Adhesive Bridge (Maryland Bridge) – Minimal Invasiveness, When to Choose

The adhesive bridge, also known as the Maryland bridge (after Johns Hopkins University where it was developed), is one of the most underrated and underrepresented prosthetic solutions in Polish dental practices. The reason: it does not require preparation of abutment teeth. This changes everything – biologically, psychologically, and long-term.

What is an Adhesive Bridge and How Does it Differ from a Traditional Bridge?

Traditional Bridge (classical bridge):

• Requires grinding (preparation) of both abutments
• The abutment functions based on mechanical retention – we grind the walls of the custom abutment with a taper
• Patients are often uncomfortable when they learn that the abutment tooth will be ground irreversibly

Adhesive Bridge (Maryland):

• Zero abutment preparation – teeth remain unchanged
• The retainer wing has fine perforations and roughened surfaces – this provides mechanical retention for micro-objects of enamel
• Adhesive cementation only – the retainer wing is bonded to the enamel via resin
• Result: minimal intervention, reversibility – if the bridge fails, the tooth can be re-cemented or an additional layer of adhesive can be applied

Indications for Adhesive Bridges

1. Missing a single tooth in a young person – before an implant A patient lost an incisor (tooth #7 or #10) in an accident. An implant is planned – the patient is awaiting osseointegration (3–6 months). An adhesive bridge is an ideal temporary solution that does not damage adjacent teeth.

Later: the bridge can be removed without issues – no need to cut through a pontic, and no grinding of the abutment teeth.

2. Adjacent teeth are healthy, unprepared – biological argument A classical bridge requires grinding. A Maryland bridge does not. If the patient has healthy teeth, the argument "we will preserve the tooth structure" is universally appealing – in 2026, more and more patients are aware of this and ask about it.

3. Esthetic zone – anterior maxilla (teeth #6–11) Missing a central or lateral incisor in a young person is a perfect indication. Anterior enamel is thick, perfect for adhesive retention. The zirconia retainer wing is not visible. The bridge appears natural.

4. Patient with a history of poor clenching or bruxism If the dentist is cautious and the patient has a history of parafunction – an adhesive bridge is a safe option to try. If it fails, there is always the option of a classical bridge or an implant.

Wing Design – Key Parameters

Adhesive surface (wing size):

• Minimum 3–4 mm² on the palatal or lingual surface of the abutment teeth
• The larger the surface area, the higher the retention
• However: a larger wing = more visible, a greater esthetic problem (if metal)

Wing thickness:

• Minimum 1.5 mm for strength
• Ideal: 2–2.5 mm – balance between retention and esthetic purity

Perforations and roughening:

• Traditionally: small perforations in the wing (mechanical retention for resin)
• Newer materials: surface micro-patterns – without visible perforations

Single-winged vs. two-winged:

• Single-winged (one wing) – studies show higher survival rates than two-winged
• Why: if one wing debonds, the bridge is unstable – the dentist immediately identifies the problem and the patient returns
• Two-winged: significantly higher retention, but the problem is that debonding can be asymptomatic for some time

At deltalabs., we recommend single-winged designs – prevention is simpler than waiting for hidden problems.

Zirconia vs. Metal – Choosing the Wing Material

Metal (Co-Cr alloy, Au alloy):

• High strength
• Fatigue strength – ideal for loaded bridges
• Disadvantage: possible metallic show-through through the enamel (especially in young patients)
• In the anterior esthetic zone – problematic

Zirconia (monolithic):

• Invisible through enamel
• High strength (900–1200 MPa) – comparable to metal
• Higher cost than metal
• Milling requires a little more time

For adhesive bridges in the esthetic zone – zirconia is the first-line material.

Adhesive Cementation – Mandatory Protocol

No compromise here. An adhesive bridge requires adhesive cementation only:

1. Cleaning the wing: cleaning with alcohol or acetone
2. MDP primer (monophosphate): universal primer creating a chemical bond with zirconia and dentin
3. Enamel etching: phosphoric acid (40%, 15–30 seconds) – this is crucial
4. Bonding agent on abutment teeth: single-layer bond (Scotchbond, Adper Total)
5. Dual-cure resin cement: Variolink Esthetic, RelyX Ultimate
6. Rubber dam is mandatory – saliva and moisture can destroy the entire adhesion

The procedure is precise but standard – every practice should do this routinely.

When a Maryland Bridge Fails

1. Insufficient adhesive surface area

• <2 mm² – retention too low, the bridge immediately debonds or starts acting as an open door for bacteria

2. Lack or improper enamel preparation

• Acid etching – this is crucial. Without it, adhesion will be weak
• Glaze on the surface – must be removed

3. Deep bite

• Tongue and jaw forces can act on the bridge, causing material fatigue
• A single wing will always be at the limit of its strength

4. Bruxism

• Parafunction – lateral forces can destroy adhesion
• An adhesive bridge in cases of bruxism requires a protective splint

5. Poor cleaning

• The bridge is a "trap" for bacterial plaque
• The patient must be educated: daily flossing, interproximal cleaning, Waterpik

6. Enamel opacity (hypocalcification) of adjacent teeth

• Sometimes enamel does not have sufficient thickness – or is hypocalcified – and does not provide retention

Literature Review – Clinical Data

Prospective studies (Pjetursson BE et al., CIOR 2012; Kern M et al., JPD 2017) show:

• Survival of adhesive bridges on incisors: 80–95% over a 10-year observation period
• Survival of adhesive bridges on premolars: 70–85% over 10 years
• Main reasons for failure: debonding (40%), caries (30%), fracture (20–30%)
• Single-winged design: higher survival rate than two-winged

These data are comparable to classical bridges – but without the cost of tooth preparation.

Decision Table