This non-controlled clinical study evaluated the masking effect of an infiltrant resin on mild molar incisor hypomineralization (MIH) lesions. Thirty MIH-affected anterior teeth with creamy/ white opacities from 12 children aged 6-15 years received the application of an infiltrant resin (Icon- DMG). Standard photographs were taken before (T1), immediately after (T2), and 1 week after (T3) resin infiltration. Two calibrated examiners qualitatively analyzed the color match using the Fédération Dentaire Internationale (FDI) scale. The binomial distribution test analyzed the scores of the color match at T1 with T2 and T3, and McNemar's test analyzed the scores of the color match between T2 and T3 (α=0.05). There was a significant increase in color match between T1 and T2 (p=0.0005), between T1 and T3 (p=0.0005), and between T2 and T3 (p=0.0019). It was concluded that infiltrant resin was effective in improving the esthetic appearance of creamy/white opacities on MIH-affected anterior teeth.

This study aimed to assess the scanning time (ST) and accuracy of 10 repeated upper and lower dentition scans by four groups of operators with different professional backgrounds. There were a total of 32 participants, including dentists, nurses, postgraduates, and undergraduates (n=8). They received the same training about intraoral scanning and then performed 10 repeat scans on the plaster maxillary and mandibular dentition models in a manikin head, with the first five scans being the T1 phase and the last five scans being the T2 phase. Each ST was recorded. Trueness and precision were evaluated by root mean square (RMS) value gained from alignments of corresponding virtual models. For statistical analysis, the paired-sample t-tests, one-way ANOVA, and Pearson correlation tests were employed (α=0.05). Limiting the comparison in scan phase and scan target the sequence of STs for the four groups was the same (p<0.05), by which undergraduates, postgraduates, nurses, and dentists were in descending order. Undergraduates gained the best precision, followed by postgraduates, dentists, and nurses, in both maxillary and mandibular scanning (p<0.05). Compared with corresponding items of the T1 phase, the trueness of the T2 phase was much higher (p<0.05), while the ST of the T2 phase was much shorter (p<0.05). The operator's professional background affects the precision and scanning time but not the trueness. Most dental personnel have good access to the intraoral scanner. As the number of scans increased, the accuracy and scanning efficiency also improved.

SUMMARY There is a lack of reports in the literature on the long-term clinical performance of ultratranslucent zirconia, especially considering its use in manufacturing monolithic veneers. The purpose of this case series is to describe the aesthetic treatment steps of three patients with minimally invasive ultratranslucent zirconia veneers and to report the clinical findings up to five years. Three patients (woman: 2, man: 1; mean age: 30 years) unsatisfied with their dental aesthetics sought dental treatment. The treatment plan involved cementing ultratranslucent zirconia veneers. Air-abrasion was performed on the internal surface of zirconia with alumina particles coated by silica (silicatization), followed by silane and adhesive applications for the adhesive cementation. All veneers were adhesively cemented to enamel with resin cement (Variolink Esthetic, Ivoclar). The patients were clinically evaluated annually considering the Ryge modified/ California Dental Association criteria. After a mean follow-up of 4.33 years (4-5 years), a survival rate of 100% was detected for the 28 minimally invasive ultratranslucent zirconia veneers cemented in the 3 patients. There were no absolute failures such as debonding, veneer fracture, or secondary caries. Superficial marginal discoloration was observed in one element (maxillary left lateral incisor) of one patient. Ultratranslucent zirconia is a viable option for manufacturing veneers due to its excellent clinical performance and longevity. However, further long-term clinical studies are essential to consolidate this material as an option for esthetic restorations.

The present study aimed to evaluate the desensitizing effect of toothpaste for sensitive teeth on patient tooth sensitivity and on bleaching efficacy of the 38% hydrogen peroxide bleaching agent used for in-office bleaching compared to a regular toothpaste in a randomized clinical trial. Forty-eight patients having maxillary right central incisors with darkness greater than A1 were selected for the present double-blind randomized clinical trial. Patients were randomly allocated into two groups: the placebo group, which used regular toothpaste, and the experimental group, which used sensitivity toothpaste. The intervention consisted of applying toothpaste with the aid of an individual tray for a period of 4 minutes daily, starting one week before the first bleaching session and interrupting use immediately after the second session. After allocation to one of the groups, individuals received in-office dental bleaching with a 40-minute application of 38% hydrogen peroxide for two sessions with an interval of one week. The incidence and intensity of sensitivity were assessed using a visual analogue scale and a numeric analogue scale. Sensitivity was measured immediately before each session, 1 hour, 24 hours, and 48 hours after each bleaching session and four weeks after the second bleaching session. Tooth shade was evaluated using a spectrophotometer and by comparison with the VITA Classical Shade Guide (Vita Zahnfabrik, Bad Säckingen, Germany). Tooth shade was evaluated before the first bleaching session, one week after the first bleaching session, one week after the second bleaching session and four weeks after the second bleaching session. Participants and professionals who performed the bleaching, shade, and sensitivity assessments were blinded to the group of patients they were treating or assessing. For the incidence of hypersensitivity, the results were evaluated by comparing the groups at different evaluation times with the Mann-Whitney test for comparison between groups, the Friedman test for repeated measures, and the Tukey test for comparison of times. Shade change on the guide was analyzed using the Mann-Whitney test for comparison between groups and the Wilcoxon test for comparison between times. Shade change by the spectrophotometer was analyzed using the t-test for comparison between groups and the paired t-test for comparison between times. All analyses were performed with a significance level of 5%. There was no difference in the pattern of dental hypersensitivity between groups. For all shade measures, there was no difference between the bleaching results, and no statistically significant difference was observed between the study groups. The use of arginine-based desensitizing toothpaste did not interfere with the bleaching ability of hydrogen peroxide and was not effective in reducing the sensitivity caused by in-office tooth bleaching.

