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Objectives A variety of dental materials are available for the fabrication of telescopic crowns. The aim was to investigate the impact of material combinations and removal and insertion cycles on their retention forces. Materials and methods CAD/CAM-fabricated cobalt–chromium–molybdenum (CoCr) and zirconia (ZrO2) primary crowns were combined with polyetheretherketone (PEEK), polyetherketoneketone (PEKK), CoCr, and ZrO2 secondary crowns (four combinations included PEEK/PEKK secondary crowns in a thickness of 0.5 mm bonded to the CoCr tertiary construction), resulting in 12 different material combinations: CoCr–PEEK; CoCr–PEKK; CoCr–ZrO2; CoCr–CoCr; CoCr–PEEK 0.5; CoCr–PEKK 0.5; ZrO2–PEEK; ZrO2–PEKK; ZrO2–ZrO2, ZrO2–CoCr; ZrO2–PEEK 0.5; and ZrO2–PEKK 0.5 (n = 15 pairings per material combination). Pull-off tests were performed with a universal testing machine initially and after 500, 5000, and 10,000 removal and insertion cycles in a mastication simulator. Descriptive statistics with the Kolmogorov–Smirnov, Kruskal–Wallis, and Mann–Whitney U tests were computed (α = 0.05). Results The tested parameters, material combination, and removal and insertion cycles had significant impact on the retention force values (p < 0.001). An increase in removal and insertion cycles was associated with a decrease in retention forces within CoCr and ZrO2 secondary crowns, regardless of the primary crown material. In contrast, PEEK and PEKK secondary crowns presented higher retention load values after 10,000 cycles than initially. Conclusion Different material combinations behaved differently after simulated removal and insertion regimens. This difference should be considered during treatment planning. Clinical relevance Telescopic crown systems should be made of materials with predictable retention forces that do not deteriorate with time. The implementation of new materials and technologies facilitates reproducibility and time-saving fabrication.

The aim of this study was to evaluate the anti-biofilm effect of polyhexanide mouth rinses against oral pathogens in vitro.Biofilms of Candida albicans, Streptococcus mutans, Actinomyces naeslundii...

Objectives To evaluate the biological and physicochemical features of bioactive root canal sealers. Materials and methods Human periodontal ligament fibroblasts (hPDLF) and human osteoblasts (hOB) were exposed to eluates of three bioactive root canal sealers, GuttaFlow® bioseal (GF), BioRoot™ RCS (BR), and TotalFill® BC Sealer (TF), and the epoxy resin–based sealer AH plus® (AH). Cytotoxicity and cellular inflammatory response were evaluated. The osteogenic potential was examined using human mesenchymal stem cells (hMSC). Film thickness, flowability, and pH were assessed. Root canal treatment was performed on human extracted teeth to evaluate the sealers’ tightness towards bacterial penetration. The antibacterial activity against common pathogens in primary root canal infections was tested. Results AH was severely cytotoxic to hPDLF and hOB (p p p 2 production in hPDLF and hOB (p p p Conclusions This study revealed favorable in vitro results regarding the biocompatibility of the bioactive root canal sealers. Clinical relevance Bioactive root canal sealers may be a useful alternative to epoxy resin–based sealers.

The aim of this cross-over investigation was to analyze the effect of virtual teaching using virtual reality (VR) within a dental learning environment by preclinical students with or without dental professional experience on test performance.Preclinical students (N = 82) were randomly divided into two groups for cross-over testing of tooth morphology knowledge: (a) anterior VR-group (group 1) using the VR-glasses as an additional learning tool for the anterior tooth morphologies and (b) posterior VR-group (group 2) using it for the posterior tooth morphologies also in addition to conventional learning. All students used the VR-glasses for 1 week independent of time and location depending on group. The students had to recognize teeth (anterior or posterior within two separate tests after three [anterior test] and 6 weeks [posterior test] of practical course) and note the tooth number and characteristics in written form. Former dental experience (dental technician/assistance) was noted. Test results were analyzed to quantify the effect of virtual teaching on test scores. Data were analyzed with the Kolmogorov-Smirnov and Mann-Whitney U test (p = 0.05).By differentiating the two student groups (use of VR glasses for anterior/posterior teeth) within the dental experience group, significantly better test results (p = 0.040) were shown for group 1 in the total posterior teeth test score. Furthermore, no other significant differences, but a possible tendency, in the test results and thus no effect of the use of the VR glasses on both VR groups could be analyzed (p ≥ 0.051).Using the VR tooth learning environment predominantly did not lead to a significant improvement of test results. Anterior teeth test scores predominantly showed significantly better results than posterior teeth test scores.

The coronavirus disease 19 (COVID-19) has challenged dental health professions. This study analyzes its impact on urgent dental care in the Department of Conservative Dentistry and Periodontology, University Hospital Munich and Bavaria, Germany. Patient numbers without and with positive/suspected COVID-19 infection, their reasons for attendance, and treatments were retrospectively recorded (February–July 2020) and linked to local COVID-19 infection numbers, control measures, and numbers/reasons for closures of private dental practices in Bavaria, Germany. Patient numbers decreased within the urgent care unit and the private dental practices followed by a complete recovery by the end of July. While non-emergency visits dropped to almost zero during the first lockdown, pain-related treatments were administered invariably also in patients with positive/suspected COVID-19 infections. Reasons for practice closures were lack of personal protective equipment (PPE), lack of employees, staff’s increased health risks, and infected staff, which accounted for 0.72% (3.6% closures in total). Pain-driven urgent dental care remains a constant necessity even in times of high infection risk, and measures established at the beginning of the pandemic seem to have provided a safe environment for patients as well as oral health care providers. PPE storage is important to ensure patients’ treatment under high-risk conditions, and its storage and provision by regulatory units might guarantee a stable and safe oral health care system in the future.

Antimicrobial peptides are receiving increasing attention as potential therapeutic agents for treating biofilm-related infections of the oral cavity. Many bacteria residing in biofilms exhibit an enhanced antibiotic tolerance, which grants intrinsically susceptible microorganisms to survive lethal concentrations of antibiotics. In this study, we examined the effects of two endogenous human antimicrobial peptides, LL-37 and human Lactoferricin, on the antibiotic drug efficacy of amoxicillin, clindamycin and metronidazole in two types of polymicrobial biofilms, which aimed to represent frequent oral diseases: (1) facultative anaerobic (Streptococcus mutans, Streptococcus sanguinis, Actinomyces naeslundii) and (2) obligate anaerobic biofilms (Veillonella parvula, Parvimonas micra, Fusobacterium nucleatum). LL-37 and Lactoferricin enhanced the anti-biofilm effect of amoxicillin and clindamycin in facultative anaerobic biofilms. Metronidazole alone was ineffective against facultative anaerobic biofilms, but the presence of LL-37 and Lactoferricin led to a greater biofilm reduction. Obligate anaerobic biofilms showed an increased drug tolerance to amoxicillin and clindamycin, presumably due to metabolic downshifts of the bacteria residing within the biofilm. However, when combined with LL-37 or Lactoferricin, the reduction of obligate anaerobic biofilms was markedly enhanced for all antibiotics, even for amoxicillin and clindamycin. Furthermore, our results suggest that antimicrobial peptides enhance the dispersion of matured biofilms, which may be one of their mechanisms for targeting biofilms. In summary, our study proves that antimicrobial peptides can serve as an auxiliary treatment strategy for combatting enhanced antibiotic tolerance in bacterial biofilms.

