Comparing accuracy in guided endodontics: dynamic real-time navigation, static guides, and manual approaches for access cavity preparation - an in vitro study using 3D printed teeth.

OBJECTIVES: To assess root canal localization accuracy using a dynamic approach, surgical guides and freehand technique in vitro. MATERIALS AND METHODS: Access cavities were prepared for 4 different 3D printed tooth types by 4 operators (n = 144). Deviations from the planning in angle and bur positioning were compared and operating time as well as tooth substance loss were evaluated (Kruskal-Wallis Test, ANOVA). Operating method, tooth type, and operator effects were analyzed (partial eta-squared statistic). RESULTS: Angle deviation varied significantly between the operating methods (p < .0001): freehand (9.53 ± 6.36°), dynamic (2.82 ± 1.8°) and static navigation (1.12 ± 0.85°). The highest effect size was calculated for operating method (ηP²=0.524), followed by tooth type (0.364), and operator (0.08). Regarding deviation of bur base and tip localization no significant difference was found between the methods. Operating method mainly influenced both parameters (ηP²=0.471, 0.379) with minor effects of tooth type (0.157) and operator. Freehand technique caused most substance loss (p < .001), dynamic navigation least (p < .0001). Operating time was the shortest for freehand followed by static and dynamic navigation. CONCLUSIONS: Guided endodontic access may aid in precise root canal localization and save tooth structure. CLINICAL RELEVANCE: Although guided endodontic access preparation may require more time compared to the freehand technique, the guided navigation is more accurate and saves tooth structure.

Chairside oral prophylaxis for people with profound intellectual or multiple disabilities-a retrospective feasibility study.

OBJECTIVES: People with severe intellectual or multiple disabilities (PIMD) have been receiving dental care in a specialized unit offering special care dentistry. For most of these adult patients, the initial consultation is complaint driven. In addition, the limited ability to cooperate due to their disabilities often means that dental treatment for these patients is usually carried out under general anesthesia (GA). Chairside treatment attempts are the exception rather than the rule. This retrospective study evaluated whether consistent practice of behavioral management principles and techniques embedded in a specific dental environment enables successful dental treatment of PIMD. MATERIALS AND METHODS: The feasibility of chairside dental prophylaxis in PIMD (n=36) was analyzed: specific behavioral management techniques were applied, and professional tooth cleaning (PTC) was performed in the dental chair. Clinical data obtained from medical records and a questionnaire were analyzed. RESULTS: All patients had severe intellectual or multiple disabilities and had previously undergone at least one dental treatment under GA. Of these patients, 55.6% never had their teeth professionally cleaned before. Applying different behavioral techniques, all patients were compliant with receiving PTC in the dental chair. CONCLUSIONS: An individualized and disability-specific treatment strategy using various noninvasive and nonpharmacological behavioral guidance techniques resulted in a higher compliance rate in PIMD, which allowed chairside PTC and reduced the need for treatment under GA. CLINICAL RELEVANCE: Consistent implementation of various behavioral guidance techniques and communication strategies in a supportive environment enabled all patients to receive chairside PTC and be involved in a lifelong recall program.

Retrospective clinical study on the performance and aesthetic outcome of pressed lithium disilicate restorations in posterior teeth up to 8.3 years.

OBJECTIVES: Evaluation of cumulative survival and complication rate of monolithic lithium disilicate inlays and partial crowns performed by supervised undergraduate students up to 8.3 years of clinical service. MATERIALS AND METHODS: In this retrospective clinical study 143 lithium disilicate posterior restorations (IPS e.max Press) were examined according to the FDI criteria. A standardised questionnaire was used to determine patient satisfaction. The aesthetic outcome was evaluated by dentists and dental technicians using intraoral photographs. Data were descriptively analysed. Cumulative survival and success rates were calculated using Kaplan-Meier estimation. RESULTS: The cumulative survival rate of lithium disilicate restorations was 97.5% after a mean service time of 5.9 years and 95.0% after 8.3 years. The cumulative success rate decreased from 94.4% after 5.9 years to 30.7% after 8.3 years. Repairs were required for 7 restorations (4.9%), and 5 (3.5%) were classified as failures. The results of the questionnaire indicate a high level of patient satisfaction. The subjective aesthetics were assessed more critically by dental technicians compared to dentists. CONCLUSION: Lithium disilicate posterior restorations survived successfully up to 8.3 years when carried out by undergraduate students. CLINICAL RELEVANCE: Pressed lithium disilicate glass ceramic inlays and partial crowns are reliable treatment options in posterior teeth.

