European Organisation for Caries Research and the European Federation of Conservative Dentistry Consensus Report on Clinical Recommendations for Caries Diagnosis: Paper III - Caries Diagnosis at the Individual Level.

OBJECTIVES: The aim of the present consensus paper was to provide recommendations for clinical practice on the individual etiological and modifying factors to be assessed in the individual diagnosis of caries, and the methods for their assessment, supporting personalized treatment decisions. MATERIAL AND METHODS: The executive councils of the European Organisation for Caries Research (ORCA) and the European Federation of Conservative Dentistry (EFCD) nominated ten experts each to join the expert panel. The steering committee formed three work groups which were asked to provide recommendations on (1) caries detection and diagnostic methods, (2) caries activity assessment, and (3) forming individualized caries diagnoses. The experts responsible for "individualised caries diagnosis" searched and evaluated the relevant literature, drafted this manuscript and made provisional consensus recommendations. These recommendations were discussed and refined during the structured process in the whole work group. Finally, the agreement for each recommendation was determined using an anonymous eDelphi survey. The threshold for approval of recommendations was determined at 70% agreement. RESULTS: Ten recommendations were approved and agreed by the whole expert panel, covering medical history, caries experience, plaque, diet, fluoride, and saliva. While the level of evidence was low, the level of agreement was typically very high, except for one recommendation on salivary flow measurement, where 70% agreed. CONCLUSION: It is recommended that all aspects of caries lesion progression and activity, recent caries experience, medical conditions and medications, plaque, diet, fluoride and saliva should be synthesized to arrive at an individual diagnosis. CLINICAL RELEVANCE: The expert panel merged evidence from existing guidelines and scientific literature with practical considerations and provided recommendations for their use in daily dental practice.

Organization for Caries Research-European Federation of Conservative Dentistry Consensus Report on Clinical Recommendations for Caries Diagnosis Paper II: Caries Lesion Activity and Progression Assessment.

INTRODUCTION: This consensus paper provides recommendations for oral health professionals on why and how to assess caries activity and progression with special respect to the site of a lesion. METHODS: An expert panel was nominated by the executive councils of the European Organization for Caries Research (ORCA) and the European Federation of Conservative Dentistry (EFCD). The steering committee built three working groups that were asked to provide recommendations on (1) caries detection and diagnostic methods, (2) caries activity and progression assessment, and (3) obtain individualized caries diagnoses. The experts of work group 2 phrased and agreed on provisional general and specific recommendations on caries lesion activity and progression, based on a review of the current literature. These recommendations were then discussed and refined in a consensus workshop followed by an anonymous Delphi survey to determine the agreement on each recommendation. RESULTS: The expert panel agreed on general (n = 7) and specific recommendations (n = 6). The specific recommendations cover coronal caries on pits and fissures, smooth surfaces, proximal surfaces, as well as root caries and secondary caries/caries adjacent to restorations and sealants. 3/13 recommendations yielded perfect agreement. CONCLUSION: The most suitable method for lesion activity assessment is the visual-tactile method. No single clinical characteristic is indicative of lesion activity; instead, lesion activity assessment is based on assessing and weighing several clinical signs. The recall intervals for visual and radiographic examination need to be adjusted to the presence of active caries lesions and recent caries progression rates. Modifications should be based on individual patient characteristics.

ORCA-EFCD consensus report on clinical recommendation for caries diagnosis. Paper I: caries lesion detection and depth assessment.

