Effect of abutment types and resin cements on the esthetics of implant-supported restorations

PURPOSE@#. The aim of the study was to evaluate the optical properties of new generation (3Y-TZP) monolithic zirconia (MZ) with different abutment types and resin cement shades. @*MATERIALS AND METHODS@#. A1/LT MZ specimens were prepared (10 × 12 × 1 mm, N = 30) and divided into 3 groups according to cement shades as transparent (Tr), yellow (Y) and opaque (O). Abutment specimens were obtained from 4 different materials including zirconia (Group Z), hybrid (Group H), titanium (Group T) and anodized yellow titanium (Group AT). MZ and abutment specimens were then cemented. L*, a*, and b* parameters were obtained from MZ, MZ + abutment, and MZ + abutment + cement. ∆E001 * (between MZ and MZ + abutment), ∆E002 * (between MZ and MZ + abutment + cement) and ∆E003 * (between MZ + abutment and MZ + abutment + cement) values were calculated.Statistical analyses included 2-way ANOVA, Bonferroni, and Paired Sample t-Tests (P < .05). @*RESULTS@#. Abutment types and resin cements had significant effect on L*, a*, b*, ∆E001 *, ∆E002 *, and ∆E003 * values (P < .001). Without cementation, whereas zirconia abutment resulted in the least discoloration (∆E001 * = 0.68), titanium abutment caused the most discoloration (∆E001 * = 4.99). The least ∆E002 * = 0.68 value was seen using zirconia abutment after cementation with yellow shaded cement. Opaque shaded cement caused the most color change (∆E003 * = 5.24). Cement application increased the L* values in all groups. @*CONCLUSION@#. The least color change with/without cement was observed in crown configurations created with zirconia abutments. Zirconia and hybrid abutments produced significantly lower ∆E002 * and ∆E003 * values in combination with yellow shaded cement. The usage of opaque shaded cement in titanium/anodized titanium groups may enable the clinically unacceptable ∆E00 * value to reach the acceptable level.[J Adv Prosthodont 2023;15:114-25]

Shear bond strengths of aged and non-aged CAD/CAM materials after different surface treatments

PURPOSE@#To assess shear bond strengths (SBS) of resin composites on aged and non-aged prosthetic materials with various surface treatments. @*MATERIALS AND METHODS@#Cerasmart (CE), Vita Enamic (VE), Vita Mark II (VM), and IPS e.max CAD (EC) blocks were sliced, and rectangular-shaped specimens (14 × 12 × 1.5 mm; N = 352) were obtained. Half of the specimens were aged (5000 thermal cycles) for each material. Non-aged and aged specimens were divided into 4 groups according to the surface treatments (control, air abrasion, etching, and laser irradiation; n = 11) and processed for scanning electron microscopy (SEM). The repair procedure was performed after the surface treatments. SBS values and failure types were determined. Obtained data were statistically analyzed (P≤.05). @*RESULTS@#The material type, surface treatment type, and their interactions were found significant with regard to SBS (P<.001). Aging also had a significant effect on prosthetic material-resin composite bonding (P<.001). SBS values of non-aged specimens ranged from 12.16 to 17.91 MPa, while SBS values of aged specimens ranged from 9.46 to 15.61 MPa. Non-aged VM in combination with acid etching presented the highest score while the control group of aged CE showed the lowest. @*CONCLUSION@#Etching was more effective in achieving durable SBS for VM and EC. Laser irradiation could be considered as an alternative surface treatment method to air abrasion for all tested materials. Aging had significant effect on SBS values generated between tested materials and resin composite.

Erratum: How will surface treatments affect the translucency of porcelain laminate veneers?

There are some corrections in the body of the article.

How will surface treatments affect the translucency of porcelain laminate veneers?

PURPOSE: The purpose of this study was to evaluate whether surface treatments affect the translucency of laminate veneers with different shades and thicknesses. MATERIALS AND METHODS: A total of 224 disc-shaped ceramic veneers were prepared from A1, A3, HT (High Translucent) and HO (High Opaque) shades of IPS e.max Press (Ivoclar Vivadent) with 0.5 mm and 1.0 mm thicknesses. The ceramics were divided into four groups for surface treatments. Group C: no surface treatments; Group HF: etched with hydrofluoric acid; Group SB: sandblasted with 50-microm Al2O3; and Group L; irradiated with an Er;YAG laser. A translucent shade of resin cement (Rely X Veneer, 3M ESPE) was chosen for cementation. The color values of the veneers were measured with a colorimeter and translucency parameter (TP) values were calculated. A three-way ANOVA with interactions for TP values was performed and Bonferroni tests were used when appropriate (alpha=0.05). RESULTS: There were significant interactions between the surface treatments, ceramic shades and thicknesses (P=.001). For the 0.5-mm-thick specimens there were significant differences after the SB and L treatments. There was no significant difference between the HF and C treatments for any shades or thicknesses (P>.05). For the 1-mm-thick ceramics, there was only a significant difference between the L and C treatments for the HT shade ceramics (P=.01). There were also significant differences between the SB and C treatments except not for the HO shades (P=.768). CONCLUSION: The SB and L treatments caused laminate veneers to become more opaque; however, HF treatment did not affect the TP values. When the laminate veneers were thinner, both the shade of the ceramic and the SB and laser treatments had a greater effect on the TP values.

Peel strength of denture liner to PMMA and polyamide: laser versus air-abrasion

PURPOSE: This study investigated the effect of laser parameters and air-abrasion on the peel strength of silicon-based soft denture liner to different denture resins. MATERIALS AND METHODS: Specimens (N=180) were prepared out of three different denture base resins (Rodex, cross-linked denture base acrylic resin; Paladent, heat-cured acrylic resin; Deflex, Polyamide resin) (75 mm x 25 mm x 3 mm). A silicon-based soft denture liner (Molloplast B) was applied to the denture resins after the following conditioning methods: a) Air-abrasion (50 microm), b) Er,Cr:YSGG laser (Waterlase MD Turbo, Biolase Technology) at 2 W-20 Hz, c) Er,Cr:YSGG laser at 2 W-30 Hz, d) Er,Cr:YSGG laser at 3 W-20 Hz, e) Er,Cr:YSGG laser at 3 W-30 Hz. Non-conditioned group acted as the control group. Peel test was performed in a universal testing machine. Failure modes were evaluated visually. Data were analyzed using two-way ANOVA and Tukey's test (alpha=.05). RESULTS: Denture liner tested showed increased peel strength after laser treatment with different parameters (3.9+/-0.4 - 5.58+/-0.6 MPa) compared to the control (3.64+/-0.5 - 4.58+/-0.5 MPa) and air-abraded groups (3.1+/-0.6 - 4.46+/-0.3 MPa), but the results were not statistically significant except for Paladent, with the pretreatment of Er,Cr:YSGG laser at 3 W-20 Hz. Polyamide resin after air-abrasion showed significantly lower peel strength than those of other groups (3.1+/-0.6 MPa). CONCLUSION: Heat-cured acrylic resin, PMMA, may benefit from Er,Cr:YSGG laser treatment at 3 W-20 Hz irradiation. Air-abrasion of polyamide resins should be avoided not to impair their peel bond strengths to silicon-based soft denture liners.