The molecular weight of hyaluronic acid influences metabolic activity and osteogenic differentiation of periodontal ligament cells.

OBJECTIVE: While HA is present naturally in periodontal tissues, its molecular weight can vary widely in vivo. The objective of this study was to directly compare the biological reactions of periodontal ligament cells to four distinct molecular weights of hyaluronic acid (HA). MATERIALS AND METHODS: Immortalized human periodontal ligament cells (PDL-hTERT) were cultured for 21 days in culture medium alone (control) or enriched with osteogenic supplements (OS group). Other 4 experimental groups were cultured in OS medium with the addition of HA with different molecular weights (HMW, MMW, LMW, and ULMW). The cell morphology was examined daily. WST1 assays were performed to evaluate metabolic activity. Von Kossa staining and calcium deposition assay were used to analyze osteogenic differentiation and mineralization. RESULTS: Cell morphology remained unaltered in all groups. Cells stimulated with OS alone or with the addition of hyaluronan showed all the typical microscopic appearance of osteogenic differentiation. Metabolic activity increased in all groups over time. Hyaluronan stimulated greater metabolic activity than the control group, with LMW HA and MMW HA showing the most significant increase. All groups showed mineral deposits and calcium deposition after 21 days of stimulation. CONCLUSION: Our results suggest that hyaluronan can promote metabolic activity and mineralization of PDL-hTERT cells, with LMW HA being the most effective. CLINICAL RELEVANCE: These results shed light on how the various molecular weight fractions of HA promote tissue regeneration and repair, as well as help to identify an optimal molecular weight range for this application in periodontal tissues.

Revised FDI criteria for evaluating direct and indirect dental restorations-recommendations for its clinical use, interpretation, and reporting.

OBJECTIVES: The FDI criteria for the evaluation of direct and indirect dental restorations were first published in 2007 and updated in 2010. Meanwhile, their scientific use increased steadily, but several questions from users justified some clarification and improvement of the living document. MATERIALS AND METHODS: An expert panel (N = 10) initiated the revision and consensus process that included a kick-off workshop and multiple online meetings by using the Delphi method. During and after each round of discussion, all opinions were collected, and the aggregated summary was presented to the experts aiming to adjust the wording of the criteria as precisely as possible. Finally, the expert panel agreed on the revision. RESULTS: Some categories were redefined, ambiguities were cleared, and the descriptions of all scores were harmonized to cross-link different clinical situations with possible management strategies: reviewing/monitoring (score 1-4), refurbishment/reseal (score 3), repair (score 4), and replacement (score 5). Functional properties (domain F: fracture of material and retention, marginal adaptation, proximal contact, form and contour, occlusion and wear) were now placed at the beginning followed by biological (domain B: caries at restoration margin, hard tissue defects, postoperative hypersensitivity) and aesthetic characteristics (domain A: surface luster and texture, marginal staining, color match). CONCLUSION: The most frequently used eleven categories of the FDI criteria set were revised for better understanding and handling. CLINICAL RELEVANCE: The improved description and structuring of the criteria may help to standardize the evaluation of direct and indirect restorations and may enhance their acceptance by researchers, teachers, and dental practitioners.

Evaluation of direct restorations using the revised FDI criteria: results from a reliability study.

