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Abstract: Aim: To investigate whether a combination of mineral trioxide aggregate (MTA) and fluoride compounds affects bone cells. Methodology: Mineral trioxide aggregate (MTA) discs (ProRoot®, Dentsply Sirona, Ballaigues, Switzerland) with and without the addition of 0.1%, 0.25% and 0.5% sodium fluoride were characterized for their surface roughness by laser scanning microscopy and for the adhesion of human alveolar osteoblasts by scanning electron microscopy. Using eluates from fluoride‐enriched MTA discs, the cell proliferation was measured by monitoring the DNA incorporation of 5‐bromo‐2′‐deoxyuridine. Further, gene expression was evaluated by qPCR arrays, extracellular matrix mineralization was quantified by absorption measurement of Alizarin red stains, and effects were calculated with repeated measures analysis and post hoc P‐value adjustment. Results: Irrespective of fluoride addition, cell adhesion was similar on MTA discs, of which the surface roughness was comparable. Control osteoblasts had a curvilinear proliferation pattern peaking at d5, which was levelled out by incubation with MTA. The addition of fluoride partly restored the MTA‐related reduction in the cellular proliferation rate in a dose‐dependent manner. At the mRNA level, both fluoride and MTA modulated a number of genes involved in osteogenesis, bone mineral metabolism and extracellular matrix formation. Although MTA significantly impaired extracellular matrix mineralization, the addition of fluoride supported the formation of mineralized nodules in a dose‐dependent manner. Conclusion: The addition of fluoride modulated the biocompatibility of MTA in terms of supporting bone cell proliferation and hard tissue formation. Hence, fluoride enrichment is a trend‐setting advancement for MTA‐based endodontic therapies. [ABSTRACT FROM AUTHOR]

Aim To evaluate the effects of various mixing solutions on the biocompatibility of mineral trioxide aggregate ( MTA). Methodology Human alveolar osteoblasts ( hOAs) were incubated with eluates of 24 h-set cement discs of MTA mixed with sterile H2O, 3% sodium hypochlorite (Na OCl), 4% articaine (Ultracain® D-S), 0.9% NaCl, Ringer's solution or citrated blood, respectively. The cell proliferation in the presence of eluates was assessed by real-time cell analysis, and the expression of genes associated with proliferation (histone H3, HistH3), inflammation (interleukin-6, IL-6, matrix metalloproteinases 1 and 3, MMP1, MMP3) or apoptosis (caspase 3, Casp3) was analysed by qPCR after 24 and 72 h. The ultrastructure of cells grown on cement discs was visualized by scanning electron microscopy ( SEM), whilst actin cytoskeleton was monitored by fluorescence staining in the presence of eluates after 7 and 14 days. A repeated-measure analysis was performed, and P-values were adjusted by Tukey. Results Whilst articaine- MTA sustained hOA proliferation patterns similar to H2O- MTA, Na OCl- MTA reduced hOA proliferation and significantly increased the expression of MMP1 and MMP3. The addition of H2O and articaine modulated the gene expression of Casp3 or Hist3H3. The use of NaCl, Ringer and blood induced mRNA levels comparable to matched controls. With the exception of Na OCl- MTA, SEM and FM revealed regular hOA morphology for all mixing solutions. Conclusions Na OCl was highly cytotoxic for hOAs whilst all other mixing solutions can be considered as convenient biocompatible mixing solutions as alternatives to H2O for clinical use. [ABSTRACT FROM AUTHOR]

Unlabelled: In the 19th century, the mouthwash Listerine® was formulated from four essential oils. Later, the oils were replaced by their marker substances. To keep them in solution, 24-27% ethanol was added as a vehicle. This is an update of our previous review on the efficacy and safety of Listerine®.Method: PubMed was searched for clinical studies on the therapeutic benefits and safety of Listerine® from the end of 2011 to the end of October 2015.Results: Sixteen studies were found and extracted. Three of the four 6-month studies were of sound confirmatory design. Two of these investigated Listerine® and one Listerine Zero®. The evidence of effectiveness for Listerine®, based on the bulk of three confirmatory studies and numerous exploratory studies carried out so far, is strong, but only moderate for Listerine® Zero and poor for Listerine® Cool Blue. In the three safety studies identified, we found methodological flaws that biased the results.Conclusions: Evidence is accumulating that Listerine® is effective in improving oral health, but the absence of systematic toxicological studies means that an accurate safety assessment cannot be made. [ABSTRACT FROM AUTHOR]

