Marginal Adaptation of In Vitro Class II Restorations Made Out of Bulk or Conventional Composite Using Single- or Multi-Layered Techniques.

Objective: Testing the influence of various restorative materials (conventional or bulkfill composites) and filling techniques (single- or multi-layered techniques) on the in vitro marginal adaptation of large class II direct composites with supra and sub-gingival margins subjected to thermomechanical loading (TML). Methods: A total of 40 prepared teeth were attributed randomly to five experimental groups. In Group 1, restorations were made of multi-layered high-viscosity conventional composite (Tetric EvoCeram); in Groups 2 and 3, restorations were made of a high viscosity bulkfill composite (Tetric EvoCeram Bulk Fill) applied in one (Group 2) or three layers (Group 3); in Groups 4 and 5, restorations were made of a flowable bulkfill composite (SDR flow) applied in one (Group 4) or two layers (Group 5), covered with a layer of high-viscosity conventional composite (Ceram-X Universal). A single adhesive (OptiBond FL) was used in all groups. All specimens were submitted to a staged TML comprising three phases (2 × 500,000 and 1,000,000 cycles) at 50 N with 3350 thermal cycles (5 to 55 °C) every 500,000 cycles. The tooth-restoration interfaces on proximal surfaces were evaluated quantitatively by scanning electron microscopy, before and after each TML phase, hence at three timepoints (T0, T1, T2 and T3). The following segments were considered for evaluation: proximal, vertical enamel margins (assessed individually on both restoration sides), cervical enamel (restoration side above CEJ) and cervical dentin margin (restoration side below the CEJ). Results: TML induced a significant reduction in continuous adaptation at both enamel and dentin margins in all groups, with percentages of continuous margins ranging from 75.2 to 91.8% at T0, and decreasing to values ranging from 21.3 to 73.9% at T3. Both composite systems and layering protocols had a significant influence on marginal adaptation of the restorations, with statistical associations depending on the restoration group and the timepoint considered. Defective margins in enamel were all of a cohesive nature with micro-fractures, while in dentin, interfacial gaps were the main defect observed. Conclusions/Clinical significance: The present results highlighted significant degradation of marginal adaption after long-term in vitro fatigue test using materials even with high-viscosity conventional resin composites, applied with a proper layering approach in medium-large sub-gingival cavities. While no significant differences were observed at the dentin cervical margins, there was a tendency for better adaptation at the enamel margin when using a higher modulus material with a multi-layered technique.

In Vitro Evaluation of Tooth-Whitening Potential of Peroxide-Free OTC Dental Bleaching Agents.

Purpose: To evaluate and compare the tooth-whitening potential of five over-the-counter (OTC), peroxide-free dental bleaching methods as well as an experimental tooth-whitening solution containing 0.1% hydrogen peroxide complexed with doping agents with a gold standard (positive control) containing 16% carbamide peroxide. Material and Methods: Eighty permanent bovine incisor teeth were randomly allocated to eight different groups. Two teeth from each group were immerged into five staining solutions represented by coffee, tea, red wine, and curry mixed in warm oil or distilled water (control group) and stored at 37 °C for 28 days in an incubator. The teeth were then reallocated to the eight groups, resulting in ten samples per group, and each group was matched with a bleaching product. The bleaching procedures were executed following the manufacturer's recommendations. The color of each sample was assessed over a white and black background using a quantitative numerical measurement approach with a calibrated spectrophotometer. Spectrophotometric measurements were performed after exposing the teeth to the bleaching agent for 60 min (T2), 100 min (T3), and 200 min (T4), and ΔE00 was calculated. Results: When analyzed over a white background, the mean ΔE00 values ranged from 2.14 (placebo) to 6.32 (Opalescence PF). When analyzed over a black background, the mean ΔE00 values ranged from 2.31 (placebo) to 5.78 (Opalescence PF). Statistically significant ΔE00 color changes over time for the eight groups and five staining solutions at T1 and T4 were assessed for both backgrounds using repeated ANOVA followed by Fisher's LSD post hoc test (p-value < 0.01). Conclusions: All tested over-the-counter whitening kits except one exhibited positive color variation. However, the individual performance differed vastly from one brand to the other, and the overall performance was less effective compared to the conventional carbamide-peroxide-based positive control.