OBJECTIVES: The purpose of this in vitro reliability study was to determine the intra- and inter-examiner agreement of the revised FDI criteria including the categories "fracture of material and retention" (F1) and "caries at restoration margin" (B1). MATERIALS AND METHODS: Forty-nine photographs of direct tooth-coloured posterior (n = 25) and anterior (n = 24) restorations with common deficiencies were included. Ten dental experts repeated the assessment in three blinded rounds. Later, the experts re-evaluated together all photographs and agreed on a reference standard. Statistical analysis included the calculation of Cohen's (Cκ), Fleiss' (Fκ), and weighted Kappa (wκ), the development of a logistic regression with a backward elimination model and Bland/Altman plots. RESULTS: Intra- and inter-examiner reliability exhibited mostly moderate to substantial Cκ, Fκ, and wκ values for posterior restorations (e.g. Intra: F1 Cκ = 0.57, wκ = 0.74; B1 Cκ = 0.57, wκ = 0.73/Inter F1 Fκ = 0.32, wκ = 0.53; B1 Fκ = 0.41, wκ = 0.64) and anterior restorations (e.g. Intra F1 Cκ = 0.63, wκ = 0.76; B1 Cκ = 0.48, wκ = 0.68/Inter F1 Fκ = 0.42, wκ = 0.57; B1 Fκ = 0.40, wκ = 0.51). Logistic regression analyses revealed significant differences between the evaluation rounds, examiners, categories, and tooth type. Both the intra- and inter-examiner reliability increased along with the evaluation rounds. The overall agreement was higher for anterior restorations compared to posterior restorations. CONCLUSIONS: The overall reliability of the revised FDI criteria set was found to be moderate to substantial. CLINICAL RELEVANCE: If properly trained, the revised FDI criteria set are a valid tool to evaluate direct and indirect restorations in a standardized way. However, training and calibration are needed to ensure reliable application.

A comprehensive in vitro comparison of the biological and physicochemical properties of bioactive root canal sealers.

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 < 0.001). The bioactive sealers were generally less cytotoxic. IL-6 levels in hPDLF were elevated in the presence of AH (p < 0.05). AH and GF suppressed IL-6 production in hOB (p < 0.05). AH and BR stimulated the PGE2 production in hPDLF and hOB (p < 0.05). BR was the only sealer that led to calcium deposits in hMSC (p < 0.05). TF and AH showed the lowest film thickness and the highest flowability. Bacterial tightness was best in teeth filled with AH and BR. All sealers showed similar antimicrobial activity, but the overall antimicrobial efficacy was moderate as the bacteria were reduced by just one log scale (p < 0.05). 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.

Clinical performance of a new fissure sealant-results from a 2-year randomized clinical trial.

OBJECTIVES: The aim of this randomized clinical trial (RCT) was to explore the clinical survival of a new, Bis-GMA-free pit and fissure sealant (Helioseal F Plus) in comparison to an established control material (Helioseal F). MATERIAL AND METHODS: This in vivo study was designed as a prospective, 2-year, two-centre RCT with a split-mouth design. The initial study population consisted of 92 adolescents who were followed up 1 month (N = 89), 6 months (N = 88), 1 year (N = 85) and 2 years (N = 82) after sealant application. The attrition rate was 10.9% after 2 years. At each examination, the sealant retention and presence of caries were recorded. The statistical analysis included the calculation of Kaplan-Meier survival curves, log-rank tests and a Cox proportional hazard regression model. RESULTS: No adverse events during the application or any of the follow-up visits were documented. The proportion of completely intact sealants and those with minimal loss was almost identical in both groups at 85.9% (Helioseal F Plus) and 86.5% Helioseal F) after 2 years of observation. The regression analysis revealed operator dependency; no significant differences were found between the materials, the study centres, the chosen isolation technique and patient age or sex. CONCLUSION: The newly developed sealant can be evaluated as at least equivalent in terms of survival and retention behaviour compared to the established control material. CLINICAL RELEVANCE: The new sealant can be recommended for clinical use. With respect to the material properties (Bis-GMA-free, less light polymerisation time and better thixotropic behaviour), it offers additional advantages with clinical relevance.

Artificial intelligence-based diagnostics of molar-incisor-hypomineralization (MIH) on intraoral photographs.