The transfer of 3D implant position planning to the clinical site is challenging. The aim of this study was to compare in vitro this transfer accuracy by using dynamic real-time navigation or static surgical guides.Deviations between planned and actual pilot drill positions were calculated (Denacam and NobelGuide; each n = 90), matching pre- and postoperative CBCT images: entry point, angle, tip (each 3D); depth, mesiodistal/bucco-oral entry points, and angles (each 1D). The influence of the maxilla and mandible, implant region (anterior/posterior), and marker position (ipsilateral/contralateral, Denacam only) was investigated (Mann-Whitney U test).No significant differences occurred regarding entry point (3D), mesiodistal/bucco-oral entry points (1D) or mesiodistal angle (1D) (P0.05). The angular and tip deviations (3D) were significantly smaller using Denacam (2.16 ± 0.59 degrees, 0.80 ± 0.55 mm; NobelGuide 2.54 ± 1.19 degrees, 1.09 ± 0.56 mm; P = 0.024, P0.0001). The deviations in depth and bucco-oral angle (1D) were significantly smaller using NobelGuide (1.05 ± 0.50 mm, 1.02 ± 1.16 degrees; Denacam 1.50 ± 0.64 mm, 1.51 ± 0.82 degrees; P0.0001). Significantly smaller deviations occurred within the mandible (Denacam, 5/8 parameters). Region and marker position showed no influence. No distinct influences were found with the use of NobelGuide.Denacam might possibly be a promising alternative to static surgical guides.

Antimicrobial peptides (AMPs) represent important facets of the immune system controlling infectious diseases. However, pathogens show varying susceptibilities to AMPs. This study investigates the susceptibilities of strains of Streptococcus mutans (SM), Actinomyces naeslundii (AN), and Lactobacillus spp. (LB) towards AMPs and if there are correlations between the appearance of such high-risk strains and clinical caries status. Plaque samples were collected from patients along with clinical examinations. Bacterial strains were identified via selective media, matrix-assisted laser desorption/ionization analysis-time of flight (MALDI-TOF), and arbitrary-primed-PCR (AP-PCR). Each strain was tested for susceptibility to LL-37, HBD-2, HNP-1, and HNP-3 or phosphate-buffered saline as negative control in a biofilm model on hydroxylapatite discs. Survival rates and resulting risk classification for each strain were determined. Correlations were calculated between the number of high-risk strains (all/S. mutans) appearing in patients and their clinical caries status. Forty-seven patients were included with mean DMFT values of 11.4 ± 8.7. A total of 8 different SM, 30 LB, and 47 AN strains were detected. One-way ANOVA indicated that type/concentration of AMPs had major influence on reductions of Lactobacilli and Actinomyces. Seventeen strains of AN, 2 of SM, and 6 of LB had low susceptibilities to AMPs. The number of such strains in patients showed significant positive correlations to the DMFT values (all p = 0.001; r = 0.452; S. mutans p

Modern teaching formats have not been considered necessary during the COVID-19 pandemic with uncertain acceptance by students. The study’s aim was to describe and evaluate all measures undertaken for theoretical and practical knowledge/skill transfer, which included objective structured practical examinations (OSPEs) covering a communication skills training. The students’ performance in the OSPE as well as the theoretical knowledge level were assessed, of which the latter was compared with previous terms. In conservative dentistry and periodontology (4th and 5th year courses), theoretical teaching formats were provided online and completed by a multiple-choice test. Practical education continued without patients in small groups using the phantom-head, 3D printed teeth, and objective structured practical examinations (OSPEs) including communication skills training. Formats were evaluated by a questionnaire. The organization was rated as very good/good (88.6%), besides poor Internet connection (22.8%) and Zoom® (14.2%) causing problems. Lectures with audio were best approved (1.48), followed by practical videos (1.54), live stream lectures (1.81), treatment checklists (1.81), and virtual problem-based learning (2.1). Lectures such as .pdf files without audio, articles, or scripts were rated worse (2.15–2.30). Phantom-heads were considered the best substitute for patient treatment (59.5%), while additional methodical efforts for more realistic settings led to increased appraisal. However, students performed significantly worse in the multiple-choice test compared to the previous terms (p &lt, 0.0001) and the OSPEs revealed deficits in the students’ communication skills. In the future, permanent available lectures with audio and efforts toward realistic treatment settings in the case of suspended patient treatment will be pursued.

Aesthetic alternatives to stainless-steel crowns for restoring primary molars attain growing interest. We studied the mechanical properties of prefabricated zirconia crowns and conventional crowns. Three brands of prefabricated zirconia crowns were compared with computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crowns, preveneered stainless-steel crowns, and conventional stainless-steel crowns regarding: (i) fracture load under each of three conditions [no pretreatment, artificial aging in saliva for 12 wk, and after chewing simulation/thermocycling (1.68 × 106 cycles/5-55°C)]; and (ii) survival rate during chewing simulation, considering decementation, fracture, chipping, fatigue cracks, and occlusal holes. Without pretreatment, the prefabricated zirconia crowns showed mean fracture load values between 893 N and 1,582 N, while the corresponding values for CAD/CAM zirconia crowns and preveneered stainless-steel crowns were 2,444 N and 6,251 N. Preveneered stainless-steel crowns showed significantly lower fracture loads after artificial aging (5,348 N after saliva aging; 3,778 N after chewing simulation) than without artificial aging, whereas the fracture load of zirconia crowns was not influenced negatively. The survival rate of the different groups of zirconia crowns and preveneered stainless-steel crowns during chewing simulation was 100%, but only 41.7% for the stainless-steel crowns. These in-vitro data suggest that prefabricated zirconia crowns are aesthetically and durable alternatives to stainless-steel crowns for primary molars.

