Influence of previous provisional cementation on the bond strength between two definitive resin-based luting and dentin bonding agents and human dentin

Effect of Immediate Dentin Sealing on the Bonding Performance of Indirect Restorations: A Systematic Review

The popular immediate dentin sealing (IDS) technique is used to improve the bond strength of indirect restorations. This systematic review assessed whether bond strength is affected by the type of aging conditions, bonding agents, flowable resin composites, impression materials, temporary materials, and/or resin cement used within the IDS procedure. A comprehensive database search of PubMed, Embase, Scopus, Ovid Medline, Web of Sciences, Cochrane Library, Dentistry & Oral Sciences Source, and ProQuest was carried out up to 30 January 2024 without publication year or language limitations. Only in vitro full-texts regarding the effect of IDS on bond strength were included, and the quality of their methods was assessed via a Risk of Bias (RoB) test. In total, 1023 pertinent studies were initially found, and 60 articles were selected for review after screening for the title, abstract, and full texts. IDS application improves the bond strength of indirect restorations to dentin and reduces the negative effects of temporary materials on the bond durability of final indirect restorations. Filled dentin bonding agents or combinations with flowable resin composite are preferred to protect the IDS layer from conditioning procedures.

Effect of Temporary Cement, Surface Pretreatment and Tooth Area on the Bond Strength of Adhesively Cemented Ceramic Overlays-An In Vitro Study

Several viewpoints have been reported regarding the effect of temporary cements, different surface pretreatment protocols before adhesive cementation, and predictive factors. This in vitro study tested if temporary cement, pretreatment of the tooth surface, the size of enamel or dentine influence adhesive cementation to zirconia ceramics. Twenty premolars were prepared for determination of enamel and dentin area, bond strength test and failure analysis. The samples were divided into two groups: untreated prior adhesive cementation (n = 10) and with temporary cementation done, pretreated prior adhesive cementation (n = 10). Zirconia overlays (Katana Zirconia STML) were cemented on the grounded flat teeth surfaces using Panavia V5. An additional six premolars underwent dentine tubule analysis with SEM to detect temporary cement residues after temporary cementation on an untreated tooth surface (n = 3) and on a pretreated surface (n = 3). The independent sample t-test was used to compare the two groups and the means of the total tooth, dentin or enamel areas did not differ significantly between the untreated and pretreated specimens. The mean tensile bond strength was significantly (p = 0.005) higher in the pretreated specimens (337N) than in the untreated ones (204N). The overall multivariable linear regression model with three predictors (surface pre-treatment, enamel area and dentine area) was significant (p = 0.003), among which the size of enamel was the strongest predictor (β = 0.506; p = 0.049), followed by the pretreatment effect (β = 0.478; p = 0.001) and the size of dentin area (β = -0.105; p = 0.022).

Survival analysis up to 7 years of 621 zirconia monolithic single crowns with feather-edge margins fabricated with a cast-free workflow starting from intraoral scans: A multicentric retrospective study

STATEMENT OF PROBLEM

Clinical studies on the fabrication of monolithic zirconia restorations with a feather-edge tooth preparation from digital scans and a cast-free fully digital workflow are lacking.

PURPOSE

The purpose of this retrospective multicentric study in private practices was to evaluate the outcomes of monolithic zirconia crowns fabricated with feather-edge margins and a cast-free approach.

MATERIAL AND METHODS

A total of 621 teeth were prepared with feather-edge margins and restored with monolithic zirconia crowns fabricated with a fully digital cast-free workflow. Data were analyzed by using the Kaplan-Meier test and descriptive statistics. The clinical evaluation adopted the California Dental Association-modified criteria after recalling all patients between April and July 2021.

RESULTS

The clinical survival of 619 of 621 crowns, including recemented crowns placed in 427 patients (217 men, 220 women) over 5 years (2014 to 2019 with crowns in service between 12 and 85 months), was analyzed. The 2 excluded crowns were delivered to patients who dropped out of the study. Of the 619 crowns, 5 failed during the follow-up period: 4 teeth were extracted because of fracture and 1 restoration fractured. No other technical or biological failures were observed. The mean overall survival time was 84.4 months (standard error, 0.255; 95% confidence interval for the mean, 83.92 to 84.92). The overall survival probability was 99.1% up to 85 months.

CONCLUSIONS

The clinical outcomes of the monolithic zirconia crowns with feather-edge margins evaluated were comparable with outcomes reported using other margin designs and materials.

