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

Abstract 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.

Available resin cements could be classified as conventional (etch and rinse), self-etch, and self-adhesive (all-in-one) resin cements based on the application protocols (Figure 1) (Migliau, 2017;Pegoraro et al., 2007).Generally, resin cement selection is affected by required retention, isolation possibility, esthetic criteria, mechanical properties of restorative materials, and the bonding substrate (dentin or enamel) (Manso et al., 2011;Sunico-Segarra & Segarra, 2015).For enamel, adhesion mainly occurs through the penetration of resin into microporosities created by acid etching (Van Landuyt et al., 2007).In the dentin, adhesion is more complex and happens when the resin entangles the exposed collagen fibers (Van Landuyt et al., 2007).Dentin porosity, hydrophilicity, and the hydroxyapatite composition of the collagen matrix compromise the adhesion in dentin (Migliau, 2017).Cementum, in comparison, is less hard and more permeable to a variety of materials (Kaneshiro et al., 2008).
The clinical outcomes, performance, and success of PCRs are largely affected by appropriate cement selection.Adhesive cements comprise a wide range of types, compositions, and characteristics (Figure 1 and Table 1) (Abo-Hamar et al., 2005;Ashy & Marghalani, 2022;Behr et al., 2009;Borges et al., 2008;Bouillaguet et al., 2000;Burgess et al., 2010;Carvalho et al., 2004;Casselli & F I G U R E 1 The classification of commercially available resin cements based on the application procedure.
T A B L E 1 Features of different resin cement systems: advantages, disadvantages, and indications.
− More steps are required compared to other types (Burgess et al., 2010).
Advantages Disadvantages
Self-adhesive cements Single step − Lower technique sensitivity and fewer steps required compared to two other groups (Behr et al., 2009;Manso et al., 2011).

| MATERIALS AND METHODS
This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) (Liberati et al., 2009) 2).

| RESULTS
The advantages, disadvantages, and indications of resin cements were among the interesting subjects in the literature.There were several studies (14 articles) on the characteristics of self-etch and self-adhesive cements (single step); however, fewer studies (five articles) were available on their indications (Table 1).However, Therefore, the present study also dealt with the appropriate product for cementation among the available resin cements based on the literature reviewed (Figure 1).In addition, 12 catalogs were also consulted to compile a table that summarized the manufacturer's recommendations on the use of resin cements in various situations (Table 3) (3M Dental Products Laboratory, 1998;3M Oral Care, 2016;Dentsply Sirona, 2016, 2017;GC America Inc., 2023;Inside Dentistry, 2019;Ivoclar Vivadent AG, 2018a, 2018b;Kuraray Noritake Dental Inc., 2018;PANAVIA 21 brochure, (n.d.); PANAVIA F 2.0 brochure, 2012; Panavia SA Cement Universal, 2019).

Improvements in esthetic restorative materials and technologies
have caused an ever-increasing application of PCRs in routine dental practices.Since dealing with the cementation of PCRs calls for familiarity with these restorations, different types of PCRs will be briefly elaborated, and then the resin cement selection criteria will be discussed based on the articles reviewed.
T A B L E 2 Systematic review search strategy.Inlay is a minimally invasive restoration that restores small to medium dental lesions, (Felden et al., 1998) onlay is used for medium to extensive defects with cuspal coverage, (Felden et al., 1998;Ferro et al., 2017) and vonlay is a combination of onlay and ceramic veneer (McLaren et al., 2015).These PCRs can be made of metal, ceramic (preferably), or composite materials (McGill & Holmes, 2012).