In this single-blinded, prospective, randomized, controlled clinical trial, the effectiveness of an ozone gas or NaOCl/CHX disinfection protocol was compared within the root canal treatment of apical periodontitis. Sixty permanent teeth were randomly allocated to one technique. The clinical/radiographic assessment criteria included clinical symptoms, periapical index (PAI), and size of the apical lesion. In both groups, the root canal was mechanically cleaned and irrigated with NaCl and EDTA. Ozone gas (32 g m−3) or NaOCl (3 %) was applied followed by a 1-week inter-appointment dressing (Ca(OH)2). As final disinfection, ozone gas (ozone group) or CHX 2 % (NaOCl group) was applied. Microbial samples were taken after preparing the access cavity, after chemo-mechanical treatment and after inter-appointment dressing by sterile paper points. Microbial identification was performed by mass spectroscopy (MALDI-TOF-MS) and 16S-rRNA gene sequencing. The treated teeth were blindly re-evaluated after 6/12 months. Success rates, the decrease in PAI, the size of apical lesions and bacterial reduction were compared between groups (Fischer’s exact test, Mann-Whitney U test). There were no significant differences between the success rates (ozone group: 96.2/95.5 % after 6/12 months; NaOCl group: 95.5/95.2 % after 6/12 months). The differences in the decreases in PAI values and apical lesion sizes were also insignificant after 6 and 12 months. The bacterial reduction showed no significant differences between groups after chemo-mechanical treatment and after inter-appointment dressing. The most commonly found bacterial genera were Streptococcus spp., Parvimonas spp. and Prevotella spp. The here used ozone gas and NaOCl/CHX protocols showed no difference in bacterial reduction in the sampled areas of the root canals. Within the limitations of the study, ozone gas seems to be a possible alternative disinfection agent within the root canal treatment of apical periodontitis.

Introduction: Assessment of practical skills in undergraduate dental education has difficulties, including a lack of transparency/objectivity in student evaluations. This prospective study investigated whether agreement between student- and faculty-based assessments increased when students were trained to use the assessment criteria. Materials and methods: Assessment criteria were available for 6 tasks in the Phantom course of Conservative Dentistry: Class II cavity preparation, composite restoration, gold and ceramic partial crown preparation, trepanation and access cavity preparation, and root canal filling. Forty-two students were allocated to three different assessment training groups. Students' self-assessments of practical tests were compared with instructors' assessments, depending on training intensity and task type (Pearson's rho, ANOVA, Tukey's post hoc test, Kruskal-Wallis test). Students/instructors were questioned regarding benefits/drawbacks of the criteria. Results: Student self-assessments showed either consent (24.2%), overestimation (31%) or underestimation (44.8%). Gender differences were negligible. Regarding pass-ing/failing grades, more intensive training yielded significantly increased agreement only for preparation of gold partial crowns (rho = +0.313, P = 0.044). Ratings exhibited significant differences amongst tasks ( P = 0.002), for example, trepanation assessment had significantly lower differences than gold or ceramic preparation assessments. These discrepancies decreased with increased training. Students consistently reported benefitting most from learning the criteria for gold preparations, followed by composite and ceramic preparations. They also reported that learning the criteria was beneficial for knowledge transfer/feedback. Instructors rated the criteria as helpful for task evaluation and feedback efficiency. Conclusions: Pre-defined assessment criteria may increase consistency between student self-assessment and instructor assessment depending on the task, improving transparency and feedback in dental education.

To evaluate differences in physical characteristics and sealing ability of root-end-fillings made with these materials compared to the gold standard (ProRoot MTA).The physical characteristics of ProRoot MTA, Medcem MTA and Biodentine were evaluated regarding setting time, flow, film thickness, solubility and radiopacity according to the German Institute for Standardization (EN-ISO 6878). To investigate their sealing ability as root-end-fillings, a glucose penetration model was used. 60 human extracted single-rooted teeth were endodontically treated, root-end resections performed and divided in three groups of 20 teeth, using either ProRoot MTA, Medcem MTA or Biodentine as root-end-filling material. After 30 days, glucose concentrations were determined photometrically, followed by statistical analysis (Kruskal-Wallis test, Mann-Whitney U-test).Biodentine showed the fastest setting time (12 minutes) and lowest film thickness (0.11± 0.01 mm), whereas Medcem MTA showed the best values regarding solubility (0.1%) and flow (9.5± 0.02 mm). ProRoot MTA revealed the highest radiopacity (7.58± 0.1 mm aluminum equivalent). The glucose leakage in the Medcem MTA group was significantly lower than in the ProRoot MTA group (P= 0.011). Biodentine showed lower leakage than ProRoot MTA (P= 0.031).As Medcem MTA showed significantly lower leakage than the other materials tested, it may be an alternative for root-end-fillings with comparable physical characteristics to the current gold standard. With the exception of the high solubility, Biodentine performed well regarding leakage and setting time.

The aim of this in vitro study was to consecutively determine the effect of three bonding agents on the prevention of enamel demineralisation at the bracket-periphery and to compare the suitability of micro-computed tomography (μCT) scans and quantitative light-induced fluorescence (QLF) to detect changes within subsurface lesions.The effect of a resin-modified glass ionomer cement (RMGI) (Fuji Ortho LC), a compomer (Assure) and a composite (Transbond XT) on the prevention of enamel demineralisation at the bracket-periphery was examined. After 7, 14, 21 and 28 days of pH cycling, the teeth (N = 45) were examined by consecutive μCT scans and by using a customised QLF set-up.Particularly for the RMGI and for the compomer, the QLF and μCT scans showed that the formation and the body of the lesion were not precisely located at the enamel next to the bracket margin. There was an area that was almost protected. The progression of demineralisation was decreased for the RMGI and the compomer-treated teeth.For bonding orthodontic brackets, the RMGI and compomer were comparably able to decrease the progression of white spot lesions (WSL), although the RMGI showed marginally superior protection. Both methods (QLF and μCT scans) were suitable for investigating the longitudinal fluoride effects on WSL, though these effects were more accurately described by mineral (fluorescence) loss or volume changes than by lesion depth.The progression of WSL at the bracket-periphery could be altered by using fluoride-releasing bonding agents for bracket application. This approach represents a minimally invasive preventive measure.

This retrospective clinical study aimed to determine the success rate of autotransplanted impacted or retained teeth along with a patient satisfaction survey and to analyze the influence of relevant clinical and radiographic parameters.Fifty-seven teeth (37 canines, 10 molars, seven premolars, three incisors) in 45 patients (median 15 years) were evaluated over a mean of 1.6 years. The success criteria were pocket probing depth ≤3.5 mm, mobility grade ≤ II, Periotest ≤30 and complete alveolar bone healing. The influencing parameters were oral hygiene, smoking, periodontal screening index, occlusal/proximal contacts, horizontal position, dental age, pulp obliteration and degree of displacement. Furthermore, bone height was measured.The overall success rate was 74%, along with a high patient satisfaction. The survival rate was 96% after a mean follow-up of 1.6 years. The favorable factors were proper oral hygiene, non-smoking, good general periodontal condition, proximal contacts and pulp obliteration. An increase in or maintenance of bone level was found in 96%.Autotransplantation of impacted or retained teeth is an appropriate treatment, if orthodontic alignment has failed, especially in growing patients.