The open sandwich technique is a reliable alternative to amalgam placement in deep proximal box preparations, where proper isolation and enamel bonding may not be possible. It is often difficult to prepare the box for composite placement without affecting the resin-modified glass ionomer (RMGI) that has been placed in the gingival portion. We hypothesized that RMGI surfaces that are roughened or those that use all steps in the manufacturing bonding protocol, including the priming solution, applied before placing a bonded composite increment, would have greater composite/RMGI shear bond strength. Shear bond strengths (SBS) of RMGI tested in the presence and absence of SiC roughening and primer-coating were tested using a fourth-generation dentin bonding agent to composite after thermocycling. Twenty specimens for four test conditions were fabricated and investigated. Data were subjected to a two-way ANOVA and the Holm-Sidak post-hoc test. Placing dentin primer on unabraded RMGI provided a statistically significant improvement in SBS, but only modestly. Furthermore, because bond failure consistently occurred within the RMGI itself, none of the surface modifications have a clinically relevant impact on SBS at the RMGI to the composite interface. Clinicians should be aware that they need not avoid RMGI abrasion and do not need to incorporate all components of a fourth-generation bonding system when covering an RMGI sandwich layer with composite.

This case report describes the clinical protocols for using injectable flowable resin-based composite veneers without tooth reduction as long-term prototype restorations, followed by conservative feldspathic veneer restorations. The patient's primary concern was to improve her smile. After clinical evaluation, injectable flowable resin composite veneers were recommended as long-term prototypes followed by conservative tooth preparation and ceramic veneers. Flowable composite veneers were created with a transparent silicone index fabricated from a diagnostic wax-up approved by the patient. No tooth reduction was required to place this type of composite veneer. Later, a printed reduction guide was used to provide conservative tooth preparation followed by the cementation of thin feldspathic porcelain veneers under full isolation with a rubber dam. Injectable flowable resin-based composite veneers can successfully act as long-term esthetic prototypes before ceramic veneers. The outcome of these restorations is very predictable because the diagnostic wax-up anatomy is transferred to the mouth through the transparent silicone index, and they can be placed without tooth reduction. Conservative tooth preparation can be performed on the composite veneers so that minimal tooth structure is removed to maximize the bonding performance of ceramic veneers.

The objective of this study was to compare the effect of solvent in universal adhesives (UA) and the application of an extra layer of hydrophobic bonding resin on enamel shear bond strengths (SBS). Crowns of 224 bovine mandibular incisors were embedded in acrylic resin, wet-polished up to 600-grit silicon carbide paper and assigned to 3 UAs with different solvents (n=32): ethanol-based UA (ADU, AdheSE Universal, Ivoclar Vivadent); isopropanol-based UA (PBU, Prime&Bond Universal, Dentsply Sirona); and acetone-based UA (OPT, OptiBond Universal, Kerr Co). The same UAs were also applied with an extra layer of a hydrophobic bonding resin (HLB, Heliobond, Ivoclar Vivadent): ADU + HLB; PBU + HLB; and OPT + HLB. HLB alone was used as control. Enamel was etched with 37.5% H3PO4 (Kerr Gel Etchant, Kerr Co) for 15 seconds, rinsed with water, and air dried. UAs were applied according to the respective manufacturer's instructions. After adhesive application, composite cylinders (Filtek Z250, 3M Oral Care) were built up and light-cured (40 seconds/increment, 40 J/cm2) keeping the light tip in contact with the mold. Specimens were stored in water for 24 hours (24H) or for 6 months (6M). A knife-edged metallic rod (Ø=2.8-mm semicircular notch) loaded the composite cylinders until fracture. Mode of failure was analyzed with optical microscopy (40×). Statistics included twoway analysis of variance (ANOVA; adhesive strategy and water storage) and Tukey honestly significant difference (HSD) post hoc test (α=95%). Mean enamel SBS ranged from 3.6 (±2.2) MPa (HLB/6M) to 24.7 (±7.1) MPa (ADU + HLB/6M). ANOVA revealed significant differences for adhesive strategy (p≤0.001) but no significant differences for water storage (p>0.05). All UAs resulted in similar mean enamel SBS with or without an extra layer of HLB at 24H. After 6M, only ADU resulted in higher enamel SBS when an extra layer of HLB was applied. All UAs resulted in higher mean enamel SBS than HLB (control). Most failures were adhesive exception for PBU/HLB/6M, which had mostly mixed failures. UAs resulted in statistically higher enamel SBS than the nonsolvated hydrophobic bonding resin (control), regardless of the solvent in their composition. Application of an extra layer of hydrophobic bonding resin over UAs did not improve mean enamel SBS for isopropanol- and acetone-based UAs but did improve mean enamel SBS for the ethanol-based UA after 6M. Resin composite bonding to enamel using a hydrophobic bonding resin alone is not recommended.

