Universal Dental Adhesives: How to Choose by Evidence and Indication

Universal, or multimode, dental adhesives allow clinicians to choose more than one etching strategy. Their flexibility does not mean that products share the same application method, curing requirements, or indirect-restoration indications. Select the system by substrate, restoration type, curing access, and the relevant manufacturer instructions for use (IFU). 

Quick clinical answer

For many direct composite restorations with enamel margins, selective phosphoric-acid etching of enamel followed by an IFU-supported adhesive protocol is a practical starting point. Pre-etching improves enamel bonding in laboratory evidence, but dentin strategy and clinical outcomes remain product-dependent. Laboratory rankings exist; they do not establish a universally best adhesive or a clinically validated survival ranking. (Cuevas-Suárez et al., 2019) (Matos et al., 2020) (Karaduman et al., 2026)

What “universal” means

Multimode describes flexibility in tooth-etching strategy—not automatic compatibility with every cement, primer, or restoration. Many products contain 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP), a functional monomer, but the whole formulation and prescribed technique matter. (BISCO IFU, Rev 5/25) (3M technical product profile) (Karaduman et al., 2026)

Etching mode	Separate phosphoric-acid step	Adhesive sequence
Self-etch	None on enamel or dentin.	Apply the selected adhesive/primer as instructed; uncut enamel may still require pre-etching.
Selective enamel etch	Enamel only, followed by rinsing.	Apply the selected adhesive/primer to enamel and dentin.
Etch-and-rinse	Enamel and dentin, followed by rinsing.	Maintain the IFU-specified dentin moisture condition before adhesive application.

 

All-Bond Universal, G2-Bond Universal, and Scotchbond Universal Plus permit these strategies in the documents examined. Clearfil SE Bond is a two-step self-etch comparator, not a universal/multimode adhesive; do not transfer total-etch or activator instructions from another Clearfil product. 

Clinical selection: start with the case

Clinical situation	Selection decision	Boundary or stop point
Non-carious cervical lesion (NCCL) with enamel margins	Consider selective enamel etching within the selected product protocol. Assess the substrate and whether restoration is indicated.	NCCL evidence does not establish one dentin strategy for every product. (Matos et al., 2020) (Ñaupari-Villasante et al., 2023)
Class I/II composite with enamel margins	Choose an IFU-supported mode and confirm isolation and light access before bonding.	NCCL retention results alone cannot establish posterior restoration survival. (Polesso Patias et al., 2025) (Hickel et al., 2023)
Subgingival margin or persistent contamination	Improve isolation and identify the contaminant before selecting or repeating the adhesive sequence.	Do not cure over a visibly contaminated surface; reconsider the restorative approach if adequate isolation cannot be maintained. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)
Sclerotic cervical dentin	Clean and assess the surface; select an established product-specific protocol.	Do not prescribe routine aggressive roughening or prolonged acid etching from this guide; the cited trials do not justify a single universal modification. (Matos et al., 2020) (Ñaupari-Villasante et al., 2023)
Deep carious preparation with intact dentin	Establish pulpal diagnosis and caries-management plan before the bonding protocol.	Cavity depth alone is not an indication for direct pulp capping. (ESE S3 guideline, 2023) (Duncan and El-Karim, 2025)
Pulp exposure	Pause routine adhesive placement and assess vital pulp therapy or endodontic management.	Universal adhesive is not a substitute for an indicated pulp-treatment material. G2-Bond explicitly contraindicates pulp capping. (GC IFU, 11/2020) (Duncan and El-Karim, 2025)
Indirect restoration or post	Identify both the restoration substrate and the cement/adhesive combination; check where light is required.	“Dual-cure compatible” does not mean the adhesive itself can self-cure. (BISCO IFU, Rev 5/25) (Scotchbond Universal Plus IFU, 07/2020)

 

Universal adhesive comparison and compatibility

The following products illustrate different architectures and handling requirements. The selection is illustrative, not exhaustive, and is not a product ranking. Chemistry information is limited to what the manufacturer sources support.

