showed signs of erosion. Dietary factors, oral hygiene behaviour, systemic diseases and salivary calcium and phosphate concentration were not associated with the presence of erosion. CONCLUSIONS: Erosive tooth wear of primary teeth was frequently seen in primary dentition. As several children showed progressive erosion into dentine or exhibited severe erosion affecting many teeth, preventive and therapeutic measures are recommended. [ABSTRACT FROM AUTHOR]

Aim To compare ex vivo the accuracy of two impedance quotient apex locators with different scales and frequencies of the measuring circuit. Methodology In each root of 193 extracted human teeth, electronic working length determination (ELD) was carried out with a newly constructed measuring unit. In all cases, ELD was performed using the apex locators Justy II® (Hager & Werken, Duisburg, Germany) and Raypex 4® (VDW, Munich, Germany) on the scale points (sp) 0/0.5/1 of each device. A Miller Needle reaching working length was fixed with composite. The corresponding sp and the differences to the other sp were recorded. After histological preparation of the apical region, the teeth were examined under a light microscope. The distances of the Miller Needle tips to the target intervals ‘minor foramen–major foramen’ and ‘apical canal constriction’ (apical constriction) were determined for each sp for both devices. The data were statistically analysed by a chi-square test. Results Precise determination of the target interval ‘minor foramen–major foramen’ was successful with Raypex 4 in 94.8% (sp 1), 90.7% (sp 0.5) and 72.5% (sp 0) of cases and with Justy II in 59.6% (sp 1), 92.2% (sp 0.5) and 68% (sp 0) of cases. No measurement carried out by Raypex 4 and by Justy II on sp 1 was beyond the major apical foramen. However, on sp 0.5, there were eight measurements for Raypex 4 and four measurements for Justy II beyond the major apical foramen. Overinstrumentation was also recorded for sp 0 in 49 specimens (Raypex 4) and 59 specimens (JustyII). The major apical constriction was met exactly by Raypex 4 in 50.7% (sp 1), 14% (sp 0.5) and 5.2% (sp 0) of cases and by Justy II in 32.1% (sp 1), 23.8% (sp 0.5) and 4.1% (sp 0) of cases. The differences between the determination made with the sp suggested by the manufacturers for Raypex 4 (sp 1) and Justy II (sp 0.5) were not significant ( P > 0.05) for the target interval ‘minor foramen–major foramen’ and significant ( P ≤ 0.05) for the apical constriction. The differences between the sp of each device were significant ( P ≤ 0.05) for both target intervals. Conclusions It is possible to determine the region between the minor and major apical foramen with electronic apex locators ex vivo. The best results were obtained using the sp advised by the manufacturers. Raypex 4 gave the best results on sp one without any measurement beyond the apical foramen. Use of ELD does not result in precise determination of the apical constriction. [ABSTRACT FROM AUTHOR]

To evaluate the enamel erosive potential of modified acidic soft drinks under controlled conditions in an artificial mouth.From each of 144 bovine incisors one enamel sample was prepared. Labial surfaces of the samples were ground flat, polished and covered with adhesive tape, leaving an exposed area. The samples were distributed among four (A–D) groups for treatment with A: Coca-Cola, B: Sprite; C: Sprite light, D: orange juice. Either 1.0 mmol l−1 calcium (Ca) or a combination (comb.) of 0.5 mmol l−1 calcium plus 0.5 mmol l−1 phosphate plus 0.031 mmol l−1 fluoride was added to the beverages. Samples of each group were subdivided into three subgroups (-original; -Ca and -comb.) for treatment with original and modified drinks. De- and remineralization cycles were based on a standard protocol described earlier. Surface loss of the specimens was determined using profilometry after test procedure.In all subgroups, loss of enamel was observed. The enamel loss recorded for the samples rinsed with original Sprite and original orange juice was significantly higher compared with all other solutions (P = 0.001). Lowest enamel loss was recorded for the original Coca-Cola group (P = 0.001). With the exception of Coca-Cola, demineralization with the modified beverages led to significantly lower losses compared with the respective original solutions.Modification of the test soft drinks with low concentrations of calcium or a combination of calcium, phosphate and fluoride may exert a significant protective potential with respect to dental erosion. [ABSTRACT FROM AUTHOR]

