Indirect Resin Composite Inlays Cemented with a Self-adhesive, Self-etch or a Conventional Resin Cement Luting Agent: A 5 Years Prospective Clinical Evaluation

Outcome measurements and quality of randomized controlled clinical trials of tooth-supported fixed dental prostheses: A systematic review and qualitative analysis

STATEMENT OF PROBLEM

The lack of consensus regarding a standardized set of outcome measurements and noncompliance with current reporting guidelines in clinical trials of tooth-supported fixed dental prostheses (FDPs) hamper interstudy comparability, compromise scientific evidence, and waste research effort and resources in prosthetic dentistry.

PURPOSE

The primary objective of this systematic review was to identify all primary and secondary outcome measurements assessed in randomized controlled trials (RCTs) of tooth-supported FDPs. Secondary objectives were to assess their methodological quality by using the Cochrane Collaboration's risk of bias tool (RoB, v2.0) and their reporting quality by means of a standardized 16-item CONSORT assessment tool through published reports.

MATERIAL AND METHODS

An electronic search was conducted in MEDLINE, EMBASE, and Cochrane library to identify all RCT-related articles published in the past 10 years. Differences in RoB were tested with the Pearson chi-squared test, and those in CONSORT score with the Student t test.

RESULTS

A total of 64 RCTs from 79 publications were deemed eligible. The diversity of outcome measures used in the field is apparent. Twenty percent of the included studies had a low RoB, 79% showed some concerns, and 1% had a high RoB. The mean ±standard deviation CONSORT compliance score was 22.56 ±3.17. Trials adhered to the CONSORT statement reported lower RoB than those that did not adhere (P<.001). RCTs with a low RoB reported more comprehensive adherence to CONSORT guidelines than those with some concerns (MD 4 [95% CI 1.52-6.48]; P=.004).

CONCLUSIONS

A standardized core outcome reporting set in clinical research on tooth-supported FDPs remains evident. Adherence to the CONSORT statement continues to be low, with some RoB concerns that can be improved.

Touch-cure activation by marketed universal resin luting cements of their associated primer to dentin

PURPOSE

The aim of this study was to investigate the dentin shear bond strength (SBS) and bonding interface of three recently developed "universal" resin luting cements based on different modalities.

METHODS

The dentin SBS and interfacial analysis of three recently launched "universal" resin luting cements, namely, G-Cem One, RelyX Universal and Panavia SA cement universal, were studied. All bonding protocols, including the previous use of their dedicated primer or universal adhesive in touch-cure mode or light-cure mode were performed. Variolink Esthetic LC used in conjunction with Scotchbond Universal Plus was used as a control group. For each group (n = 9), 10 specimens were tested for dentin SBS and two were examined by scanning electron microscopy. SBS were analyzed by two-way ANOVA followed by Dunnett's test.

RESULTS

SBS values showed that the three "universal" resin luting cements tested exhibit different adhesive behaviors. G-Cem One with its touch-cure activated primer had a greater SBS to dentin (25.5 MPa) than that of the control group (22.1 MPa).

CONCLUSION

"Universal" resin luting cements have variable efficacy when used in self-curing mode. The touch-curing mode is also of concern but may show high potential for some formulations.

The influence of Zircos-E® etchant, silica coating, and alumina air-particle abrasion on the debonding resistance of endocrowns with three different preparation designs

OBJECTIVES

The study aimed to evaluate the debonding resistance of three different endocrown designs on molar teeth, using three different zirconia surface pretreatments.

MATERIAL AND METHOD

Ninety human mandibular first molars were divided into three main groups: endocrowns without ferrule, with 1 mm ferrule, and with 2 mm ferrule. The subgroups were defined by their surface pretreatment method used (n = 15): 50 μm alumina air-particle abrasion, silica coating using 30 μm Cojet™ particles, and Zircos-E® etching. The endocrowns were fabricated using multilayer zirconia ceramic, cemented with self-adhesive resin cement, and subjected to 5000 thermocycles (5-55°C) before debonding. The data obtained were analyzed using a two-way ANOVA.