Effect of temporary cements and their removal methods on the bond strength of indirect restoration: a systematic review and meta-analysis

OBJECTIVES

For a conventional indirect restoration, temporary cementation inevitably contaminated collapsed dentin collagen. The purpose of this review was to evaluate the optimal strategy for minimizing its negative effects.

MATERIAL AND METHODS

Databases such as PubMed, Web of Science, EMBASE, and the Cochrane Library were searched for in vitro studies, involving the influence of immediate dentin sealing (IDS), different temporary cements, and their removal strategies on dentin bond strength. The meta-analysis used the inverse variance method with effect method of the standardized mean difference and statistical significance at p ≤ 0.05. The I² value and the Q-test were used to assess the heterogeneity.

RESULTS

A total of 14 in vitro trials were subjected to the meta-analysis. Within the study's limitations, we assumed that IDS eliminated the negative effects of temporary bonding, achieving the comparable immediate bond strength with the control (p = 0.46). In contrast, under delayed dentin sealing (DDS), temporary cementation statistically decreased bond strength (p = 0.002). Compared with resin-based and non-eugenol zinc oxide cements, polycarboxylate and calcium hydroxide cements performed better on bond strength with no statistical difference from the control group (p > 0.05). Among the removal methods of temporary cements, the Al₂O₃ abrasion restored the decreased bond strength (p = 0.07) and performed better than hand instruments alone (p = 0.04), while pumice removal slightly reduced the bond strength in contrast with the control group (p = 0.05, 95% CI =  - 1.62 to 0).

CONCLUSIONS

The choices of IDS, polycarboxylate and calcium hydroxide temporary cements, Al₂O₃ abrasion removal method were feasible and efficient to enhance the bond strength.

CLINICAL RELEVANCE

It is worthwhile applying IDS technique, polycarboxylate and calcium hydroxide temporary cements during indirect restoration. The Al₂O₃ abrasion of cleaning dentin can minimize the negative effects of temporary cement.

The effect of mechanical and chemo-mechanical temporary cement cleaning methods on shear bond strength with self-adhesive resin cement (an in-vitro study)

BACKGROUND

Adhesive tooth-colored restorations are strongly dependent on the substrate surface cleanliness to allow intimate contact between resin cement and dentin surface, so several methods were adopted for the total cleaning of temporary cement residues. This study aimed to assess the effect of mechanical and chemo-mechanical cleaning methods of temporary cement on the immediate shear bond strength of self-adhesive resin cement to dentin surface.

METHODS

Forty freshly extracted lower first premolars were cut to expose a flat dentin surface. Discs of temporary crown composite resin material were constructed and cemented to the flat dentin surface using resin-based and non-eugenol temporary cement then stored at room temperature in distilled water. Dividing of samples into two groups according to the method of temporary cement cleaning. Group I (n = 20) mechanical cleaning using the rotary instrument, and group II (n = 20) chemo-mechanical cleaning using chlorhexidine-containing scrub. CAD/CAM reinforced Composite discs were bonded to the dentin surface using self-adhesive composite resin cement, then measurement of shear bond strength was done using a universal testing machine. Further analysis of failure mode after debonding was performed by Scanning electron microscope.

RESULTS

No statistically significant difference was found between the mean shear bond strength of the two cleaning methods (P-value = 0.636). Regardless of the cleaning method, the group cemented with resin-based temporary cement showed statistically significantly higher mean shear bond strength than non-eugenol temporary cement (P-value = 0.048).

CONCLUSION

Both cleaning methods (mechanical and chemo-mechanical) applied in this study were effective in cleaning temporary cement remnants from the dentin substrate surface with statistically significant differences between results of shear bond strength with significantly higher values recorded with resin-based temporary cement.

The impact of provisional intraradicular retainers cementation with temporary methacrylate-based resin in the bond strength of glass fiber posts to root dentin

