Dpto. Odontología

Aim: To establish the relationship between dental erosion prevalence in children aged 6-14 and all the aetiological factors that lead to the development of the lesions. Materials and methods: Study design: A correlational cross-sectional study of a sample of 400 Valencian children was conducted. First, a questionnaire was completed to analyse the patients' health status, their dietary and oral hygiene habits, the kind of school they attended and their parents' academic level. Then, a clinical exploration of the permanent dentition was done, calculating the BEWE index and the risk of erosion for each patient. Results: The prevalence of dental erosion of the studied sample was 22.3%. A positive correlation was observed between the presence of dental erosion and the frequent intake of fruit juices, carbonated and isotonic drinks (p<0.05), presenting a higher correlation if the liquid was kept in the mouth before swallowing. Aetiological factors such as the use of inhalers in patients with asthma (p=0.006), frequency of vomiting and regurgitation (p<0.001), frequent swimmers (p<0.001) or a low socioeconomic status (p<0.05) were also positively associated to the development of erosive lesions. Statistics: A descriptive and inferential statistical analysis was performed, using the Mann-Whitney U and the Kruskal-Wallis tests in the latter. Conclusion: The results of this study suggest that the frequent intake of fruit juices, carbonated and isotonic drinks, the use of inhalers and belonging to a low socioeconomic level family are factors positively associated to the development of erosive lesions.

Purpose: To compare after five-year simulated pulpal pressure (SPP) the degradation of adhesive-dentin interfaces created using two simplified adhesives applied with different bonding strategies. Materials and Methods: A two-step self-etch (CSE: Clearfil SE Bond) adhesive was used as a control multistep adhesive. The tested experimental materials were two simplified adhesives, a one-step self-etch (CS3: Clearfil S3 Bond) and a self-priming etch-and-rinse adhesive (SB2: Adper Single-Bond 2). Half of the bonded specimens were submitted to microtensile bond strength (μTBS) testing after 24 h. The other half submitted to SPP for five years before μTBS testing. Nonfractured sticks were evaluated using transmission electron microscopy (TEM). Scanning electron microscopy (SEM) was used to evaluate silver-nitrate nanoleakage within the interface. Data were statistically analyzed by two-way ANOVA and Tukey’s test (p < 0.05). Results: Prolonged SPP induced bond-strength reduction for both SB2 and CS3. All bonding approaches showed increased nanoleakage after aging. The two simplified adhesives showed severe degradation at the resin-dentin interface. TEM revealed that the main degradation patterns for the etch-and-rinse adhesive SB2 was collagen breakdown, while polymer hydrolysis along with filler debonding was mainly observed in CS3. Conclusions: Simplified adhesives applied in etch-and-rinse mode are mainly characterized by hydrolysis and collagen degradation. In self-etch mode, simplified adhesives may principally show hydrolysis of the polymeric matrix and/or at the interface of fillers and coupling agent. The use of multistep self-etching adhesives may guarantee greater dentin bond durability compared to simplified adhesives.

The aim of this study was to evaluate the infuence of boron-nitride nanotubes (BNNTs) on the properties of resin-based light-curing dental sealants (RBSs) when incorporated at diferent concentration. RBSs were formulated using methacrylate monomers (90 wt.% TEGDMA, 10 wt.% BisGMA). BNNTs were added to the resin blend at 0.1 wt.% and 0.2 wt.%. A Control group without fller was also designed. Degree of conversion, ultimate tensile strength, contact angle, surface free energy, surface roughness and color of the RBSs were evaluated for the tested materials. Their cytotoxicity and mineral deposition ability (Bioactivity) were also assessed. A suitable degree of conversion, no efect in mechanical properties and no cytotoxic efect was observed for the experimental materials. Moreover, the surface free energy and the surface roughness decreased with the addition of BNNTs. While the color analysis showed no diference between specimens containing BNNTs and the control group. Mineral deposition occurred in all specimens containing BNNTs after 7d. In conclusion, the incorporation of BNNTs may provide bioactivity to resin-based dental sealants and reduce their surface free energy.