OBJECTIVE: The aim of this study was to develop and validate a deep learning-based convolutional neural network (CNN) for the automated detection and categorization of teeth affected by molar-incisor-hypomineralization (MIH) on intraoral photographs. MATERIALS AND METHODS: The data set consisted of 3241 intraoral images (767 teeth with no MIH/no intervention, 76 with no MIH/atypical restoration, 742 with no MIH/sealant, 815 with demarcated opacity/no intervention, 158 with demarcated opacity/atypical restoration, 181 with demarcated opacity/sealant, 290 with enamel breakdown/no intervention, 169 with enamel breakdown/atypical restoration, and 43 with enamel breakdown/sealant). These images were divided into a training (N = 2596) and a test sample (N = 649). All images were evaluated by an expert group, and each diagnosis served as a reference standard for cyclic training and evaluation of the CNN (ResNeXt-101-32 × 8d). Statistical analysis included the calculation of contingency tables, areas under the receiver operating characteristic curve (AUCs) and saliency maps. RESULTS: The developed CNN was able to categorize teeth with MIH correctly with an overall diagnostic accuracy of 95.2%. The overall SE and SP amounted to 78.6% and 97.3%, respectively, which indicate that the CNN performed better in healthy teeth compared to those with MIH. The AUC values ranging from 0.873 (enamel breakdown/sealant) to 0.994 (atypical restoration/no MIH). CONCLUSION: It was possible to categorize the majority of clinical photographs automatically by using a trained deep learning-based CNN with an acceptably high diagnostic accuracy. CLINICAL RELEVANCE: Artificial intelligence-based dental diagnostics may support dental diagnostics in the future regardless of the need to improve accuracy.

Treatment Plan and Challenges in Full-Mouth Rehabilitation of a Quadriplegic Patient: A Clinical Report.

Spinal cord injuries lead to physical limitations, and the resulting levels of dependency and emotional distress have devastating consequences on individuals' oral health. A 46-year-old patient with incomplete quadriplegia due to a complicated medical history presented for prosthetic rehabilitation. The patient's ability and tolerance to be treated in the dental chair was assessed. Prosthetic treatment options were discussed considering his dependency on alternating caregivers. The final treatment plan involved restorative treatment, implant-supported crowns, an implant-supported fixed dental prosthesis and, in the upper jaw, an implant-supported overdenture to allow proper oral hygiene. The dental treatment sessions were performed with frequent interruptions in the dental chair, whereas the implants were placed under general anesthesia in the maxillo-facial surgery department. The final treatment plan resulted in a compromise between the prosthetic recommendation and the patient's wish. The decisive factor for choosing an implant-supported overdenture rather than an implant-supported fixed dental prosthesis in the upper jaw was the inability of the patient to maintain adequate hygiene measures by himself and his dependence on the caregivers. This clinical report demonstrates how special care dentistry can improve quality of life, even in people with severe physical and/or mental impairments. We would like to encourage dental professionals to provide high-quality care for patients with disabilities in particular, and this practice is in line with the requirements of the UN convention on the rights of persons with disabilities.

Influence of cleaning methods after 3D printing on two-body wear and fracture load of resin-based temporary crown and bridge material.

OBJECTIVES: To investigate the impact of different cleaning methods on the fracture load and two-body wear of additively manufactured three-unit fixed dental prostheses (FDP) for long-term temporary use, compared to the respective outcomes of milled provisional PMMA FDPs. MATERIALS AND METHODS: Shape congruent three-unit FDPs were 3D printed using three different resin-based materials [FPT, GCT, NMF] or milled [TEL] (N = 48, n = 16 per group). After printing, the FDPs were cleaned using: Isopropanol (ISO), Yellow Magic 7 (YEL), or centrifugal force (CEN). Chewing simulation was carried out with a vertical load of 50 N (480,000 × 5 °C/55 °C). Two-body wear and fracture load were measured. Data were analyzed using global univariate ANOVA with partial eta squared, Kruskal-Wallis H, Mann-Whitney U, and Spearman's rho test (p < 0.05). RESULTS: TEL showed less wear resistance than FPT (p = 0.001) for all cleaning methods tested. Concerning vertical material loss, NMF and GCT were in the same range of value (p = 0.419-0.997), except within FDPs cleaned in ISO (p = 0.021). FPT showed no impact of cleaning method on wear resistance (p = 0.219-0.692). TEL (p < 0.001) showed the highest and FPT (p < 0.001) the lowest fracture load. Regarding the cleaning methods, specimens treated with ISO showed lower fracture load than specimens cleaned with CEN (p = 0.044) or YEL (p = 0.036). CONCLUSIONS: The material selection and the cleaning method can have an impact on two-body wear and fracture load results. CLINICAL RELEVANCE: Printed restorations showed superior two-body wear resistance compared to milled FDPs but lower fracture load values. Regarding cleaning methods, ISO showed a negative effect on fracture load compared to the other methods tested.