Buchalla W, Lennon ÁM, Attin T. Fluorescence spectroscopy of dental calculus. J Periodont Res 2004; doi: 10.1111/j.1600-0765.2004.00747.x© Blackwell Munksgaard 2004 Correct diagnosis of the presence and extent of subgingival calculus is important for periodontal treatment planning and reassessment after periodontal therapy. Traditional tactile methods often lack sensitivity. The present investigation shall contribute to understanding the fundamental fluorescence properties that may be useful for optical detection of both supra- and subgingival calculus. The aim of this study was to investigate emission spectra from supra- and subgingival calculus under a wide range of excitation wavelengths. Extracted human molars with either supragingival or subgingival calculus deposits on the root surface were selected ( n = 3 each). Emission spectra were recorded from the calculus of each tooth and corresponding areas of clean root surfaces using a fluorescence spectrophotometer at excitation wavelengths from 360 nm up to 580 nm in steps of 20 nm. The spectra were corrected for the wavelength dependent instrument sensitivity and normalized to peak intensity (the highest peak was set at 1.0). Emission spectra of calculus exhibited distinct fluorescence bands between 570 and 730 nm not present in clean root surfaces. This fluorescence emission was strongest for excitation wavelengths from 400 to 420 nm. No differences were observed between supra- and subgingival calculus. Human dental calculus can clearly be differentiated from clean root surfaces by emission spectrophotometry. The characteristic fluorescence emission of supra- and subgingival calculus may be due to a variety of porphyrin derivatives and may provide the basis for future diagnostic procedures. [ABSTRACT FROM AUTHOR]

Hoer D, Attin T. The accuracy of electronic working length determination. International Endodontic Journal, 37, 125–131, 2004. To determine in vivo the accuracy of two impedance quotient apex locators under clinical conditions. Electronic working length determination was carried out before extraction in 79 human teeth with 93 root canals. In 51 root canals, the determination was performed using the apex locator Justy II® (Hager & Werken, Duisburg, Germany); in 42 canals, the apex locator Endy 5000® (Loser, Leverkusen, Germany) was used. A root canal instrument was fixed at working length with composite material prior to extraction followed by the exposure of a radiograph. After histological preparation of the apical region, the teeth were examined under a light microscope. The distance of the file tips to the target intervals ‘minor foramen – major foramen’ and ‘apical canal constriction’ was determined. These values were compared with the calculated working lengths, determined by radiographic assessment. The data were statistically analysed by a paired t-test. For both apex locators and both target intervals, no significant differences between the electronic and radiographical assessments were recorded. The probability of determining the area between minor and major foramen was 82.4% for Justy II and 81% for Endy 5000. However, accurate determination of the apical constriction was only successful in 51% (Justy II) and 64.3% (Endy 5000) of canals. Variation of the inaccurate measurements was higher for Endy 5000 than for Justy II. Under clinical conditions, it is possible to determine the region between the minor and major apical foramen with electronic length measuring devices (ELD). However, use of these devices does not result in precise determination of the apical constriction. [ABSTRACT FROM AUTHOR]

Internal bleaching procedures such as the walking bleach technique can be used for whitening of discoloured root-filled teeth. The walking bleach technique is performed by application of a paste consisting of sodium perborate-(tetrahydrate) and distilled water (3% H[SUB2]O[SUB2]), respectively, in the pulp chamber. Following a critical review of the scientific literature, heating of the mixture is contra-indicated as the risk of external cervical resorption and the formation of chemical radicals is increased by application of heat. An intracoronal dressing using 30% H[SUB2]O[SUB2] (should not be) used in order to reduce the risk of inducing cervical resorption. This review provides advice based on the current literature and discusses how the walking bleach technique can lead to successful whitening of non-vital root-filled teeth without the risks of side- effects. [ABSTRACT FROM AUTHOR]

summary Aim of the study was to evaluate the influence of tea applied at various time intervals after bleaching of enamel on intrinsic tooth colour. Ninety bovine specimens were distributed among six groups (A–F, n =15). The samples of group A–D were bleached with the 10% carbamide peroxide (CP) gel VivaStyle for 8 h, followed by storing in artificial saliva for the remaining period of the day. The specimens were removed from the saliva at different intervals (A: 0 min, B: 60 min, C: 240 min) and immersed in freshly prepared black tea for 10 min. Group D (bleaching, no tea), E (no bleaching, but tea) and F (no bleaching, no tea) served as controls. These procedures were repeated for 8 days. Colour was measured at baseline, after each day, and after final cleaning using the CIELab-system. Then Δb (initial b -value – final reading), ΔL , and composite colour (ΔE ) were statistically analysed. External bleaching (A–D) led to a distinct whitening effect with lower Δb - (=reduction in yellow) and higher ΔL -values (=increase in brightness) compared with controls. The Δb - and ΔL -values of the samples A–C were not significantly different from the samples which were bleached only. No significant difference was observed comparing specimens of group A–C. It is concluded that application of tea directly after bleaching with 10% CP does not significantly effect the outcome of a bleaching treatment irrespective of the time interval elapsed between the bleaching procedure and the contact of the tooth surface with tea. [ABSTRACT FROM AUTHOR]