This study aimed to evaluate the performance of accelerating procedures for bonding of orthodontic brackets in vitro by comparing different adhesives (etch-and-rinse, self-etch) and polymerization procedures (curing devices, time). The performance was characterized by three parameters: (1) the bond strength achieved, (2) the incidence of enamel damage, and (3) the extent of residual composite on the tooth. Bracket bonding was performed on 500 extracted human teeth after application of either an etch-and-rinse adhesive or a one-step self-etch adhesive. Two different two-component self-etch adhesives (Clearfil SE and Transbond Plus) and two single-component self-etch adhesives (Ideal and iBond) were investigated after using different polymerization procedures (light-emitting diode for 10 or 20 s or plasma arc curing device for 3 or 6 s). The bond strength, incidence of enamel damage, and extent of residual composite on the tooth were measured. Single-component self-etch adhesives gave the lowest bond strengths. No significant difference in bond strength could be detected between the two-component self-etch adhesives and the etch-and-rinse method. There was a 70.3 % risk for enamel damage at bond strengths above 12 MPa, but only 5 % risk below 12 MPa and no risk below 8.2 MPa. The risk of enamel damage increased by an odds ratio increment of 1.3 for each additional MPa above 8.2 MPa. Single-component self-etch adhesives showed the lowest bond strengths, caused limited enamel damage, and generally left less residual composite on the tooth. The nature of the adhesive greatly influences the resultant bond strength, the risk of enamel damage, and the extent of residual composite on the teeth.

A pulpotomy is the therapy for management of pulp exposures due to caries in symptom-free primary molars. The aim was to longitudinally compare the relative effectiveness of the Er:YAG laser, calcium hydroxide and ferric sulphate techniques with dilute formocresol in retaining symptom-free molars. Two hundred primary molars in 107 healthy children were included and randomly allocated to one technique. The treated teeth were blindly reevaluated after 6, 12, 18, 24 and 36 months. Descriptive data analysis and logistic regression analysis accounting for multiple observations per patient by generalised estimating equation were used. Additionally, various influences including tooth type, upper and lower jaws, type of anaesthesia, operator and the final restoration on treatment success were evaluated (Wald chi-square test). After 36 months, the following total (considering clinical and clinically symptom-free radiographic failures) and clinical success rates were determined (in percent): Formocresol 72 (92), laser 73 (89), calcium hydroxide 46 (75), ferric sulphate 76 (97). No significant differences were detected between formocresol and any other technique after 36 months. However, the odds ratio of failure appeared to be three times higher for calcium hydroxide than for formocresol. No significant differences in total success rates were seen regarding the aforementioned influencing clinical parameters. The correct diagnosis of the pulpal status, bleeding control and the specific technique are highly important for long-term success of pulpotomies in primary molars. According to the presented long-term data, pulpotomies using ferric sulphate revealed the best treatment outcome among the used techniques, while calcium hydroxide resulted in the lowest success rates after 3 years. Therefore, we can recommend ferric sulphate for easy and successful treatment of primary molars with caries-exposed pulps.

Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 μg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.

The ability of a restorative material to withstand fracture is of crucial importance especially in stress-bearing area. Therefore, the study aims to analyse the fracture toughness of a large number of dental restorative materials categories. The fracture toughness (K IC ) of 69 restorative materials belonging to ten materials categories—micro-hybrid, nanofilled, microfilled, packable, ormocer-based, and flowable resin-based composites (RBC), compomers and flowable compomers, as well as glass ionomer cements (GIC) and resin-modified GIC was measured by means of the single-edge notched-beam method after storing the samples (n = 8) for 24 h in distilled water. Data were analyzed with the one-way analysis of variance (ANOVA) followed by the Tukey’s test and partial eta-squared statistics (p

Demineralization around the bracket is an undesired side effect of orthodontic treatment. The aim of this in-vitro study was to evaluate the efficacy of 5 bonding agents to prevent enamel demineralization. Two quantification methods were used.Eighty-five extracted teeth were randomly allocated to 5 groups: (1) Transbond Plus SEP and Transbond XT (both, 3M Unitek, Seefeld, Germany), (2) 37% phosphoric acid, Pro Seal (Reliance Orthodontic Products, Itasca, Ill) and Transbond XT, (3) Clearfil Protect Bond (Kuraray Medical, Okayama, Japan) and Transbond XT, (4) 37% phosphoric acid and Light Bond (Reliance Orthodontic Products), and (5) Ortho Conditioner and Fuji Ortho LC (both, GC, Tokyo, Japan). In-vitro caries was created by pH cycling for 30 days. After demineralization, the teeth were scanned with a commercial cone-beam microtomographic system. Then the teeth were examined by polarized light microscopy.The 2 methods of examination showed significant differences among the 5 groups according to lesion depth and mineral loss (P0.01). The resin-modified glass ionomer cement (group 5) had the lowest values for lesion depth and mineral loss.Fuji Ortho LC showed a significantly smaller lesion depth and less mineral loss compared with the other materials. The cone-beam microtomographic system is suitable for evaluation of subsurface lesions and has considerable advantages.

Introduction Our aim in this randomized clinical trial was to compare the failure rates of orthodontic brackets by using 2 self-etching primers (SEPs) (Transbond Plus [3M Unitek, Seefeld, Germany] and Clearfil Protect Bond [Kuraray Medical, Okayama, Japan]) with a split-mouth design. Additionally, the effect of Clearfil Protect Bond was investigated regarding inhibition of plaque accumulation and demineralization. Methods A total of 480 brackets were bonded in 24 patients with the SEPs. The observation period was 12 months. One week after bonding and at every third recall, the plaque index and a visual rating of the enamel adjacent to the bracket were assessed at the lateral incisors and the first premolars. Additionally, DIAGNOdent (KaVo, Biberach, Germany) values were measured. Results Over the investigation time, 26 failures were recorded. Five occurred with the brackets bonded with Transbond Plus, and the rest with Clearfil Protect Bond ( P = 0.002). The additionally observed parameters had no significant differences. Conclusions The failure rate with Clearfil Protect Bond was significantly higher. For our patients, who had adequate oral hygiene, there was no benefit with regard to plaque accumulation and prevention of demineralization with Clearfil Protect Bond.

Aim To assess the antimicrobial efficacy of aqueous (1.25-20 microg mL(-1)) and gaseous ozone (1-53 g m(-3)) as an alternative antiseptic against endodontic pathogens in suspension and a biofilm model. Methodology Enterococcus faecalis, Candida albicans, Peptostreptococcus micros and Pseudomonas aeruginosa were grown in planctonic culture or in mono-species biofilms in root canals for 3 weeks. Cultures were exposed to ozone, sodium hypochlorite (NaOCl; 5.25%, 2.25%), chlorhexidine digluconate (CHX; 2%), hydrogen peroxide (H(2)O(2); 3%) and phosphate buffered saline (control) for 1 min and the remaining colony forming units counted. Ozone gas was applied to the biofilms in two experimental settings, resembling canal areas either difficult (setting 1) or easy (setting 2) to reach. Time-course experiments up to 10 min were included. To compare the tested samples, data were analysed by one-way anova. Results Concentrations of gaseous ozone down to 1 g m(-3) almost and aqueous ozone down to 5 microg mL(-1) completely eliminated the suspended microorganisms as did NaOCl and CHX. Hydrogen peroxide and lower aqueous ozone concentrations were less effective. Aqueous and gaseous ozone were dose- and strain-dependently effective against the biofilm microorganisms. Total elimination was achieved by high-concentrated ozone gas (setting 2) and by NaOCl after 1 min or a lower gas concentration (4 g m(-3)) after at least 2.5 min. High-concentrated aqueous ozone (20 microg mL(-1)) and CHX almost completely eliminated the biofilm cells, whilst H(2)O(2) was less effective. Conclusion High-concentrated gaseous and aqueous ozone was dose-, strain- and time-dependently effective against the tested microorganisms in suspension and the biofilm test model.