Treatment outcomes after uncomplicated and complicated crown fractures in permanent teeth.

OBJECTIVES: The objectives of this retrospective clinical study were to describe characteristics of crown fractures in permanent teeth and to investigate the survival of pulp vitality and restorations in uncomplicated and complicated crown fractures. MATERIALS AND METHODS: This retrospective study collected information from patients suffering from dental trauma who were treated between January 2004 and June 2017. The study population consisted of 434 patients (253 males/181 females; mean age 20.7 years) with 489 uncomplicated and 127 complicated crown fractures. The Kaplan-Meier survival curves and Cox proportional hazard regression analyses were performed to explore the data statistically. RESULTS: The mean observation time was 522 days. Uncomplicated crown fractures without luxation showed a higher success rate of 82.3% (345/419) than complicated crown fractures without luxation (72.3%, 73/101). An additional luxation in uncomplicated crown fractures resulted in significantly reduced success rates in terms of survival of the pulp and restoration. Direct restorations survived significantly better independent of the fracture mode than did adhesively reattached crown fragments. No superiority of mineral trioxide aggregate or calcium hydroxide as pulp capping agent in complicated crown fractures was documented. Approximately 85.5% of all complications occurred within 2 years after the accident. CONCLUSION: The treatment of crown fractures resulted mostly in successful outcomes and only a moderate number of complications were observed. CLINICAL RELEVANCE: Primary dental management of crown fractures should follow recently published clinical guidelines, and close monitoring over at least 2 years seems to be justified.

Targeting antibiotic tolerance in anaerobic biofilms associated with oral diseases: Human antimicrobial peptides LL-37 and lactoferricin enhance the antibiotic efficacy of amoxicillin, clindamycin and metronidazole.

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.

Inhibitory effect of LL-37 and human lactoferricin on growth and biofilm formation of anaerobes associated with oral diseases.

This study was conducted to evaluate the antimicrobial potential of the antimicrobial peptides (AMP) LL-37 and human Lactoferricin (LfcinH) on the planktonic growth and biofilm formation of oral pathogenic anaerobes related to caries and periodontitis. Multi-species bacterial suspensions of either facultative anaerobic bacteria (FAB: Streptococcus mutans, Streptococcus sanguinis, Actinomyces naeslundii) or obligate anaerobic bacteria (OAB: Veillonella parvula, Parvimonas micra, Fusobacterium nucleatum) were incubated with different concentrations of AMP solutions for 8 h. Planktonic growth was registered with an ATP-based cell viability assay for FAB and via plate counting for OAB. Biofilms were grown on ZrO2 discs for 4 days in a mixture of the multi-species bacterial suspensions and AMP solutions. Biofilm mass was quantified using a microtiter plate biofilm assay with crystal violet staining. An overall planktonic growth inhibition and biofilm mass reduction of FAB and OAB was registered for LL-37 and LfcinH. Significant inhibitory threshold concentrations of LL-37 were observed in all experiments (p < 0.0001). No significant threshold was observed for LfcinH. Biofilm mass of OAB was barely reduced by LfcinH. The complete mechanisms of the AMPs are not fully understood yet. While LL-37 shows promising features as potential therapeutic for biofilm-associated oral diseases, LfcinH seems unsuitable for this particular indication. For clinical AMP use, further investigations will be necessary.

Effect of polyhexanide as antiseptic mouth rinse against oral pathogens in an in vitro biofilm model.