OBJECTIVES: The aim of the present consensus paper was to provide recommendations for clinical practice considering the use of visual examination, dental radiography and adjunct methods for primary caries detection. MATERIALS AND METHODS: The executive councils of the European Organisation for Caries Research (ORCA) and the European Federation of Conservative Dentistry (EFCD) nominated ten experts each to join the expert panel. The steering committee formed three work groups that were asked to provide recommendations on (1) caries detection and diagnostic methods, (2) caries activity assessment and (3) forming individualised caries diagnoses. The experts responsible for "caries detection and diagnostic methods" searched and evaluated the relevant literature, drafted this manuscript and made provisional consensus recommendations. These recommendations were discussed and refined during the structured process in the whole work group. Finally, the agreement for each recommendation was determined using an anonymous Delphi survey. RESULTS: Recommendations (N = 8) were approved and agreed upon by the whole expert panel: visual examination (N = 3), dental radiography (N = 3) and additional diagnostic methods (N = 2). While the quality of evidence was found to be heterogeneous, all recommendations were agreed upon by the expert panel. CONCLUSION: Visual examination is recommended as the first-choice method for the detection and assessment of caries lesions on accessible surfaces. Intraoral radiography, preferably bitewing, is recommended as an additional method. Adjunct, non-ionising radiation methods might also be useful in certain clinical situations. CLINICAL RELEVANCE: The expert panel merged evidence from the scientific literature with practical considerations and provided recommendations for their use in daily dental practice.

General diseases and medications in 687 patients reporting on adverse effects from dental materials.

OBJECTIVES: Examination of patients claiming adverse effects from dental materials can be very challenging. Particularly, systemic aspects must be considered besides dental and orofacial diseases and allergies. Therefore, the aim of this study was to investigate a cohort of 687 patients reporting on adverse effects from dental materials focusing on findings related to known general diseases or conditions or medication-related findings with relevance to their subjective complaints. METHODS: Six hundred eighty-seven patients visiting a specialized consultation on claimed adverse effects from dental materials were retrospectively investigated for their subjective complaints, findings related to known general diseases or conditions, medication-related findings, dental and orofacial findings, or allergies with relevance to their subjective complaints. RESULTS: The most frequent subjective complaints were burning mouth (44.1%), taste disorders (28.5%), and dry mouth (23.7%). In 58.4% of the patients, dental and orofacial findings relevant to their complaints could be found. Findings related to known general diseases or conditions or medication-related findings were found in 28.7% or 21.0% of the patients, respectively. Regarding medications, findings related to antihypertensives (10.0%) and psychotropic drugs (5.7%) were found most frequently. Relevant diagnosed allergies toward dental materials were found in 11.9%, hyposalivation in 9.6% of the patients. In 15.1% of the patients, no objectifiable causes for the expressed complaints could be found. CONCLUSIONS: For patients complaining of adverse effects from dental materials, findings related to known general diseases or conditions and medications should be given particular consideration, while still in some patients, no objectifiable causes for their complaints can be found. CLINICAL RELEVANCE: For patients complaining about adverse effects from dental materials, specialized consultations and close collaboration with experts from other medical fields are eligible.

Endodontic regeneration: hard shell, soft core.

A loss of organs or the destruction of tissue leaves wounds to which organisms and living things react differently. Their response depends on the extent of damage, the functional impairment and the biological potential of the organism. Some can completely regenerate lost body parts or tissues, whereas others react by forming scars in the sense of a tissue repair. Overall, the regenerative capacities of the human body are limited and only a few tissues are fully restored when injured. Dental tissues may suffer severe damage due to various influences such as caries or trauma; however, dental care aims at preserving unharmed structures and, thus, the functionality of the teeth. The dentin-pulp complex, a vital compound tissue that is enclosed by enamel, holds many important functions and is particularly worth protecting. It reacts physiologically to deleterious impacts with an interplay of regenerative and reparative processes to ensure its functionality and facilitate healing. While there were initially no biological treatment options available for the irreversible destruction of dentin or pulp, many promising approaches for endodontic regeneration based on the principles of tissue engineering have been developed in recent years. This review describes the regenerative and reparative processes of the dentin-pulp complex as well as the morphological criteria of possible healing results. Furthermore, it summarizes the current knowledge on tissue engineering of dentin and pulp, and potential future developments in this thriving field.

[Amalgam and alternatives-discussions on mercury reduction in the environment]. / Amalgam und Alternativen ­ Diskussionen zur Quecksilberreduktion in der Umwelt.