Listerine® is one of the most popular mouthwashes worldwide and claims to combat harmful bacteria. In the past century, its recipe was changed from an essential oil mouthwash to a five-component mixture (thymol, menthol, eucalyptol, and methyl salicylate dissolved in 27% ethanol). The aim of this study was to get preliminary information about the antimicrobial activities of individual Listerine® components and their mixtures. We tested the bacterial strains Streptococcus mutans, Enterococcus faecalis, and Eikenella corrodens and the yeast Candida albicans. The established minimum inhibitory concentration (MIC) assay and the minimum bactericidal/fungicidal concentration (MBC/MFC) assay were applied. None of the combinations of two phenols at the concentrations contained within Listerine® were associated with either an additive or synergistic effect. Thymol had lower MIC and MBC/MFC values than the other Listerine® components and Listerine® against E. corrodens and C. albicans. The mixtures consisting of eucalyptol, methyl salicylate, and thymol were the most effective against S. mutans and E. faecalis and more effective than Listerine®. Our results demonstrate that the phenols and their concentrations as contained within Listerine® could be further optimized in terms of selecting those which increase their general effectiveness, at concentrations that do not induce harm. [ABSTRACT FROM AUTHOR]

Aim To evaluate whether artificial resin teeth could replace extracted human teeth in pre-clinical endodontic training and if this teaching approach influences the outcome of root canal treatment on patients. Methodology In a pre-clinical training course, students of group 1 ( n = 44) performed simulated endodontic exercises on four plastic blocks and three extracted human teeth. Students of group 2 ( n = 45) performed their exercises on plastic blocks and artificial resin teeth (Real-T Endo, Acadental, Lenexa, KS, USA). Both groups performed their first root canal treatments on patients in the following term. Radiographs taken during root canal treatment were used for the evaluation of treatment outcome. Distances between the master cone or the root filling and the radiographic apex as well as iatrogenic errors were assessed, and comparisons were made using Fischer's exact test. Results In the pre-clinical course root canal treatments performed by students of group 2 were more often classified as acceptable and a higher number of iatrogenic errors were observed in group 1. When root canal treatments were performed on patients for the first time, no significant difference was observed between the groups in terms of radiographic technical quality of root fillings. Conclusions The application of artificial teeth instead of extracted human teeth had no effect on the technical quality of root fillings in terms of position in relation to the root apex or the creation of aberrations. [ABSTRACT FROM AUTHOR]

Aim To investigate the use of a zinc oxide/zinc sulphate-based cement ( Coltosol® F, Coltène Whaledent, Cuyahoga Falls, OH, USA) as a temporary filling material during multiple-visit root canal treatments and the occurrence of cracks within the filling material or the tooth. Methodology Root canals of one hundred and twenty-two extracted human molars were prepared using Pro Taper instruments up to size F2. After root canal preparation, standardized mesial-occlusal-distal cavities were prepared. The buccal-lingual/palatal width of the cavities was 4.5 mm), so that the remaining cavity walls had a mean thickness of 3.5 mm. Teeth were checked for cracks and fracture lines using a stereomicroscope with 10× magnification. A calcium hydroxide slurry was used as an intracanal dressing. The teeth were divided into three groups. In the Coltosol group, the cavity was filled with Coltosol® F. In the Coltosol- Clearfil group, a 2-mm layer of Coltosol® F was placed into the coronal pulp chamber, the remaining cavity was filled with Clearfil™. In the Clearfil group, a foam pellet was placed onto the orifices of the root canals, the remaining cavity was filled with Clearfil™. In the control group, the cavities were left without any filling material. The teeth were stored in water at 37 °C for 14 days and examined every 24 h under a stereomicroscope for fracture lines occurring on the tooth surface or in the filling material. Results In the Coltosol group, fractures within the filling material were observed in 28 (85%) of 33 teeth. 13 (39%) teeth had tooth fractures. Amongst these teeth, 8 (61%) had root fractures, 1 (8%) had a crown fracture and 4 (31%) had a root-crown fracture. Conclusion Coltosol® F, when used alone as a restorative material, led to tooth fractures in Class II cavities in teeth undergoing root canal treatment. Tooth fractures may occur 4 days after placement of the filling. [ABSTRACT FROM AUTHOR]

Aim To investigate whether the preclinical application of an electronic root canal length measurement device ( ERCLMD) leads to more accurate working length ( WL) determinations in a preclinical endodontic course and if this exercise effects the technical quality of root canal procedures when treatments are performed on patients for the first time. Methodology Root canal treatments performed by two consecutive groups of third year students (group 1: n = 39, group 2: n = 44) were compared in the preclinical course and when root canal treatments were performed on patients in the following term. Two different teaching models were applied in the preclinical endodontic course. WL in group 1 was determined with radiographs only. The teaching model applied in group 2 allowed the application of an ERCLMD. When treatments were performed on patients, both groups used the same technique to determine WL. It was first determined using an ERCLMD and verified radiographically. Master cone and root filling lengths were evaluated using radiographs, and comparisons between both groups were made using Fischer's exact test. Results Root fillings performed by students of group 2 were more often classified as acceptable. This observation was made in the preclinical endodontic course and when treatments were performed on patients. Conclusions The application of an ERCLMD in combination with radiographs is more accurate to determine WL than radiographs alone. Students practiced the use of ERCLMDs with the new model and benefited from this experience when performing their first root canal treatments on patients. [ABSTRACT FROM AUTHOR]

