Evaluation of the bond strength of resin cements used to lute ceramics on laser-etched dentin

Risk Factors with Porcelain Laminate Veneers Experienced during Cementation: A Review

The clinical success of porcelain laminate veneers (PLVs) depends on many clinical and technical factors, from planning to execution, among which adhesive cementation is of significant importance. This procedure carries many risk factors if not optimally executed. The objective of this study was to document the clinical parameters affecting successful cementation procedures with a focus on the adhesive strength, integrity, and esthetics of the PLVs. A literature search was conducted through MEDLINE, complemented by a hand search using predefined keywords. Articles published in English between 1995 and 2023 were selected. According to this review, the success and longevity of PLVs rely in great part on the implementation of a precise cementation technique, starting from field isolation, adequate materials selection for adhesion, proper manipulation of the materials, the seating of the veneers, polymerization, and elimination of the excess cement. Several clinical steps performed before cementation, including treatment planning, preparation, impression, and adequate choice of the restorative material, could affect the quality of cementation. Scientific evidence suggests careful implementation of this process to achieve predictable outcomes with PLVs. The short- and long-term clinical success of adhesively luted PLVs is tributary to a deep understanding of the materials used and the implementation of clinical protocols. It is also contingent upon all the previous steps from case selection, treatment planning, and execution until and after the cementation.

Evaluation of bond strength of resin cement to Er:YAG laser-etched enamel and dentin after cementation of ceramic discs

The purpose of this study was to investigate the shear bond strength (SBS) of ceramic discs luted to differently etched enamel and dentin surfaces. Occlusal surfaces of 64 carious-free human molars and vestibule surfaces of 64 first maxillary incisors were ground to get flat superficial dentin and flattened enamel respectively. After generating 4 groups according to the surface etching method (37% orthophosphoric acid, Er:YAG laser-contact handpiece/scanning handpiece (1 or 2 times of scanning)), ceramic discs were luted to the surfaces with adhesive resin cement (Variolink N, Vivadent Ets., Schaan/Liechtenstein). After etching and cementation, thermocycling of 5000 cycles (Sd Mechatronık Gmbh, Feldkirchen-Westerham, Germany) and SBS test (Servopulser EHFFD1; Shimadzu, Kyoto, Japan) were performed respectively. The surface morphologies of 2 specimens, etched enamel and dentin, prepared for each group were examined with SEM analysis. Failure modes were determined under a USB digital microscope. Data were analyzed with one-way analysis of variance (ANOVA) and Tukey HSD test (α = 0.05). SBS values in dentin surfaces showed statistically significant differences (p < 0.05) among tested groups. The highest SBS among dentin groups was determined in the group which had 2 times etching by Er:YAG laser (11.42 MPa) by a scanning handpiece. No statistical differences were observed in the other dentin or enamel groups. Laser etching seems to be a viable alternative to acid etching on both enamel and dentin surfaces while double etching of dentin with a scanning handpiece can improve the adhesion.

Dentin bond strength of bioactive cement in comparison to conventional resin cement when photosensitized with Er,Cr:YSGG Laser

Objective:

The purpose of the present study was to assess dentin shear bond strength (SBS) and mode of bond failure of bioactive cement (BA) in comparison to conventional resin cement when photosensitized by Er,Cr: YSGG Laser (ECL).

Methods:

The present in-vitro study was carried out from March 2019 to May 2019. Sixty permanent non-carious, intact, non-fractured molars were isolated and mounted vertically in acrylic resin. Buccal surface of each molar tooth was ground, polished and surface treated with ECL. Ketac conditioner was applied on the surface washed and air dried surface. Tetric -N-Bond adhesive was applied on forty-five samples and light cured. The specimens were allocated into four groups (n=15) according to the type of cement used i.e., Calibra (C), BA, Variolink II (V) and Maxcem-Elite (ME). For SBS testing was performed using the universal testing machine. Eight samples from each group were assessed for modes of failure. Means and standard deviations were compared using analysis of variance (ANOVA) and Tukey’s post hoc test at a significance level of p < 0.05.