Product	Architecture / modes	Compatibility and important limitations
All-Bond Universal — BISCO	One-bottle, light-cured, ethanol/water-based; contains MDP. Self-etch, selective enamel etch, and etch-and-rinse.	Manufacturer describes compatibility with light-, dual-, and self-cured materials without a separate activator. The adhesive itself requires light-curing. Contraindicated with a history of severe methacrylate-resin allergy; IFU cautions about ZOE residues. (BISCO IFU, Rev 5/25)
G2-Bond Universal — GC	Separate 1-PRIMER and 2-BOND; HEMA-free. Functional monomers include MDP, MDTP, and 4-MET. Three tooth-etching options.	Direct dual-cure core composites must be light-cured. Retrieved IFU excludes chemically cured composite resin, eugenol-containing materials, desensitizers, pulp capping, and specified allergies. Indirect/post use follows designated cement/core protocols, not an inferred universal combination. (GC IFU, 11/2020) (GC product information)
Scotchbond Universal Plus — 3M/Solventum	One-bottle; contains MDP, HEMA, polymeric acid, ethanol/water, and optimized silanes. Manufacturer describes a Bis-GMA-free formulation. Three etching modes.	Integrated dual-cure accelerator: no separate DCA required. Tooth-side adhesive is light-cured for direct restorations and other adhesive resin cements; RelyX Universal is the specified exception. Known acrylate allergy is contraindicated. (Scotchbond Universal Plus IFU, 07/2020) (3M technical product profile)
Clearfil SE Bond — Kuraray Noritake	Separate self-etching primer and bond; contains MDP. Dedicated two-step self-etch comparator.	Manufacturer technique information describes direct light-cured composite/compomer use and additional specified indications. It is not Clearfil SE Bond 2 or Universal Bond Quick; check its own full IFU before extending use. (Kuraray product/technique information)

 

Compatibility statements are manufacturer indications, not proof of equal long-term clinical outcomes for every material pairing. The source documents have different dates and regional scopes; use the current IFU supplied for your market and the exact product version.

Choosing an etching strategy

Enamel margins and uncut enamel

A laboratory systematic review found improved enamel bond strength after phosphoric-acid pre-etching. For G2-Bond, the retrieved IFU specifically requires selective enamel etching on non-bur-cut enamel; Scotchbond Universal Plus also directs etching of unprepared enamel, with a stated pit-and-fissure-sealant exception. Enamel etching time must therefore come from the selected product/etchant protocol, not from a single timer for all universal adhesives. (Cuevas-Suárez et al., 2019) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

Dentin: avoid blanket rules

A 15-study laboratory meta-analysis found no statistically significant overall difference between self-etch and etch-and-rinse dentin bond strength; aged values decreased relative to immediate values. Another review found formulation-dependent responses to dentin etching. These results support choosing by product and technique rather than declaring dentin etching always necessary or always harmful. (Chen et al., 2022) (Cuevas-Suárez et al., 2019)

Clinical findings also differ. Original Scotchbond Universal performed better in etch-and-rinse than self-etch in one five-year NCCL trial, while a Futurabond U trial detected no significant strategy difference after five years. Neither finding is a protocol mandate for all adhesives. Original Scotchbond Universal evidence must not be relabeled as evidence for Universal Plus. (Matos et al., 2020) (Ñaupari-Villasante et al., 2023)

Application, solvent evaporation, and light curing

Application method is product-dependent: rubbing, contact time, number of coats, and an undisturbed waiting period are not interchangeable. A primer-drying instruction also must not be applied automatically to a subsequent bonding resin. The examples below concern direct tooth bonding, not restoration-intaglio priming or root-canal cementation. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

System / source scope	Application	Drying / film endpoint	Adhesive curing
All-Bond Universal; Asia-Pacific Rev 5/25	Two separate scrubbed coats, 10–15 seconds per coat; no curing between coats.	Air-dry at least 10 seconds to no visible movement and a uniform glossy appearance. If the stated endpoint is not achieved, follow the IFU reapplication sequence.	10 seconds under the specified curing conditions. (BISCO IFU, Rev 5/25)
G2-Bond Universal; retrieved IFU revised 11/2020	Apply 1-PRIMER immediately after dispensing; leave undisturbed for 10 seconds. Apply 2-BOND after primer drying.	1-PRIMER: oil-free air at maximum pressure for 5 seconds with suction; thin, glossy, immobile film. 2-BOND: gentle air for uniform film distribution.	Use the intensity/distance-dependent table in the IFU; do not substitute a universal exposure time. (GC IFU, 11/2020)
Scotchbond Universal Plus; retrieved IFU valid 07/2020	Rub into the tooth surface for 20 seconds; rewet applicator if necessary.	Gentle air for at least 5 seconds until a shiny film no longer moves. Reapply if the film is not shiny, as directed.	10 seconds for the direct-restoration sequence. Indirect tooth-side exceptions and intaglio instructions are separate. (Scotchbond Universal Plus IFU, 07/2020)
Clearfil SE Bond; manufacturer technique page	Apply PRIMER and leave for 20 seconds; do not rinse. Then apply BOND.	Dry primer with mild air; distribute bond evenly with mild air.	Manufacturer technique page states 10 seconds; confirm the complete local IFU and curing requirements. (Kuraray product/technique information)