Tchorz JP, Hellwig E, Altenburger MJ. An improved model for teaching use of electronic apex locators. International Endodontic Journal, 45, 307-310, 2012. Abstract Aim To develop a simple, practical and inexpensive model, which enables the use of electronic apex locators (EALs) during pre-clinical and continuing education. Methodology Extracted teeth were placed in a mould and embedded in acrylic resin. The resin was applied in two consecutive steps to form a cavity around the root apices. A closable plastic tube serves as a valve, and a steel wire connects to the EAL. Results With its semi-closed reservoir for conductive fluids surrounding the root apices, the new model enables working length measurements of root canals using EALs. Conclusions The model simulates the clinical situation for endodontic teaching purposes, as it allows working length determination of root canals as recommended. The measuring results of the EAL can be verified by radiography. At the same time, the roots are not directly visible and accessible to the user, allowing a precise evaluation and grading of the treatment. [ABSTRACT FROM AUTHOR]

Scaffolds used in the field of tissue engineering should facilitate the adherence, spreading, and ingrowth of cells as well as prevent microbial adherence. For the first time, this study simultaneously deals with microbial and tissue cell adhesion to rapid prototyping-produced 3D-scaffolds. The cell growth of human osteosarcoma cells (CAL-72) over a time period of 3-11 days were examined on three scaffolds (PLGA, PLLA, PLLA-TCP) and compared to the adhesion of salivary microorganisms and representative germs of the oral flora ( Porphyromonas gingivalis, Prevotella nigrescens, Candida albicans, Enterococcus faecalis, Streptococcus mutans, and Streptococcus sanguinis). Scanning electron microscopy (SEM), cell proliferation measurements, and determination of the colony forming units (CFU) were performed. The cell proliferation rates on PLLA and PLLA-TCP after 3, 7, and 11 days of cultivation were higher than on PLGA. On day 3 the proliferation rates on PLLA and PLLA-TCP, and on day 5 on PLLA-TCP, proved to be significantly higher compared to that of the control (culture plate). The strain which showed the most CFUs on all of the investigated scaffolds was P. gingivalis, followed by E. faecalis. No significant CFU differences were determined examining P. gingivalis among the biomaterials. In contrast, E. faecalis was significantly more adherent to PLGA and PLLA compared to PLLA-TCP. The lowest CFU values were seen with C. albicans and P. nigrescens. Salivary born aerobic and anaerobic microorganisms adhered significantly more to PLGA compared to PLLA-TCP. These results supported by SEM point out the high potential of PLLA-TCP in the field of tissue engineering. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011. [ABSTRACT FROM AUTHOR]

Biofilm formation was evaluated on the following titanium and zirconia implants in vivo: machined titanium (Ti‐m), modified titanium (TiUnite®), modified zirconia (ZiUnite®), machined alumina‐toughened zirconia (ATZ‐m), sandblasted alumina‐toughened zirconia (ATZ‐s), and machined zirconia (TZP‐A‐m). Bovine enamel slabs were used as controls. Surface morphologies were examined by atomic force (AFM) and scanning electron microscopy (SEM). The surface wettability was also determined. Twelve healthy volunteers wore a splint system with the tested materials. After 3 and 5 days the materials were examined by fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM). The levels of Streptococcus spp., Veillonella spp., Fusobacteriaum nucleatum, and Actinomyces naeslundii were quantitatively determined. The biofim thickness was found to be between 19.78 and 36.73 μm after 3 days and between 26.11 and 32.43 μm after 5 days. With the exception of Ti‐m the biofilm thickness after 3 days was correlated with surface roughness. In addition to Streptococcus spp. as the main component of the biofilm (11.23–25.30%), F. nucleatum, A. naeslundii, and Veillonella spp. were also detected. No significant differences in biofilm composition on the implant surfaces could be observed. In total, the influence of roughness and material on biofilm formation was compensated by biofilm maturation. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010. [ABSTRACT FROM AUTHOR]

Aim To compare ex vivo an experimental setup consisting of an electronic apex locator (EAL) and endodontic motor with an established product (Tri Auto ZX) for accuracy of length control during root canal treatment with three different types of files. Methodology An experimental setup consisting of porous spongy material and an electrolyte was used. Sixty anterior teeth were randomly assigned to six groups. Access cavities were prepared. During root canal treatment, constant length monitoring was performed either with the Tri Auto ZX or the Raypex®5 apex locator attached to an endodontic motor (Endo IT professional) using ProTaper, Mtwo or FlexMaster files. After root canal preparation the distances between file tip and major apical foramen and file tip and minor apical foramen were measured using a microscope and analysed using two-wayanova to evaluate the accuracy of the two systems. Results Distances between the file tip and the major apical foramen were not significantly different between the file systems and the two EALs. In cases treated with FlexMaster significantly larger distances between file tip and minor apical foramen were found compared to Mtwo and ProTaper. No significant differences were observed between the two EALs. After preparation of the root canals with the Tri Auto ZX, multiple minor apical foramina were mechanically widened. Conclusion With the limitation of this laboratory study the combination of EAL and endodontic motor was as accurate as the Tri Auto ZX system in terms of length control during root canal preparation. [ABSTRACT FROM AUTHOR]