Dental amalgam has been successfully used for the restoration of carious lesions for more than 180 years. It is clinically characterized by high longevity and low technique sensitivity. For decades, dental amalgam has been discussed in the public, especially due to its roughly 50% mercury content. Since the Minamata Convention was published in 2013 with the primary goal of reducing the anthropogenic mercury release into the environment, the previously muted amalgam discussion has received fresh impetus. Another considerable disadvantage of amalgam is its silver/greyish color, which simply no longer matches patients' esthetic demands.The present paper describes the basic problems with amalgam against the background of multiple biological, clinical, and health policy factors. Possible consequences of the Minamata Convention concerning legal regulations as well as the use of dental biomaterials and therefore also relating to the future national healthcare system are discussed. Finally, possible amalgam alternatives and the urgent need for biomedical research towards restorative dentistry are presented, embedded into the crucial question of whether we are actually conducting the correct debate.

Tooth survival and clinical outcomes up to 26 years after guided tissue regeneration therapy in deep intra-bony defects: Follow-up investigation of three randomized clinical trials.

AIM: To investigate tooth survival and clinical long-term outcomes up to 26 years following guided tissue regeneration (GTR) therapy in deep intra-bony defects. METHODS: Patients from three prospective clinical split-mouth studies, which investigated the outcomes of GTR therapy, were re-evaluated 21-26 years after surgery independent of the membrane type used, and tooth survival was assessed according to several site-specific and patient-related factors. RESULTS: About 50 patients contributing 102 defects were available for this long-term follow-up. After up to 26 years (median 23.3 years), 52.9% of the teeth were still in situ. The median survival of the extracted teeth was 13.8 years. Patients with diabetes mellitus and/or smoking history lost significantly more teeth in the long term. Compared to the 1-year situation, there was no new median CAL loss after up to 26 years in the teeth which were still in situ. CONCLUSIONS: Within the limitations of this study, our data show that more than 50% of the initially seriously diseased teeth were still in situ up to 26 years following GTR therapy despite an overall limited adherence to SPT. In the majority of these teeth, the CAL gain 1 year after GTR could be maintained over this long period.

Longevity of posterior composite and compomer restorations in children placed under different types of anesthesia: a retrospective 5-year study.

OBJECTIVES: The aims of this study were (i) to assess cumulative survival rates of class II resin-based composite and compomer restorations in primary molars with a 5-year observation period and (ii) to analyze the influence of different types of anesthesia and different localizations of the restorations in the teeth. METHODS: Patient charts of a private practice for pediatric dentistry were screened for class II resin-based composite (Spectrum TPH3) and compomer (Dyract Posterior; both Dentsply DeTrey) restorations in primary molars with a 5-year observation period used with Adper Prompt L-Pop (3M-ESPE). One restoration per patient (age ≤ 6 years at placement) was randomly selected. RESULTS: Two hundred sixty restorations were included (43% resin-based composites, 57% compomers). After 5 years, cumulative survival rates were 43% for resin-based composite and 49% for compomer restorations with no statistically significant differences. There was a tendency for higher survival rates for restorations placed under N2O inhalation sedation or general anesthesia. Distal-occlusal compomer restorations showed significantly lower survival rates (p = 0.003) as compared to mesial-occlusal compomer restorations. CONCLUSION: Within the limitations of the study, we conclude that type of restorative material as well as the type of anesthesia do not influence restoration survival rates, although restorations placed in patients receiving N2O inhalation sedation or general anesthesia tend to perform better as compared with patients receiving no anesthesia or only local infiltration. CLINICAL RELEVANCE: Resin-based composite and compomer restorations show similar survival rates of more than 43% (annual failure rates less than 11.5%) after 5 years for restoration of primary molars.

Influence of autogenous platelet concentrate on combined GTR/graft therapy in intra-bony defects: A 13-year follow-up of a randomized controlled clinical split-mouth study.

AIM: To investigate the clinical long-term outcomes 13 years following guided tissue regeneration (GTR) in deep intra-bony defects with and without additional application of autogenous platelet concentrate (APC). METHODS: In 25 patients, two deep contra-lateral intra-bony defects were treated according to GTR using ß-TCP and bio-resorbable membranes. In test defects, APC was applied additionally. After 13 years, clinical healing results were assessed and compared to results at baseline and after 1 year. Furthermore, a tooth survival analysis was carried out. RESULTS: After 13 years, 22 patients were available for tooth survival analysis showing 81.8% of test and 86.4% of control teeth still in situ. Based on the 15 patients still available for split-mouth analysis, median CAL was 10.0 mm in test and 12.0 mm in control sites at baseline. After 1 year, both groups revealed significant CAL gains of 5.0 mm, followed by a new CAL loss of 1.0 mm in the following 12 years. There were no significant differences between test and control sites. CONCLUSION: Within the limits of this study, the data show that most of the CAL gain following GTR can be maintained over 13 years. The additional use of APC had no positive influence on the long-term stability.