RESULTS

All test specimens survived the thermocyclic aging. The results indicated that both the preparation design and the surface treatment had a significant impact on the resistance to debonding of the endocrowns (p < .001). The 2 mm ferrule followed by the 1 mm ferrule designs exhibited the highest debonding resistance, both were superior to the endocrown without ferrule. Zircos-E® etching and silica coating yielded comparable debonding resistance, which were significantly higher than alumina air-particle abrasion. All endocrowns demonstrated a favorable failure mode.

CONCLUSIONS

All designs and surface treatments showed high debonding resistance for a single restoration. However, ferrule designs with Zircos-E® etching or silica coating may represent better clinical options compared to the nonferrule design or alumina airborne-particle abrasion. Nonetheless, further research, including fatigue testing and evaluations with different luting agents is recommended.

Self-adhesive resin cement versus conventional cements on the failure rate of indirect single-tooth restorations: A systematic review and meta-analysis of randomized clinical trials

STATEMENT OF PROBLEM

Cementation is one of the most critical steps that influence the failure rates of indirect restorations. Self-adhesive resin cements arose out of the need for technical simplification of this procedure to reduce the risk of operative errors, with good acceptance by clinicians. How the failure rate of indirect single-tooth restorations cemented with self-adhesive resin cements compares with the failure rate of those cemented conventionally is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis of randomized clinical trials was to compare self-adhesive resin cements versus conventional cements on the failure rates of indirect restorations.

MATERIAL AND METHODS

The review was registered at the International Prospective Register of Systematic Reviews (PROSPERO - CRD42020215577). The search strategy was adapted for 5 databases (PubMed, The Cochrane Library, EMBASE, Web of Science, and LILACS) and 1 nonpeer-reviewed literature source (clinicaltrials.gov). The strategy was guided by the problem/population, intervention, comparison, outcome (PICO) question: adults indicated for indirect restorations -P, self-adhesive resin cement -I, conventional cement-C, failure rates-O. The risk of bias was assessed using the Cochrane risk of bias (RoB2) tool and guidelines. Meta-analysis merged the results from included studies by pooling the hazard ratios and standard errors, available or estimated. The certainty of evidence was assessed by using the classification of recommendations, evaluation, development, and evaluation (GRADE) approach.

RESULTS

Nine randomized clinical trials were included in qualitative and quantitative analysis. Eight studies detected nonsignificant differences in failure rates between cements. Only 1 study reported a significantly higher failure rate on single-tooth ceramic crowns luted with self-adhesive resin cement. Nonsignificant differences were detected after the results from all studies had been pooled.

CONCLUSIONS

Based on clinical evidence, self-adhesive resin cements can be recommended for the cementation of indirect single-tooth restorations with a similar risk of failure to conventional cements.

A comprehensive review of resin luting agents: Bonding mechanisms and polymerisation reactions

The field of dentistry is constantly evolving and increasingly embracing minimally invasive approaches. One such approach, which is bonding to the tooth structure, particularly enamel, has been shown to offer the most predictable outcomes. However, there are instances where significant tooth loss may limit treatment options for a restorative dentist. In these scenarios, indirect restoration might be the preferred treatment option. This literature review provides a comprehensive examination of the currently available resin luting agents and their bonding requirements. It provides valuable insights for dental professionals seeking an in-depth understanding of the current state of the field and the future prospects of dental adhesion.

Resin cement selection for different types of fixed partial coverage restorations: A narrative systematic review

OBJECTIVE

The aim of this study was to review the selection criteria of resin cements for different types of partial coverage restorations (PCRs) and investigate if the type of restorations or restorative materials affect the type of selected resin cement.

MATERIALS AND METHODS

An electronic search (1991-2023) was performed in PubMed, Medline, Scopus, and Google Scholar databases by combinations of related keywords.

RESULTS

A total of 68 articles were included to review the selection criteria based on the advantages, disadvantages, indications, and performance of resin cements for different types of PCRs.