Dentistry-applied bioceramic materials are ceramic materials that are categorized asbioinert, bioactive and biodegradable. They share a common characteristic of being specificallydesigned to fulfil their function; they are able to act as root canal sealers, cements, root repair or fillingmaterials. Bioactivity is only attributed to those materials which are capable of inducing a desiredtissue response from the host. The aim of this study is to present a systematic review of availableliterature investigating bioactivity of dentistry-applied bioceramic materials towards dental pulp stemcells, including a bibliometric analysis of such a group of studies and a presentation of the parametersused to assess bioactivity, materials studied and a summary of results. The research question, based onthe PICO model, aimed to assess the current knowledge on dentistry-based bioceramic materials byexploring to what extent they express bioactive properties inin vitroassays and animal studies whenexposed to dental pulp stem cells, as opposed to a control or compared to different bioceramic materialcompositions, for their use in the dentin-pulp complex therapy. A systematic search of the literaturewas performed in six databases, followed by article selection, data extraction, and quality assessment.Studies assessing bioactivity of one or more bioceramic materials (both commercially available ornovel/experimental) towards dental pulp stem cells (DPSCs) were included in our review. A total of37 articles were included in our qualitative review. Quantification of osteogenic, odontogenic andangiogenic markers using reverse transcriptase polymerase chain reaction (RT-PCR) is the prevailingmethod used to evaluate bioceramic material bioactivity towards DPSCs in the current investigativestate, followed by alkaline phosphatase (ALP) enzyme activity assays and Alizarin Red Staining(ARS) to assess mineralization potential. Mineral trioxide aggregate and Biodentine are the prevalentreference materials used to compare with newly introduced bioceramic materials. Available literaturecompares a wide range of bioceramic materials for bioactivity, consisting mostly ofin vitroassays.The desirability of this property added to the rapid introduction of new material compositions makesthis subject a clear candidate for future research.Keywords:bioactivity; bioceramic materials; dental pulp stem cells; systematic reviewMaterials2019,12, 1015; doi:10.3390/ma12071015www.mdpi.com/journal/materials Materials2019,12, 10152 of 301. IntroductionWithin the field of biomedical therapeutics, we can highlight the concept of tissue engineeringto refer to the development of procedures and biomaterials that aim to devise new tissues to replacethose damaged, following the principles of cellular and molecular biology and taking as a premise thesearch for “biological solutions for biological problems” [1].In 2007, the American Association of Endodontists adopted the term “regenerative endodontics”to refer to the concept of tissue engineering applied to the restoration of root canal health, in a waythat continuous development of the root and tissues surrounding it is promoted [2].The introduction of the so-called bioceramic materials meant a great advance for this newparadigm in endodontic therapy [3], given their biocompatible nature and excellent physicochemicalproperties [4]. Categorized as bioinert, bioactive and biodegradable [5], dentistry-applied bioceramicmaterials are ceramic materials which share a common characteristic of being specifically designed tofulfil their function; they are able to act as root canal sealers, cements, root repair or filling materials [4].Applied to vital pulp therapy, bioceramic materials can be used in cases of pulp exposition fromtrauma, caries or other mechanical causes, as direct pulp cappers [6].Properties like biocompatibility and bioactivity are to be expected in dentistry-applied bioceramicmaterials for their use in vital pulp therapy [7]. The first one refers to the “ability to perform as asubstrate that will support the appropriate cellular activity, including the facilitation of molecularand mechanical signaling systems, in order to optimize tissue regeneration, without eliciting anyundesirable local or systemic responses in the eventual host” [8], while bioactivity goes even further,and is only attributed to those materials which are capable of inducing a desired tissue responsefrom the host [9] by the use of biomimetic approaches [10]. The term differs depending on the fieldin which it is implemented, being related to the cellular effects induced by biologically active ionsand substances released from biomaterials in the field of tissue engineering, but referred to as thebiomaterial’s capability of forming hydroxyl apatite mineral on its surface bothin vitroandin vivointhe field of biomaterial science [11].Considering these desirable characteristics of bioceramic materials, it seems convenient to analyzethe interaction between human dental pulp stem cells (hDPSCs), which are post-natal stem cellswith mesenchymal stem cell (MSCs)-like characteristics, like auto-renewal ability and multilineagedifferentiation potential [12], and them; as their combined use could mean and advancement in thefield of regenerative endodontics.Cytotoxicity and biocompatibility of a wide range of bioceramic materials towards dental stemcells (DSCs) have been investigated in numerous studies [13–17]; among others. The well-knownPro-Root MTA (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA) has been shown to increaseosteoblast, fibroblast, cementoblast, odontoblast and pulp cell differentiation, but its handling difficultyamong other limitations encourages for a search for alternative materials [13]. Materials like Biodentine(Septodont, Saint Maurdes-Fosses, France) and TheraCal LC (Bisco Inc., Schaumburg, IL, USA) areexamples of bioceramic materials introduced posteriorly in dentistry for their use in vital pulp therapyas blood clot protectors in pulpal revascularization procedures, standing out for their consistency,easier manipulation and tricalcium silicate composition [16].However, to the best of the authors’ knowledge, there has been no effort to sort and summarizestudies analyzing bioactivity of such materials into more homogenous subgroups that would allow foran easier analysis of the evidence.