Germany has a three-tiered system of education at secondary school level, divided into the school types 'Hauptschule', Realschule' and 'Gymnasium'. All students receive, when aged 6-12 years, a uniform annual dental examination and oral health education programme. Objectives: The aim of this cross-sectional study was to report on the dental caries levels of school-age children stratified into these three different school types at secondary school level to enable oral healthcare personnel to administer a focused, school-based dental screening and education programme according to patients' needs rather than a uniform dental examination. Methods: A representative, random sample of 12-year-old school children in Freiburg (Germany) was examined and dental caries was recorded using WHO criteria. Results: A total of 322 12-year-old children participated. The mean DMFT was 0.69. An examination of the distribution of the DMFT score revealed that its distribution is positively skewed. For this reason, this study provides summary analyses based on medians and a non-parametric rank sum test. The non-parametric Kruskal-Wallis H-test showed a highly significant difference between median scores across the different school types ( P-value = 0.004). The significance was a result of the 'Gymnasium' distribution of DMFT scores which differed markedly from the other two school types. Conclusions: The finding of the present study suggests that it may be useful to stratify the school dental screening and education programme according to school type and to prioritize children who attend 'Realschule' and 'Hauptschule'. This shift should systematically target children with the greatest need for dental care. [ABSTRACT FROM AUTHOR]

Aim To evaluate the tensile bond strength between two different composite resin cores and (ClearfilTMCore, MultiCore® Flow) and fibre posts (DT Light Post®), with and without silanization of the post surface. Methodology Forty fibre posts were shortened to a length of 15 mm. Specimens were then produced by covering the upper 3 mm of the posts with standardized composite core build-ups. The bonding surfaces of twenty posts were treated with silane coupling agent (Monobond-S). Four experimental groups were formed: G1: ClearfilTMCore; G2: Monobond-S + ClearfilTMCore; G3: MultiCore® Flow; G4: Monobond-S + MultiCore® Flow. Each post was positioned upright in a post centric device with moulds to ensure standardized shapes of the abutments. After tensile bond strength testing, the type of failure at the interface was determined. The results obtained were compared using an unpaired sample t-test. Results The mean tensile bond strengths and standard deviations were [MPa] 10.08 ± 0.92 for ClearfilTMCore, 10.47 ± 1.05 for ClearfilTMCore + silane; 6.65 ± 0.79 for MultiCore® Flow and 6.91 ± 0.83 for MultiCore® Flow + silane. Statistical analysis revealed that ClearfilTMCore achieved significantly higher bond strengths than MultiCore® Flow ( P < 0.0001). Post silanization had no significant effect. All tested specimens had an adhesive failure mode. Conclusion Type of composite had a significant effect on tensile bond strength. Silanization of fibre post surfaces had no effect on core retention. [ABSTRACT FROM AUTHOR]

The aim of this study was to test whether the status of the adjacent tooth surface has an influence on the signal of a new laser fluorescence (LF) device for the detection of approximal caries. Seventy-eight teeth were selected from a pool of extracted permanent human molars, frozen at −20°C until use. Before being measured the teeth were defrosted, cleaned, and any calculus removed. As a control, a defined approximal surface of each tooth was measured with the LF device holding the tip with the detecting- and the reverse-side on it, but without a neighboring tooth contacting the surface. The proximal site under examination was then placed adjacent to a tooth, which had deep dentinal caries, a composite restoration, a provisional ZnO-Eugenol restoration, or a ceramic restoration. The adjacent tooth with the ZnO-Eugenol restoration, the composite restoration, and the dentinal caries all demonstrated a statistically significant increase of LF readings on sound tooth surfaces. Teeth with enamel or dentinal caries were only slightly (and not statistically significantly) influenced by the different types of neighboring surfaces compared with the control LF readings. It can be concluded that caries detection of approximal tooth surfaces with the new LF system might be influenced by the condition of the adjacent tooth surface. [ABSTRACT FROM AUTHOR]

Aim To compare the detectability of residual Epiphany and gutta-percha after root canal retreatment using a dental operating microscope and radiographic examination with the residual area measured after rendering the roots transparent. Methodology Sixty extracted single-rooted maxillary central incisor teeth were enlarged to apical size 40. Thirty canals were filled using vertically compacted Epiphany, the remainder were filled with vertically compacted gutta-percha and AH Plus sealer. After re-instrumentation to apical size 50, radiographs of the roots were taken in buccolingual and mesiodistal direction. Residual filling material was categorized by three observers using the radiographs and a dental operating microscope. The area of remaining material that was made visible by radiographs was measured with the aid of a computer image analysis programme. After clearing the roots, areas of residual filling material on the root canal wall were measured using a microscope. Results Computer image analysis of the radiographs showed significantly smaller areas of remaining gutta-percha and Epiphany compared with the analysis of the transparent teeth that revealed only one absolutely clean root (Epiphany). Especially in the gutta-percha group, the scores determined by the observers using radiographic examination gave an over-optimistic impression of cleanliness compared with the scores determined by the visualization through the microscope. Conclusion Especially for remaining gutta-percha, the operating microscopes provided better detection of residual root filling material in retreated maxillary incisor teeth. [ABSTRACT FROM AUTHOR]

