Bacterial adhesion and surface properties of computer-aided design-computer-aided manufacturing restorative materials.

PURPOSE: This study aimed to evaluate the surface properties and bacterial adhesion of computer-aided design-computer-aided manufacturing (CAD-CAM) restorative materials. METHODS: Four CAD-CAM resin-based blocks (Vita Enamic, Shofu block HC, Cerasmart [CS] and Lava Ultimate [LU]) and a leucite-reinforced glass ceramic block (IPS Empress CAD) were used in the present study. Specimens prepared with dimensions of 10 × 10 × 1 mm were polished. Surface characteristics were assessed with hydrophobicity and surface free energy (SFE) analysis. Surface roughness was measured using a profilometer, and elemental and topographic evaluations were performed with SEM-EDX analysis. After being kept in artificial saliva for 1 h, Streptococcus mutans (S. mutans) and Streptococcus mitis (S. mitis) were incubated separately in 5% CO2 atmosphere at 37°C for 24 h. The adhered bacteria were counted as ×108 CFU/mL. RESULTS: Surface roughness, contact angle and SFE measurement values were found to be in the range of 0.144-0.264 Ra, 28.362°-70.074° and 39.65-63.62 mN/m, respectively. The highest adhered amount of S. mutans was found in CS and the lowest in LU, while there was no significant difference between the amounts of adhered S. mitis. CONCLUSION: Despite differences in the surface properties of the materials used for the study, the materials exhibited identical properties with respect to bacterial adhesion.

The diagnostic performance of the Java-based software colorization tool in the diagnosis of dental caries: an in vitro study.

OBJECTIVE: This in vitro study aimed to compare the diagnostic outcomes of caries detection in premolar and molar teeth on digital periapical radiographs viewed as grayscale images and in the Java-based software (JBS) pseudocolor spectrum. METHOD AND MATERIALS: The study comprised 92 premolar or molar human teeth (n = 46 with caries and n = 46 without clinical caries). For each tooth, digital periapical radiographic images (DPRIs), JBS pseudocolor images, and stereomicroscope images were collected, and caries presence and depth were recorded. In JBS pseudocolor images, regions of interest (ROIs) were detected, and ROI values for caries area (ROI1), non-caries area (ROI2), mesial area (ROI3), and distal area (ROI4) were obtained. The degree of inter-observer agreement was determined using the kappa coefficient, and the sensitivity and specificity of the methods were assessed using ROC analysis. RESULTS: While neither method was consistent with stereomicroscopy in determining caries depth (P < .005), for both observers the kappa value of JBS pseudocolor images were slightly higher than those for DPRIs. ROI1 was found to be significantly lower than ROI2 (P < .001), whereas no difference was found between ROI3 and ROI4 (P = .877). For both observers, the sensitivity and specificity obtained from JBS pseudocolor were above 89%. CONCLUSION: JBS pseudocolor images can be used for caries detection and offer high sensitivity and specificity.

Effect of cavity disinfection protocols on microtensile bond strength of universal adhesive to dentin / Efecto de los protocolos de desinfección de cavidades en la fuerza de adhesión microtensil del adhesivo universal a la dentina

Abstract The purpose of this study was to compare the effect of different disinfection protocols of dentin on bond strength of an MDP-containing universal adhesive. Twelve extracted mandibular third molars were separated horizontally at the mid-coronal of crown to get smooth and sound dentin surfaces using low-speed diamond saw. The teeth were randomly fallen into four groups: chlorhexidine (CHX), ozone, Er,Cr:YSGG laser irradiation (LASER) and no treatment (control). After cavity disinfection application, a universal adhesive (G-Premio Bond) was applied to the surface of dentin according to self-etch mode as instructed by the manufacturer. After incremental built-up of composite resin (Charisma Smart), the specimens were immersed in distilled water at 37°C for 24h. Dentin/composite beams with 1 mm² cross sectional area were produced and micro-tensile bond strength (µTBS) was applied on these beams (n=20). Failure mods were determined under a stereomicroscope at ×40. The resin penetration of samples stained with Rhodamine B fluorochrome dye was examined with a confocal laser scanning microscope. Statistical analysis was performed with SPSS-22. Test results were analyzed using One-way Anova and Tukey HSD Post-Hoc tests (p0.5). All applications of cavity disinfection procedures decreased the µTBS of the resin-dentin interface.