Effect of bleaching agent extracts on murine macrophages.

OBJECTIVES: The aim of this study was to evaluate the cytotoxicity and the influence of bleaching agents on immunologically cell surface antigens of murine macrophages in vitro. MATERIALS AND METHODS: RAW 264.7 cells were exposed to bleaching gel extracts (40% hydrogen peroxide or 20% carbamide peroxide) and different H2O2 concentrations after 1 and 24-h exposure periods and 1-h exposure and 23-h recovery. Tests were performed with and without N-acetyl cysteine (NAC) and buthionine sulfoximine (BSO). Cell viability was determined by MTT assay. The expression of surface markers CD14, CD40, and CD54 with and without LPS stimulation was detected by flow cytometry, while the production of TNF-α was measured by ELISA. Statistical analysis was performed using the Mann-Whitney U test (α = 0.05). RESULTS: Extracts of bleaching agents were cytotoxic for cells after a 1-h exposure; cells could not recover after 24 h. This effect can be mitigated by the antioxidant NAC and increased by BSO, an inhibitor of glutathione (GSH) synthesis. LPS stimulated expression of all surface markers and TNF-α production. Exposure to bleaching agent extracts and H2O2 leads to a reduction of TNF-α, CD14, and CD40 expression, while the expression of CD54 was upregulated at non-cytotoxic concentrations. Whereas NAC reduced this effect, it was increased in the presence of BSO. CONCLUSIONS: Extracts of bleaching agents were irreversibly cytotoxic to macrophages after a 1-h exposure. Only the expression of CD54 was upregulated. The reactions are mediated by the non-enzymatic antioxidant GSH. CLINICAL RELEVANCE: The addition of an antioxidant can downregulate unfavorable effects of dental bleaching.

Antimicrobial photodynamic therapy vs. local minocycline in addition to non-surgical therapy of deep periodontal pockets: a controlled randomized clinical trial.

OBJECTIVES: To investigate the additional influence of either antimicrobial photodynamic therapy (aPDT; Helbo® Photodynamic Systems) or local application of minocycline microspheres (MC; Arestin, OraPharma) on clinical and microbiological healing results in deep periodontal pockets (PPD ≥6 mm) following non-surgical periodontal therapy (SRP). MATERIALS AND METHODS: Forty-five patients with chronic periodontitis were evaluated: test group aPDT + SRP (n = 15), positive control group MC + SRP (n = 15), and negative control group SRP-alone (n = 15). Clinical and microbiological healing parameters were recorded in every patient for four experimental teeth at baseline, 6 weeks, and 3, 6, and 12 months. Wilcoxon signed-rank test and Mann-Whitney U test were used for statistical analysis (α = 0.05). RESULTS: Significant improvements in clinical and microbiological parameters were found for all groups after 6 weeks and 3, 6, and 12 months. Differences between groups were not statistically significant. Changes after 12 months [median (25/75%)] are as follows: reduction in PPD [mm]: aPDT + SRP 2 (1/3), MC + SRP 3 (1/4), SRP-alone 2 (1/3); percentage of residual BOP positive teeth [%]: aPDT + SRP 75 (25/100), MC + SRP 33.3 (0/50), SRP-alone 66.7 (25/75). CONCLUSIONS: Within the limitations of this study, neither the applied aPDT system nor MC showed a significant additional influence on clinical and microbiological healing outcomes in deep periodontal pockets compared to SRP alone. CLINICAL RELEVANCE: In deep periodontal defects, the efficacy of non-surgical periodontal treatment seems not to be improved by adjunctive use of antimicrobial photodynamic therapy or minocycline microspheres.