CONCLUSIONS

The survival and success of PCRs are largely affected by appropriate cement selection. Self-curing and dual-curing resin cements have been recommended for the cementation of metallic PCRs. The PCRs fabricated from thin, translucent, and low-strength ceramics could be adhesively bonded by light-cure conventional resin cements. Self-etching and self-adhesive cements, especially dual-cure types, are not generally indicated for laminate veneers.

Bond Strength of a Novel Universal Resin Cement to Dentin with or without an Adhesive Bonding Agent: An In Vitro Study

AIM

The purpose of this study was to evaluate the bond strength and fracture mode of universal resin cement to dentin compared to self-adhesive and adhesive resin cement with and without an adhesive bonding agent.

MATERIALS AND METHODS

Seventy-two molar teeth were sectioned to expose coronal dentin, divided into three groups, and assigned to RelyX Universal (universal), RelyX Ultimate (adhesive), or RelyX Unicem 2 (self-adhesive) cements from 3M. The 3 groups were further subdivided into 2 subgroups of 12 specimens each, with or without the use of an adhesive bonding agent. Lithium-disilicate discs were bonded to the dentin surface using the cements, stored for 24 hours in distilled water, and subjected to 2,000 thermocycles before shear bond strength testing and fracture mode analysis.

RESULTS

Significant differences in bond strength and fracture mode were found between groups based on cement or the use of a bonding agent. Both the universal and adhesive cements had significantly greater bond strengths to dentin with the use of a bonding agent versus no bonding agent. With the self-adhesive cement, there was no significant increase in bond strength to dentin with the use of a bonding agent.

CONCLUSION

The novel universal resin cement had similar bond strengths to dentin as the adhesive cement with the use of a bonding agent, and similar bond strengths as the self-adhesive cement without the use of a bonding agent. The adhesively bonded universal cement had the greatest percentage of mixed and cohesive fractures.

CLINICAL SIGNIFICANCE

When greater adhesion is needed clinically, the novel universal resin cement may be used with an adhesive bonding agent. However, when less adhesion is needed, it could be used without a bonding agent in self-adhesive mode.

Resin composite cements: Current status and a novel classification proposal

OBJECTIVES

Currently, a classification of resin cements that includes relatively recently formulated ("universal") cements is lacking. Furthermore, the terminology used to define different resin cements in the scientific reports is inconsistent. Accordingly, this work aims to: (i) propose a novel classification of resin composite cements; (ii) disambiguate the term "universal cements" and (iii) present an overview of the properties of these cements.

METHODS

An analysis of peer-reviewed literature (PubMed search), as well as market research on definitive resin composite cements were performed.

RESULTS

A tendency toward simplified and versatile luting materials was observed both in the scientific literature and on the dental market with the advent of self-adhesive/one-step resin cements. However, additional priming procedures were necessary to improve their bonding performance in certain clinical situations. Hence, several cements that can be applied both in adhesive and self-adhesive mode were introduced. These cements are associated with a universal adhesive resin, that can be used as a tooth and/or restorative material primer, without the need for other priming systems, regardless of the substrate. These systems should be considered truly universal. Therefore, we hereby suggested a new classification of resin-based cements: (1) adhesive/multi-step; (2) self-adhesive/one-step; (3) universal cements (one- or multi-step). Despite promising in vitro results, clinical trials and long-track laboratory studies are necessary to confirm the reliability of the universal cements.

CONCLUSIONS

This review presented the current advances in the field of resin-based cements, which are reflected in the proposed classification. The term "universal cement" was disambiguated, which will help standardize the terminology used in published research.

CLINICAL SIGNIFICANCE

The classification of resin-based cements and a better understanding of the proper terminology will help standardize the terminology in published research, as well as improve the understanding of the clinical practitioners of the different indications and possible modalities of use of the available cements.

Selective adhesive luting: A novel technique for improving adhesion achieved by universal resin cements

OBJECTIVE

We aimed to introduce the concept of "Selective adhesive luting-SAL" which is explained through clinical steps and supported by preliminary laboratory evidence.