 

A shiny surface is not evidence of inadequate drying. Several IFUs require a glossy film. Stop for persistent visible film movement, pooling, contamination, or failure to reach the prescribed endpoint—not for gloss alone. Conversely, a matt/discontinuous film can mean insufficient adhesive in systems whose IFU requires shine. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

Direct composite workflow

1.      Establish diagnosis, restorative indication, relevant allergy history, and the intended adhesive/composite pairing. If the pulp is exposed, leave this routine workflow and follow the pulp-management pathway. (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020) (Duncan and El-Karim, 2025)

2.      Achieve and maintain isolation. Remove preparation debris and temporary-material residues using a compatible method; do not add a desensitizer or disinfectant by default. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

3.      Choose self-etch, selective enamel etch, or etch-and-rinse within the product indications. Rinse etchant thoroughly and preserve the specified dentin moisture condition. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

4.      Apply the required coats and the exact rubbing or waiting sequence. For two-bottle systems, keep the primer and bond steps distinct. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

5.      Evaporate solvent and distribute the resin using the specified air pressure, duration, and endpoint. Inspect line angles and cavity floors for pooled material. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

6.      Confirm a clean curing tip, suitable light output, and access to the entire adhesive surface. Position and expose according to the IFU; do not shorten exposure because the light is marketed as high-power. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020)

7.      Place, adapt, and cure composite according to its own instructions. Finish, check contacts and occlusion, and document the restoration and relevant follow-up plan. (GC IFU, 11/2020) (Hickel et al., 2023)

For example, GC’s retrieved IFU specifies 10 seconds at 700–1200 mW/cm² when the tip distance is under 10 mm and 20 seconds when it exceeds 10 mm. Its higher-output table uses different times. This illustrates why “light-cure for 10 seconds” cannot be generalized to every device, distance, and adhesive. Use the original table and curing-unit instructions. (GC IFU, 11/2020)

Does one-bottle or HEMA-free chemistry decide the choice?

One-bottle systems combine several functions; two-step systems separate the primer from a bonding layer. This changes handling and the composition of the cured interface. Laboratory results may favor a particular architecture under selected conditions, but architecture alone does not establish clinical survival. (Brkanović et al., 2023) (Karaduman et al., 2026)

HEMA means 2-hydroxyethyl methacrylate. It helps wetting and formulation miscibility, while hydrophilicity can contribute to water uptake. HEMA-free does not mean methacrylate-free or allergy-free: G2-Bond’s IFU still lists methacrylate-related allergy contraindications. Evaluate the whole formulation, indications, and technique instead of using HEMA status as a durability score. (3M technical product profile) (Karaduman et al., 2026) (GC IFU, 11/2020)

Indirect restorations: separate tooth and restoration protocols

Glass ceramics: lithium disilicate and silane

For conventional glass-ceramic bonding, surface treatment commonly uses extraoral hydrofluoric-acid (HF) etching followed by an indicated silane/ceramic primer. Approved self-etch ceramic-primer protocols may be alternatives. Identify the ceramic and cement system before selecting the pretreatment; do not transfer concentration or time between ceramics or products. (Scotchbond Universal Plus IFU, 07/2020) (Lima et al., 2024)

The presence of silane in a universal adhesive does not prove equivalence to a separate glass-ceramic primer. A laboratory meta-analysis favored HF plus a specific glass-ceramic primer over HF plus a silane-containing universal adhesive overall, with subgroup exceptions. In a 2025 lithium-disilicate study using NX3 cement and 500 thermocycles, separate silane increased bond strength with original Scotchbond Universal, Universal Plus, and Clearfil Universal Bond Quick, but not with Universal Bond II. These are laboratory findings—not demonstrated crown or veneer survival benefits. (Lima et al., 2024) (Tannen et al., 2025)

Clinical decision: use a ceramic/cement combination with an explicit surface-treatment protocol. Where it calls for a separate silane, do not omit that step because an adhesive is labeled universal. Where the manufacturer supports a simplified protocol, identify that exact combination and consider the independent evidence; do not modify it by arbitrarily stacking primers. (BISCO IFU, Rev 5/25) (Scotchbond Universal Plus IFU, 07/2020) (Lima et al., 2024)