Summary The aim of the present in vitro study was to evaluate the effect of carbamide peroxide (CP) bleaching on fluoride uptake in enamel. Additionally, the susceptibility for erosion in bleached and fluoridated enamel was tested. Each four enamel specimens were prepared from 44 bovine incisors. The four samples gained from each tooth were distributed among four groups (A–D) of 44 specimens each: A: (unbleached/unfluoridated) served for determination of baseline fluoride concentration; B: (unbleached/fluoridated) four times in 2000 ppm NaF solution (2 min); C: (bleached/unfluoridated) four times in 10% CP (8 h); D: (bleached/fluoridated) four times in 10% CP and fluoridation. In 22 specimens of each group both KOH-soluble and structurally bound fluoride were determined in the outermost 30 μm of the enamel. In the remaining specimens erosions were induced by immersing the samples in 5 mL of 1% citric acid (20 min) and microhardness was evaluated before and after demineralization. Statistical analysis showed that KOH-soluble fluoride uptake was similar for group B and D specimens. Structurally bound fluoride uptake after fluoride application in unbleached samples was significantly higher than in bleached ones. Bleaching only resulted in a highly significant fluoride loss. In all samples erosion caused a significant microhardness loss. The study showed that pre-treatment of enamel with CP followed by fluoridation does not improve erosive resistance. Moreover the study reveals that CP treatment decreases concentration of structurally bound fluoride in enamel which could not be outweighed by fluoridation with 2000 ppm NaF. It is concluded that it is not feasible to improve fluoride uptake in enamel with a pre-treatment with 10% CP. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the fluoride uptake/release of polyacid-modified resin composites (compomers) in neutral and acidic buffer solutions. Two compomers (Dyract® and Compoglass®) were tested and the conventional glass–ionomer cement (GIC) Vivaglass Base® served as a control. Forty specimens were fabricated from each of the respective materials. Twenty of these specimens were placed in artificial saliva and the other 20 specimens in a fluoridated dentifrice slurry for 5 min. Then, 10 fluoridated and 10 non-fluoridated specimens were immersed in a neutral buffer solution (pH 6·8), and the other specimens were immersed in an acidic solution (pH 4·0). After 1, 2, 3, 4, and 5 days the samples were again placed in either a fluoridated dentifrice slurry or saliva for 5 min, after which time they were transferred to fresh buffer solutions. The fluoride content of the solutions was assessed with a fluoride sensitive electrode. Fluoride release from all the materials decreased continuously during the experiment, with a significantly higher release in the acidic solution compared to the neutral buffer solution. Fluoridation did not result in an increased fluoride release for the compomers. However, the conventional GIC revealed a significantly higher fluoride release after fluoridation. It is concluded that Dyract® and Compoglass® can not be replenished with fluoride, irrespective of the pH value of the environment. [ABSTRACT FROM AUTHOR]

The objective of the study was to evaluate the remineralizing capacity of different fluoride treatments on dental enamel bleached with carbamide peroxide (Opalescence®). Sixty bovine enamel slabs were subjected to four cycles comprising bleaching (12 h) and remineralization in artificial saliva (8 h). The samples were evenly distributed among four groups (A–D). During the first hour of the remineralization period the specimens in group A were covered with a fluoride varnish (Duraphat®; 2.23% F-). In group B the enamel slabs were stored in a fluoride solution (0.2% F- as NaF) for 1 min prior to remineralization. Group C did not receive a fluoride treatment, and group D (control) was stored in distilled water instead of bleaching. Microhardness (VHN) was evaluated before the experiments and after the second and fourth cycle, respectively. Final hardness was calculated as percentage of the initial hardness. Analysis of variance was applied to the data followed by pairwise comparisons with corrected level of significance (P < 0.01). Hardness decreased significantly in groups A-C compared to the control group (D). The bleached and unfluoridated specimens (group C) showed a significantly higher hardness loss compared to the fluoridated specimens, whereas no significant difference was observed between the two fluoridated groups. It is concluded that remineralization of bleached enamel is improved by application of highly concentrated fluorides. [ABSTRACT FROM AUTHOR]