Time-and cost-effective 3-dimensional-printing workflow to rehabilitate worn dentitions: A clinical report.

Current restorative methods of restoring worn or eroded dentition present drawbacks that may deter dentists or patients from pursuing complete mouth rehabilitation. A novel additive manufacturing approach using 3D-printed definitive composite resin restorations is described as a less technique-sensitive and more cost-effective alternative. These restorations are straightforward to repair, modify, or replace.

Efficiency of 3D-printed composite resin restorations compared with subtractive materials: Evaluation of fatigue behavior, cost, and time of production.

STATEMENT OF PROBLEM: Three-dimensionally (3D)-printed composite resins have been marketed as materials for definitive restorations. However, limited information is available regarding the stability of the adhesive interface and the efficiency of 3D-printed composite resins. PURPOSE: The purpose of this in vitro study was to evaluate the integrity of the marginal adhesive interface before and after thermal and mechanical fatigue of an initial formulation of a 3D-printed composite resin and to evaluate the efficiency of this manufacturing method. MATERIAL AND METHODS: Freshly extracted molars were prepared for onlays and adhesively restored with either 3D-printed composite resin (VarseoSmile Crown Plus) (Group 3D), milled composite resin (Tetric CAD) (Group MCOMP), milled PMMA (Telio CAD) (Group PMMA), and milled lithium disilicate (IPS e.max CAD) (Group EM). Marginal analysis was performed under a scanning electron microscope before and after fatigue by thermomechanical cyclic loading, and initial and terminal percentages of continuous margin (%CM) were compared. The time required for the production of each type of restoration was recorded, and the production costs were also compared. RESULTS: Before aging, 3D, MCOMP, and EM presented comparable values of %CM (69.8%, 75.9%, and 63.1%, respectively) that were statistically significantly higher (P<.05) than those of PMMA (45.1%). After aging, 3D and EM had comparable results (44.7% and 43.7%, respectively), which were lower than those of the MCOMP group (68.5%) but higher than those of the PMMA group (20.5%). Regarding time efficiency, 3D printing took less time than MCOMP or PMMA if more than 8 restorations were fabricated. For the production costs, 3D printing was 5.5, 8.7, and 10.2 times less expensive than PMMA, MCOMP, and EM, respectively. The initial equipment cost was also lower for the additive manufacturing method. However, 3D printing did not always considerably reduce waste. CONCLUSIONS: In terms of marginal adaptation, the evaluated initial formulation of a 3D-printed composite resin behaved similarly to other well-established definitive restoration materials and better than milled PMMA, both before and after fatigue. Three-dimensionally printed resins present advantages in terms of equipment and consumable costs, even for a single restoration, but also for production time when more than 8 restorations were fabricated.

Effect of light-curing time and direction on microhardness of a light-cured resin composite to cement CAD-CAM restorations.

PURPOSE: To evaluate the effect of light-curing exposure time and location on polymerization of a restorative bulk-fill resin composite to lute endocrowns. METHODS: A light-cured restorative bulk-fill resin composite (Filtek One Bulk Fill) was submitted to direct light-curing by a high-power LED light-curing unit for 20 seconds as the positive control group (n= 10). Five more groups (n= 10) were light-cured in a natural tooth mold from two sites (labial and lingual) through a nanohybrid resin composite CAD-CAM restoration (Lava Ultimate A2 LT), for different irradiation times: 90 seconds per site, 40 seconds per site, 30 seconds per site, 20 seconds per site and 10 seconds per site. Vickers microhardness measurements were made at two different depths and test/control ratios were calculated. Ratios of 0.8 were considered as an adequate level of curing. A quantile regression was run to identify the minimally sufficient time of light-curing, and a two-way ANOVA was used to compare the results to previous findings and evaluate the effect of curing location. RESULTS: Analysis showed that 40 seconds x 2 is the minimal irradiation time that presents a test/control ratio above 0.8. Quantile regressions showed that the required irradiation time to reach a test/control ratio of 0.8 at a confidence level of 95% is 41.5 seconds and 39.2 seconds at 200 µm and 500 µm depths in the luting agent, respectively. There was no statistically significant difference between microhardness of the two depths except for the irradiation time of 10 seconds. The two-site to three-site light curing comparison showed no statistically significant difference except for the 90-second time. CLINICAL SIGNIFICANCE: Systematic light-curing through the labial, lingual and occlusal surfaces of thick indirect restorations is not always required for sufficient polymerization and can even waste valuable clinical time especially in the case of multiple restorations luted with resin composites.