| Occlusal veneer and overlay
Occlusal veneer is an ultrathin, bonded treatment for teeth that are worn down or eroded in the occlusal surface, (Magne et al., 2010) and overlay covers all the cusps (Felden et al., 1998) for correcting the anatomy of posterior teeth.They have many advantages, such as protection of dental structure, recovery of masticatory function and esthetic, (Schlichting et al., 2016;Yazigi et al., 2017) simplicity of cementation, (Carvalho et al., 2014) and being more conservative than onlays and full-coverage crowns (Magne et al., 2010;Schlichting et al., 2016).
Search results flowchart diagram according to preferred reporting items for systematic reviews and meta-analyses.
T A B L E 3 Manufacturers' recommendations for selecting proper resin cement.Self-adhesive Self-cure Metal, PFM, resin/composite, ceramic and porcelain inlays, onlays, crowns and bridges and endodontic posts.
Light-cure Translucent ceramics and composites.

| Endocrown
Endocrown is a single PCR made of acid-etchable metal ceramic, ceramic, or composite materials for endodontically treated teeth with large coronal destruction (Biacchi & Basting, 2012).This monoblock restoration is an alternative to post and crown with many advantages, such as an easy and time-saving preparation procedure, esthetic appeal, resistance to failure, and conservation of tooth structure (Biacchi et al., 2013;Dietschi et al., 2008).Endocrown relies on macro-and micromechanical retention (Biacchi & Basting, 2012;Biacchi et al., 2013).

| Laminate veneer
Laminate veneer is a thin indirect ceramic or composite layer bonded to the tooth's facial surface (da Cunha et al., 2014) to reproduce a natural appearance with minimal or no preparation (da Cunha et al., 2014;Layton & Walton, 2007).Dental laminate is indicated to restore discolored, malpositioned, or malcontoured teeth (Alabdulwahhab et al., 2015).
Clinical studies have reported good results for more than 10 years (Layton & Walton, 2007;Layton et al., 2012).
The PCR could also be used as a retainer for fixed prostheses to reduce the extension of tooth preparation.This type of prosthesis uses metallic or ceramic extensions bonded to adjacent teeth and could be a Maryland bridge, laminate bridge, or inlay bridge (Edelhoff et al., 2016;Pahlevan, 2006;Trushkowsky, 2008).These types of PCR-retained prostheses have the same considerations for bonding as single-tooth PCRs; however, the bonding, loading, and occlusal considerations should be followed more precisely.Considering the higher failure rate, PCR-retained prostheses could be indicated for temporary restorations, small spans, and younger patients with lower bite force (Ibbetson, 2004;Trushkowsky, 2008).These restorations, generally, are not suggested in deep vertical overlap, long-span edentulous space, when the abutments are mobile, or when the patient has parafunctional habits (Ibbetson, 2004).

| DISCUSSION
PCR is an indirect fixed prosthesis that tries to replace the demolished tooth structure while preserving more remaining tooth structure compared to conventional prostheses (Donovan & Chee, 1993).This type of restoration aims to recover full mechanical function, strength, and esthetic while protecting the remaining tooth structure, improving periodontal health through the accessibility of margins, simplifying daily maintenance, and reducing gingival and pulpal irritations (Dallı et al., 2012;Ruiz, 2015).Selecting the appropriate resin cement is one of the key factors that determines the success and longevity of PCR (Santos et al., 2009) | 1103 bonded (Borges et al., 2008;Hackman et al., 2002;Hekimoğlu et al., 2000;Tanoue et al., 2003).This highlighted the rejection of the null hypothesis.In the next paragraphs, the results of the reviewed articles are summarized based on the queries a dentist might ask in a clinical situation for cementing a PCR with resin cement: 4.1 | Light, dual, or self-cure resin cement?
Light-cure resin cements are not suitable for metallic restorations; however, they could be, and in fact, they are preferred to be used for metal-free PCRs (Borges et al., 2008;Vargas et al., 2011).Ceramic PCRs are relatively thin, and their appearance is affected by the cement color; light-cured resin cements are generally preferred to provide immediate final polymerization, esthetic, and strength.Light-cure cements offer sufficient working time, facilitate excess cement removal before polymerization, provide better color stability as they do not contain chemical amine initiators, cure completely in a shorter time, and quickly seal the margins compared to self-and dual-cured resins (Simon & Darnell, 2012;Simon & de Rijk, 2006;Tanoue et al., 2003).However, for areas with difficult access or where the curing light cannot penetrate (due to opacity, thickness, or material type), self-or dual-cure resin cements could be used (Heboyan et al., 2023;Simon & Darnell, 2012).Dual-cure cement can be set through chemical reaction alone; however, light curing is necessary to reach the maximum degree of polymerization (El-Badrawy & El-Mowafy, 1995;Manso et al., 2011).When the thickness of material is more than 1.5 mm in low-glass ceramics (e.g., lithium disilicate, zirconia lithium silicate, and glass-infiltrated ceramics), dual-cure resin cements are indicated, while translucent ceramics (feldspathic or leucite-reinforced ceramics) could be cemented reliably by light-curable resin cements (Borges et al., 2008;Hackman et al., 2002;Simon & Darnell, 2012).