Abstract Attin T, Buchalla W, Zirkel C, Lussi A. Clinical evaluation of the cleansing properties of the noninstrumental technique for cleaning root canals. International Endodontic Journal , 35 , 929–933, 2002. Aim The purpose of the present study was to evaluate noninstrumentation technology (NIT) for root-canal cleansing in vivo . Methodology A total of 22 teeth that were to be extracted in 18 patients were treated with NIT for 30 min with 3.0% NaOCl. After extraction, the remaining organic debris in the root canals was evaluated histologically and categorized as the percentage of the corresponding canal length in the apical, middle and coronal regions of the roots. Percentage of residual debris was categorized as follows: D1, 0%; D2, 1–50% and D3, 51–100%. Results In the coronal region, 55% of the roots were totally clean (D1), whereas 12% and 33% were scored as D2 and D3, respectively. The middle section was evaluated as D1 in 27%, D2 in 18% and D3 in 55%. In the apical region, only 21% of the roots were totally cleaned; the remaining 79% were scored as D3. Conclusion The results indicate that the noninstrumental technique for cleaning root canals needs further modifications for achieving acceptable results under clinical conditions. [ABSTRACT FROM AUTHOR]

Aim: We investigated the in vitro effect of Limosilactobacillus reuteri DSM 17938 supernatant on the inflammatory response of human gingival fibroblasts (HGF) challenged by lipopolysaccharide (LPS) or elevated glucose levels., Methods: HGF were exposed to LPS (1 μg/mL), glucose (5, 12 mM or 25 mM), and dilutions of supernatant prepared from L. reuteri DSM 17938 (0.5 × 10 7 , 1.0 × 10 7 , 2.5 × 10 7 , and 5.0 × 10 7  CFU/mL). After 24 h cell viability and levels of cytokines (IL-1β, IL-6 and IL-8) and TLR-2 were determined., Results: None of the tested L. reuteri (DSM 17938) supernatant concentrations reduced the viability of HGF. Supernatant concentrations (2.5 × 10 7 and 5 × 10 7  CFU/mL) significantly (p < .05) decreased the production of IL-1β, IL-6, IL-8, and TLR-2 in the presence of LPS. In contrast, inflammatory markers were not reduced by L. reuteri supernatant in the presence of glucose. Glucose concentrations of 12 mM and 24 mM still lead to an elevated production of the investigated biochemical mediators., Conclusion: While L. reuteri (DSM 17938) supernatant attenuates the inflammatory response of HGF to LPS in a dose-dependent manner, elevated glucose levels suppress this action. These in vitro results support the overall anti-inflammatory efficacy of L. reuteri supplementation in plaque-associated periodontal inflammations., (© 2024 The Authors. Journal of Periodontal Research published by John Wiley & Sons Ltd.)

Objectives: To evaluate minimally invasive restorations' capacity to mask discolored teeth and explore the impact of ceramic thickness, translucency, and cement color., Materials and Methods: Twenty-four assessment pairs of naturally colored and discolored bovine dentin samples were formed, using lithium disilicate specimens in six different thicknesses (0.3-0.8 mm), two different translucencies (high, low), and two cements (transparent, tooth-colored). Evaluators assessed the color differences in each assessment pair, and the threshold for detecting a color difference was determined using sequential testing and the Bonferroni-Holm method., Results: A thickness of 0.6 mm effectively masked color differences using high translucent ceramic with transparent cement, detectable differences were still observed at 0.7/0.8 mm. A threshold thickness of 0.4 mm was seen using high translucent ceramic and tooth-colored cement, with color differences still discernible at 0.5 and 0.8 mm. A threshold thickness of 0.4 mm was detected using low translucent ceramic and transparent cement, while detectable differences persisted at 0.5, 0.7, and 0.8 mm. A 0.5 mm threshold thickness was observed when using low translucent ceramic and tooth-colored cement, and no detectable color differences were detected beyond this thickness., Conclusions: Masking can be achieved with a thickness of 0.4-0.5 mm using a low translucent material and tooth-colored cement., Clinical Significance: Understanding the impact of ceramic thickness, translucency, and cement color can aid clinicians in making informed decisions for achieving the best esthetic outcomes while preserving tooth structure. Effective masking can be accomplished with ceramic thicknesses starting at 0.4 mm, especially when employing a low translucent material and tooth-colored cement. However, clinicians should be aware that discolorations may still be detectable in certain scenarios when using minimally invasive lithium disilicate restorations., (© 2023 The Authors. Journal of Esthetic and Restorative Dentistry published by Wiley Periodicals LLC.)