HF safety boundary: extraoral intaglio etching and intraoral ceramic repair are different procedures. Never take an extraoral-only etchant into the mouth. For intraoral repair, select a repair protocol and products explicitly permitted for that indication, protect soft tissues, and follow the etchant IFU/SDS if HF is involved. If safe isolation or the permitted use is uncertain, stop and select a supported alternative. This guide does not provide a generic intraoral HF protocol. (BISCO IFU, Rev 5/25) (3M technical product profile)

Zirconia: cleaning, air abrasion, and MDP

Do not HF-etch zirconia. Its pretreatment differs from glass ceramics: follow a validated cleaning/decontamination sequence after try-in, use controlled air abrasion only where permitted, and apply the indicated MDP-containing primer, adhesive, or cement. The ceramic and cement manufacturers determine permitted particle size, pressure, and sequence. (3M technical product profile) (BISCO IFU, Rev 5/25) (Scotchbond Universal Plus IFU, 07/2020)

Do not use phosphoric acid as a zirconia cleaner by habit. The examined manufacturer documents warn against phosphoric-acid cleaning of zirconia, alumina, and metal before bonding; phosphate can block sites involved in MDP interaction. An MDP-containing adhesive does not eliminate the need to clean and prepare the substrate. (3M technical product profile) (BISCO IFU, Rev 5/25) (Scotchbond Universal Plus IFU, 07/2020)

Dual-cure compatibility does not mean adhesive self-curing

For Scotchbond Universal Plus, no separate dual-cure activator is required. The formulation includes an accelerator, but the adhesive is still light-curing. The examined IFU requires tooth-side light-curing for direct restorative indications and other adhesive resin cements, including RelyX Ultimate; RelyX Universal is the specified matched-cement exception. Do not transfer the predecessor’s separate-DCA instructions to Plus. (Scotchbond Universal Plus IFU, 07/2020) (3M technical product profile)

The surface matters: when Plus is used as a primer on the restoration intaglio, its IFU states not to light-cure that adhesive layer. By contrast, All-Bond’s examined IFU recommends light-curing its restoration-side layer and describes alternative primers where light-curing is not desired. “Always cure the adhesive before seating” and “never cure it before seating” are both inadequate universal rules. (Scotchbond Universal Plus IFU, 07/2020) (BISCO IFU, Rev 5/25)

G2-Bond provides another boundary: its direct dual-cured core build-up indication requires light-curing the core material, while its indirect/post sections refer to G-CEM LinkForce and GRADIA CORE protocols. The IFU states not to mix 2-BOND with dual-cure activators. Do not infer a generic cement/activator sequence from a direct-restoration indication. (GC IFU, 11/2020)

Before cementation, record: exact adhesive version; cement/core identity; tooth-side and intaglio treatment; whether and where adhesive light-curing is required; any designated activator; and whether adequate light access is possible. If any requirement cannot be met, select another expressly supported combination before proceeding. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

Repair, metal, composite, and posts

Repair surfaces may contain several substrates in one site. Identify exposed ceramic, zirconia, metal, composite, and tooth structure separately and treat each with the corresponding repair instructions. For example, GC directs a separate silane coupling agent on glass/hybrid ceramic repair surfaces and warns not to apply G-Multi PRIMER to tooth surfaces. A repair sequence is not the same as direct tooth bonding. (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

Post cementation is not covered by the direct protocol matrix. Use the post, root-canal adhesive, and cement instructions together, including excess-material removal and curing access. A dual-cure cement does not automatically rescue a light-cured adhesive deep in a canal. (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020) (BISCO IFU, Rev 5/25)

Stop criteria and troubleshooting

Before adhesive curing: stop if the endpoint is not met

·        Blood, saliva, crevicular fluid, or incompatible pretreatment residue remains on the bonding surface. Re-establish isolation before recovery. 

·        The adhesive visibly moves after the required drying sequence, pools in line angles, or fails the product’s prescribed film appearance. Correct using that product’s drying/reapplication directions. Gloss alone is not a stop criterion. 

·        The curing light, tip position, or access cannot satisfy the exposure conditions. Correct the light/access problem rather than guessing a compensatory exposure. 

·        The materials are contraindicated or compatibility cannot be established. Do not improvise an activator mixture. 