| Which type of resin cement is preferred?
Conventional resin cement (etch and rinse type) provides predictable bond strength to enamel with proven long-term clinical success (Peumans et al., 2005;Simon & de Rijk, 2006;Swift & Bayne, 1997).
The bonding mechanism to dentin is through resin penetration in exposed collagen fibrils (Peumans et al., 2005).This penetration could provide high bond strength if the steps are followed properly; however, multiple steps in conventional resin cements and the effect of the water content of dentin might compromise the efficiency of dentin bonding (Burgess et al., 2010;Casselli & Martins, 2006).Selfetch resin cement, although having a weaker bond to enamel, provides higher bond strength in dentin (Cekic et al., 2007;Simon & de Rijk, 2006).Self-etch systems (with a pH of about 2) could not expose the collagen fibers completely for acceptable cement penetration, and additional ionic bonding and specific functional monomers are needed to enhance their adhesive efficiency (Van Landuyt et al., 2007;Peumans et al., 2005).Functional monomers are classified based on their bonding potential; 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP), for instance, could establish a strong and stable chemical bond with hydroxyapatite, which increases the diffusion and adhesion of self-etch resin cement (Ashy & Marghalani, 2022;Carvalho et al., 2004;Wang et al., 1991;Watanabe et al., 1994).Self-adhesive cement does not require dentin conditioning (Tay et al., 1995).Although the bond strength of selfadhesive resin cements to dentin and enamel has been reported to be adequate, it is significantly less than conventional or self-etch types (Carvalho et al., 2004;Simon & de Rijk, 2006).Self-etching and selfadhesive cements are particularly indicated for teeth with extensive defects when the predominant exposed structure is dentin.However, even in such a situation, self-etching cement is preferred because of its higher and more durable bond strength (Manso et al., 2011;Sunico-Segarra & Segarra, 2015).
There is no way for light to penetrate through metal; however, considering the probability of light penetration through tooth structure, a dual-cure cement might still be efficient with a high degree of conversion and good physical properties (Manso et al., 2011).Some resin cement manufacturers suggest special types of their products for each type of PCR (  AG, 2018a).Ceramic restorations could affect light penetration because of their thickness and opacity.Thick (above 1.5-2 mm) and opaque (noglass) ceramics inhibit light penetration, and therefore, self-or dual-cure cements could provide more predictable results (Hekimoğlu et al., 2000;Sadan et al., 2005;Simon & Darnell, 2012).Thin (<1.5 mm) or more translucent materials (high glass ceramic), however, could benefit from the advantages of light-curable, conventional resin cements (Borges et al., 2008;Vargas et al., 2011).Inlays, onlays, laminate veneers, and other PCRs fabricated from high-glass ceramics or composites could take advantage of adhesive cementation with light-curable cements in totaletch mode (Borges et al., 2008;Hekimoğlu et al., 2000;Pissaia et al., 2015;Simon & de Rijk, 2006;Vargas et al., 2011).Dual-cure resin cements could also be recommended considering their color and opacity varieties, low solubility in oral fluids, high radiopacity, high bond strength to dental tissues, and increased durability (Kilinc et al., 2011;Pegoraro et al., 2007;Rosenstiel et al., 1998).In a 5-year prospective clinical evaluation, total etch dual-cure resin cement showed better clinical performance regarding marginal discoloration and marginal adaptation than self-etch and selfadhesive resin cements (Eltoukhy et al., 2021).Time-dependent discoloration attributed to tertiary amine content in dual-cure cements, (Kilinc et al., 2011;Rosenstiel et al., 1998) however, calls for the application of amine-free versions.Variolink Esthetic DC (Ivoclar Vivadent), Panavia V5 (Kuraray Noritake Dental), NX3 Nexus (Kerr Dental), and G-CEM Linkforce (GC Corporation) are among amine-free dual cure resin cements introduced for use in esthetic veneers when light cure cement could not be applied (Atay et al., 2019).
4.4 | How to prepare the surface of the restoration?
Silica-based ceramics have shown high bonding strength (up to 71.5 MPa) to resin cement, (Kamada et al., 1998;Nagai et al., 2005;Roulet et al., 1995) provided that correct preparation methods are followed.Sandblasting with 50-µm aluminum oxide particles (at 80 psi) or 4%-9.5% hydrofluoric acid (HF) etching followed by subsequent silanization have been proposed for surface preparation (Kamada et al., 1998;Manso et al., 2011;Roulet et al., 1995).The glass phase will be dissolved in HF to create micromechanical retention (Borges et al., 2003).Etching with HF and silane application is preferred over air abrasion since a higher failure rate and complications have been reported with the latter on thin veneers (Friedman, 1998;Shaini et al., 1997).
The present study tried to review the available studies on resin cement selection in different types of PCRs.However, the main restriction returns to the limited clinical studies on the long-term durability of bonding provided by resin cements.Further studies on new restorative materials and the long-term durability of bonding by improved versions of cements are encouraged, as are evaluative studies on cement durability in challenging situations, namely structural deficiencies of enamel or dentin (e.g., amelogenesis or dentinogenesis imperfecta), excessive loading situations, and reduced height or width of bonded abutments.