The oral cavity is colonized by a plethora of bacteria, fungi, and archaea, including streptococci of the mitis group (MSG) and the yeast Candida albicans. This study aims to investigate the role of streptococcal species in the development of oral biofilm and the cross-kingdom interactions between some of the members of the commensal MSG and the pathogen yeast C. albicans using a multispecies supragingival biofilm model. A total of nine different in vitro biofilms were grown, quantified with culture analyses, and visually examined with confocal laser scanning microscopy (CLSM). A four-species biofilm without any streptococcal species was used as a basic biofilm. In each subsequent inoculum, one species of MSG was added and afterward combined with Streptococcus mutans. The eight-species biofilm contained all eight strains used in this study. Culture analyses showed that the presence of S. mutans in a four-species biofilm with Streptococcus oralis or S. oralis subsp. tigurinus did not differ significantly in C. albicans colony-forming unit (CFU) counts compared to biofilms without S. mutans. However, compared to other mitis species, Streptococcus gordonii combined with S. mutans resulted in the lowest CFUs of C. albicans. Visual observation by CLSM showed that biofilms containing both S. mutans and one species of MSG seemed to induce the formation of filamentous form of C. albicans. However, when several species of MSG were combined with S. mutans, C. albicans was again found in its yeast form., (© 2023 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Antibacterial properties of toothpastes enable chemical plaque control in limited-access tooth regions that are mechanically not sufficiently reached by toothbrushes. Therefore, this study aimed to compare different microbial methods to assess antimicrobial toothpaste properties and evaluate different toothpastes in terms of their antibacterial efficacy against different oral microorganisms in an in vitro setting. Six toothpaste suspensions with varying antibacterial supplements were applied to a multispecies biofilm model (Actinomyces oris, Candida albicans, Fusobacterium nucleatum, Streptococcus oralis, and Streptococcus mutans) as well as to each microorganism. A culture method was used to assess the anti-biofilm effects and two different agar diffusion assays were performed for testing the antimicrobial effect on each microorganism. The measurements of the culture and diffusion analyses were statistically normalized and compared and toothpastes were ranked according to their antimicrobial efficacy. The results of both agar diffusion assays showed a high correlation across all tested species (Spearman correlation coefficients ρ s  > 0.95). The results of the multispecies biofilm model, however, substantially differed in its assessment of antibacterial properties (ρ s ranging from 0.22 to 0.87) compared to the results of both diffusion assays. Toothpastes with amine fluoride (with and without stannous fluoride), and toothpastes with triclosan resulted in the highest antimicrobial efficacy. Activated carbon supplements in toothpastes were comparable in their antimicrobial action to the negative control NaCl. The appropriate selection of a broad range of oral microorganisms seems crucial when testing the chemical impact of toothpaste and toothpaste supplements., (© 2022 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Objective: The aim of this study was to evaluate and compare surface roughness, gloss, and color change of dental enamel after being brushed with toothpastes containing diamond powder and traditional abrasives., Materials and Methods: Seventy enamel slabs were derived from 70 bovine incisors. The slabs were brushed with six different toothpastes and artificial saliva as a negative control. The specimens were then stained with black tea mixed with citric acid (3 days, pH = 4) and again brushed with the same toothpastes. R a (contact profilometer), gloss (glossmeter), and color (CIE L* a* b* system) values were measured after each step., Results: Emoform-F Diamond (contains diamond powder and traditional abrasives) offered significantly the best improvement of R a and gloss values after the first brushing sequence and the best recovery of the brightness of enamel after staining and second brushing sequence (P < .05). AMC 2.5 (contains only diamond powder as abrasive) was not able to offer such improvement., Conclusion: Diamond powder as an additional abrasive in toothpastes could be able to offer a further improvement of R a , gloss, and color values of enamel., (© 2020 Wiley Periodicals, Inc.)