OBJECTIVE: The aim of this study was to evaluate the anti-biofilm effect of polyhexanide mouth rinses against oral pathogens in vitro. MATERIAL AND METHODS: Biofilms of Candida albicans, Streptococcus mutans, Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, methicillin-resistant Staphylococcus aureus and Fusobacterium nucleatum were grown on 10 mm diameter hydroxyapatite discs for 5 days. Biofilms were exposed to test substances for 30 s (ProntOral, polyhexanide 0.15%, chlorhexidine 0.2%). Another test set simulating blood contamination in the oral cavity was performed by submerging the discs in defibrinated sheep blood prior to antimicrobial exposure. Biofilm mass was determined via crystal violet staining. The proliferation potency of the cells after antimicrobial exposure was evaluated by plating serially diluted suspensions from extracted biofilms on agar plates and determining the number of colony-forming units (CFU/ml). Mann-Whitney-U, Kruskal-Wallis and Dunn's test were used for statistical analyses. RESULTS: Regardless of blood contamination ProntOral led to a significant reduction of biofilm mass in all strains. Chlorhexidine and polyhexanide reduced biofilm mass in five out of six strains and in only four strains after blood contamination. All agents significantly reduced CFU/ml from S. mutans, A. actinomycetemcomitans and F. nucleatum biofilms. C. albicans and S. aureus biofilms were only affected by ProntOral and polyhexanide. None of the antiseptics significantly reduced the CFU/ml for A. naeslundii biofilms. After blood contamination ProntOral and polyhexanide significantly reduced CFU/ml in all strains, whereas CHX tended to increase the CFU/ml. CONCLUSIONS: Polyhexanide mouth rinses seem to be suitable disinfectants against oral pathogens without their anti-biofilm potential being impaired by blood.

Survival analysis of adhesive reattachments in permanent teeth with crown fractures after dental trauma.

BACKGROUND/AIM: When patients have saved tooth fragments in case of crown fractures, reattachment is considered as the treatment of choice. With respect to the need to provide clinical outcome data regarding adhesively reattached fragments, the aim of this practice-based clinical study was to evaluate the survival of reattached fragments after crown fractures in permanent teeth. MATERIALS AND METHODS: Records from patients treated at Ludwig-Maximilians-University between 2004 and 2017 were analyzed to collect clinical and radiographic data regarding the management of fractured teeth that were treated with an adhesive reattachment. The study population consisted of 109 patients comprising 135 reattached fragments divided into uncomplicated (N = 84/135) and complicated (N = 51/135) crown fractures. The Kaplan-Meier Survival estimator was used to estimate the survival probability of primary reattachments after uncomplicated and complicated crown fractures. RESULTS: Overall, 77.4% (N = 65/84) and 66.6% (N = 34/51) of the primarily applied reattachments in uncomplicated fractured teeth and complicated fractured teeth, respectively, survived over the period of observation. The survival rate for adhesive reattachment in all teeth was 84.4% (N = 114/135) after 608.2 days (±983.1 days). The data further suggest that in the case of a detachment, repeated reattachment might be a valuable restoration strategy. CONCLUSIONS: Adhesive reattachment is a good first-choice treatment option in cases of crown fractures when the fractured fragment has been saved.

Comparison of novel and established caries diagnostic methods: a clinical study on occlusal surfaces.

BACKGROUND: The purpose of this prospective clinical diagnostic study with validation was to compare the diagnostic accuracy of near-infrared transillumination (NIRT), laser fluorescence measurement (LF), alternating current impedance spectroscopy (ACIS) and their combinations as adjunct methods to visual examination (VE) for occlusal caries detection using a hybrid reference standard. METHODS: Ninety-six first and second non-cavitated permanent molars from 76 individuals (mean age 24.2) were investigated using (VE) (ICDAS) and bitewing radiography (BWR), as well as NIRT, LF and ACIS. The findings of BWR and NIRT were evaluated by two examiners while the other examinations were conducted by one calibrated dentist. The hybrid reference standard consisted of non-operative validation based on the results of VE and BWR and operative validation. Statistical analysis included cross-tabulations, calculation of sensitivity, specificity and area under the receiver operating characteristic curve at three diagnostic thresholds: caries in general, enamel caries and dentin caries. RESULTS: NIRT, LF and ACIS exhibited high sensitivity for caries in general [1.00 (1.00-1.00), 0.77 (0.65-0.88), 0.75 (0.63-0.87)) and for dentin caries (0.97 (0.91-1.03), 0.76 (0.76-0.90), 0.64 (0.47-0.80)]. Sensitivity values for enamel caries were weak (0.21, 0.11, 0.37). Specificity values did not fall below 0.65 (NIRT) for all categories and methods, except for NIRT at the caries detection threshold (0.27). A combination of LF and ACIS with VE improved the diagnostic performance at the overall and the enamel caries threshold. The other methods showed fair to excellent discrimination at the overall caries threshold (NIRT 0.64, LF 0.89 and ACIS 0.86) and acceptable discrimination at the dentin caries threshold (NIRT 0.82, LF 0.81 and ACIS 0.79). AUROC for enamel caries exhibited the weakest discrimination. Accuracy was 65.6% for VE, 69.8% for BWR, 50.0% for NIRT, 53.1% for LF and 74.0% for ACIS. Reliability assessment for BWR and NIRT showed at least substantial agreements for all analyses. CONCLUSIONS: The methods, NIRT, LF and ACIS, revealed different potential but no impeccable performance for occlusal caries detection. All are suitable instruments to detect hidden carious lesion in dentin. As auxiliaries to VE, LF and ACIS showed an increase in diagnostic performance.