CLINICAL CONSIDERATIONS

Cementation with rubber dam is difficult to perform in case of short abutment teeth and/or subgingival crown margins. By means of universal resin cements/universal adhesive systems, which can be employed in self-adhesive as well as adhesive luting procedures, this paper presents a novel technique allowing clinicians to perform reliable cementation where rubber dam isolation is difficult. The SAL technique entails the application of a universal adhesive system only on easily accessible abutment surfaces, enabling simultaneous adhesive and self-adhesive luting in different portions of the abutment. The SAL clinical workflow is explained through prosthodontic rehabilitation of maxillary right central incisor affected by microdontia and restored with a lithium-disilicate crown. Furthermore, our laboratory microshear bond strength study supports the rationale behind SAL application demonstrating higher bond strength even when the adhesive resin is placed only on one portion of the cementation substrate.

CLINICAL SIGNIFICANCE

This article advocates the application of SAL technique in clinical situations where effective adhesive luting is uncertain, since it can improve the adhesion between the tooth and universal resin cements.

Brief Narrative Review on Commercial Dental Sealants-Comparison with Respect to Their Composition and Potential Modifications

The scope of this paper is to compare different dental sealants and flow materials indicated for sealing pits and fissures considering their chemical formula. The narrative review aims to address the following questions: What is the essence of different dental sealants' activity, how does their chemical formula affect their mechanisms of caries prevention, and what makes a dental sealant efficient mean of caries prevention? Another vital issue is whether the sealants that contain fluoride, or any other additions, have potentially increased antimicrobial properties. An electronic search of the PubMed, Cochrane, Web of Science, and Scopus databases was performed. The following keywords were used: (dental sealants) AND (chemical composition). Additionally, information about composition and indications for clinical use provided by manufacturers were utilized. All of the considered materials are indicated for use both in permanent and primary dentition for sealing fissures, pits, and foramina caeca. The selection of suitable material should be made individually and adjusted to conditions of the sealing procedure and patient's needs. Cariostatic mechanisms increasing sealants' effectiveness such as fluoride release are desired in modern dentistry appreciating preventive approach. The review aims are to find crucial elements of sealants' composition which affect their cariostatic mechanisms.

Long-term survival of monolithic tooth-supported lithium disilicate crowns fabricated using a chairside approach: 15-year results

OBJECTIVES

To investigate the clinical performance of chairside fabricated tooth-supported posterior single crowns from lithium disilicate ceramic.

MATERIALS AND METHODS

Thirty-four crowns (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein) were inserted between 2006 and 2007 and again evaluated after 15 years. Survival and success rates were calculated according to Kaplan-Meier, and the quality of the crowns was evaluated by using modified United States Public Health (USPHS) criteria.

RESULTS

Twenty-two crowns were available for recall; six patients were defined as dropouts. The mean observation period was 15.2 years (± 0.2). Six failures occurred (1 technical/5 biological) resulting in a survival rate of 80.1%. The success rate was 64.2%. The roughness of the crowns increased (p = 0.021) and the majority of adhesive gaps were discolored (p = 0.001) in comparison to baseline. The color, tooth, and crown integrity remained stable over the follow-up period (p ≥ 0.317).

CONCLUSION

The fabrication of tooth-supported lithium disilicate crowns using a chairside approach yielded acceptable long-term survival and success rates. Due to discoloration, the long-term use of dual-cure self-adhesive resin cements might result in unpleasing esthetic results.

CLINICAL RELEVANCE

The performance of posterior lithium disilicate single crowns revealed excellent to good clinical quality and an acceptable number of events after 15 years of clinical service.

Survival rate and treatment success of glass fiber posts cemented with two adhesive cementation strategies after up to 106 months: a randomized clinical trial

OBJECTIVES

The objective of this study is to evaluate the longevity of two fiber post cementation strategies in a prospective, multicenter, non-inferiority, double-blind randomized controlled trial.