·        A pulp exposure is encountered or the diagnosis no longer supports routine restorative treatment. Reassess before adhesive placement. (Duncan and El-Karim, 2025)

Contamination recovery depends on timing

When contamination occurs	Decision
Before adhesive application	Identify the contaminant, remove it by an IFU-compatible method, and restore the prescribed substrate condition before application. Do not assume all disinfectants/astringents are harmless.
After application, before curing	Use the product-specific recovery sequence. GC’s retrieved IFU directs washing and drying the tooth, then repeating the procedure by reapplying material. Do not transfer this wording unchanged to every system.
After adhesive curing	Do not simply place composite over the contaminant or assume the pre-cure recovery sequence applies. Consult a product-supported post-cure recovery protocol; if none is established, reassess and select a defensible corrective approach before continuing.

 

Diagnose postoperative symptoms before replacing the restoration

Ask about stimulus, onset, duration, spontaneous/nocturnal pain, and change over time. Examine margins, contacts, occlusion, and tooth integrity; use pulpal sensibility testing and periapical assessment when indicated. The ESE recommends combining pain history with clinical findings and suggests cold testing, possibly supplemented by electric pulp testing. Do not diagnose adhesive failure from sensitivity alone. (Hickel et al., 2023) (Duncan and El-Karim, 2025)

Finding	Assessment / action	Avoid
Brief provoked sensitivity	Review symptom trend, pulpal findings, occlusion, exposed dentin, and restoration quality; address an identified cause and arrange individualized reassessment. (Hickel et al., 2023) (Duncan and El-Karim, 2025)	An automatic diagnosis of leakage or a fixed unsourced waiting period.
Spontaneous/nocturnal or worsening pain; percussion tenderness; swelling	Promptly reassess pulpal/apical disease and determine treatment or referral from the diagnosis. (Duncan and El-Karim, 2025)	Repeated adhesive replacement without diagnostic assessment.
Marginal stain or white line	Clean and inspect; distinguish superficial staining, a localized gap, fracture, and caries. Monitoring, refurbishment, reseal, repair, or replacement depends on findings. (Hickel et al., 2023)	Calling discoloration recurrent caries or proven leakage.
Localized chipping or partial defect	Assess remaining restoration and accessible substrate; repair may preserve sound material when appropriate. (Hickel et al., 2023)	Automatic full replacement of a repairable defect.
Completely loose/lost direct restoration	Identify failure contributors and reassess the tooth before replacement; a lost direct restoration generally requires replacement. (Hickel et al., 2023)	Rebonding without checking diagnosis, isolation, cure, and substrate.
Loose but otherwise sound indirect restoration	Assess integrity, fit, tooth condition, and cause of loss. Recementation/re-luting may be possible after suitable surface recovery. (Hickel et al., 2023)	Assuming every indirect debond requires a new restoration.

 

Deep dentin and exposed pulp are separate decisions

For an intact deep preparation, choose caries removal and pulp protection according to pulpal diagnosis and the applicable restorative/endodontic guidance; then bond to the indicated surfaces. Pulp exposure moves the case into vital pulp treatment or endodontic management, not ordinary adhesive application. The ESE framework emphasizes diagnosis and, for exposed-pulp vital treatment, an enhanced aseptic protocol with dental dam, magnification, antimicrobial lavage, and hydraulic calcium silicate cement. This is a pathway boundary, not a complete pulp-treatment protocol. (ESE S3 guideline, 2023) (Duncan and El-Karim, 2025)

Handling and allergy precautions

Avoid skin and mucosal contact with uncured adhesive and use the specified protective equipment and no-touch technique. Acrylates can penetrate commonly used gloves: the Plus IFU directs discarding contaminated gloves, washing hands, and re-gloving. Review the patient’s relevant allergy history and the specific contraindications; HEMA-free is not synonymous with nonallergenic. (Scotchbond Universal Plus IFU, 07/2020) (GC IFU, 11/2020)

Close bottles promptly, protect dispensed material from light, respect storage and expiry instructions, and discard single-use accessories. Bottle disinfection/reprocessing instructions vary: do not apply one manufacturer’s bottle-cleaning method to another. Follow the SDS for flammability, exposure, and spill procedures. (BISCO IFU, Rev 5/25) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

Evidence summary: what changes a clinical decision?