First comparison of a new dynamic navigation system and surgical guides for implantology: an in vitro study.

AIM: 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. MATERIALS AND METHODS: 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). RESULTS: No significant differences occurred regarding entry point (3D), mesiodistal/bucco-oral entry points (1D) or mesiodistal angle (1D) (P > 0.05). 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, P < 0.0001). 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; P < 0.0001). 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. CONCLUSION: Denacam might possibly be a promising alternative to static surgical guides.

[Molar incisor hypomineralisation (MIH)-discussion of prevalence and etiology with special reference to the results from the Munich birth cohorts GINIplus and LISA]. / Molaren-Inzisiven-Hypomineralisation (MIH). Häufigkeit und mögliche Ursachen unter besonderer Berücksichtigung der Ergebnisse aus den Münchner Geburtskohorten GINIplus und LISA.

After caries, molar incisor hypomineralisation (MIH)-also known as chalky teeth-is one the most common dental diseases in children and adolescents. In addition to aesthetic limitations, especially on the anterior teeth, hypersensitivities and enamel breakdowns on permanent molars are of functional importance. While the MIH prevalence rates range from ~ 10% to ~ 30% and is well described, the situation regarding aetiology is unsatisfactory. Although efforts have been made in the past to clarify the aetiology, no plausible reason is available so far. Aetiology research has to be judged as methodologically challenging, since it should ideally be embedded in prospectively planned birth cohort studies. The aim of this article is to summarize typical clinical characteristics of MIH, epidemiological findings and potential causes with special reference to the earlier published results from the two Munich birth cohort studies GINIplus and LISA.

Actovegin® reduces PMA-induced inflammation on human cells.

PURPOSE: The effect of Actovegin® was investigated on PMA- and LPS-induced human peripheral blood mononuclear cells (PBMCs). METHODS: PBMCs (1 × 106 cells/ml) from five blood donors (2 f, 3 m; 45-55 years) were grown in medium and exposed to Actovegin® in the presence or absence of PMA or LPS. Supernatants were collected to assess the concentration of cytokines (TNF-α, IL-1beta, IL-6 and IL-10). The reactive oxygen species (ROS) were assessed by a ROS-GloTM H2O2 assay. RESULTS: Stimulation of cells by PMA or LPS (without Actovegin®) significantly increased the secretion of IL-1beta, IL-6, IL-10 and TNF-α from PBMCs, compared to controls. Pre-treatment of cells with Actovegin® (1, 5, 25, 125 µg/ml) plus PMA significantly decreased the secretion of IL-1beta from PBMCs, compared to controls (PMA without Actovegin®). In contrast, addition of Actovegin® (1, 5, 25, 125 and 250 µg/ml) plus LPS did not alter the IL-1beta production, compared to controls (LPS without Actovegin®). TNF-α, IL-6 and IL-10 do not contribute to the reduction of inflammatory reactions with Actovegin®. CONCLUSIONS: Actovegin® can reduce the PMA-induced IL-1beta release and the ROS production from PBMCs. These findings may help to explain the clinically known positive effects of Actovegin® on athletic injuries with inflammatory responses (e.g., muscle injuries, tendinopathies).