Gloss retention of direct composites and corresponding CAD/CAM composite blocks.

OBJECTIVES: To compare gloss retention of four different resin composites with their corresponding CAD/CAM composite blocks. MATERIALS AND METHODS: Four direct resin composites (Filtek Supreme XTE A2 Body (3M, USA), Tetric EvoCeram A2 (Ivoclar Vivadent, Liechtenstein), GrandioSO x-tra A2 (VOCO, Germany), G-aenial Universal A2 (GC, Japan)), and their corresponding CAD/CAM composite blocks were tested. A total of 288 samples were prepared and three different tests were performed: brushing, exposition to acidic fluoride gel and exposition to alcoholic solution. Gloss values were obtained by means of a glossmeter at T0 before aging and T60 after 1 h of aging. RESULTS: Mean gloss values ranged from 0.9 after brushing tests to 79.0 after the alcohol test witnessing a high gloss variability depending on the materials and the aging test. Statistical analysis by means of two-way repeated measures ANOVA followed by Fisher's LSD post-hoc test revealed significant differences between materials, storage media, and their interactions. CONCLUSION: Gloss retention seems to be dependent on the composite type (direct or CAD/CAM block) and composite brand and varies in respect to the type of aging. CAD/CAM materials showed a higher resistance toward alcohol exposure.

In vitro evaluation of marginal adaptation in medium- and large size direct class II restorations using a bulk-fill or layering technique.

OBJECTIVES: to test if cavity dimensions and restorative protocol have potential to influence in-vitro adaptation of class II restoration after simulated thermo-occlusal stressing. METHODS: A total of 32 prepared teeth were randomly assigned to one of the 4 experimental groups depending on cavity size, composite system and filling technique; group 1: small cavity and multi-layered conventional restorative composite (Tetric Evo-ceram: TEC), group 2: small cavity and flowable bulk-filled composite (SDRFlow: SDR) + one single occlusal layer of conventional restorative composite (TEC), group 3: large cavity and multilayered conventional restorative composite (TEC) and group 4: large cavity and bulk-filled flowable composite (SDR) + one single occlusal layer conventional restorative composite (TEC). All specimens were submitted to 500'000 cycles of thermomechanical loading (50 N, 5 to 55 °C). The proximal tooth-restoration interface was analyzed quantitatively by SEM, prior and after thermomechanical loading. RESULTS: Before loading, continuous enamel adaptation varied from 61.49% (Gr 1) to 68.39% (Gr 4) proximally and from 50.93% (Gr2) to 68.65% (Gr1) cervically, with no statistical difference among groups for both segments. After thermomechanical loading, continuous enamel adaptation varied from 36.6% (Gr2) to 46.6% (Gr1) proximally, without significant difference, and from 20.2% (Gr4) to 51.3% (Gr1) cervically; statistical differences in cervical enamel adaptation were found in-between groups 1 and 2 (p = 0.0479), 1 and 4 (P = 0.0116), 2 and 3 (p = 0.0028) and 3 and 4 (p = 0.001). Before loading, dentin continuous adaptation varied from 55.32% (Gr3) to 81.82% (Gr4) with statistical difference in-between those groups (p = 0.045); after loading, dentin continuous adaptation varied from 31.56% (gr2) to 51% (Gr4) with a statistical difference between those 2 groups (p = 0.019). The drop in adaptations values after loading was significant in all groups and segments. CONCLUSIONS: The impact of the restorative technique and cavity size on marginal adaptation appeared essentially after simulated fatigue for enamel adaptation. Cervical enamel and dentin continuous adaption of small and large bulk-filled restorations dropped significantly while the change was lower in layered restorations made of conventional restorative composite. CLINICAL SIGNIFICANCE: Restorations made with bulk-filled flowable composite behaved differently from layered ones using conventional resin composite, according to cavity size and loading.