OBJECTIVES: To determine the clinical performance of a laser fluorescence device (DIAGNOdent pen, KaVo) to discriminate between different occlusal caries depths (D(0)-D(1-4); D(0-2)-D(3,4)) in permanent molars. METHODS: In this prospective, randomized two-centre-study 120 sound/uncavitated carious sites in 120 patients were measured after visual and radiographic caries assessment. In cases of operative intervention (n=86), the lesion depths after caries removal were recorded (reference). In cases of preventive intervention (n=34), the sites were reassessed visually/radiographically after 12 months to verify the status assessed before (reference). The discrimination performance was determined statistically (Mann-Whitney test, Spearman's rho coefficient, and areas under the receiver operating characteristic curves (AUCs)). Sensitivities (SE) and specificities (SP) were plotted as a function of the measured values and cut-off values for the mentioned thresholds suggested. RESULTS: Sound sites (n=13) had significantly minor fluorescence values than carious sites (n=107) (P

To assess the effect of ozone gas on the mechanical properties of different classes of dental adhesives.Extracted molars were sectioned perpendicularly to their long axis for obtaining dentin slices to be bonded with one of the following adhesives: PrimeBond NT (Dentsply), Excite (Ivoclar-Vivadent), Syntac/Heliobond (Ivoclar-Vivadent) and Silorane System Adhesive (3 M-ESPE). Prior to bonding, the slices were sectioned in two halves: one was treated with ozone gas for 120 s (4.2g/m3; HealOzone, KaVo) and the other served as control. The Vicker's hardness (VH), elastic modulus (E), elastic work (We/Wtot) and the creep (Cr) of the materials were measured with an automatic micro hardness indenter (Fischer) 30 min and 24 h after bonding procedure. Data were analyzed with the multivariate ANOVA followed by the Tukey's test and partial eta-squared statistics.The adhesive and the time of testing were significant factors affecting the investigated parameters (p0.001; etap2or=0.06). Dentin treatment, though significant, exerted a minimal effect on mechanical properties (etap2or=0.01). Ozone did not consistently affect the mechanical properties at both, 30 min and 24 h measurements, as all variations were below 10%. Small differences between ozone and control resulted only in the Cr and We/Wtot of Excite and in the VH of the Silorane System Adhesive at the 30 min measurement; and in the We/Wtot, Cr and VH of the Syntac/Heliobond system after 24h.Ozone gas did not compromise the mechanical properities of the tested adhesives. Thus, its application on dentin prior to bonding procedures is possible, without impairing the performance of the final restoration.

Objective: To compare the severity of clinical inflammation parameters and the level of the inflammatory mediator interleukin (IL)–1β during orthodontic treatment by using brackets and bands. In addition, the effect of a chlorhexidine-containing varnish was investigated. Materials and Methods: This prospective randomized controlled trial included 40 healthy children who required an orthodontic treatment of mild crowding. Either brackets or bands were randomly allocated to the premolars with a split-mouth design. Twenty of the children received a chlorhexidine-containing varnish during the treatment (0, 12, 24 weeks), while the remaining children served as a control group. Prior and until 24 weeks after the insertion, data were recorded regarding the pocket depth (PD), the gingival appearance (gingival index [GI]), and the plaque accumulation (plaque index [PI]). Gingival crevicular fluid was collected as well. A quantitative enzyme-linked immunoassay technique was used to detect differences in IL-1β. Results: The PDs and the gingival index of teeth with brackets showed significantly lower values in comparison with teeth treated with bands (P = .0001). The IL-1β levels confirmed these findings. In contrast, the PI showed higher values for the teeth with brackets (P = .0001). The teeth that received a chlorhexidine-containing varnish showed significantly lower values in the follow-ups for most of the evaluated parameters (PDBand, PIBand, PIBracket, GIBand, GIBracket; P < .015). Conclusion: The clinically observed parameters as well as the IL-1β levels reflected the higher impact of bands on gingival health. These values showed a significant decrease after application of a chlorhexidine-containing varnish. However, the PI showed higher values for the teeth with brackets.

To test the hypothesis that there is no difference in the bond strength with or without contamination with artificial saliva when using two different self-etching primers (Transbond Plus and iBond) in comparison with a conventional acid-etching method (37% phosphoric acid and Transbond XT) for bonding of orthodontic brackets.One hundred fifty extracted human premolars were randomly allocated to six different groups, with 25 teeth in each group. Orthodontic metal brackets (APC II, Victory Twin 22 UNIV) were used. For contamination, a saliva replacement (Ptyalin) was applied. After contamination the surface was air-dried for 5 seconds and the bonding procedure continued. The bonded teeth were stored in deionized water at 37 degrees C for 30 days and then thermocycled for 24 hours before debonding with a universal testing machine. The load was recorded at bond failure. The location of adhesive failure was determined under magnification using the adhesive remnant index (ARI).Clinically acceptable bond strengths were found for all primers used in this study. The contamination by saliva significantly decreased the bond strength when using the conventional acid-etching method (t = 0.0001). Self-etching primers were less influenced by saliva contamination. There was no significant difference in the ARI score among the groups (P.05).Saliva contamination significantly decreased the bond strength when the conventional acid-etching method was used. The self-etching primers were influenced the least. The bond strengths achieved for the self-etching primers and the conventional etching method after saliva contamination were not significantly different.

Ozone has been proposed as an alternative oral antiseptic in dentistry, due to its antimicrobial power reported for gaseous and aqueous forms, the latter showing a high biocompatibility with mammalian cells. New therapeutic strategies for the treatment of periodontal disease and apical periodontitis should consider not only antibacterial effects, but also their influence on the host immune response. Therefore, our aim was to investigate the effect of aqueous ozone on the NF-kappaB system, a paradigm for inflammation-associated signaling/transcription. We showed that NF-kappaB activity in oral cells stimulated with TNF, and in periodontal ligament tissue from root surfaces of periodontally damaged teeth, was inhibited following incubation with ozonized medium. Under this treatment, IkappaBalpha proteolysis, cytokine expression, and kappaB-dependent transcription were prevented. Specific ozonized amino acids were shown to represent major inhibitory components of ozonized medium. In summary, our study establishes a condition under which aqueous ozone exerts inhibitory effects on the NF-kappaB system, suggesting that it has an anti-inflammatory capacity.