Resumen El propósito de este estudio fue comparar el efecto de diferentes protocolos de desinfección de la dentina sobre la fuerza de unión de un adhesivo universal que contiene MDP. Doce terceros molares mandibulares extraídos se quebraron horizontalmente en la mitad de la corona para obtener superficies de dentina lisas y sólidas utilizando una sierra de diamante de baja velocidad. Los dientes se dividieron aleatoriamente en cuatro grupos: clorhexidina (CHX), ozono, irradiación con láser Er,Cr:YSGG (LASER) y ningún tratamiento (control). Después de la aplicación de la desinfección de la cavidad, se aplicó un adhesivo universal (G-Premio Bond) a la superficie de la dentina según el modo de autograbado indicado por el fabricante. Después de la obturación con resina compuesta (Charisma Smart), las muestras se sumergieron en agua destilada a 37°C durante 24h. Se produjeron porciones de dentina/resina con un área de sección transversal de 1 mm² y se aplicó una fuerza de adhesión microtensile (µTBS) (n=20). Los modos de falla se determinaron bajo un microscopio estereoscópico a ×40. La penetración de la resina de las muestras teñidas con colorante fluorocromo rodamina B se examinó con un microscopio de barrido láser confocal. El análisis estadístico se realizó con SPSS-22. Los resultados de las pruebas se analizaron utilizando las pruebas post-hoc Anova unidireccional y Tukey HSD (p0.5). Todas las aplicaciones de procedimientos de desinfección de cavidades redujeron el µTBS de la interfaz resina-dentina.

Evaluation of surface characteristic and bacterial adhesion of low-shrinkage resin composites.

This study aimed to examine the surface characteristics of low shrinkage composites and adhesion of Streptococcus mutans and Streptococcus mitis to these materials. Control material (glass) and three low shrinkage composites (Charisma Diamond, Kalore GC, Beatiful II LS) were used. After polishing procedure was applied to composite specimens, surface roughness (SR), surface free energy (SFE), and contact angle measurements were performed. Surfaces of composite were analyzed using scanning electron microscope and energy-dispersive X-ray spectroscopy. After pellicle formation with artificial saliva, S. mutans and S. mitis biofilms were incubated in 5% CO2 for 24 h at 37°C and were analyzed using confocal laser scanning microscopy. The lowest SR and highest SFE values were found in the control group. While the contact angle of control was statistically lower than composites, statistically difference was not found between composite groups. S. mutans adhesion of composites was significantly lower than control group, but there was no significant difference between composites. S. mitis adhesion of all groups was statistically similar. SR did not affect the S. mutans and S. mitis adhesion. Less adherence of S. mutans to low shrinkage composites was associated with low SFE and high contact angle values. Even though the highest SR was observed in the Charisma Diamond, no difference was found between the composites in terms of bacterial adhesion.

Do resin-based composite CAD/CAM blocks release monomers?

OBJECTIVE: The present study aimed to identify and quantify the elution of monomers of five different resin-based CAD/CAM blocks (RCBs) using HPLC. METHODS: Five different RCBs were used in the study: GC Cerasmart (CS), Voco Grandio blocs (GR), 3M Lava Ultimate (LU), Shofu Block (SB), and Vita Enamic (VE). Fifteen samples from each material were prepared using a low-speed precision diamond saw (ISOMET Buehler, Lake Bluff, IL, USA) at 5 × 5 × 4 mm size. After the preparation of samples, an extraction solution was mixed with %75/%25 ethanol/water. The samples were stored in the amber-colored bottles during three different immersed periods as 1 h, 24 h, and 90 days (n = 5). After immersion, 0.5 ml solutions were taken from each bottle and analyzed using HPLC. RESULTS: A total of 16.7 µg/ml of monomers from SB, 13.4 µg/ml of monomers from GR, 13.2 µg/ml of monomers from CS, and 6.7 µg/ml of monomers from LU were found after 3-m immersion. TEGDMA after 3-m of immersion was only released from the SB group, and also BisEMA was released from the CS group. Among the specimens immersed for 1 h, UDMA was released the least from the LU group and the most from the GR group (p < 0.05). Correspondingly, 24 h and 3 m after immersion, the highest release of monomers was found in the GR (p < 0.05). CONCLUSIONS: When the monomer release from RCBs was evaluated, it was shown that these materials released methacrylate-based monomers except VE, especially if they were kept in a solvent solution for a long time such as 3 m. CLINICAL SIGNIFICANCE: The novel resin-based CAD/CAM blocks might monomer release, which may cause cytotoxic effects. But, the detected amount of monomer release is below the estimated daily limit.