| CONCLUSION
Based on the results of the literature review, the following conclusions can be drawn: • Self-and dual-cure resin cements have been recommended for the cementation of metallic PCRs (for conventional cementation or adhesive luting).
• The PCRs fabricated from thin (<1.5-2 mm), translucent (highglass), and low-strength ceramics or composites could be adhesively bonded by light-cure and conventional (etch and rinse) adhesive resin cements.Thick and opaque ceramic restorations could be cemented by self-curing or dual-curing resin cements.Dual-cure cement showed significantly higher bond strength compared to selfcure cement.

Raeisosadat et al. (2020)
Base metal alloy (nickel-chrome alloy) Effect of different surface treatments on the shear bond strength of resin cement: sandblasting, Er:YAG laser, Er:YAG laser after sandblasting, MKZ metal primer after sandblasting.
Er:YAG laser treatment provided the highest shear bond strength between metal alloy and resin cement.
• Self-etching and self-adhesive cements, especially those in dualcure types, are not indicated for laminate veneers.
T A B L E 4 (Continued)
The ideal zirconia preparation protocol was using a combination of sandblasting with 50 μm Al 2 O 3 particles and selfadhesive resin cement containing 10-MDP.
Manso et al. (2011) and Abo-Abo-Hamar et al. (2005) had extensively dealt with the indications of these cements.There was no article summarizing the classification of different types of resin cements and commercial brands in the studies reviewed.
based inlay and onlay/Maryland bridge, glass ceramic inlay and onlay/veneer, oxide ceramic inlay and onlay/Maryland bridge, resin composite inlay and onlay/veneer, resin nanoceramic inlay and onlay/veneer.

Table 3
Studies' outcomes on different resin cements and surface pretreatments.