Objective— Recent studies have provided strong evidence for the presence of ozone in atherosclerotic lesions. In addition, modification of LDL has been suggested to be involved in atherosclerosis. In the present study we wanted to investigate whether LDL exposed to ozone (ozLDL) is able to modulate the NF-κB system, as a paradigm for inflammatory signaling. Methods and Results— We showed that activation of NF-κB by lipopolysaccharide (LPS), a prototypic inducer of innate immunity, was reversibly inhibited by ozLDL in monocytic THP-1 cells in a dose-dependent manner, whereas tumor necrosis factor (TNF) signaling was not affected. This was not attributable to a direct ozone effect or solely the presence of lipoprotein, and neither required direct contact to LPS nor was accompanied by a change in LPS binding. Comparable inhibitory effects of ozLDL were observed in human monocyte/macrophages and endothelial cells. The presence of ozLDL led to a decrease in LPS-induced IκΒα proteolysis and a reduction of κB-dependent transcription/target-gene expression. Furthermore, ozLDL markedly lowered stimulus-induced IκΒ kinase (IKK) activity and phosphorylation/proteolysis of interleukin (IL)-1 receptor-associated kinase-1 (IRAK-1). Finally, cholesterol ozonization products were identified as effective ozLDL inhibitory compounds. Conclusion— Our study demonstrated that ozLDL inhibited NF-κB and IRAK-1–associated signaling which may impair immune function and promote apoptosis.

The aim of this retrospective trial was to investigate differences in mesiodistal and vestibulo-oral crown sizes of naturally, fully-erupted permanent maxillary teeth between patients with and without palatal canine displacement. 115 patients (mean age: 14 years 10 months; females: 77 males: 38) treated in the Department of Orthodontics, University of Munich were included in the study. 65 of the patients showed at least one palatally-displaced canine. Diagnosis and the location of the displacement were determined on the basis of standardized radiographs and confirmed by surgical documentation. Each maxillary tooth’s mesiodistal and vestibulo-oral width was measured using a dial caliper on each dental cast. Excluded were partially-erupted teeth and surfaces with caries or restorations that had to be measured. An analysis of available space was made by evaluating the pre-treatment dental casts of all patients included in the study. Comparing the tooth widths of patients with unilateral canine displacement with the corresponding contralateral quadrants, we noted a statistically significant difference, namely that the central and lateral incisors and the canines of the affected side were narrower than those of the non-affected side in the same patient. Moreover, the displaced upper canines showed an increase in vestibulo-oral dimension. Overall tooth width (including all tooth groups) in patients with palatally-displaced canines was significantly less than that in the control group. However, when comparing the crown diameters of unilaterally- and bilaterally-affected patients, no differences in tooth-size were observed. The space-analysis showed excessive dental-arch space in patients with a palatally-displaced canine. Patients affected by palatal canine displacement showed significantly smaller maxillary tooth size.

Ectodermal dysplasia is a rare hereditary disorder with a characteristic physiognomy. The case of a 5-year-old child with hypohidrotic ectodermal dysplasia and complete anodontia is presented. Because of the anodontia and the need for treatment at an early age, the prosthetic management of such a young child can be difficult. Complete dentures were provided to encourage a normal psychological development and to improve the function of the stomatognathic system.

There are many ways to produce all-ceramic crowns. Computer-aided design and computer-aided manufacturing (CAD/CAM) procedures compete against conventional fabricated restorations. As different methods of production may produce variable results, this study aims to compare chairside and laboratory-based CAD/CAM systems to conventional crowns regarding their similarity to original tooth morphology, number of occlusal contacts, occlusal adjustment time, and subjective aesthetic perception. Impressions of caries-free jaws were taken, and the resulting gypsum casts were scanned with a laboratory scanner. Preparations for all-ceramic full crowns were performed on first molars, and three different restorations were made: CEREC restorations (CER), laboratory-produced CAD/CAM crowns (LABCAD), and conventional waxed-up/pressed ceramic crowns (CONV). Time for occlusal adaptation and the number of occlusal contacts were noted. Two dentists performed aesthetic gradings of restorations. Statistical analysis included one-way ANOVA with least significant difference (LSD) post hoc test, t test, and Kruskal-Wallis test. Metrical deviations of the re-scanned crowns to the original, unprepared tooth surface were 220.55 ± 54.31 μm for CER, 265.94 ± 61.39 for LABCAD, and 252.44 ± 68.77 μm for CONV group. One-way ANOVA showed significant lower deviations for the CER group. LABCAD crowns showed significantly more occlusal contacts, whereas CONV crowns required the least time for occlusal adaptation and showed excellent aesthetic gradings. All three methods had pros and cons regarding different parameters. Further improvements of CAD/CAM software shall lead to restorations comparable to conventional restorations in all aspects, especially in aesthetics. All tested methods of production for all-ceramic crowns produced clinically acceptable results. Thus, in an individual case, the method chosen can be determined by the dentist’s preference.

To evaluate the anti-microbial effect of gaseous and aqueous ozone on biofilms of caries pathogen microorganisms with regard to concentration and time dependency.Biofilm cultures of Actinomyces naeslundii, Streptococcus mutans and Lactobacillus paracasei were grown on nitro-cellulose-membranes for 48 hours. The membranes were cut into equal-sized pieces and exposed to chlorhexidine digluconate (CHX) (positive control; 0.1-20%), gaseous (1-64 g m3) and aqueous ozone (1.25-20 microg ml(-1)) for 60 seconds. The influence of exposure time (30-120 seconds) was tested for exemplary concentrations of the three agents. Colony forming units of bacteria were counted. The bacteria survival rate was given as percentage of the negative control (PBS for CHX/aqueous ozone, ambient air for gaseous ozone).There was no difference in bacterial reduction of different species with general reduction close to zero for high concentrations of all agents. Univariate ANOVA with partial eta-squared (Eta2) statistics showed major effects for concentration/contact time of the agent on bacteria survival. High concentrated gaseous and aqueous ozone seem to be potential alternatives to CHX with equivalent antimicrobial activity.