Objective:To evaluate the effect of a new application method of bulk-fill flowable compositeresin material on bond-strength, nanoleakage, and mechanical properties of dentine bonding agents.Materials and methods: Sound extracted human molars were randomly divided into: manufacturer ’sinstructions (MI), manual blend 2 mm (MB2), and manual blend 4 mm (MB4). Occlusal enamelwas removed and flattened, dentin surfaces were bonded by Prime & Bond universal (Dentsplyand Optibond FL, Kerr). For the MI group, adhesives were applied following the manufacturer’sinstructions then light-cured. For MB groups, SDR flow+bulk-fill flowable composite resin wasapplied in 2- or 4-mm increment then manually rubbed by a micro brush for 15 s with uncured dentinebonding agents and the mixture was light-cured. Composite buildup was fabricated incrementallyusing Ceram.X One, Dentsply nanohybrid composite resin restorative material. After 24-h waterstorage, the teeth were sectioned to obtain beams of about 0.8 mm2for 24-h and thermocycledmicro-tensile bond strength at 0.5 mm/min crosshead speed. Degree of conversion was evaluatedwith micro-Raman spectroscopy. Contraction gaps at 24 h after polymerization were evaluated andatomic force microscopy (AFM) nano-indentation processes were undertaken for measuring thehardness across the interface. Depth of resin penetration was studied using a scanning electronmicroscope (SEM). Bond strength data was expressed using two-way ANOVA followed by Tukey’stest. Nanoindentation hardness was separately analyzed using one-way ANOVA. Results: Factors“storage F=6.3” and “application F=30.11” significantly affected the bond strength to dentine.For Optibond FL, no significant difference in nanoleakage was found in MI/MB4 groups betweenbaseline and aged specimens; significant difference in nanoleakage score was observed in MB2 groups.Confocal microscopy analysis showed MB2 Optibond FL and Prime & Bond universal specimensdiffusing within the dentine. Contraction gap was significantly reduced in MB2 specimens in bothadhesive systems. Degree of conversion (DC) of the MB2 specimens were numerically more comparedto MS1 in both adhesive systems. Conclusion: Present study suggests that the new co-blend techniquemight have a positive effect on bond strengths of etch-and-rinse adhesives to dentine.

The aim of this study was to evaluate the effect of light-curing protocols on two modern resin composites using different airinhibition coating strategies. This was accomplished by assessing the amount of monomer elution, surface microhardness, and composite discoloration in different storage conditions. A total of 120 specimens were prepared using Filtek Supreme XTE (3M ESPE, Seefeld, Germany) and CeramX Universal (Dentsply DeTrey, Konstanz, Germany). Specimens were light-cured in air as per manufacturer’s instructions or in the absence of oxygen. This latter condition was achieved using three different approaches: (i) transparent polyester strip; (ii) glycerin; (iii) argon gas. Specimens were assessed for release of monomers, Vickers hardness, and discoloration after storage in different solutions. The results were analyzed with ANOVA one-way test followed by Student-Newman-Keuls test. Moreover, multiple comparisons of means were performed using the Student t-test (p<0.05). The amount of monomers released from the tested specimens was very low in all conditions. The presence of oxygen induced some decrease in microhardness.The highest discoloration values, for bothmaterials, were obtained after ageing in red wine. In case finish and polish procedures are awkward to achieve in posteriors composite restoration, light-curing in the absence of oxygen should be considered, especially when performing composite restoration in esthetic areas.