Chemical composition of temporary cements interferes in the bond strength and quality of the bond interface of glass fiber posts to root dentin. The aim of the present study was to evaluate the influence of different temporary cements on the bond strength of fiberglass posts and resin cement. Thirty-two maxillary central incisor roots were standardized at 15 mm length. The root canals were prepared with Reciproc R50 and filled with a R50 single cone and AH Plus. Ten mm of filling material was removed with a heated Schilder condenser, leaving 5 mm of apical filling material. The roots were randomly distributed into 4 groups (n = 8). In the control group, the root canal was prepared with a standard drill according to the post diameter (DC #1, FGM, Joinville, Brazil), irrigated with 5 mL of distilled water and immediately received the fiberglass post cemented with self-adhesive resin cement. For the other groups, cores were made with temporary intraradicular retainers cemented with different temporary cements: methacrylate-based resin (Bifix Temp - Voco), calcium hydroxide-based (Provicol - Voco) and zinc oxide-based - eugenol-free (Relyx Temp NE - 3M). After 7 days, mechanical removal of the temporary retainers, preparation, irrigation of the root canal and cementation of the fiberglass post were performed, following the same protocol that had been performed in the control group. The roots were sectioned to obtain 3 slices per root third. The most cervical section of each third was used for the push-out test and failure pattern analysis, while the most apical section was subjected to analysis of the adhesive interface by scanning electron microscopy (SEM). The BS data were compared between groups using the two-way ANOVA and Tukey post-test. The failure pattern results were expressed in percentage and compared between groups using the chi-square test and the material adaptation data at the bond interface were evaluated using the Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. The results showed higher BS in the cervical third, with a higher value in the control group (10.8 ± 0.94) and Bifix Temp group (9.78 ± 0.71), with no statistically significant difference between these groups (P > .05). The middle and apical thirds showed no statistically significant difference (P > .05). As regards the type of failure, a higher percentage of mixed adhesive failures was observed for all groups. Analysis of the adhesive interface by SEM showed that the temporary cement Bifix Temp showed greater adaptation at the bond interface. It was concluded that the methacrylate-based resin temporary cement showed the highest bond strength values and best adaptation to root dentin than the zinc oxide-based and calcium hydroxide-based temporary cements.

Cement selection criteria for full coverage restorations: A comprehensive review of literature

BACKGROUND

Proper cement selection in fixed prosthesis plays a determinative role in providing long-term serviceability, retention, caries prevention, and patient satisfaction. This study, reviews different luting agent characteristics and their application based on different clinical situations and different types of full coverage restorations.

MATERIAL AND METHODS

An electronic search was conducted through PubMed, Medline, and Google scholar using following keywords or combinations: restoration, full coverage, PFM, porcelain fused to metal, all ceramic, zirconia, ceramic, casting, fixed partial denture, cement*, dental cement, cement selection, and retention. The most related articles were selected for review.

RESULTS

Choosing a proper luting agent is highly dependent on scientific knowledge regarding the characteristics of restorative materials and luting agents. Conventional cements could be indicated in various situations; however, some restorative materials or clinical situations call for resin-cements to provide predictable retention, support, and durability.

CONCLUSIONS

Conscious selection of retentive cement for each type of restoration/material is necessary to provide predictable successful treatment and reduce the potential complications. Key words:Adhesive cement, dental bridgework, dental cements, dental crowns, dental porcelain, prostheses and implants.

Substantial in-vitro and emerging clinical evidence supporting immediate dentin sealing

The application of resin adhesive to freshly cut dentin after teeth preparation, the so-called immediate dentin sealing (IDS) has been suggested as an alternative to the delayed dentin sealing (DDS), a technique in which resin adhesive is applied just before final bonding of indirect restorations.

The aim of this review is to demonstrate the evidence of the claimed advantages made by the proponents of IDS technique.

The results of this review revealed substantial in-vitro evidence supporting the IDS benefits including improved bond strength, reduced dentin permeability, improved restorations’ adaptation, and increased fracture strength of the restorations. Clinical studies have shown that IDS improves survival of ceramic laminate veneers bonded to prepared teeth with increased exposure of dentin. Moreover, it has been shown that IDS reduces post-cementation hypersensitivity in full coverage restorations, which is characterized by exposure of a large number of dentinal tubules. The selection of filled resin adhesive that is capable of producing thick adhesive layer appears to contribute to the success of the technique. Furthermore, careful management of the oxygen inhibition layer before conventional impression making and proper cleaning of the residual temporary cement used with provisional restorations appears to affect the outcome of the restorations.

Immediate Dentin Sealing: A Literature Review

Purpose

The immediate application of a dentin-bonding agent after tooth preparation and before impression-taking (immediate dentin sealing [IDS]) has been suggested to provide several advantages concerning bacterial microleakage, hypersensitivity, and bonding quality. We reviewed the literature and clarified certain aspects related to each step of IDS application.

Materials and Methods

The search strategy comprised an electronic research in MEDLINE, Cochrane, Ovid and Scopus for studies published from January 1990 to December 2020 regarding the IDS technique and including both in vitro and clinical studies.

Results

After exclusion of irrelevant or duplicate articles, 88 articles focusing on aspects of the IDS technique were assessed. IDS seems to be advantageous with regard to bond strength, gap formation, bacterial microleakage, and dentin hypersensitivity. However, issues arising from interaction with impression materials, the provisional phase, and conditioning methods before cementation require further investigation.