Effect of Multiple Enamel Surface Treatments on Micro-Shear Bond Strength.

Objectives: The aim of this study was to evaluate the effect of different enamel surface treatments on the micro-shear bond strength. Materials and methods: Sixty-four approximal surfaces from freshly extracted molars were randomly assigned to eight groups, according to combinations of the following enamel surface treatments: ground or unground, 37.5% phosphoric acid etching time of 15 or 30 s, and with or without primer application. The same bonding agent (Optibond FL™ Adhesive, Kerr) was then used for all groups, and a 1.8 mm diameter resin composite (Harmonize™, Kerr) cylinder was built up on the bonded surface. Samples underwent a shear force test at a crosshead speed of 1 mm/min until failure. Bond strength was calculated, and failure modes were inspected under an optical microscope. Results: Bond-strength values ranged from 8.2 MPa for 15 s etched unground enamel with primer application to 19.6 MPa for 30 s etched ground enamel without primer application. ANOVA and Fisher's LSD post hoc tests revealed significant differences between the groups. Conclusions: Etching time and grinding have a statistically significant effect on the micro-shear bond strength of a three-step etch-and-rinse adhesive system on enamel. Primer application does not seem to be beneficial for enamel adhesion.

Fracture strength of non-invasively reinforced MOD cavities on endodontically treated teeth.

The purpose of this in-vitro study was to evaluate the fracture resistance and failure mode of non-invasively reinforced endodontically treated mandibular molars. Sixty freshly extracted defect-free mandibular molars were divided into four experimental groups with extensive MOD cavities on endodontically treated teeth with different restoration types and one control group with intact teeth (n = 12). The groups were as follows: "Normal": direct resin composite; "Ring": glass fiber-reinforced strip (Dentapreg) wrapped around buccal and lingual walls followed by direct resin composite; "Inlay": indirect CAD/CAM resin composite inlay; "Onlay": indirect CAD/CAM resin composite onlay; "Intact": Intact teeth (Control). Tetric EvoCeram and Adhese Universal (Ivoclar Vivadent) were used for direct restorations and Tetric CAD (Ivoclar Vivadent) adhesively luted with Adhese Universal and Variolink Esthetic LC (Ivoclar Vivadent) were used for indirect restorations. All teeth were submitted to thermo-mechanical cyclic loading. All samples were then submitted to a compressive load until fracture. Fracture load was noted and teeth were analyzed to classify the failure mode as either catastrophic (C) or non-catastrophic (NC). No statistically significant difference was found between fracture strength of the five groups when all specimens were considered (p = 0.1461). Intact group showed the lowest percentage of catastrophic failures (41.67%). Ring group presents less catastrophic failures (75%) than Normal group (83.34%), and failures of indirect restorations-Inlay and Onlay-were almost all catastrophic (91.67% and 100%, respectively).

Influence of mechanical and chemical degradation on surface gloss of direct and CAD-CAM resin composite materials.

PURPOSE: To compare the gloss retention of four resin based materials, two direct resin composites (Tetric EvoCeram and Filtek Supreme) and two indirect resin composite CAD-CAM blocks (Tetric CAD and Lava Ultimate). METHODS: 36 samples of 1 mm thickness were readied of each test material and manually polished with polishing discs (Sof-Lex) up to the finest grit size. Three gloss measurements per sample were taken (one every 120 degrees of sample rotation) by means of a glossmeter (Novo-Curve) for a total of 60 values obtained per tested material. Samples of each material were then randomly divided into three equal groups and aged with 75% alcohol (Group 1), amine fluoride gel (Elmex gelée) (Group 2) or mechanical brushing (Group 3). Another set of gloss measurements was performed on all samples after 1 hour of aging. Gloss values were statistically evaluated by means of repeated measures ANOVA and Fisher's LSD post-hoc tests. RESULTS: Gloss retention values ranged from 59.0 (Tetric EvoCeram) to 70.9 (Lava Ultimate) for alcohol, from 59.3 (Filtek Supreme) to 67.5 (Lava Ultimate) for Elmex gelèe and from 33.3 (Tetric EvoCeram) to 53.4 (Lava Ultimate) for mechanical brushing. Statistical analysis revealed: (1) significant difference between intial and final gloss values for all materials and groups; (2) significant difference between final gloss values of all the materials in the alcohol group; (3) significant difference between final gloss values of Lava Ultimate and all the other materials in the Elmex gelèe group; (4) significant difference between final gloss values of Lava Ultimate and Tetric CAD with the other tested materials in the brushing group. CLINICAL SIGNIFICANCE: Direct resin composites in general are widely used, and CAD-CAM resin composite materials are becoming progressively more accessible. Making the choice between direct and indirect techniques is still a challenge, and understanding the advantages of CAD-CAM resin composites in the form of higher gloss retention, which translates into higher durability of esthetics, may be one the parameters facilitating the decision.