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

The aim of the present in vitro study was to determine the penetration depth of dentine bonding agents into carious dentine as a possible strategy in caries treatment of deep lesions. Forty-eight extracted carious teeth were used for the experiments and divided in four groups. In a split-tooth design, one half of each tooth was treated without caries excavation, and the second half after caries excavation. In group 1 the teeth were treated with Prime & Bond 2.0 without phosphoric acid etching, and in group 2 with phosphoric acid etching. In group 3, the teeth were treated with All-Bond 2 without phosphoric acid etching, and in group 4 with phosphoric acid etching. Bonding agents were marked with an orange dye prior to application. The composition of the bonding agents had no significant influence on penetration depths. The mean thickness of the outer, necrotic caries zone in unexcavated specimens was 117 µm (±126). Bonding agents penetrated significantly deeper into unexcavated carious dentine (mean 124 ± 76 µm) compared with excavated dentine (11 ± 14 µm) and sound dentine (3 ± 4 µm). Acid etching significantly reduced the thickness of the outer caries zone, and the penetration depth of the bonding agents into unexcavated carious specimens by approximately 50%, and increased it into sound dentine. The results indicate that dentine bonding agents could completely penetrate the unexcavated outer carious dentine in 90% of specimens. Further studies are required to determine whether further caries activity is arrested after treatment with dentine bonding procedures. [ABSTRACT FROM AUTHOR]

The treatment of teeth using veneer restorations combines aesthetic and functional improvements with a low destructive technique. Different kinds of tooth preparation techniques are described in the literature for this kind of restoration. This in vitro study aimed to examine the influence of the incisal preparation on the loadability of teeth restored with porcelain laminate veneers. Thirty-six selected mandibular incisors were randomly assigned to three groups with 12 teeth per group. In the first group, only the facial surface was prepared. In the second group, the preparation included a rounded incisal edge and a distinct chamfer lingually. The third group served as an unprepared control. Empress® veneers were then fabricated and cemented with a low viscous luting composite material. After 120 days storage in Ringer's solution, the specimens were loaded incisally to the point of failure. Statistical analysis of the results showed significant differences between the series (P=0·0103). Group 2 (with preparation of the incisal edge) exhibited the lowest fracture resistance (466±99 N) (N, mean forces). When prepared only facially, the teeth restored with Empress® veneers reached the strength of unprepared teeth. Compared with the biting force described for incisors in the literature, the in vitro loadability reached in this investigation seems to jusitify the clinical use of both preparation designs tested. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate whether the skills of final-year dental students in the diagnostic interpretation of bitewing radiographs could be improved by additional didactic instruction. 6 consecutive classes of students in the same stage of education (last semester in the Department of Operative Dentistry) took part in the investigation from 1995 to 1998. At the beginning of each semester, the same in vivo made bitewing radiograph was demonstrated in a separate radiology revison lecture and interpreted with the students. The intensification of the training in the diagnosis of bitewing radiographs was made when the 4th class of students started. At the end of each semester, each student of the 6 consecutive classes was asked to evaluate the same bitewing radiograph, which had been demonstrated at the start of the semester. The students were not told that they had already diagnosed from this radiograph before. The results of the radiographic diagnosis were then analyzed using an evaluation system paying special attention to the treatment decision. True positive and true negative diagnoses were scored as correct and false positives and false negatives as incorrect. There was no significant difference (ANOVA) in the ability to diagnose from bitewing radiographs between the groups of students who received, and those who did not receive, additional training. The benefits of this type of additional instruction in the last semester in the Department of Operative Dentistry seem only to be important in some individual cases. [ABSTRACT FROM AUTHOR]

This in vitro study evaluated the effect of different luting procedures on the proper seating of ceramic inlays and on the marginal seal through microleakage testing. Sixty mesial-, occlusal-, distal- (MOD) cavities were prepared in third molars, and distributed among four groups. In the control group 1, the cavity surface was treated with dentin and enamel bonding agents; ceramic inlays were placed into the cavity and light cured. In group 2, the dentin and enamel bonding agents were cured prior to the placing of the inlays, and following the insertion. In group 3, the inlays were luted without enamel bonding. In group 4, the inlays were cemented using a one-bottle bonding and two times light curing. The groups with only one time light curing at the end of the luting process exhibited the smallest luting space following cementation. The smallest dye penetration values were obtained for the two groups with separate light curing of the dentin bonding agent. Reducing the film thickness of polymerized dentin bonding agents, i.e. by changing the composition of the bonding agents, could facilitate proper seating of ceramic inlays together with a better marginal seal. [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]