Objectives: Short dental implants are frequently placed, however, little is known about the effect of the loading force regarding an enhanced crown-to-implant ratio. The aim of this study was therefore to assess bone density changes after a 3-year period, on radiographs acquired from a randomized, controlled two-centre clinical study comparing implants of 6 and 10 mm of length., Materials and Methods: Three predefined areas were chosen on standardized X-rays in order to assess grey-scale values of the peri-implant bone: One at the tip of the apex and two at half-length on the mesial and distal sides of the implant. Radiographs at all follow-up appointments had previously been calibrated using control fields in areas of constant density., Results: Around short implants, peri-implant bone displayed significantly higher differences in grey-scale values (p = .031) after 3 years, indicating a higher degree of mineralization. This phenomenon was not observed around long implants., Conclusions: A higher degree of mineralization around short implants was recorded. Whether this finding goes along with hampered bone adaptability, and accordingly, higher failure rates of short implants must be studied further in long-term clinical trials., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: To assess the effect of concomitant subgingival rinsing with 10% PVP-iodine during subgingival instrumentation on the prevalence and magnitude of bacteraemia of oral origin., Materials and Methods: Subgingival instrumentation was performed with water or PVP-iodine rinse in patients with periodontitis. Prior to instrumentation, subjects gargled for 1 min with the allocated liquid. Pockets were then rinsed for 1 min and subgingivally instrumented with liquid-cooled (water/PVP-iodine) ultrasonic scalers (1 min). Two minutes later, a blood sample from the arm vein was drawn using a lysis centrifugation blood culture system for quantitative microbiological analysis. Non-parametric statistical tests were performed to assess differences in the prevalence and extent of bacteraemia between groups., Results: Of the 19 samples in each group, oral-borne bacteraemia was detected in 10 of the control and 2 of the test samples. With an average of 3.0 [1; 5] colony forming units, significantly less bacteria and bacteraemia were found in the test group compared to the controls (12.2 [1; 46]) (p = 0.003). Anaerobic bacteria were not found in the test group., Conclusions: Bacteraemia after subgingival instrumentation with concomitant PVP-iodine rinsing is reduced but not eliminated. Therefore, it might be recommended for patients at a high risk of endocarditis or infection of endoprostheses. However, preventive antibiotic treatment should not be omitted., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This study investigated the influence of modulated photo-activation on axial polymerization shrinkage, shrinkage force, and hardening of light- and dual-curing resin-based composites. Three light-curing resin composites (SDR bulk-fill, Esthet X flow, and Esthet X HD) and one dual-curing material (Rebilda DC) were subjected to different irradiation protocols with identical energy density (27 J cm(-2) ): high-intensity continuous light (HIC), low-intensity continuous light (LIC), soft-start (SS), and pulse-delay curing (PD). Axial shrinkage and shrinkage force of 1.5-mm-thick specimens were recorded in real time for 15 min using custom-made devices. Knoop hardness was determined at the end of the observation period. Statistical analysis revealed no significant differences among the curing protocols for both Knoop hardness and axial shrinkage, irrespective of the composite material. Pulse-delay curing generated the significantly lowest shrinkage forces within the three light-curing materials SDR bulk-fill, Esthet X flow, and Esthet X HD. High-intensity continuous light created the significantly highest shrinkage forces within Esthet X HD and Rebilda DC, and caused significantly higher forces than LIC within Esthet X flow. In conclusion, both the composite material and the applied curing protocol control shrinkage force formation. Pulse-delay curing decreases shrinkage forces compared with high-intensity continuous irradiation without affecting hardening and axial polymerization shrinkage., (© 2014 Eur J Oral Sci.)