Surface properties and bacterial adhesion of bulk-fill composite resins.

OBJECTIVES: The aim of the present study was to evaluate the Streptococcus mutans and Streptococcus mitis adhesion and related surface properties of bulk-fill resin composite. METHODS: Four novel bulk-fill composite with different composition were used; Sonic Fill-2 (KSF), Filtek BulkFill (FBF), Admira Fusion X-tra (AFX), Beautifil Bulk Restorative (SBB) and a control group (glass) were included in the study. After standardized surface polishing procedure, surface properties of composite specimens were evaluated using surface roughness (SR) measurements by a profilometer, hydrophobicity and surface free energy (SFE) analyses, elemental and topographic analyses by SEM-EDS. To evaluate the bacterial adhesion, composite specimens were immersed in artificial saliva and mucin for pellicle development. After 1-h immersion, bacterial suspension was added to the pellicle-coated specimens, which were incubated at 37 °C in 5% CO2 atmosphere for 24 h. Adhered bacteria counts were determined as x108 Cfu/ml. Bacterial adhesion was also investigated using confocal laser scanning microscopy. RESULTS: No statistically significant differences were found among bulk fill composites in terms of surface roughness while glass showed the lowest Ra values. The lowest contact angle values were found in the control group and Sonic Fill-2 while the highest SFE values were observed in these materials. No statistically significant differences were found between the S. mutans counts. For S. Mitis adhesion, the highest value was found in Sonic Fill-2 and no significant differences were observed between the other groups. CONCLUSIONS: SR of bulk-fill composite resins had no effect on bacterial adhesion. However, bacterial adhesion increased with higher SFE values. CLINICAL SIGNIFICANCE: Although the surface roughness of composites used in the study is similar, in clinically, S. mitis adhesion may be more in the KSF group because of high surface free energy.

Discoloration and translucency changes of CAD-CAM materials after exposure to beverages.

STATEMENT OF PROBLEM: Color and translucency changes of recently introduced composite resin blocks after long-term exposure to various staining agents have not been fully investigated. PURPOSE: The purpose of this in vitro study was to evaluate the color stainability and translucency changes of computer-aided design and computer-aided manufacturing (CAD-CAM) materials immersed in beverages with staining potential. MATERIAL AND METHODS: Three types of CAD-CAM blocks were used: 3M Lava Ultimate (LU), GC Cerasmart (CS), and VITA Enamic (VE). Forty-five rectangular specimens (1.5-mm thickness) of each product were prepared. The specimens were divided into 3 subgroups (n=15 in each) according to the immersion beverage. The specimens were then immersed in distilled water, red wine, and coffee for 30 days. Color parameters (ΔE00), the translucency parameter, and the contrast ratio were determined after 24 hours and 1 month. The Kruskal-Wallis and Mann-Whitney U tests and the Wilcoxon, Freidman, and repeated measurement ANOVA tests were used for statistical analysis (α=.05). RESULTS: None of the materials showed clinically perceptible color changes except CS specimens immersed in coffee for 24 hours. The materials immersed in red wine and coffee for 1 month showed greater discoloration than those immersed in water (P<.05). The LU immersed in red wine showed the highest translucency changes, and VE was more resistant to translucency changes, as compared with the other materials tested. The contrast ratio values of the LU material were higher than those of the CS and VE materials in all the beverages. CONCLUSIONS: The red wine and coffee caused significant changes in the color and translucency of these novel CAD-CAM materials after a long immersion period.

Efficacy of ceramic repair material on the bond strength of composite resin to zirconia ceramic.