METHODS

A total of 152 teeth, with adequate endodontic treatment and loss of coronal structure and bilateral simultaneous posterior occlusal contacts, were randomly allocated to receive glass fiber posts cemented with a conventional cementation strategy (CRC group: adhesive system + resin cement) (Adper Single Bond + RelyX ARC; 3 M-ESPE) or a self-adhesive cementation strategy (SRC group: self-adhesive resin cement; RelyX U100/U200; 3 M-ESPE). The patients were recalled annually for clinical and radiographical evaluation with a 93% recall rate (142 teeth, with 74 at CR groups and 68 at SRC group). The primary outcome was survival rate, considering the fiber post debonding (loss of retention). The secondary outcome included the success rate of the prosthetic treatment with crown debonding, post fracture, and tooth loss (not related to post failure). Both outcomes were evaluated annually. The Kaplan-Meier method and Cox regression with 95% confidence interval were used for the statistical analysis.

RESULTS

For the primary outcome (failures directly related to fiber posts cementation strategy), there were 4 fiber post debondings (2 per group), 8 root fractures (3 for SRC group and 5 for CRC group), and one mixed failure (debonding combined with root fracture for CRC), with both strategies presenting similar survival rates (p = 0.331), with 88.9% for the CRC group and 90.9% for the SRC group. For the secondary outcome (failures not related to fiber post cementation strategies), there were 8 crown debondings, 3 post fractures, and 3 tooth losses, with no statistically difference between groups (p = 0.701), with 77% for SRC and 82% for CRC.

CONCLUSION

Fiber post cementation strategies with conventional or self-adhesive resin cement presents similar tooth survival and success rates.

TRIAL REGISTRATION

NCT01461239 CLINICAL RELEVANCE: Both adhesive cementation strategies led to high survival and success rates and are indicated for fiber post cementation, even after a long follow-up period (up to 106 months).

Dental Luting Cements: An Updated Comprehensive Review

The cementation of indirect restoration is one of the most important steps in prosthetic and restorative dentistry. Cementation aims to bond the prosthetic restoration to the prepared enamel or enamel and dentine. Successful cementation protocols prevent biofilm formation at the margin between tooth and restoration and minimize mechanical and biological complications. With the advancements in dental cements, they have been modified to be versatile in terms of handling, curing, and bond strengths. This review presents updates on dental cements, focusing on the composition, properties, advantages, limitations, and indications of the various cements available. Currently, dental restorations are made from various biomaterials, and depending on each clinical case, an appropriate luting material will be selected. There is no luting material that can be universally used. Therefore, it is important to distinguish the physical, mechanical, and biological properties of luting materials in order to identify the best options for each case. Nowadays, the most commonly used dental cements are glass-ionomer and resin cement. The type, shade, thickness of resin cement and the shade of the ceramic, all together, have a tangible influence on the final restoration color. Surface treatments of the restoration increase the microtensile bond strength. Hence, the proper surface treatment protocol of both the substrate and restoration surfaces is needed before cementation. Additionally, the manufacturer's instructions for the thin cement-layer thickness are important for the long-term success of the restoration.

Clinical reliability of self-adhesive luting resins compared to other adhesive procedures: A systematic review and meta-analysis

OBJECTIVES

This systematic review aimed to collect and interpret the randomized clinical trials (RCTs) that investigated the outcome of the self-adhesive luting resins (SA) compared to total-etch (TE), selective etch with dentin adhesives (Sle), selective etch without dentin adhesives (SleSA) or self-etch adhesives (SE).

DATA SOURCES

A thorough search of Internet databases was conducted without language restrictions, and the search ran up to and including April 2022. The illegible records citations were checked for more relevant clinical studies.

STUDY SELECTION/RESULTS

The inclusion criteria were randomized controlled trials (RCTs) that compared self-adhesive luting resins with total-etch, selective-etch, or self-etch adhesives regarding postoperative sensitivity, incidences of debonding, and survival rates of indirect restorations. From 1732 records, 9 RCTs met the eligibility criteria. Three RCTs compared total-etch adhesive to self-adhesive luting resin for intracoronal restorations, one RCT compared selective etch to self-adhesive luting resin for inlays, and 5 RCTs compared self-adhesive to other protocols for partial ceramic crowns. Postoperative sensitivity showed a non-statistically significant difference between SA and other adhesive protocols, SA revealed a non-statistically significant difference in debonding and survival to TE, but a lower statistically significant difference to Sle, SleSA, and SE.