The aim of the study was to evaluate the effects of erosion and abrasion on resin-matrix ceramic CAD/CAM materials [CERASMART (GC); VITA ENAMIC (VITA Zahnfabrik); Lava Ultimate (3 M)] in comparison to feldspar ceramic (VITABLOCS Mark II, VITA Zahnfabrik) and resin composite materials (ceram.x universal, Dentsply Sirona). Daily brushing and acid exposure were simulated using a brushing apparatus and a solution of 0.5 vol% citric acid. Microhardness, surface roughness, and substance loss were measured at baseline and after simulation of 1 and 3 years of function. All materials showed a decrease in microhardness after 3 years and an increase in surface roughness (Ra) after 1 and 3 years. The Ra increase was statistically significantly lower for the resin-matrix ceramics than for feldspar ceramic and similar to composite material. After 3 years, only feldspar ceramic showed no significant substance loss. In conclusion, resin-matrix ceramics demonstrate reduced roughening compared to feldspar ceramics, potentially improving restoration longevity by preventing plaque buildup, but differences in abrasion resistance suggest the need for further material-specific research. Future research should aim to replicate clinical conditions closely and to transition to in vivo trials., (© 2023 The Authors. European Journal of Oral Sciences published by John Wiley & Sons Ltd on behalf of Scandinavian Division of the International Association for Dental Research.)

This study aimed to investigate the effects of an oral health optimized diet on the composition of the supragingival oral plaque in a randomized controlled trial. Participants of the standard diet group (n = 5) had a diet high in processed carbohydrates and did not change their dietary behavior during the observation. The healthy diet group (n = 9) had to change the diet after 2 weeks from a diet high in processed carbohydrates to a diet low in carbohydrates, rich in omega-3 fatty acids, rich in vitamins C and D, antioxidants and fiber for 4 weeks. Saliva and supragingival plaque samples were taken at the end of week two and eight of the observation period to investigate the composition of microbiota in saliva and supragingival plaque. Data were subjected to an exploratory analysis to identify significant differences. Statistically significant differences were only found in the healthy diet group between the baseline (week 2) and the final sample (week 8) for specific species in plaque and saliva samples. A reduction of the total counts of Streptococcus mitis group, Granulicatella adiacens, Actinomyces spp., and Fusobacterium spp. was found in plaque samples of the healthy diet group. In saliva samples of the healthy diet group, the total counts of Actinomyces spp. and Capnocytophaga spp. decreased. A diet low in carbohydrates, rich in omega-3 fatty acids, rich in vitamins C and D, and rich in fiber reduced Streptococcus mitis group, Granulicatella adiacens, Actinomyces spp., and Fusobacterium spp. in the supragingival plaque., (© 2020 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Background: Oral malodor is a very discomforting condition deriving from the presence of volatile sulfur compounds in the expired air. In halitosis of intraoral etiology, the volatile sulfur compounds are metabolic products of the oral microorganisms within the biofilm coating the tongue dorsum as well as other tissues in the oral cavity. The aim of this study was to characterize and compare the microbial composition of tongue biofilm in volunteers suffering from halitosis and healthy volunteers by means of both the culture method and culture-independent cloning technique., Results: A high bacterial variety (more than 80 different species) was detected using the combination of both methods. A distinct bacterial composition was revealed in the halitosis-associated biofilms compared with the health-associated biofilms. Actinomyces graevenitzii was shown to be significantly associated with the halitosis condition. The culture method identified 47 species, included Veillonella rogosae, never isolated from the tongue biofilm of halitosis patients so far. In the healthy condition, the culture-dependent method showed that the most frequent species were Streptococcus parasanguinis among the aerobes and Veillonella spp. among the anaerobes. The culture-independent cloning method detected more than 50 species. Streptococci, in particular S. mitis/oralis, S. pseudopneumoniae, and S. infantis as well as Prevotella spp., were found most frequently in halitosis patients. Streptococcus salivarius and Rothia mucilaginosa were found more frequently in the healthy condition., Conclusions: The combination of the culture-dependent and culture-independent cloning techniques allowed for a widespread analysis of the tongue biofilm in halitosis patients. The results can support further pharmacological research for new antimicrobial agents and halitosis therapy strategies., (© 2019 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Aim: Aim of this study was to investigate the influence of an anti-inflammatory diet on different parameters in patients with gingivitis., Materials and Methods: Thirty patients were randomly allocated to an experimental and a control group stratified by their plaque values. The experimental group had to change to a diet low in processed carbohydrates and animal proteins, and rich in omega-3 fatty acids, vitamin C, vitamin D, antioxidants, plant nitrates and fibres for 4 weeks. The control group did not change their diet. Both groups suspended interdental cleaning. Periodontal parameters were assessed by a blinded dentist. Serological and subgingival plaque samples were taken at baseline and end., Results: While there were no differences regarding the plaque values, the experimental group showed a significant reduction in gingival bleeding (GI Baseline: 1.04 ± 0.21, GI End: 0.61 ± 0.29, p < 0.05), a significant increase in Vitamin D values and a significant weight loss. There were no inter-group differences regarding the inflammatory serological parameters, the serological omega fatty acids, nor the subgingival microbiome composition., Conclusion: The evaluated diet could significantly reduce gingivitis in a clinically relevant range, while serological inflammatory parameters and the subgingival microbiome seem to be unaffected in this study duration. (German Clinical Trials Register; DRKS00009888)., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: To evaluate and compare the mean surface roughness (Ra) of one ceramic and one resin composite material used for indirect restorations, after grinding and repolishing by intraoral means., Materials and Methods: The materials used were the lithium disilicate glass ceramic IPS e.max Press (EMP) and the indirect resin composite restoration system Gradia (GR). Twelve specimen disks were prepared from each material according to the manufacturer of each material. Five initial measurements of the Ra (Ra 1 ) were made on each specimen as a referral basis, and the specimens were ground with a fine (red) diamond bur. The specimens were repolished using (a) Komet Dialite Polishing Kit for EMP and (b) Enhance Finishing and Polishing System and Prisma Gloss Polishing Paste for GR. Five final Ra (Ra 2 ) measurements were performed on each specimen. All measurements were made using a laser profilometer. Scanning electron microscopy (SEM) was also used to visualize the initial surface morphology and the morphological changes on the specimens' surface after repolishing., Results: A highly significant difference was found between Ra 1EMP and Ra 2EMP (p < 0.001), between Ra 1GR and Ra 2GR (p < 0.001), as well as between Ra 2EMP and Ra 2GR (p < 0.001), when compared in pairs. A highly significant difference (p < 0.001) was also found between ΔRa EMP and ΔRa GR , with ΔRa GR being higher than ΔRa EMP . The Ra GR values were higher than the Ra EMP values at all times. SEM revealed that both EMP and GR repolished surfaces presented with irregularities; however, in GR specimens major voids and craters were present., Conclusions: EMP was found to perform better when polished by intraoral means compared with GR. Both materials exhibited Ra 2 above the critical threshold for increased plaque accumulation and periodontal inflammation. If enamel-to-enamel roughness found in occlusal contact areas is considered as baseline, both materials were clinically acceptable after repolishing., (© 2015 by the American College of Prosthodontists.)