Objective. The aim of this study was to investigate whether the growth of soft tissue and bone in children with traumatic tooth loss or agenesis of teeth can be developed reliably, using a new technique of autogenous primary canine transplant. Study Design. A total of 10 patients (age range, 7-13 years) were treated either for trauma or for agenesis (n ¼ 14 primary canine transplants). In addition to the clinical examination, patients were subjected to radiologic examinations with regard to root resorption, bone height, and soft tissue level. Results. With an average survival rate of 87%, the average survival time of the transplants using the Kaplan-Meier estimator was 5.2 years. In all cases, soft tissue and bone growth was effectively developed. Conclusions. Autogenous primary canine transplant is a reliable surgical method for rehabilitating children in the early mixed dentition after traumatic tooth loss, enabling adequate soft tissue and bone growth. (Oral Surg Oral Med Oral Pathol Oral Radiol 2015;119:158-169) The lack of a permanent upper incisor, either due to traumatic loss in the early mixed dentition (ages 6 to 10 years) or due to congenital tooth agenesis, always presents the dentist with the difficult task of satisfactorily rehabilitating the affected patients in terms of both aesthetics and function. Epidemiologic studies have found that in Europe, every second child experiences a tooth trauma before the age of 16 years 1,2 ;8 % to 10% of all dental injuries are injuries with loss of permanent teeth. 3 In contrast to traumatic tooth loss, multiple aplasia of teeth is rather rare in the maxillary anterior region. Nevertheless, it presents the dentist with a difficult task, as natural bite raising with alveolar process growth does not occur, owing to the absence of tooth development. The incidence of aplasia in adolescent dentition is found to be approximately 8%. 4 The loss of a permanent tooth in adolescent dentition, and also agenesis of the corresponding tooth, is always accompanied by an inhibition of the vertical and horizontal alveolar process growth. 5 Especially between the ages of 6 and 10 (in the so-called early mixed dentition), a fixed restoration of existing primary or traumatically incurred tooth gaps is not possible because during this time, neither orthodontic gap closure nor endosseous implantation are available as treatment options. Endosseous implants placed before the completion

The aim of this study was to assess the diagnostic performance and accuracy of four plaque indices for orthodontic patients. The plaque accumulation of 140 maxillary incisors with bonded brackets was recorded using intra-oral photographs and assessed using four different plaque indices: the orthodontic plaque (OP) index, the modified orthodontic plaque (MOP) index, the Quigley and Hein (QHP) index and the modified Navy plaque (MNP) index. The assessment was performed twice within a time interval of 4 weeks by four different examiner groups: orthodontists, dentists, students and orthodontic assistants. No significant differences were detected for the OP and MOP indices among the examiner groups. A significant difference was found for the QHP and MNP indices. The inter- and intra-examiner reliability of the OP and MOP indices was good. In contrast, the reliability for the QHP and MNP indices was moderate to poor with few exceptions. The discrimination performance of the OP and MOP indices was excellent. The sum of the sensitivity and specificity was generally lower for the QHP and MNP indices compared with the OP and MOP indices. OP and MOP indices showed good performance. The QHP and MNP indices are not appropriate for orthodontic purposes. Traditional plaque indices reflect the typical pattern of plaque accumulation for patients without multi-bracket appliances. The performance of these indices for orthodontic patients has never been investigated. Orthodontic plaque indices that focus on the surface along the gingival margin and areas around the bracket exhibit higher diagnostic performance and accuracy compared with traditional indices.

Recently, it has become possible to reconstruct complete occlusal surfaces using the biogeneric tooth model. This study aimed to mathematically assess and compare the morphologic agreement between original morphology and CAD-reconstructed, waxed-up and CAM partial crowns.Thirty-nine intact first permanent molars (39 participants) were included. Impressions, bite registrations and three gypsum replicas were made. Preparations for CAD/CAM partial crowns were performed and scanned. The restorations were biogenerically reconstructed (CEREC® v3.80) and milled. Wax-ups of these preparations were scanned as well as the milled restorations and original teeth. Discrepancies were evaluated by matching the scans with the original morphologies (Match3D, output: volume/area, z difference) and by contact patterns. The discrepancies were compared between CAD-reconstructions and either wax-ups or milled restorations (paired t test, α = 0.025 for two multiple tests).The mean differences between natural tooth morphology (triangular stabilisation 71.8%) and biogeneric reconstructions, wax-ups and milled restorations (triangular stabilisation 87.2%) were: 184 ± 36 μm (volume/area), 187 ± 41 μm (z difference); 263 ± 40 μm (volume/area), 269 ± 45 μm (z difference) and 182 ± 40 μm (volume/area), 184 ± 41 μm (z difference). Differences associated with biogeneric reconstructions were significantly less than those of wax-ups (volume/area and z difference, p 0.0001), but not significantly different than those of milled restorations (p = 0.423 (volume/area), p = 0.110 (z difference)).CAD software enables a closer reconstruction of teeth than do wax-ups, even when no cusps remain. The milling device is precise enough to transfer CAD into the final restoration.This study shows that state of the art CAD/CAM can effectively produce natural tooth morphology and may be ideal for fixed partial dentures.

High bond strengths are required in order to avoid bracket failure during treatment while brackets should be removable. In addition, chair time should be kept at a minimum. Therefore, the aim of this study was to investigate any differences in bracket's bond strength to enamel by reducing the polymerization time and the steps of bonding procedure. Five hundred teeth were randomly allocated into 20 groups. The groups were established considering the investigated curing units (quartz–tungsten–halogen (QTH) and light-emitting diode (LED), each with two different polymerization times) and the used bonding agents (Clearfil SE Bond, Transbond Plus, Ideal1, iBond, and Transbond XT Primer following acid etching). The brackets were debonded using a shear-peel load and used to calculate the bond strength. The location of adhesive failure was registered by using the modified adhesive remnant index (ARI). The influence of the parameters curing unit, curing time, and bonding agent as well as their interaction products on bond strength showed that the bonding agent influenced the bond strength most followed by curing time. The parameter curing unit as well as all the generated interaction products of it showed a lower impact. Regarding the ARI, the bonding agent exhibited also the highest influence. Using a LED resulted in comparable bond strengths as the QTH curing device also at shorter exposure times. Additionally, the two-component self-etching primers showed similar bond strengths compared to the acid-etching method. Chair time can be reduced by using two-component self-etching primers and LED without decrease of bond strength.

OBJECTIVES: The aim of this randomised clinical trial was to investigate if a laser fluorescence device is able to discriminate between sound and carious approximal sites and between enamel and dentinal lesions, as well as to find appropriate cut-off values. METHODS: One hundred and seventeen sound or uncavitated carious sites in permanent molars were visually and radiographically examined, then either opened or not, after which their laser fluorescence was measured. Forty-three lesions were opened, the caries removed and the clinically identified caries depths were registered in addition to the radiographical scoring. Seventy-four sites were radiographically deemed sound or had enamel caries and were not opened. Here, the radiographical scorings were registered. RESULTS: Taking the radiographic scoring as gold standard for all investigated approximal sites, sound sites (D(0), n=40) showed significantly lower laser fluorescence measurements than carious sites (D(1-4), n=77) (Mann-Whitney test, P

Pulpotomy is the accepted therapy for the management of cariously exposed pulps in symptom-free primary molars; however, evidence is lacking about the most appropriate technique. The aim of this study was to compare the relative effectiveness of the Er:YAG laser, calcium hydroxide, and ferric sulfate techniques with that of dilute formocresol in retaining such molars symptom-free. Two hundred primary molars in 107 healthy children were included and randomly allocated to one of the techniques. The treated teeth were blindly re-evaluated after 6, 12, 18, and 24 months. Descriptive data analysis and logistic regression analysis, accounting for each patient’s effect by a generalized estimating equation (GEE), were used. After 24 months, the following total and clinical success rates were determined (%): formocresol 85 (96), laser 78 (93), calcium hydroxide 53 (87), and ferric sulfate 86 (100). Only calcium hydroxide performed significantly worse than formocresol (p = 0.001, odds ratio = 5.6, 95% confidence interval 2.0–15.5). In conclusion, calcium hydroxide is less appropriate for pulpotomies than is formocresol.