Effect of light-curing time on microhardness of a restorative bulk-fill resin composite to lute CAD-CAM resin composite endocrowns.

PURPOSE: To evaluate the minimal irradiation time to reach a sufficient polymerization of a photopolymerizable restorative bulk-fill resin composite to lute endocrowns. METHODS: A photopolymerizable restorative bulk-fill resin composite (Filtek One Bulk Fill) was submitted to direct light-curing by a high power LED light-curing unit for 20 seconds as the positive control group (n = 10). Five more test groups (n= 10) were light-cured in a natural tooth mold from three sites (buccal, palatal and occlusal) under a 9.5 mm thick nanohybrid resin composite CAD-CAM endocrown (Lava Ultimate A2 LT), for different irradiation times: 90 seconds per site, 40 seconds per site, 30 seconds per site, 20 seconds per site and 10 seconds per site. Vickers microhardness measurements were made at two different depths and test/control ratios were calculated. Ratios of 0.8 were considered as an adequate level of curing. RESULTS: Analysis shows that 30 seconds x 3 was the minimal irradiation time that presented a test/control ratio above 0.8. Quantile regressions showed that the required irradiation time to reach a test/control ratio of 0.8 at a confidence level of 95% was 38 seconds and 37 seconds for 200 µm and 500 µm, respectively. There was no statistically significant difference between microhardness of the two depths except for the irradiation time of 10 seconds. A 120-second (40 seconds per buccal, palatal and occlusal site) light-curing of photopolymerizable bulk-fill resin composite to lute a resin composite CAD-CAM endocrown restoration can be considered sufficient to reach adequate polymerization.

Transit amplifying cells coordinate mouse incisor mesenchymal stem cell activation.

Stem cells (SCs) receive inductive cues from the surrounding microenvironment and cells. Limited molecular evidence has connected tissue-specific mesenchymal stem cells (MSCs) with mesenchymal transit amplifying cells (MTACs). Using mouse incisor as the model, we discover a population of MSCs neibouring to the MTACs and epithelial SCs. With Notch signaling as the key regulator, we disclose molecular proof and lineage tracing evidence showing the distinct MSCs contribute to incisor MTACs and the other mesenchymal cell lineages. MTACs can feedback and regulate the homeostasis and activation of CL-MSCs through Delta-like 1 homolog (Dlk1), which balances MSCs-MTACs number and the lineage differentiation. Dlk1's function on SCs priming and self-renewal depends on its biological forms and its gene expression is under dynamic epigenetic control. Our findings can be validated in clinical samples and applied to accelerate tooth wound healing, providing an intriguing insight of how to direct SCs towards tissue regeneration.

Staining susceptibility of resin composite materials.