Aim: The aim of this study was to assess whether oral hygiene-related self-efficacy is correlated with current oral hygiene and might influence the outcome of oral hygiene instruction., Materials and Methods: Hundred and twenty-six patients filled out questionnaires about oral hygiene-related self-efficacy, general self-efficacy, oral hygiene-related knowledge and demographic variables. Plaque and gingival inflammation were measured and an individual oral hygiene plan was conducted. After 6 months, oral hygiene indices were assessed again., Results: Women had significantly higher scores in oral hygiene-related self-efficacy than men (women mean 60.40 ± 9.41; men mean 56.04 ± 11.55; p = 0.039) and oral hygiene-related self-efficacy was significantly correlated with general self-efficacy independent from the age of the patients (r = 0.3114, p = 0.0004). Higher scores in oral hygiene-related self-efficacy were significantly correlated with lower scores of gingival bleeding for non-smoking patients (r = -0.301, p = 0.0066), usage of a professional tooth cleaning within these 6 months (p = 0.0406), reappearance to the follow-up appointment (p = 0.0303), and higher goals in inter-dental cleaning plans (p = 0.0189)., Conclusion: Oral hygiene-related self-efficacy is an influencing factor in the oral hygiene behaviour and has the potential to predict patients' oral hygiene outcomes., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Artificial teeth are a useful teaching aid during endodontic education. This article describes the development of a simple and inexpensive model that can be equipped with artificial teeth. It shows that working length determination in artificial root canals using electronic apex locators is possible and that the embedding media has no influence on measurements. The model supports the application of current endodontic techniques and facilitates a validated evaluation of the treatments between students. Artificial teeth can be removed for visualization and replaced for further endodontic exercises.

The elution of monomers from composite materials influences the biocompatibility of dental restorations. The purpose of the present study was to investigate the elution of monomers [bisphenol A glycidyl methacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), and bisphenol A (BPA)] from two light-cured materials (nanohybrid and ormocer) and from a chemically cured composite material, after different curing times (0, 20, 40 and 80 s) and different storage periods (24 h, 7 d, 28 d, and 1 yr after curing). Each specimen was stored in 1 ml of 75% ethanol. This medium was renewed after 24 h, 7 d, 28 d, and 1 yr. The ethanol samples were analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). The amount of monomers released from the nanohybrid and the chemically cured composite was significantly higher than released from the ormocer. The curing time exerted a significant effect on the release of monomers. For the nanohybrid, less monomer was released after increasing the curing time. For the ormocer, 80 s of curing resulted in a higher degree of monomer release. The effect of storage differed between the monomers. Although the elution of TEGDMA was significantly decreased after storage for 28 d and 1 yr, a similar amount of BisGMA was released at each storage time-point analyzed, even after 1 yr. The present study showed that ormocer released a very small amount of monomers compared with the other materials.