CONCLUSIONS

Postoperative sensitivity might not be affected by the adhesive protocol. In relatively short observation, TE revealed comparable survival to SA for intracoronal restorations. SE and Sle exhibited the best clinical outcomes, followed by SleSA. Selective etch, and self-etch adhesives are preferable to self-adhesive resins.

CLINICAL SIGNIFICANCE

The significance of enamel etching and the superiority of self-etching adhesives over self-adhesive luting resins for reliable and durable bonding and improved clinical outcomes. However, long-term RCTs, particularly for total-etch comparison to self-adhesive luting resins, might be recommended to derive further evidence.

Update on Dental Luting Materials

A dental luting material aids in the retention and stability of indirect restorations on the prepared tooth structure. In dentistry, clinicians are using a wide range of luting materials for the cementation of indirect restorations. Zinc oxide eugenol and non-eugenol cements, zinc phosphate cement, zinc polycarboxylate cement, glass ionomer cement and resin cements are common dental cements used in dentistry. Each luting material or cement possesses unique properties and clinical implications. An ideal luting cement should be biocompatible, insoluble, resistant to thermal and chemical assaults, antibacterial, aesthetic, simple and easy to use. It should have high strength properties under tension, shear and compression to resist stress at the restoration-tooth interface, as well as adequate working and setting times. So far, no luting material possesses all of these properties of an ideal cement. Scientists have been modifying the conventional luting cements to improve the material's clinical performance and developing novel materials for clinical use. To achieve the best clinical outcome, clinicians should update their knowledge and gain a good understanding of the luting materials so that they can make a wise clinical decision on the material selection and obtain an insight into the development of luting cements. Therefore, the objective of this study is to provide a discussion on the physical, chemical, adhesive and aesthetic properties of common luting materials. The clinical indications of these luting materials are suggested based on their properties. In addition, overviews of the modification of the conventional luting materials and the newly developed luting materials are provided.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2021 dental literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to coverage of this broad topical area. Specific subject areas addressed, in order of the appearance in this report, include COVID-19 and the dental profession (new); prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence daily dental treatment decisions with an emphasis on future trends in dentistry. With the tremendous volume of dentistry and related literature being published daily, this review cannot possibly be comprehensive. Rather, its purpose is to update interested readers and provide important resource material for those interested in pursuing greater details on their own. It remains our intent to assist colleagues in negotiating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the patients and dental problems they encounter.

Internal and Marginal Adaptation of Adhesive Resin Cements Used for Luting Inlay Restorations: An In Vitro Micro-CT Study

Adequate internal adaptation and marginal sealing of resin luting cements are of particular importance for the success of cemented ceramic inlays. The purpose of this study was to investigate the initial adaptation of different resin cements at the tooth-inlay restoration interface at enamel versus dentin surfaces. Thirty-two extracted human molars were allocated to four groups. One Class II cavity was prepared in each tooth. In each group, half of the cavities’ gingival floors were on enamel while the other halves were on cementum. Lava Ultimate CAD/CAM inlays were luted to the cavities using the following adhesive systems: RelyX Unicem, RelyX Ultimate, eCement, and Variolink Esthetic DC. After staining teeth with silver nitrate solution, marginal and internal gap volumes were determined using micro-CT images. Statistical analyses were conducted by independent t test and one-way ANOVA followed by post hoc Tukey test (p < 0.05). The internal and marginal gap volume values were the highest for Variolink Esthetic DC at the dentin surface (0.629 ± 0.363) and (2.519 ± 1.007), respectively, and the lowest for RelyX Unicem at the enamel surface (0.005 ± 0.004) and (0.009 ± 0.003), respectively. The internal and marginal adaptation on the enamel surface for RelyX Unicem and RelyX Ultimate resin cements were comparable to each other and to eCement but significantly better than Variolink Esthetic DC cement. Regardless of the adhesive resin system used, adaptation on enamel is superior to that on dentin surfaces.