PURPOSE: To evaluate the color stability of three resin-based materials continuously exposed to various staining agents. METHODS: 144 disc-shaped specimens were made of each of the three tested composites (Essentia, Brillant, Inspiro). Half of them were 1 mm thick, the other half 1.2 mm thick. The thicker group was then polished up to 4,000 grit and reduced to 1 mm thickness, also. All specimens, after 24-hour dry storage in an incubator, received an initial color measurement by means of a calibrated reflectance spectrophotometer (SpectroShade). Specimens were then divided into six groups (n=6) and immersed in five staining solutions or artificial saliva (control). All specimens were kept in an incubator at 37°C for 28 days. Staining solutions (red wine, curry mixed in water, curry mixed in oil, tea and coffee) were changed every 7th day to avoid bacteria or yeast contamination. After 28 days of storage, spectrophotometric measurements were repeated and L*a*b* scores once more recorded to determine the color (ΔE00) changes. RESULTS: All tested materials showed significant color changes after 28 days staining immersion. ΔE00 of polished samples varied from 1.1 (Essentia/distilled water measured over a white background as well as Essentia, Inspiro/distilled water measured over a black background) to 32.5 (Inspiro/wine measured over a white background). CLINICAL SIGNIFICANCE: Staining of restorative materials seems to be dependent on the composition of the product itself. Unpolished samples were more prone to staining than the polished ones.

Psychometric Properties and Factor Structure of the Short Form of the Affective Lability Scale in Adult Patients With ADHD.

Objective: Affective lability is an important dimension of adult ADHD, associated with marked impairments and worse outcomes. A valid and quick tool to measure affective lability may therefore be of interest. Method: In 187 adult ADHD patients, we explored psychometric properties of the Affective Lability Scale-Short Form (ALS-18 items). We analyzed the construct validity and the external validity of the scale. Patients were compared with 48 healthy adult controls. Results: The three-factor structure of the ALS-18 presented a good fit and a good internal consistency. The correlations between the ALS-18 and ADHD symptoms and other psychological dimensions were, respectively, low and moderate. ALS-18 scores were higher in patients than in healthy adults. Conclusion: ALS-18 showed good psychometric properties in ADHD adult patients, allowing us to recommend the implementation of ALS-18 in assessing affective lability for clinical and research purposes. Use of ALS-18 should improve the clinical assessment of affective lability in adult ADHD patients.

Impulsivity and its association with childhood trauma experiences across bipolar disorder, attention deficit hyperactivity disorder and borderline personality disorder.

BACKGROUND: Impulsivity is a core feature of the attention-deficit/hyperactivity disorder (ADHD) and is one of the DSM-V diagnostic criteria for borderline personality disorder (BPD). Impulsivity is also present in bipolar disorder (BD). Impulsivity has been linked to adverse behavior (suicidality,…) and to traumatic childhood experiences. Our study explored impulsivity in BPD, BD, ADHD and healthy controls (CTRL) and investigated the impact of early trauma on impulsivity. METHODS: 744 patients with BD (n = 276), BPD (n = 168), ADHD (n = 173) or a combination (BPD_BD, n = 29; BPD_ADHD, n = 94, BD_BPD_ADHD n = 13) and 47 controls were included. All subjects were completed the Baratt Impulsivity Scale (BIS-10) and the Childhood Trauma Questionnaire (CTQ). RESULTS: BD reported the same levels of impulsiveness as CTRL. When BPD and BD are co-morbid, impulsivity increased to reach the level of BPD. Impulsiveness was significantly associated to traumatic childhood event for BD and CTRL, not for BPD and AHDH. LIMITATIONS: Impulsivity was assessed on the basis of a self-report questionnaire and not by the mean of an objective measure such as a neuropsychological test. Moreover, we don't know what treatment our pathological subjects were receiving. But, ADHD and BPD, despite the probable treatment, were more impulsive than healthy CTRLs who did not take medications. CONCLUSIONS: Impulsivity is probably not a feature of BD but is associated with the presence of traumatic childhood experiences, especially for euthymic patients, unlike BPD and ADHD. So, it seems essential to assess the presence of early trauma to reduce the impulsivity and improve the evolution of BD.

Prominin-1 controls stem cell activation by orchestrating ciliary dynamics.