Self-adhesive Luting of Partial Ceramic Crowns: Selective Enamel Etching Leads to Higher Survival after 6.5 Years In Vivo.

PURPOSE: To investigate the influence of selective enamel etching on long-term clinical performance of partial ceramic crowns (PCCs) luted with a self-adhesive luting material (RXU: RelyX Unicem). MATERIALS AND METHODS: At baseline, 34 patients received the intended treatment: two PCCs (Vita Mark II; Cerec 3D) for the restoration of extended lesions with multiple-cusp coverage were placed in a split-mouth design with a self-adhesive luting material, one without (RXU) and one with selective enamel etching (RXU+E). Patients were evaluated clinically (modified USPHS criteria) at baseline and up to 6.5 years (70 to 88 months). The chi-square test was used for statistical analyses (α=0.05). Clinical survival of all restorations (n=68) after 6.5 years was evaluated by Kaplan-Meier analysis. RESULTS: After 6.5 years, 18 patients (9 male, 9 female; median age 41, range 25 to 59 years) with 36 RXU and RXU+E restorations were available for clinical assessment (patient recall rate: 53%), with 13 RXU and 14 RXU+E PCCs placed in molars and 5 RXU and 4 RXU+E PCCs in premolars. Clinically, no statistically significant differences between the luting procedures were detected. Both RXU and RXU+E revealed significant changes over time with respect to marginal adaptation (significant deterioration) and marginal discoloration (significant increase). RXU revealed no cases of postoperative hypersensitivity and RXU+E only did so at baseline (n=5). Kaplan-Meier analysis showed a cumulative survival for RXU of 60% and for RXU+E of 82%, indicating a significantly higher survival rate for RXU+E. CONCLUSION: Clinically, RXU and RXU+E perform similarly. In PCC restorations with multiple-cusp coverage, lack of retention due to adhesive preparation, and little dentin available for adhesion caused by extensive core buildups or cavity linings, selective enamel etching is recommended.

Controlled, prospective, randomized, clinical split-mouth evaluation of partial ceramic crowns luted with a new, universal adhesive system/resin cement: results after 18 months.

OBJECTIVES: A new universal adhesive with corresponding luting composite was recently marketed which can be used both, in a self-etch or in an etch-and-rinse mode. In this study, the clinical performance of partial ceramic crowns (PCCs) inserted with this adhesive and the corresponding luting material used in a self-etch or selective etch approach was compared with a self-adhesive universal luting material. MATERIAL AND METHODS: Three PCCs were placed in a split-mouth design in 50 patients. Two PCCs were luted with a combination of a universal adhesive/resin cement (Scotchbond Universal/RelyX Ultimate, 3M ESPE) with (SB+E)/without (SB-E) selective enamel etching. Another PCC was luted with a self-adhesive resin cement (RelyX Unicem 2, 3M ESPE). Forty-eight patients were evaluated clinically according to FDI criteria at baseline and 6, 12 and 18 months. For statistical analyses, the chi-square test (α = 0.05) and Kaplan-Meier analysis were applied. RESULTS: Clinically, no statistically significant differences between groups were detected over time. Within groups, clinically significant increase for criterion "marginal staining" was detected for SB-E over 18 months. Kaplan-Meier analysis revealed significantly higher retention rates for SB+E (97.8 %) and SB-E (95.6 %) in comparison to RXU2 (75.6 %). CONCLUSION: The 18-month clinical performance of a new universal adhesive/composite combination showed no differences with respect to bonding strategy and may be recommended for luting PCCs. Longer-term evaluation is needed to confirm superiority of SB+E over SB-E. CLINICAL RELEVANCE: At 18 months, the new multi-mode adhesive, Scotchbond Universal, showed clinically reliable results when used for luting PCCs.

Remineralizing amorphous calcium phosphate based composite resins: the influence of inert fillers on monomer conversion, polymerization shrinkage, and microhardness.