To investigate, with a randomized controlled clinical study, the effect of ozone on non-cavitated initial occlusal fissure caries compared with untreated contra-lateral control lesions (split mouth) considering the patient's current caries risk.Forty-one patients with 57 pairs of lesions were enrolled in the study (mean age 7.7 +/- 2.2 years; upper jaw n=29, lower jaw n=28). Gaseous ozone (HealOzone) was applied once for 40 seconds to the randomly assigned test molar of each pair without the use of remineralizing solutions. Lesion progression or reversal was monitored by the laser fluorescence system DIAGNOdent for up to 3 months and the deterioration or improvement compared between the ozone-treated lesions and the untreated control lesions (in pairs). This was done for the whole study population and a subgroup of patients with high current caries risk (lesion pairs n=26).After 3 months, explorative data analysis revealed that the ozone-treated lesions showed significantly more caries reversal or reduced caries progression than the untreated control lesions within the group of patients at high current caries risk (Wilcoxon-Test, P= 0.035). There was no statistical significance examining the whole study population. From the data it can be concluded that ozone application significantly improved non-cavitated initial fissure caries in patients at high caries risk over a 3-month period.

The aim of this investigation was to ascertain whether the use of a fluoride-releasing, light-curing sealant (Pro Seal™, Reliance Orthodontic Products, Itasca, IL, USA) results in differences in shear-peel bond strength when teeth are etched via the conventional acid-etching method and with self-etching primers (SEP), respectively. We also examined whether Pro Seal™ functions as a substitute for the bonding agents recommended by the manufacturers. To carry out this study, we randomly allocated 300 extracted molars (ISO 11405) into twelve groups (n = 25). The brackets used (Victory Series™, Twin UBi 0T/0A .022, 3M Unitek, Seefeld, Germany) were bonded using the same layer thickness of adhesive. The teeth were then stored for 24 h in de-ionized water (37 °C) and subsequently thermocycled. The brackets were debonded using a universal testing machine with a crosshead speed of 0.5 mm/min. For statistical evaluation we used the one-way analysis of variance (ANOVA [α = 0.05]) and the post hoc Tukey test and Weibull analysis. We could establish that the use of Pro Seal™ does not have a negative influence on shear-peel bond strength. When the compomer Assure™ was used, Pro Seal™ even led to an increase in shear-peel bond strength, especially when it was applied using the bonding agent recommended by the manufacturer. The highest Weibull modulus (m) was found for the self-etching primer IDEAL 1® without using Pro Seal™ (m = 6.5) and the lowest for First Step™ SEP when using Pro Seal™ (m = 2.2). There were also clear differences in characteristic shear-peel bond strength (σ0) within some of the groups investigated. Although the statistical evaluation showed no significant negative influence on the shear-peel bond strength either when Pro Seal™ was used in addition, or when that fluoride-releasing, light-curing sealant was substituted for the bonding agent recommended by the manufacturer, the Weibull analysis showed that the use of Pro Seal™ in combination with SEP resulted in bond strength values that were less reliably reproducible.

Summary Objectives The literature reports mixed results regarding the efficacy of intraoral topical anesthetics. Only a few studies have been performed in children. Some non-placebo controlled studies have been carried out to compare the efficacy in reducing children's injection pain between different topical anesthetics Methods In a randomized, double blind, placebo controlled study with split-mouth design 104 children were enrolled to evaluate the efficacy of four topical anesthetics (Gingicain ® Spray, Gingicaine ® Topical Anesthetic, Legecain-Solution ® , EMLA ® Creme) when used prior to buccal injections within the conservative treatment of carious upper primary molars. The heart rate change and a Face Pain Scale were used as primary variables. The Visual Analog Scale, the modified Children's Hospital Pain Scale and the Sound-Eyes-Motor Scale were also evaluated. Results There was no significant difference between the placebo and any corresponding topical anesthetic with regard to the primary variables (HRC and FPS). A significant difference was found in favour of Gingicain® Spray and Gingicaine ® Topical Anesthetic according to secondary variables (VAS, S(E)MS). Conclusion While the secondary variables point to a benefit of the topical anesthetics Gingicain ® Spray and Gingicaine ® Topical Anesthetic compared to placebo, the results of the primary variables showed no differences in effectiveness of topical anesthetics and their corresponding placebos.

To evaluate different regimens of enamel conditioning on the retention of a pit and fissure sealant.100 extracted human molars were randomized into 10 experimental groups (n = 10). Conditioning of occlusal pits and fissures was performed with either 37% H3PO4, diamond bur and 37% H3PO4, Er:YAG laser, Er:YAG laser and 37% H3PO4, air abrasion (3 different settings), air abrasion (3 different settings) and subsequent acid etching with 37% H3PO4. 24 hours after placing a compomer-based sealant, the specimens were artificially aged by thermocycling (5/55 degrees C; x1000) and immersed in basic fuchsin dye for another 24 hours. After sectioning, dye penetration along the enamel-resin-interface was determined (% of the fissure depth). Data were statistically analyzed with Kruskal-Wallis H test and Mann-Whitney U test. For qualitative investigations, two further specimens of each group were analyzed in the SEM.Conventional acid etching resulted in significantly superior sealant retention than conditioning with either the Er:YAG laser or air abrasion (irrespective of particle size or air pressure). If mechanical conditioning of the laser or air abrasion was followed by acid-etching, results were statistically equal to the acid-etch only group.

To evaluate the 3-year clinical performance of the compomer Hytac in Class I and II cavities of permanent posterior teeth.53 restorations were placed in 14 patients. The compomer Hytac was used with the self-etching adhesive Hytac OSB (total bonding) without additional enamel-etching with phosphoric acid according to manufacturer's instructions. Restorations were rated at baseline and 3 years according to modified USPHS criteria in relation to tooth type (molar, premolar), size and class of cavities, isolation type (rubber dam, cotton rolls) and use of a calcium hydroxide liner. After 3 years, 39 restorations (73.6%) were available for examination. Statistical analysis was performed using Mann-Whitney U test and Fisher's exact test.After 3 years, three restorations failed (7.7%). The success rate was therefore 92.3% with an average annual failure rate of 2.6%. There was no statistically significant difference (P0.05) found concerning neither of the USPHS criteria nor the failures between any of the restoration groups.