Objective: To volumetrically evaluate soft tissue changes of different ridge preservation techniques compared to spontaneous healing 6 months after tooth extraction., Materials and Methods: In each of 40 patients, one single-rooted tooth was extracted and four treatment modalities were randomly assigned to the following groups (n = 10 each): A) ß-tricalcium-phosphate-particles with a polylactid coating (ß-TCP), B) demineralized bovine bone mineral with 10% collagen covered with a collagen matrix (DBBM-C/CM), C) DBBM with 10% collagen covered with an autogenous soft tissue punch graft (DBBM-C/PG), D) spontaneous healing (control). Impressions were obtained before extraction and 6 months later, casts were digitized and volumetric changes at the buccal soft tissues were determined. One-way anova was performed and pair-wise Wilcoxon rank sum test with Bonferroni-Holm method was applied for comparison of differences between two groups., Results: After 6 months, horizontal contour changes accounted for -1.7 ± 0.7 mm (A), -1.2 ± 0.5 mm (B), -1.2 ± 0.7 mm (C) and -1.8 ± 0.8 mm (D). None of the group comparisons reached statistical significance., Conclusions: Six months after tooth extraction all groups revealed a horizontal volume change in the buccal soft tissue contour. Application of DBBM-C/CM or DBBM-C/PG reduced the amount of volume resorption compared to ß-TCP or spontaneous healing without reaching statistically significant difference., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To evaluate the radiographic changes of the alveolar ridge following application of different ridge preservation techniques 6 months after tooth extraction., Materials and Methods: Four treatment modalities were randomly assigned in 40 patients: β-tricalcium-phosphate-particles with polylactid coating (β-TCP), demineralized bovine bone mineral with 10% collagen covered with a collagen matrix (DBBM-C/CM), DBBM-C covered with an autogenous soft-tissue graft (DBBM-C/PG) and spontaneous healing (control). Cone-beam computed tomography scans were performed after treatment and 6 months later., Results: After 6 months, the vertical changes ranged between -0.6 mm (-10.2%) for control and a gain of 0.3 mm (5.6%) for DBBM-C/PG on the lingual side, and between -2.0 mm (-20.9%) for β-TCP and a gain of 1.2 mm (8.1%) for DBBM-C/PG on the buccal side. The most accentuated ridge width changes were recorded 1 mm below the crest: -3.3 mm (-43.3%, C), -6.1 mm (-77.5%, β-TCP), -1.2 mm (-17.4%, DBBM-C/CM) and -1.4 mm (-18.1%, DBBM-C/PG). At all three levels, DBBM-C with either CM or PG was not significantly differing (p > 0.05), while most other differences between the groups reached statistical significance (p < 0.05)., Conclusions: Application of DBBM-C, covered with CM or PG, resulted in less vertical and horizontal changes of the alveolar ridge as compared with controls 6 months after extraction., (© 2012 John Wiley & Sons A/S.)

Unlabelled: The morphologic and metric assessment of mucogingival soft tissue dimensions is of great multidisciplinary clinical and academic interest, in order to quantify and monitor gingival changes while in treatment, e.g., during periodontal, restorative, prosthetic, orthodontic, or implant therapy. Pink esthetics play an increasingly important role in the overall treatment success, and therefore have to be monitored throughout therapy. The purpose of this article was to identify and summarize methods, which aim at quantifying gingival dimensions in terms of morphology, thickness, and volume, with respect to their accuracy and practicability. The introduced measurement methods should further facilitate personalized treatment planning and monitoring., Clinical Significance: Mucogingival esthetics play an increasingly important role whenever treatment results are evaluated. Several qualitative and (semi)quantitative methods for measuring soft tissue dimensions are available. New methods like CAD/CAM (computer-aided design and computer-aided manufacturing) technologies are emerging and allow practitioners to reliably monitor their patient's soft tissues throughout therapy. Future improvements may help to develop better treatment strategies in terms of optimized preservation and creation of gingival morphology, especially in the esthetic zone., (© 2011 Wiley Periodicals, Inc.)

This study investigated the influence of time delay and duration of photo-activation on linear polymerization shrinkage, shrinkage force, and hardening of a dual-cured core build-up resin composite. The test material (Rebilda DC) was light-cured for 20 or 60 s either early (2 min) or late (7 min) after the start of mixing. Non-irradiated self-cured specimens served as controls. Linear shrinkage and shrinkage force were measured for 60 min using custom-made devices. Knoop hardness was determined at the end of the observation period. Self-cured controls, showing a linear shrinkage similar to that of specimens early light-cured for 20 s generated the lowest shrinkage force and hardness. A shorter light exposure time (20 s vs. 60 s) reduced linear shrinkage, shrinkage force, and hardness when early light-curing was performed, but did not affect the three properties in specimens light-cured late after the start of mixing. Late photo-activation increased linear shrinkage, irrespective of irradiation time, and resulted in a higher shrinkage force and hardness for short light exposure time. A moderate correlation was found between the two shrinkage properties studied (r(2) = 0.65). In conclusion, improvements in shrinkage behavior of the tested core build-up material were associated with inferior hardening, making it important to adapt curing protocols to the clinical situation.