Results:

The highest mean SBS was observed in group ECL-C (21.55±3.08). The lowest mean SBS was displayed in group ECL-ME (14.25±3.55). Mean SBS values for group ECL-C (21.55±3.08) and group ECL-V (20.74±4.15) were comparable (p <0.05). Similarly, SBS values of group ECL-BA (15.48±3.62) and group ECL-ME (14.25±3.55) were comparable (p <0.05).

Conclusion:

Dentin surface conditioned with Er,Cr: YSGG and bonded to C and V cements exhibit favourable bond strength values.

Effect of Surface Treatments on the Shear Bond Strength of Indirect Esthetic Restorative Materials to Dentin

AIM

The purpose of this research was to evaluate the influence of air abrasion, hydrofluoric acid, and combination of air abrasion and hydrofluoric acid on the shear bond strength between dentin and CEREC, VITA VM7, and E-max.

MATERIAL AND METHODS

Ninety extracted human lower molars were used. The teeth were divided into three groups (n = 30) according to the surface treatment (air abrasion, hydrofluoric acid, and air abrasion + hydrofluoric acid). Each group was then subdivided into three subgroups (n = 10) according to the ceramic material (CEREC, E-max, and VITA VM7). Shear bond strength was determined by the compressive mode of force applied at the ceramic-tooth interface. The collected data were analysed using two-way analysis of variance (ANOVA), and Tukey's post-hoc test statistical significance was set at P < 0.05.

RESULTS

The highest mean shear bond strength value was recorded with the CEREC group treated by hydrofluoric acid (8.01MPa). While the least mean shear bond strength was recorded with the Cerec group but when treated by air abrasion alone, it was 4.33MPa.

CONCLUSION

Hydrofluoric acid etching for various types of ceramic restoration improved the bond strength to dentin.

Bonding Strategies of Resin Cement to Er, Cr:YSGG Lased Dentin: Micro-CT Evaluation and Microshear Bond Strength Testing

Aims

Pretreatment of the tooth surface is essential for establishing effective micromechanical retention between it and the restoration. The purpose of this study was to evaluate the bond strength between the resin and the Er, Cr:YSGG laser irradiated dentin and to examine morphologic characterization of the dentin-resin interface. In addition, the study evaluated the quantity of opened and closed dentinal tubules.

Subjects and Methods

Thirty extracted human molars were sectioned into samples of 1 mm thickness. The samples were randomly assigned to two groups containing 15 specimens each. Surface treatments were not applied to the samples in the control group and the samples in the experimental group were irradiated with an Er,Cr:YSGG laser. Two resin cement samples were polymerized on the surface of each sliced dentin. The micro-shear bond strength (μSBS) between dentin and cement (n = 30 for each group) was measured with a universal testing machine. The topography and morphology of the resin-dentin interface were evaluated by micro-CT (n = 20 for each group). The areas of closed tubular space, closed porosity, area of open tubular space, open porosity, total area of tubular space and fractal dimension were investigated by micro-CT. Statistical analysis used: The data for each parameter were analyzed by Shapiro-Wilk and Student's t test (p<0.05).

Results

μSBS values for control group were higher than experimental group. Dentin surfaces in the control group revealed less closed and more opened dentin tubules compared to the experimental group. Total area of tubular space was found to have decreased due to the laser ablation. There was no significant difference between the fractal dimensions of the control and experimental groups.

Conclusions

The lased dentin surface was not favorable for the bonding mechanism due to alterations in the dentinal structure.

Effect of Er,Cr:YSGG Laser at Different Output Powers on the Micromorphology and the Bond Property of Non-Carious Sclerotic Dentin to Resin Composites

BACKGROUND

The objective of this study was to investigate the influence of Er,Cr:YSGG laser irradiated at different powers on the micromorphology and the bonding property of non-carious sclerotic dentin to resin composites.