Limited information is available on the time-dependent or dosage-dependent cariostatic efficacy of highly concentrated fluoride compounds. This good clinical practice-conforming, double-blind, placebo-controlled, crossover in situ study tested the hypothesis that a 1.0% amine fluoride fluid is superior to a 0.5% amine fluoride fluid regarding fluoride retention and mineral change in initial caries enamel lesions over a period of 28 d. Fluoride retention was significantly higher after application of the two fluoride fluids compared with placebo but had decreased in both groups to similar levels after only 1 wk. Mineral gain was significantly higher for both verum groups compared with placebo. The use of 1% fluoride fluid resulted in significantly higher remineralization compared with the use of 0.5% fluoride fluid. For both fluoride fluids mineral gain followed a linear relationship with time during the experimental period, indicating a possible further uptake of mineral, even after 4 wk.

Objectives: The aim of this observer-blind, controlled, three-cell cross-over study was to evaluate the influence of an amine fluoride/stannous fluoride (Meridol, 250 ppm; ASF) and a chlorhexidine mouthrinse (CHX; Chlorhexamed forte, 0.2%) compared with water on in situ biofilm growth., Material and Methods: After a professional toothcleaning seven volunteers had to wear a special acrylic appliance, in which six specimens each were inserted to allow the build-up of intra-oral biofilms. The volunteers had to rinse twice daily for 1 min. with 10 ml of the allocated mouthrinse. After 48 h of wearing, the specimens with the adhering biofilms were removed from the splints and stained with two fluorescent dyes, which selectively stain vital bacteria green and dead bacteria red. Under the confocal laser scanning microscope biofilm thickness (BT) was evaluated. To examine bacterial vitality (BV%) the biofilms were scanned (1 microm sections) and digital images were made. An image analysis program was used to calculate the mean BV as well as the BV of the single sections. After a wash-out period of 14 days a new test cycle was started., Results: The use of CHX and ASF resulted in a BT of 8.4+/-4.4 mum and 15.7+/-9.9 compared with 76.7+/-29.4 mum using water. The mean vitality (in %) was reduced from 66.1+/-20.4 to 23.3+/-11.6 and 23.9+/-12.4 using CHX and ASF, respectively. Both active solutions reduced BT and BV significantly compared with water (p<0.001). Differences between the two active solutions were not significant (p>0.05)., Conclusion: Both mouthrinses showed antibacterial and plaque-reducing properties against the in situ biofilm. The study design enables the examination of an undisturbed oral biofilm and for the first time shows the influence of antibacterial components applied under clinical conditions regarding biofilm formation., ((c) Blackwell Munksgaard, 2005.)

The objective of this study was to evaluate the effects of irradiation on microhardness of dentin. Dentin blocks from the cervical region of bovine incisors were treated as follows: (1) no irradiation; (2) irradiation of specimens up to 60 Gy (2 Gy/day, 5 days/week); (3) no irradiation, but fluoridation of specimens for 5 min/d; (4) irradiation of specimens and daily fluoridation. Knoop hardness number (KHN) of the control specimens was 62.63+/-14.75 (mean+/-SD). This was significantly different from the irradiated dentin samples (8.74+/-2.59 KHN). Hardness of the fluoridated dentin specimens was 11.19+/-1.95 KHN in the non-irradiated group and 10.03+/-2.76 KHN in the irradiated groups, respectively. Within the limitations of an in vitro study, it is concluded that dentin is severely affected by irradiation. This could be an explanation for the frequently observed side-effects of irradiation like loss of enamel, gap formation at the amelodentinal junction, and caries of the cervical region. Fluoridation with acidic gels decreases microhardness of dentin surface, and does not prevent softening due to radiation, when saliva is absent.

Plaque surface area after rinsing with a tea, containing low levels of fluoride, was evaluated in 30 human volunteers with a single-blind, one-operator, three-period, three-treatment cross-over study. The mouthwashes employed were: (1) tea (Darjeeling first flush:< 0.2 ppm F-), (2) Meridol(R), (3) control (tap water:< 0.2 ppm F-). During the experiment the participants refrained from oral hygiene procedures and rinsed their mouth three times a day after each meal with 20 ml of the respective rinse. After 3 d standardized photographs were taken of the upper canines and premolars and the plaque areas were measured planimetrically. Statistical analysis showed a marked decrease in plaque surface area after rinsing with Meridol, whereas no difference in plaque surface area was observed after mouthrinsing with tea and tap water, respectively.