AIM: To determine if the addition of inert fillers to a bioactive dental restorative composite material affects its degree of conversion (DC), polymerization shrinkage (PS), and microhardness (HV). METHODS: Three amorphous calcium phosphate (ACP)-based composite resins: without added fillers (0-ACP), with 10% of barium-glass fillers (Ba-ACP), and with 10% of silica fillers (Si-ACP), as well as commercial control (Ceram•X, Dentsply DeTrey) were tested in laboratory conditions. The amount of ACP (40%) and the composition of the resin mixture (based on ethoxylated bisphenol A dimethacrylate) was the same for all ACP materials. Fourier transform infrared spectroscopy was used to determine the DC (n=40), 20 min and 72 h after polymerization. Linear PS and Vickers microhardness (n=40) were also evaluated. The results were analyzed by paired samples t test, ANOVA, and one-way repeated measures ANOVA with Student-Newman-Keuls or Tukey's post-hoc test (P=0.05). RESULTS: The addition of barium fillers significantly increased the DC (20 min) (75.84±0.62%) in comparison to 0-ACP (73.92±3.08%), but the addition of silica fillers lowered the DC (71.00±0.57%). Ceram•X had the lowest DC (54.93±1.00%) and linear PS (1.01±0.24%) but the highest HV (20.73±2.09). PS was significantly reduced (P<0.010) in both Ba-ACP (1.13±0.25%) and Si-ACP (1.17±0.19%) compared to 0-ACP (1.43±0.21%). HV was significantly higher in Si-ACP (12.82±1.30) than in 0-ACP (10.54±0.86) and Ba-ACP (10.75±0.62) (P<0.010). CONCLUSION: Incorporation of inert fillers to bioactive remineralizing composites enhanced their physical-mechanical performance in laboratory conditions. Both added fillers reduced the PS while maintaining high levels of the DC. Silica fillers additionally moderately improved the HV of ACP composites.

Dexamethasone-related osteogenic differentiation of dental follicle cells depends on ZBTB16 but not Runx2.

Dental follicle cells (DFCs) can be artificially differentiated into mineralizing cells. With a dexamethasone-based differentiation protocol, transcription factors ZBTB16 and NR4A3 are highly upregulated but Runx2 and other osteogenic marker genes are not. Previous studies have suggested the involvement of a Runx2-independent differentiation pathway. The objective of this study is to further elucidate this mechanism. Differentiation of DFCs was examined by alkaline phosphatase (ALP) staining and ALP activity measurement, by Alizarin Red S staining and by real-time reverse transcription plus the polymerase chain reaction. ZBTB16 was overexpressed by using a transient transfection method. Resulting genome-wide gene expression changes were assessed by microarray. ZBTB16 and Runx2 were inhibited by short interfering RNA transfection. Promoter binding of ZBTB16 was evaluated by chromatin immunoprecipitation. Downregulation of Runx2 had no effect on dexamethasone-induced differentiation but was effective on BMP2-induced differentiation. Downregulation of ZBTB16, however, impaired dexamethasone-induced differentiation. Genes that were upregulated by dexamethasone induction were also upregulated by ZBTB16 overexpression. Genes that were not upregulated during dexamethasone-induced differentiation were also not regulated by ZBTB16 overexpression. ZBTB16 bound directly to the promoter regions of osterix and NR4A3 but not that of Runx2. Overexpression of ZBTB16 led to changes in the gene expression profile, whereby upregulated genes were overrepresented in osteogenesis-associated biological processes. Our findings suggest that, in DFCs, a Runx2-independent differentiation mechanism exists that is regulated by ZBTB16.

Effect of selective enamel etching on clinical performance of CAD/CAM partial ceramic crowns luted with a self-adhesive resin cement.