Conclusion

There are no documented reasons preventing clinicians applying IDS in their everyday practice. On the contrary, the presented technique seems to be beneficial in certain aspects regarding indirect restorations.

The Effect of Temporary Cement Cleaning Methods on the Retention of Crowns

PURPOSE

To evaluate the effect of temporary cement cleaning methods on the retention of cemented crowns using zinc phosphate cement and resin-modified glass ionomer cement.

MATERIALS AND METHODS

Forty titanium specimens were fabricated to simulate prepared molars with minimally retentive taper. The Ni-Cr cast crowns were fabricated, temporarily cemented, and separated. The specimens were divided into four groups according to the temporary cement cleaning method (n = 10) as follows: control group (no temporary cementation), orange solvent group, ultrasonic cleaning group, and air-abrasion group. After the cleaning procedures, the specimens were cemented with definitive cements (zinc phosphate cement and resin-modified glass ionomer, RMGI, cement) and subjected to thermocycling (5000 cycles, 5-55°C, dwell time, 10 seconds). The tensile bond strength of each specimen was measured using a universal testing machine, and the results were analyzed using the Kruskal-Wallis and Mann-Whitney U test (α = 0.05).

RESULTS

When cemented with zinc phosphate cement, the statistical analysis showed that the value of the air-abrasion group was significantly higher than those of the other groups (p < 0.01). There was no statistically significant difference among the other groups. When cemented with RMGI cement, the air-abrasion group showed the lowest value, and the control group showed the highest value (p < 0.01). The difference between the ultrasonic cleaning group and the orange solvent group was not statistically significant.

CONCLUSION

The use of temporary cement did not have a significant influence on retention of permanently cemented crowns when zinc phosphate cement was used for permanent cementation. Airborne-particle abrasion after provisional cementation improved retention of crowns cemented with zinc phosphate cement; however, the use of temporary cement significantly decreased retention of permanently cemented crowns when RMGI cement was used regardless of the temporary cement cleaning method.

Effect of different surface-cleaning techniques on the bond strength of composite resin restorations

STATEMENT OF PROBLEM

Different techniques have been suggested for cleaning dentin surfaces after the removal of an interim prosthesis and before the application of a bonding agent. How different surface-cleaning techniques affect the bond strength of the composite resin restorations is not clear.

PURPOSE

The purpose of this study was to investigate the effects of different surface-cleaning techniques on the bond strength of composite resin restorations and the surface topography of the prepared tooth surfaces.

MATERIAL AND METHODS

The occlusal surfaces of 25 molars were ground until the dentin was exposed. A bonding agent and interim cement were applied on the teeth. The teeth were divided into 5 groups (n=5) according to the method used for surface-cleaning (microairborne-particle abrasion, alcohol, rubber-rotary instrument, desiccating agent, and control). Once the surfaces of the teeth had been cleaned, the same bonding material was applied to the teeth. A 5-mm-thick composite resin layer was built up. Each specimen was sectioned to microbars, and 6 centrally located beams were selected for microtensile testing (n=30) (1.10 ±0.10 mm). The data were statistically analyzed with 1-way ANOVA (1-sample Kolmogorov-Smirnov test). The Bonferroni test was used for significantly different groups (α=.05). One specimen from each group was observed under a scanning electron microscope and an atomic force microscope. Energy dispersive x-ray analysis also was performed.

RESULTS

Bond strength values were in the following descending order: microairborne-particle abrasion, desiccating agent, alcohol, rubber-rotary instrument, control. Differences between the microairborne-particle abrasion group and the remainder of the groups, desiccating agent--rubber-rotary instrument, desiccating agent-control, alcohol--rubber-rotary instrument, and alcohol-control groups, were statistically significant (P<.05). The microairborne-particle abrasion group displayed the roughest surface and a different surface topography from the remainder of the groups. Increased aluminum was observed in the microairborne-particle abrasion group.

CONCLUSIONS

Surface-cleaning techniques, except for the rubber-rotary instrument, increased the bond strength of composite resin. The roughest dentin surfaces and highest bond strength were achieved with the microairborne-particle abrasion technique.

Influence of different conditioning methods on immediate and delayed dentin sealing

STATEMENT OF PROBLEM

Data are needed to evaluate the effect of various conditioning methods on immediate and delayed dentin sealing.