Proper temporal and spatial activation of stem cells relies on highly coordinated cell signaling. The primary cilium is the sensory organelle that is responsible for transmitting extracellular signals into a cell. Primary cilium size, architecture, and assembly-disassembly dynamics are under rigid cell cycle-dependent control. Using mouse incisor tooth epithelia as a model, we show that ciliary dynamics in stem cells require the proper functions of a cholesterol-binding membrane glycoprotein, Prominin-1 (Prom1/CD133), which controls sequential recruitment of ciliary membrane components, histone deacetylase, and transcription factors. Nuclear translocation of Prom1 and these molecules is particularly evident in transit amplifying cells, the immediate derivatives of stem cells. The absence of Prom1 impairs ciliary dynamics and abolishes the growth stimulation effects of sonic hedgehog (SHH) treatment, resulting in the disruption of stem cell quiescence maintenance and activation. We propose that Prom1 is a key regulator ensuring appropriate response of stem cells to extracellular signals, with important implications for development, regeneration, and diseases.

Protection Against Discolouration by Two Over-the Counter Desensitising Products.

PURPOSE: To determine in vitro the protection potential against discolouration of two OTC (over-the-counter) desensitising products on enamel and dentin in comparison to a standard toothpaste and water by means of a spectrophotometer. MATERIALS AND METHODS: A total of 96 samples of bovine enamel-dentin complex and 48 of bovine dentin were alternatively immersed in red wine, tea, coffee or water after having been treated by a sodium monofluorophosphate- and calcium phosphate-based product (Curodont Protect), an amine fluoride-based toothpaste (Elmex Red), a stannous chloride-based toothpaste (Elmex Protection Erosion) or distilled water (negative control). Initial (T0) and final colour (T1, after 4 weeks of immersion in staining solutions) of each specimen were assessed by a spectrophotometer. Statistical analysis was done by means of repeated measures ANOVA followed by Fisher's LSD post-hoc test. Differences between T0 and T1 were considered stastistically significant at p ≤ 0.05. RESULTS: When enamel samples were measured over a black background, ΔE00 values (T0-T1) varied from 2.2 (SD 0.7) for amine fluoride-based product/water to 53.9 (SD 7.6) for amine fluoride-based-product/red wine. When dentin samples were measured over a black background, ΔE00 values (T0-T1) varied from 5.4 (SD 0.9) stannous chloride based product/water to 61.6 (SD 3.7) amine fluoride-based product/red wine. CONCLUSION: Specifically, the application of the sodium monofluorophosphate was able to statistically significantly (p ≤ 0.05) reduce discolouration induced by the staining solutions tested only on the enamel-dentin complex, while distilled water and the stannous fluoride-based product were able to statistically significantly (p ≤ 0.05) reduce discolouration induced by the staining solutions tested in pure dentin samples.

3D Digital Smile Design With a Mobile Phone and Intraoral Optical Scanner.

Extraoral facial scanning using a mobile phone has emerged as a viable, cost-effective option for certain applications not requiring high precision, such as patient education and 3-dimensional (3D) digital smile design. This technological development is particularly promising for general practitioners (GPs) who may not be able to invest in expensive,complex digital impressioning devices. This article describes and illustrates a relatively simple and accessible workflow that avails digital 3D facial scanning benefits to GPs.

What should we expect from Switzerland's compulsory dental insurance reform?

BACKGROUND: A vast and heated debate is arising in Switzerland as a result of some recent citizens' initiatives aimed at introducing compulsory dental health care insurance. The Grand Conseils of the Vaud, Geneva, and Neuchâtel cantons recently approved three public initiatives and their citizens are expected to vote on the proposal in 2018. The process of collecting signatures has begun in several other cantons and the discussion has now moved to a national level. DISCUSSION: At present, there is no scientific research that can help policy-makers and citizens to understand the main economic implications of such reform. We attempt to fill this gap by analysing three critical issues: the level and determinants of unmet needs for dental care in Switzerland; the protection of vulnerable individuals; and the economic sustainability of reform. RESULTS AND SHORT CONCLUSIONS: The results show that income is not a unique determinant of barriers to access to dental care but rather, cultural and socio-demographic factors impact the perceived level of unmet dental care needs. The reform might only partially, if at all, improve the equity of the current system. In addition, the results show that the 1% wage-based contribution that the reform promoters suggest should finance the insurance is inadequate to provide full and free dental care to Swiss residents, but is merely sufficient to guarantee basic preventive care, whereas this could be provided by dental hygienists for less.