Evidence	Finding	Clinical interpretation / limitation
Enamel/dentin laboratory review; 59 studies	Pre-etching improved enamel strength; dentin response varied by adhesive acidity category. (Cuevas-Suárez et al., 2019)	Supports enamel pretreatment considerations, not an acidity-based clinical survival ranking.
Dentin laboratory review; 15 studies	No significant overall self-etch versus etch-and-rinse difference; aged strength decreased. (Chen et al., 2022)	A pooled nonsignificant result is not proof of equivalence for every formulation.
NCCL clinical meta-analysis; 17 RCTs	No significant total-etch versus self-etch differences in assessed outcomes at 18, 24, and 36 months. Certainty varied by outcome, criteria, and follow-up. (Doshi et al., 2023)	Useful medium-term evidence; not a guarantee of equal five-year retention.
Original Scotchbond Universal; five-year NCCL RCT	39 patients, 200 restorations at baseline, 86% recall. Retention/fracture rates: 93% in both ER groups, 88.4% selective etch, 81.4% self-etch. ER differed significantly from self-etch. (Matos et al., 2020)	Product-specific clinical evidence; cannot be relabeled as Universal Plus outcomes.
Futurabond U; five-year NCCL multicenter RCT	50 participants, four strategy groups. Retention estimates ranged 78–87%; no significant strategy difference detected. (Ñaupari-Villasante et al., 2023)	Separate formulation and trial. Absence of a detected difference is not universal equivalence.
Clinical comparison review; 15 RCTs	Six-month to four-year follow-up; no significant pooled differences versus conventional adhesives in retention, marginal staining, or sensitivity. (Polesso Patias et al., 2025)	Supports clinical comparability within studied settings. Does not establish a named-product hierarchy.
Brkanović shear-bond experiment	Extracted-tooth specimens; two-month water storage with/without additional thermocycling. G2-Bond had higher values than Plus under the tested conditions. (Brkanović et al., 2023)	Not a one-year clinical survival study. Protocol/reporting concerns preclude using it as a product-selection mandate.
2026 laboratory network meta-analysis; 82 studies, 22 adhesives	Rankings varied by mode and aging; authors requested clinical validation. (Karaduman et al., 2026)	Different tests/substrates and the eligibility of original/Plus controls complicate interpretation. Do not convert rankings into survival claims.
Glass-ceramic review and 2025 silane experiment	Separate specific ceramic primer/silane improved bonding in several studied combinations, with exceptions. (Lima et al., 2024) (Tannen et al., 2025)	Laboratory-only, formulation/cement/aging dependent. Keep the exact surface-treatment protocol explicit.

 

Read bond-strength values in the context of test method, substrate, specimen geometry, surface preparation, composite/cement, and aging. Shear and microtensile results are not interchangeable clinical endpoints, and thermocycling does not establish a defined number of years in the mouth. Retention, fracture, margins, caries, and symptoms require clinical follow-up. (Brkanović et al., 2023) (Karaduman et al., 2026) (Hickel et al., 2023)

The 2023 Brkanović paper’s discussion and abstract use language suggesting an oral-year equivalent, but its reported methods are laboratory storage and thermal cycling. Its application reporting also does not clearly reproduce the separate manufacturer sequences. Use it as a limited experiment, not as evidence that a product is clinically “most effective.” (Brkanović et al., 2023)

Two illustrative selection decisions

These examples are editorial decision illustrations, not patient records or trial outcomes.

Case 1: NCCL with uncut enamel and sclerotic dentin

If restoration is indicated and isolation is achievable, identify the enamel margin and the chosen adhesive. For G2-Bond, the retrieved IFU requires selective etching of uncut enamel; then apply 1-PRIMER, leave it undisturbed for 10 seconds, dry as instructed, and apply 2-BOND. Do not substitute blanket scrubbing or aggressive dentin roughening. If contamination occurs, pause and recover before curing. (GC IFU, 11/2020)

Case 2: indirect restoration with uncertain adhesive light access

Identify ceramic and cement before choosing the adhesive. With Plus, determine separately whether tooth-side curing is required and whether the matched RelyX Universal exception applies; the restoration-side priming layer is not light-cured under the examined IFU. If using another cement and tooth-side adhesive curing cannot be achieved, do not assume the cement’s dual cure compensates. Select a supported alternative combination or change the clinical plan. (Scotchbond Universal Plus IFU, 07/2020) (3M technical product profile)

Chairside selection checklist

·        Identify substrate and exact restoration/composite/cement.

·        Confirm the local IFU covers the intended indication and product version.

·        Check relevant allergies, contraindications, and incompatible pretreatments.

·        Select an allowed etching mode; identify uncut enamel requirements.

·        Record coats, rubbing/waiting, primer drying, bond thinning, and film endpoint.

·        Confirm adhesive curing requirements separately from cement/core curing.

·        For indirect work, separate tooth-side from restoration-side instructions.

·        Confirm isolation, contamination recovery, and adequate light access.