This study aimed to evaluate the effect of human saliva in vitro and salivary flow in situ on the roughness and mineral content of bleached enamel. Dental specimens were divided into five groups (n=15): not bleached (NB); bleached (35% hydrogen peroxide) and exposed to distilled water (DW); human saliva in vitro (IV); normal salivary flow in situ (NSF); and low salivary flow (LSF) in situ. Enamel roughness (Ra, Rz) and calcium/phosphorus contents were evaluated with laser profilometry and energy-dispersive spectroscopy, respectively, at baseline (T1), after bleaching (T2), and after seven days (T3). Salivary pH and buffer capacity were evaluated with colorimetric strips and salivary calcium and phosphorus with absorbance spectrophotometry. Data were analyzed with non-parametric tests and linear regression (α=0.05). After contact with saliva, Ra and Rz of LSF=DW>IV=NSF=NB was found. For DW and LSF, the roughness of T1<T2=T3 was found. For IV, T1<T3<T2; for NSF, T1=T3<T2. Enamel calcium/phosphorus content did not change with bleaching or with saliva contact (p≥0.05). Buffer capacity and calcium concentration did not differ between LSF and NSF. Phosphorus was higher, and pH was lower in LSF. Ra and Rz were, respectively, 0.14 and 1.95 lower with NSF than LSF. The conclusions were that NSF in situ and human saliva in vitro recovered original enamel roughness. The experimental conditions did not affect enamel mineral content. Recovery of bleached enamel roughness was higher in NSF when compared to LSF, regardless of salivary pH, calcium and phosphorus concentrations, and buffer capacity.

To identify causes of the evidence-practice gap (EPG) in dentistry in Japan and analyze whether these causes are associated with: (a) improvement of EPG in minimal intervention dentistry (MID) following an educational intervention and (b) specific dentist characteristics. We conducted a mixed-methods questionnaire survey among 197 Japanese dentists that integrated both quantitative and qualitative data. Causative factors for the EPG identified in the quantitative survey were clarified by qualitative analysis. We measured the EPG in a baseline survey using an EPG measurement tool based on MID. To examine how feedback using the latest scientific evidence affected change in the EPG, we measured the EPG again immediately after feedback was provided to participating dentists. Qualitative analysis classified all dentists into one of four "EPG cause" groups, namely "evidence-", "dentist-", "patient-", and "health insurance system-related" causes. Quantitative analysis confirmed that improvement in the EPG following the feedback intervention was indeed associated with group classification. The highest concordance was found for the "evidence-related" group while the lowest concordance was in the "dentist-related" group (p=0.004). Concordance improved after evidence feedback in all groups but was lowest in the "dentist-related" group. More dentists reported practice busyness in the "dentist-related" group. In this study, we identified four groups of causes of EPG among Japanese dentists. The degree of concordance between evidence and clinical practice was the lowest in the "dentist-related" group, and the results of this study are expected to provide useful information for the development of intervention methods for closing the EPG in the future.

The objective of this study was to assess the effect of bioactive pulp-capping materials on human dental pulp stem cell (hDPSC) behavior in terms of cell viability and bioactivity via mineralization potential. Nanoparticles of 58S5 bioactive glass (nBG) powder were elaborated by a sol-gel process. Primer hDPSCs were cultured with experimental nBG, Biodentine, TheraCal LC, and ProRoot mineral trioxide aggregate (MTA) extracts. Cell viability was measured for 1, 3, and 7 days by water-soluble tetrazolium salts (WST-1) assay. Expression of mineralization-related marker genes (dentin sialophosphoprotein [DSPP] and osteocalcin [OCN]) was quantified by a real-time polymerase chain reaction. Detection of DSPP protein expression in hDPSCs was also assessed by western blotting. Alizarin red staining was used to detect the formation of mineralized nodules, and alkaline phosphatase (ALP) activity was quantified by a photometric method (days 7 and 14). All data were statistically analyzed with a one-way analysis of variance (ANOVA) and Tukey's post-hoc test (p<0.05). The cell viability of hDPSCs in all groups decreased except for nBG, and the lowest cell viability was determined in TheraCal LC at all incubation times. nBG and MTA showed significantly higher ALP activity than the control group. The tested materials elevated the calcium nodule form of hDPSCs except for TheraCal LC. The highest DSPP expression was seen in nBG for both incubation times. nBG promotes differentiation and mineralization of hDPSCs at a higher rate than other bioactive pulp-capping materials tested.