METHODS

Two hundred bovine incisors characterized by non-carious sclerotic dentin were selected, and the seventy-two teeth of which for surface morphological analysis were divided into nine groups according to various treatments (A: the control group, B: only treated with the adhesive Adper Easy One, C: diamond bur polishing followed by Adper Easy One, D-I: Er,Cr:YSGG laser irradiating at 1W, 2W, 3W, 4W, 5W, 6W output power, respectively, followed by Adper Easy One). The surface roughness values were measured by the non-contact three-dimensional morphology scanner, then the surface micromorphologies of surfaces in all groups were assessed by scanning electron microscopy (SEM); meanwhile, Image Pro-Plus 6.0 software was used to measure the relative percentage of open tubules on SEM images. The rest, one hundred twenty-eight teeth for bond strength test, were divided into eight groups according to the different treatments (A: only treated with the adhesive Adper Easy One, B: diamond bur polishing followed by the above adhesive, C-H: Er,Cr:YSGG laser irradiating at 1 W, 2 W, 3 W, 4 W, 5 W, 6 W output power, respectively, followed by the above adhesive), and each group was subsequently divided into two subgroups according to whether aging is performed (immediately tested and after thermocycling). Micro-shear bond strength test was used to evaluate the bond strength.

RESULTS

The 4W laser group showed the highest roughness value (30.84±1.93μm), which was statistically higher than the control group and the diamond bur groups (p<0.05). The mean percentages ((27.8±1.8)%, (28.0±2.2)%, (30.0±1.9)%) of open tubules area in the 4W, 5W, 6W group were higher than other groups (p<0.05). The 4W laser group showed the highest micro-shear bond strength not only in immediately tested (17.60±2.55 PMa) but after thermocycling (14.35±2.08MPa).

CONCLUSION

The Er,Cr:YSGG laser at 4W power can effectively improve the bonding property between non-carious sclerotic dentin and resin composites by increasing the roughness and mean percentage area of open tubules.

Cementation of Glass-Ceramic Posterior Restorations: A Systematic Review

Aim. The aim of this comprehensive review is to systematically organize the current knowledge regarding the cementation of glass-ceramic materials and restorations, with an additional focus on the benefits of Immediate Dentin Sealing (IDS). Materials and Methods. An extensive literature search concerning the cementation of single-unit glass-ceramic posterior restorations was conducted in the databases of MEDLINE (Pubmed), CENTRAL (Cochrane Central Register of Controlled Trials), and EMBASE. To be considered for inclusion, in vitro and in vivo studies should compare different cementation regimes involving a “glass-ceramic/cement/human tooth” complex. Results and Conclusions. 88 studies were included in total. The in vitro data were organized according to the following topics: (micro)shear and (micro)tensile bond strength, fracture strength, and marginal gap and integrity. For in vivo studies survival and quality of survival were considered. In vitro studies showed that adhesive systems (3-step, etch-and-rinse) result in the best (micro)shear bond strength values compared to self-adhesive and self-etch systems when luting glass-ceramic substrates to human dentin. The highest fracture strength is obtained with adhesive cements in particular. No marked clinical preference for one specific procedure could be demonstrated on the basis of the reviewed literature. The possible merits of IDS are most convincingly illustrated by the favorable microtensile bond strengths. No clinical studies regarding IDS were found.

The use of Erbium: Yttrium-aluminum-garnet laser in cavity preparation and surface treatment: 3-year follow-up

From the currently available choices, esthetic restorative materials for posterior teeth are limited to composite and ceramic restoration. Ceramic inlays/onlays are reliable solutions for both of these treatments. For successful treatment planning, usable ceramic and adhesive systems should be chosen by the dentist. Since the Federal Drug Administration approval of the erbium: Yttrium-aluminum-garnet (Er:YAG) laser-for caries removal, cavity preparation and the conditioning of tooth substance-in 1997, there have been many reports on the use of this technique in combination with composite resins. In addition, cavity pretreatment with the Er:YAG laser (laser etching) has been proposed as an alternative to acid etching of enamel and dentin. This case report presents the use of the Er:YAG in cavity preparation for composite resin restoration and surface treatment for ceramic onlay restoration of adjacent permanent molars.