·        Choose the case using clinical outcomes where available—not an isolated MPa ranking.

Frequently asked questions

Which universal dental adhesive is best?

No clinically validated, indication-spanning product hierarchy is established by the cited evidence. Laboratory rankings exist but do not measure restoration survival directly. Choose by substrate, indications, compatibility, and a protocol the clinic can execute reliably. (Karaduman et al., 2026) (Polesso Patias et al., 2025)

When should enamel be etched?

Consider selective etching when enamel bonding is important, particularly on uncut enamel. Check product-specific requirements: the retrieved G2-Bond and Plus instructions explicitly address unprepared enamel. (Cuevas-Suárez et al., 2019) (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020)

Should dentin be phosphoric-acid etched?

There is no single rule for every universal adhesive. Laboratory reviews and clinical trials show formulation- and follow-up-dependent findings. Use an IFU-supported mode and maintain the required dentin moisture condition. (Cuevas-Suárez et al., 2019) (Chen et al., 2022) (Matos et al., 2020) (Ñaupari-Villasante et al., 2023)

Does dual-cure compatibility mean the adhesive can self-cure?

No. Compatibility refers to interaction with the subsequent material; it does not establish adhesive self-curing. All-Bond and Plus are light-cured adhesives, with specified system-dependent instructions. (BISCO IFU, Rev 5/25) (Scotchbond Universal Plus IFU, 07/2020)

Does Scotchbond Universal Plus require a separate activator?

No separate DCA is required under the examined IFU. It contains an integrated accelerator. Tooth-side light-curing is still required for direct restorative use and other adhesive resin cements; the stated RelyX Universal exception is a matched-system instruction. (Scotchbond Universal Plus IFU, 07/2020) (3M technical product profile)

Can a universal adhesive replace separate silane for lithium disilicate?

Do not assume this from the label. Laboratory evidence favors separate specific primers/silane in several combinations, but findings have product and protocol exceptions. Follow the ceramic/primer/cement protocol and do not add or remove steps indiscriminately. (Lima et al., 2024) (Tannen et al., 2025)

Does zirconia need a separate primer?

That depends on the ceramic and cement system. An MDP-containing adhesive or cement may be an indicated component, but does not replace cleaning and permitted surface preparation. Do not clean zirconia with phosphoric acid when the selected IFU warns against it. (3M technical product profile) (Scotchbond Universal Plus IFU, 07/2020) (BISCO IFU, Rev 5/25)

What should I do after contamination?

Stop, restore isolation, identify the procedural stage, and follow the product-supported recovery sequence. Pre-cure instructions cannot be assumed to apply after curing; for GC, the retrieved pre-cure sequence is washing, drying, and repeating material application. (GC IFU, 11/2020)

Can universal adhesives be used for direct pulp capping?

Do not substitute them for an indicated pulp-treatment material. G2-Bond explicitly contraindicates pulp capping, and Plus directs use of an approved capping material. Pulp exposure requires a diagnosis-based vital-pulp/endodontic pathway. (GC IFU, 11/2020) (Scotchbond Universal Plus IFU, 07/2020) (Duncan and El-Karim, 2025)

Does HEMA-free mean more durable or allergy-free?

No. HEMA status describes one part of the formulation. Durability depends on the system and technique; a HEMA-free product can still contain methacrylates and carry allergy contraindications. (Karaduman et al., 2026) (GC IFU, 11/2020)

Scope and limitations

This is a focused educational synthesis for dental clinicians, not an exhaustive systematic review, complete pulp-treatment guide, or replacement for regional IFUs. Much comparative product evidence is laboratory-based, and substantial etching-strategy evidence comes from NCCLs. Posterior load-bearing restorations, indirect prostheses, caries-affected dentin, and pulp treatment require their own evidence and clinical assessment. Update the guide when formulations, IFUs, or relevant clinical results change. (Doshi et al., 2023) (Polesso Patias et al., 2025) (Karaduman et al., 2026) (ESE S3 guideline, 2023)

Source documentation

The linked sources below support the author–date citations in the article. Source type and inspection scope are shown to distinguish manufacturer instructions, laboratory studies, clinical evidence, and guidelines. Sources accessed or rechecked during this revision: 11 October 2026. Retrieval from a manufacturer website does not establish that an IFU is the latest version in every market.