OBJECTIVES: This study was conducted to evaluate a self-adhesive resin luting cement [RelyX Unicem 3MESPE-RXU] for luting partial ceramic crowns (PCCs) with and without selective enamel etching in a prospective, randomized clinical trial. MATERIALS AND METHODS: Thirty-four patients had received the intended treatment. Two PCCs (Vita Mark II; Cerec 3D; Sirona) had been placed in a split-mouth design: one with RXU without enamel etching (RXU), the other with RXU with selective enamel etching (RXU + E). Restorations were evaluated at baseline (BL) and after 12, 24, and 36 months (USPHS criteria). For statistical analysis, the Chi-square test was applied (α = 0.05). Clinical survival of all restorations (n = 68) after 3 years was determined using Kaplan-Meier analysis. RESULTS: Twenty three patients (12 male/11 female) were available for clinical evaluation after 3 years. 19 RXU-PCCs were placed in molars, four in premolars, 18 RXU + E-PCCs in molars, five in premolars. Concerning clinical changes, no significant differences were found between luting strategies RXU/RXU + E at all recalls. Statistically significant changes over time were observed for marginal adaptation and marginal discoloration between BL and 36 m for RXU and RXU + E. For RXU + E, postoperative hypersensitivities decreased significantly from BL (n = 6) to 36 m (n = 0). Of the 68 restorations originally included, eight RXU and four RXU + E restorations failed. At 3 years, Kaplan-Meier survival of RXU was 72.9 %, that of RXU + E 87.6 %. Survival rates were not statistically significant different. CONCLUSIONS: Although clinical survival of RXU + E is slightly better at 3 years, restorations of both groups perform similar with respect to clinical changes over time as evaluated by modified USPHS criteria. CLINICAL RELEVANCE: The self-adhesive resin cement RXU can be used in conjunction with selective enamel etching, because survival rates of PCCs in the RXU + E group were not lower but, as a trend, even better than without enamel etching.

Effect of silanized nanosilica addition on remineralizing and mechanical properties of experimental composite materials with amorphous calcium phosphate.

OBJECTIVES: Experimental composite resins with amorphous calcium phosphate (ACP) have the potential to regenerate demineralized tooth structures. The aim of the study was to investigate the effect of the addition of silanized silica nanofillers to the ACP-based composites on their mechanical properties and the kinetics of calcium and phosphate release. MATERIALS AND METHODS: The test materials comprised 5 wt% (5-ACP) or 10 wt% (10-ACP) of silanized silica admixed to the 40 wt% ACP and 50 or 55 wt% resin. The ACP control (0-ACP) contained 40 wt% ACP and 60 wt% resin. Additionally, composite material CeramX (Dentsply, Germany) was included as control. Three-point bending test was performed to calculate flexural strength and modulus of elasticity. Inductively coupled plasma atomic emission spectroscopy was used for measurement of ion release. The micromorphology of calcium phosphate depositions on composite samples has been qualitatively evaluated using a scanning electron microscope. The results were analyzed using Mann-Whitney and Wilcoxon rank sum tests (α < 0.05). RESULTS: Ion release was enhanced by the silica fillers, when compared to the 0-ACP. Although not statistically significant, flexural strength of 10-ACP was improved by 46 % compared to 0-ACP. Flexural modulus of 5-ACP was significantly higher than 0-ACP. CONCLUSIONS: The admixture of silanized fillers seems to be a promising approach for the improvement of mechanical and remineralizing properties of ACP composite resins. CLINICAL RELEVANCE: ACP-based composite resins with modified composition could serve as an effective remineralizing aid as base materials in restorative dental medicine.

Effectiveness and biological compatibility of different generations of dentin adhesives.

OBJECTIVES: Besides possessing good mechanical properties, dental materials should present a good biological behavior and should not injure the involved tissues. Bond strength and biocompatibility are both highly significant properties of dentin adhesives. For that matter, these properties of four generations of adhesive systems (Multi-Purpose/Single Bond/SE Plus/Easy Bond) were evaluated. MATERIALS AND METHODS: Eighty bovine teeth had their dentin exposed (500- and 200-µm thickness). Adhesive was applied on the dentin layer of each specimen. Following that, the microshearing test was performed for all samples. A dentin barrier test was used for the cytotoxicity evaluation. Cell cultures (SV3NeoB) were collected from testing materials by means of 200- or 500-µm-thick dentin slices and placed in a cell culture perfusion chamber. Cell viability was measured 24 h post-exposition by means of a photometrical test (MTT test). RESULTS: The best bonding performance was shown by the single-step adhesive Easy Bond (21 MPa, 200 µm; 27 MPa, 500 µm) followed by Single Bond (15.6 MPa, 200 µm; 23.4 MPa, 500 µm), SE Plus (18.2 MPa, 200 µm; 20 MPa, 500 µm), and Multi-Purpose (15.2 MPa, 200 µm; 17.9 MPa, 500 µm). Regarding the cytotoxicity, Multi-Purpose slightly reduced the cell viability to 92% (200 µm)/93% (500 µm). Single Bond was reasonably cytotoxic, reducing cell viability to 71% (200 µm)/64% (500 µm). The self-etching adhesive Scotchbond SE decreased cell viability to 85% (200 µm)/71% (500 µm). Conversely, Easy Bond did not reduce cell viability in this test, regardless of the dentin thickness. CONCLUSIONS: Results showed that the one-step system had the best bond strength performance and was the least toxic to pulp cells. In multiple-step systems, a correct bonding technique must be done, and a pulp capping strategy is necessary for achieving good performance in both properties. CLINICAL RELEVANCE: The study showed a promising system (one-step self-etching), referring to it as a good alternative for specific cases, mainly due to its technical simplicity and good biological responses.