This study aimed at evaluating the microtensile bond strength (MTBS) and fractographic features of dentine-bonded specimens created using universal adhesives applied in etch-and-rinse (ER) or self-etching (SE) mode in combination with modern ion-releasing resin-modified glass-ionomer cement (RMGIC)-basedmaterials after load cycling and artificial saliva aging. Two universal adhesives (FTB: Futurabond M+, VOCO, Germany; SCU: Scotchbond Universal, 3M Oral Care, USA) were used. Composite build-ups were made with conventional nano-filled composite (AURA, SDI, Australia), conventional resin-modified glass ionomer cement (Ionolux VOCO, Germany), or a (RMGIC)-based composite (ACTIVA, Pulpdent, USA). The specimens were divided in three groups and immersed in deionized water for 24 h, load-cycled (350,000 cycles; 3 Hz; 70 N), or load-cycled and cut into matchsticks and finally immersed for 8 months in artificial saliva (AS). The specimens were cut into matchsticks and tested for microtensile bond strength. The results were analyzed statistically using three-way ANOVA and Fisher’s LSD post hoc test (p < 0.05). Fractographic analysis was performed through stereomicroscope and FE-SEM. FTB showed no significant drop in bond strength after aging. Unlike the conventional composite, the two RMGIC-based materials caused no bond strength reduction in SCU after load-cycle aging and after prolonged aging (8 months). The SEM fractographic analysis showed severe degradation, especially with composite applied on dentine bonded with SCU in ER mode; such degradation was less evident with the two GIC-based materials. The dentine-bond longevity may be influenced by the composition rather than the mode of application (ER vs. SE) of the universal adhesives. Moreover, the choice of the restorative material may play an important role on the longevity of the finalrestoration. Indeed, bioactive GIC-based materials may contribute to maintain the bonding performance of simplified universal adhesives over time, especially when these bonding systems are applied in ER mode.

Orthodontic adhesives with antimicrobial and remineralizing properties may be an alternative to control white spot lesions around brackets. The aim of this study is to develop an experimental orthodontic adhesive containing boron nitride nanotubes (BNNT) and alkyl trimethyl ammonium bromide (ATAB). Methacrylate (BisGMA and TEGDMA) monomers were used to formulate the adhesives. Four experimental groups were produced with the addition of 0.1 wt.% BNNT (GBNNT); 0.1 wt.% ATAB (GATAB); and 0.2 wt.% BNNT with ATAB (GBNNT/ATAB); in the control group, no fillers were added (GCtrl). The degree of conversion, cytotoxicity, softening in solvent, contact angle and free surface energy, antibacterial activity, shear bond strength, and mineral deposition were evaluated. Adhesives achieved degree of conversion higher than 50% and cell viability higher than 90%. GBNNT and GATAB adhesives exhibited reduced softening in solvent. Mean free surface energy was decreased in the GBNNT adhesive. Significant reduction in bacterial growth was observed in the GBNNT/ATAB. No statistical difference was found for shear bond strength. Mineral deposition was found in GBNNT, GATAB, and GBNNT/ATAB groups after 14 and 28 days. The addition of 0.2% BNNT/ATAB to an experimental orthodontic adhesive inhibited bacterial growth and induced mineral deposition without affecting the properties of the material.

The purpose of this literature review was to evaluate the efficacy of hypnosis as a pain relieving method during and after the dental procedure. References focusing on pain and that could include anxiety and physiological parameters as evaluation criteria were taken into consideration. From the 15 studies who met inclusion criteria it was found that, when used as an individual therapy, hypnosis lead to an increase in patient’s pain threshold. However, effectiveness was directly dependent on the degree of discomfort of the dental treatment performed, with low pain procedures having a higher success rate. When used as an adjunct to local anaesthesia, hypnosis reduces the amount of postoperative analgesic consumption, helps in patients´ general comfort, and decreases anxiety levels.

INTRODUCTION AND AIMS: This study investigates the effects of the application of antimicrobial phototherapy on black-stained tooth surfaces. Key variables were area, color and time taken to reappearance of black stain following dental prophylaxis with and without antimicrobial phototherapy. Differences in bacterial composition of black stain (specifically Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Porphyromonas gingivalis) were analyzed. MATERIAL AND METHODS: The phototherapy device used was GLO™ Science LLC, New York, America, emitting light at 475 nm and a power of 3W. Light was applied in 2 cycles of 8 min on 31 volunteers. Microbial identification was carried out on DNA extracted from black plaque. This study is registered with ClinicalTrials.gov, number NCT03309748. RESULTS: Following antimicrobial phototherapy, 64.5% of patients displayed reduced pigmentation area. Plaque color was lighter in 48.4% of subjects. Pigmentation area and depth of color returned to normal levels during the course of the study. Colonization by the three bacterial species decreased, although the changes were not statistically significant. We report a key novel finding showing elevated levels of colonization by Tannerella forsythia (83.9%) in adult black stain. CONCLUSIONS: Application of phototherapy results in a reduction in area, color and bacterial colonization of black plaque in adults. The changes were not found to be statistically significant, perhaps owing to the low illumination power of the homewhitening device. For the first time, we document the elevated presence of Tannerella forsythia in adult black stain. We also demonstrate the potential application of a commercially available home-whitening device for black plaque treatment.