PURPOSE

The purpose of this study was to test bond strength and surface configuration of immediate and delayed dentin sealing surfaces after applying different surface conditioning methods.

MATERIAL AND METHODS

A total of 96 premolars were allocated to the immediate and delayed groups. The groups differed in the timing of dentin sealing. The immediate-group specimens were sealed with a self-etching adhesive immediately after preparation. The delayed-group specimens were sealed before the final ceramic restoration bonding. Provisional restorations were cemented on immediate-group and delayed-group specimens for 1 week. Four conditioning methods were used: polishing with fluoride-free pumice paste, airborne-particle abrasion with silicoated aluminum oxide, glycin, or calcium carbonate. After 24-hour storage, the shear bond strength was tested. The fractured specimens were optically inspected with a stereomicroscope. An optical 3-dimensional surface analysis was performed for quantitative and qualitative evaluation. A 2-way ANOVA with post hoc Tukey honestly significant difference tests for significant effects was performed to investigate effects of the 2 factors, sealing and conditioning, and their interaction (α=.05).

RESULTS

Two-way ANOVA found significant differences between the sealing and conditioning groups. The immediate group had significantly lower bond strengths than the delayed group. In all groups, surface polishing produced the highest bond strengths, and airborne-particle abrasion with calcium carbonate produced the lowest. Fracture analysis found more failures in the adhesive layers in the immediate groups and a prevalence of mixed failures in the delayed groups. The surface analysis found significant abrasion and roughness when airborne-particle abrasion with silicoated aluminum oxide was used for immediate and delayed dentin sealing surfaces.

CONCLUSIONS

Polishing and airborne-particle abrasion with silicoated aluminum oxide or glycin are efficient methods in conditioning immediate and delayed dentin sealing surfaces. Airborne-particle abrasion with silicoated aluminum oxide leaves significant surface alterations on both types of surfaces.

Self-adhesive resin cements: a new perspective in luting technology

Many materials are available for the fabrication of indirect restorations such as, metal alloys, resin-based composites and ceramics. Resin cements have long been valued as luting agents for indirect restorations because of their high retentive strength, resistance to wear, and low solubility. However, one of the common discouraging factors regarding their chairside use is the need of multiple-steps (etching, drying, priming and luting) for bonding. Thus the current impetus is towards the use of self-adhesive cements that require no etching, priming or bonding agents to bond to the tooth surface. Their increased popularity can be judged by the commercial availability of more than a dozen self-adhesive resin products/brands, in a short span of time. This article reviews the composition, physical and biological properties, adhesion characteristics and clinical performance of self-adhesive (resin) cements.

CLINICAL RELEVANCE

Self-adhesive resin cements are dual-cured and adhere to tooth structure without the requirement of a separate etching step and application of an adhesive/bonding agent.

A comparison of retentive strength of implant cement depending on various methods of removing provisional cement from implant abutment

PURPOSE

This study evaluated the effectiveness of various methods for removing provisional cement from implant abutments, and what effect these methods have on the retention of prosthesis during the definitive cementation.

MATERIALS AND METHODS

Forty implant fixture analogues and abutments were embedded in resin blocks. Forty cast crowns were fabricated and divided into 4 groups each containing 10 implants. Group A was cemented directly with the definitive cement (Cem-Implant). The remainder were cemented with provisional cement (Temp-Bond NE), and classified according to the method for cleaning the abutments. Group B used a plastic curette and wet gauze, Group C used a rubber cup and pumice, and Group D used an airborne particle abrasion technique. The abutments were observed using a stereomicroscope after removing the provisional cement. The tensile bond strength was measured after the definitive cementation. Statistical analysis was performed using one-way analysis of variance test (α=.05).

RESULTS

Group B clearly showed provisional cement remaining, whereas the other groups showed almost no cement. Groups A and B showed a relatively smooth surface. More roughness was observed in Group C, and apparent roughness was noted in Group D. The tensile bond strength tests revealed Group D to have significantly the highest tensile bond strength followed in order by Groups C, A and B.

CONCLUSION

A plastic curette and wet gauze alone cannot effectively remove the residual provisional cement on the abutment. The definitive retention increased when the abutments were treated with rubber cup/pumice or airborne particle abraded to remove the provisional cement.

Effect of Eugenol Exposure Time and Post-removal Delay on the Bond Strength of a Self-etching Adhesive to Dentin

The presence of a provisional restoration containing eugenol for one week or longer does not interfere with the bond strength of self-etching adhesives to dentin. If a eugenol-based provisional restoration remained in place for only 24 hours, a delay of one week re-establishes proper bond strength.