OBJECTIVE: The aim of this study was to evaluate the shear bond strength of composite resin in five different repair systems. MATERIALS AND METHODS: Sixty specimens (7 mm in diameter and 3 mm in height) of zirconia ceramic were fabricated. All specimen surfaces were prepared with a 30 µm fine diamond rotary cutting instrument with water irrigation for 10 s and dried with oil-free air. Specimens were then randomly divided into six groups for the following different intra-oral repair systems (n = 10): Group 1, control group; Group 2, Cojet system (3M ESPE, Seefeld, Germany); Group 3, Cimara® System (Voco, Cuxhaven, Germany); Group 4, Z-Prime Plus System (Bisco Inc., Schaumburg, IL); Group 5, Clearfil™ System (Kuraray, Osaka, Japan); and Group 6, Z-Bond System (Danville, CA). After surface conditioning, a composite resin Grandio (Voco, Cuxhaven, Germany) was applied to the zirconia surface using a cylindrical mold (5 mm in diameter and 3 mm in length) and incrementally filled up, according to the manufacturer's instructions of each intra-oral system. Each specimen was subjected to a shear load at a crosshead speed of 1 mm/min until fracture. One-way analysis of variance (ANOVA) and Tukey post-hoc tests were used to analyze the bond strength values. RESULTS: There were significant differences between Groups 2-6 and Group 1. The highest bond strength values were obtained with Group 2 (17.26 ± 3.22) and Group 3 (17.31 ± 3.62), while the lowest values were observed with Group 1 (8.96 ± 1.62) and Group 6 (12.85 ± 3.95). CONCLUSION: All repair systems tested increased the bond strength values between zirconia and composite resin that used surface grinding with a diamond bur.

Resin cement to indirect composite resin bonding: effect of various surface treatments.

Debonding at the composite-adhesive interface is a major problem for indirect composite restorations. The aim of this study was to evaluate the bond strength (BS) of an indirect composite resin after various surface treatments (air-abrasion with Al2O3, phosphoric acid-etchig and different applications of NdYAG laser irradiations). Fifty composite disks were subjected to secondary curing to complete polymerization and randomly divided into five experimental groups (n = 10) including Group 1, untreated (control); Group 2, phosphoric acid-etched; Group 3, air-abrasion with Al2 O3 ; Group 4, Nd:YAG laser irradiated with non-contact and Group 5, Nd:YAG laser irradiated with contact. They were then bonded to resin cement and shear BS was determined in a universal testing device at a crosshead speed of 1 mm/min. One way analysis of variance (ANOVA) and Tukey post-hoc tests were used to analyze the BS values. The highest BS value was observed in Group 4 and followed by Group 3. Tukey test showed that there was no statistical difference between Group1, 2 and 5. Furthermore, differences in BSs between Group 4 and the other groups except Group 3 were significant (p < 0.05) and also there were significant differences in BSs between Group 3 to 1 and Group 3 to 2 (p < 0.05). This study reveals that air-abrasion with Al2 O3 and Nd:YAG laser irradiation with non-contact provided a significant increase in BS between indirect composite and resin cement.

Direct laminate veneers with resin composites: two case reports with five-year follow-ups.

AIM: The aim of this report is to present five-year follow-ups of two different applications for the use of direct laminate resin-based composite veneers to improve esthetics. BACKGROUND: Defects in the maxillary anterior teeth, such as enamel hypoplasia and peg lateral, can present esthetic challenges. Furthermore, a treatment plan that can be completed in a single appointment is highly desirable. This case report presents two different clinical cases involving the use of direct laminate resin-based composite veneers with five-year follow-ups. CASE REPORT: Case 1: A 17-year-old female patient was referred for treatment of her anterior teeth, which were unesthetically altered due to enamel hypoplasia and dental caries. A treatment plan was developed that included restoring the affected teeth with direct resin-based composite laminate veneers to improve the patient's appearance. The six maxillary anterior teeth were prepared for and restored with direct resin-based composite laminate veneers. At the five-year follow-up, the patient was satisfied with the restorations both esthetically and functionally. Case 2: A 15-year-old female patient also was referred for treatment to improve the appearance of her maxillary anterior teeth. A treatment plan was developed with two objectives: (1) to restore the undersized supernumerary crown in the area of the maxillary right lateral incisor and (2) to close the anterior diastemas. The facial surfaces were conservatively prepared and resin-based composite was applied with the aid of transparent crown forms. After completion of the treatment, the patient was recalled at six-month intervals. At the five-year follow-up appointment, the restorations were intact, no adverse effects were noted, and the resultant appearance was highly satisfactory for the patient. SUMMARY: The use of direct resin-based composite laminate veneers and adhesive bonding systems has been shown to provide an esthetic alternative to metal-ceramic or all-ceramic crowns for the rehabilitation of anterior teeth. This treatment option offers another advantage, namely a lower cost compared to an indirect technique. Other more complex and costly treatment options in the future are not ruled out. CLINICAL SIGNIFICANCE: In the present two cases, the initial and five-year follow-up results support the use of direct resin-based composite laminate veneers with minimal altering of healthy tooth structure. Such results should encourage clinicians to seek a cost-effective technique such as direct resin restorations to improve a patient's esthetic appearance in a single appointment.