Blue light kills Aggregatibacter actinomycetemcomitans due to its endogenous photosensitizers.

OBJECTIVES: The aim of this study was to demonstrate that the periodontal pathogen Aggregatibacter actinomycetemcomitans (AA) can be killed by irradiation with blue light derived from a LED light-curing unit due to its endogenous photosensitizers. MATERIALS AND METHODS: Planktonic cultures of AA and Escherichia coli were irradiated with blue light from a bluephase® C8 light-curing unit with an emission peak at 460 nm, which is usually applied for polymerization of dental resins. A CFU-assay was performed for the analysis of viable bacteria after treatment. Moreover, bacterial cells were lysed and the lysed AA and E. coli were investigated for generation of singlet oxygen. Spectroscopic measurements of lysed AA and E. coli were performed and analyzed for characteristic absorption and emission peaks. RESULTS: A light dose of 150 J/cm(2) induced a reduction of ≥5 log10 steps of viable AA, whereas no effect of blue light was found against E. coli. Spectrally resolved measurements of singlet oxygen luminescence showed clearly that a singlet oxygen signal is generated from lysed AA upon excitation at 460 nm. Spectroscopic measurements of lysed AA exhibited characteristic absorption and emission peaks similar to those of known porphyrins and flavins. CONCLUSIONS: AA can be inactivated by irradiation with blue light only, without application of an exogenous photosensitizer. CLINICAL RELEVANCE: These results encourage further studies on the potential use of these blue light-mediated auto-photosensitization processes in the treatment of periodontitis for the successful inactivation of Aggregatibacter actinomycetemcomitans.

In-vitro-cytotoxicity of self-adhesive dental restorative materials.

OBJECTIVES: Although the introduction of self-adhesive composites in restorative dentistry is very promising, the innovation of new materials also presents challenges and unknowns. Therefore, the aim of this study was to investigate the cytotoxicity of four different self-adhesive composites (SAC) in vitro and to compare them with resin-modified glass ionomer cements (RM-GIC), a more established group of materials. METHODS: Samples of the following materials were prepared according to ISO 7405/10993-12 and eluted in cell culture medium for 24 h at 37 °C: Vertise Flow, Fusio Liquid Dentin, Constic, Surefil One, Photac Fil and Fuji II LC. Primary human pulp cells were obtained from extracted wisdom teeth and cultured for 24 h with the extracts in serial dilutions. Cell viability was evaluated by MTT assay, membrane disruption was quantified by LDH assay and apoptosis was assessed by flow cytometry after annexin/PI staining. RESULTS: Two SAC (Constic and Vertise Flow) and one RM-GIC (Photac Fil) significantly reduced cell viability by more than 30% compared to the untreated control (p < 0.001). Disruptive cell morphological changes were observed and the cells showed signs of late apoptosis and necrosis in flow cytometry. Membrane disruption was not observed with any of the investigated materials. CONCLUSION: Toxic effects occurred independently of the substance group and need to be considered in the development of materials with regard to clinical implications. CLINICAL SIGNIFICANCE: SAC have many beneficial qualities, however, the cytotoxic effects of certain products should be considered when applied in close proximity to the dental pulp, as is often required.