BISCO. All-Bond Universal instructions for use. Asia-Pacific document IN-195R7, Rev 5/25. Manufacturer-hosted IFU; English instructions inspected. Open source

GC. G2-BOND Universal instructions for use. Manufacturer-hosted multilingual document; English instructions inspected. Last revised 11/2020. Open source

GC. G2-BOND Universal product information. Manufacturer source for HEMA-free formulation and functional monomers; not independent outcome evidence. Open source

3M/Solventum. Scotchbond Universal Plus instructions for use. Document 3100023493/02; information valid as of July 2020. English instructions inspected. Open source

3M. Scotchbond Universal Plus Adhesive technical product profile. Manufacturer source for composition and integrated accelerator; comparative marketing claims are not treated as independent clinical proof. Open source

Kuraray Noritake. CLEARFIL SE BOND product and application information. Manufacturer page inspected; lists IFU v.01.10.2025. The linked full regional IFU remains an editorial verification task. Open source

Cuevas-Suárez CE, et al. Bonding Performance of Universal Adhesives: An Updated Systematic Review and Meta-Analysis. J Adhes Dent. 2019;21(1):7–26. DOI: 10.3290/j.jad.a41975. PubMed abstract inspected; in-vitro evidence. Open source

Chen H, et al. Comparison of bond strength of universal adhesives using different etching modes: A systematic review and meta-analysis. Dent Mater J. 2022;41(1):1–10. DOI: 10.4012/dmj.2021-111. Publisher abstract inspected; in-vitro evidence. Open source

Doshi K, et al. Effect of adhesive strategy of universal adhesives in noncarious cervical lesions – an updated systematic review and meta-analysis. BDJ Open. 2023. DOI: 10.1038/s41405-022-00124-6. Publisher discussion inspected; clinical review. Open source

Matos TP, et al. Five-year clinical evaluation of a universal adhesive: A randomized double-blind trial. Dent Mater. 2020;36(11):1474–1485. DOI: 10.1016/j.dental.2020.08.007. PubMed abstract inspected; original Scotchbond Universal, not Plus. Open source

Ñaupari-Villasante R, et al. Five-year clinical evaluation of universal adhesive applied following different bonding techniques: A randomized multicenter clinical trial. Dent Mater. 2023;39(6):586–594. DOI: 10.1016/j.dental.2023.04.007. PubMed abstract inspected; Futurabond U. Open source

Polesso Patias M, et al. Comparative clinical performance of universal adhesives versus etch-and-rinse and self-etch adhesives: a meta-analysis. Clin Oral Investig. 2025;29:352. DOI: 10.1007/s00784-025-06427-w. Publisher abstract inspected; full methods not independently appraised. Open source

Brkanović S, et al. Comparison of Different Universal Adhesive Systems on Dentin Bond Strength. Materials. 2023;16(4):1530. DOI: 10.3390/ma16041530. Primary methods and results inspected; in-vitro shear testing. Open source

Karaduman YD, et al. Comparison of universal adhesives used in different etching modes on dentin bond strength: a systematic review and network meta-analysis. BMC Oral Health. 2026;26:1632. Published 19 June 2026. DOI: 10.1186/s12903-026-08982-4. Primary methods/results inspected; in-vitro network analysis. Open source

Lima RBW, et al. Effect of universal adhesives and self-etch ceramic primers on bond strength to glass-ceramics: A systematic review and meta-analysis of in vitro studies. J Prosthet Dent. 2024;131(3):392–402; online 2022. DOI: 10.1016/j.prosdent.2022.01.011. PubMed abstract inspected. Open source

Tannen DL, et al. Bond Strength of Silane-Containing Universal Bonding Agents to Lithium Disilicate. J Clin Exp Dent. 2025;17(4):e358–e365. DOI: 10.4317/jced.62011. Full text inspected; composition table is not used to establish Plus chemistry. Open source

Hickel R, et al. Revised FDI criteria for evaluating direct and indirect dental restorations—recommendations for its clinical use, interpretation, and reporting. Clin Oral Investig. 2023;27:2573–2592; online 2022. DOI: 10.1007/s00784-022-04814-1. Consensus assessment framework; full text inspected. Open source

Duncan HF, et al. Treatment of pulpal and apical disease: The European Society of Endodontology (ESE) S3-level clinical practice guideline. Int Endod J. 2023;56(Suppl 3):238–295. DOI: 10.1111/iej.13974. Guideline identity and scope checked. Open source

Duncan HF, El-Karim I. Endodontic S3-level clinical practice guidelines: the European Society of Endodontology process and recommendations. Br Dent J. 2025;238:580–586. DOI: 10.1038/s41415-025-8335-x. Full guideline summary inspected for diagnosis and vital pulp therapy recommendations. Open source