A dental crown restores a damaged tooth that is still present, while a dental bridge replaces one or more missing teeth by anchoring a pontic to adjacent abutment teeth. The distinction sounds simple, and it usually is: a crown covers a tooth, and a bridge spans a gap. The decision becomes more involved when a tooth is fractured below the gum line, when several teeth are missing in a row, or when the adjacent teeth are healthy enough to avoid preparation. Patients in Gorham, Westbrook, Portland, and surrounding Cumberland County communities face this choice when a tooth breaks beyond repair or when an extraction leaves a space that affects chewing and alignment. Morgan Dental Care evaluates crowns and bridges at 94 Main Street in Gorham, and the practice helps patients compare each restoration against the condition of their own teeth rather than against a generic recommendation. This guide explains what each restoration does, when each one fits, how materials change the outcome, and how maintenance determines how long the work lasts. It connects to the practice’s broader guide to choosing dental care in Gorham and to detailed articles on crown versus bridge selection, crown materials, same-day crowns, crown failure and replacement, and bridge maintenance.
Table of Contents
What a Dental Crown Does | What a Dental Bridge Does | Crown vs Bridge | When a Crown Fits | When a Bridge Fits | Materials | Treatment Process | Longevity and Maintenance | Cost Factors | Decision Framework | FAQs
Key Takeaways
- A dental crown covers a tooth that remains in the mouth. A dental bridge replaces a tooth that is missing.
- A crown prepares one tooth. A conventional bridge prepares at least two abutment teeth.
- Crowns and bridges are fixed prostheses. Neither is removable like a denture.
- Material choice changes strength, appearance, and preparation depth. Zirconia, lithium disilicate, and porcelain-fused-to-metal behave differently under load.
- Same-day crowns use chairside CAD/CAM to mill and deliver a ceramic restoration in one visit. The workflow fits single teeth more often than multi-unit bridges.
- Maintenance determines how long both restorations survive. A bridge adds a cleaning challenge because the pontic blocks normal floss access.
What a Dental Crown Does
A dental crown covers the entire visible portion of a tooth from the gum line to the biting surface. The restoration encircles the tooth, seals exposed dentin, and redistributes chewing forces across the remaining structure. Dentists use crowns when a tooth has lost enough substance that a filling cannot safely hold the remaining walls together.
Clinical indications for a crown
A tooth with more than 50 percent of its coronal structure replaced by decay or a previous restoration qualifies for a crown. A tooth that has undergone root canal treatment also qualifies for a crown because endodontic access and dehydration reduce fracture resistance. Cracks that extend into dentin, fractures involving a cusp, and severe wear from bruxism create the same structural deficit. The crown does not replace the root. The natural root remains, and the crown protects what is left above the gum line.
A crown does not replace a missing tooth. This limitation separates a crown from a bridge and from an implant crown. A crown on a natural tooth depends on a root that is still present and stable. When the root is gone, the replacement option changes.
What a Dental Bridge Does
A dental bridge replaces one or more missing teeth by suspending a pontic between two or more abutment teeth. The abutment teeth receive crowns, and the pontic connects to those crowns through rigid connectors. The prosthesis is cemented or bonded into place and remains fixed.
Abutment, pontic, and connector
An abutment tooth supports the bridge. A pontic is the false tooth that fills the gap. A connector joins the pontic to the abutment crowns. A three-unit bridge uses two abutments and one pontic. A four-unit bridge can replace two adjacent missing teeth with two abutments and two pontics. The design must distribute force across the abutments without overloading any single tooth.
A bridge does not replace the missing tooth root. The pontic rests above the gum and does not stimulate bone in the extraction site. Bone resorption continues after tooth loss, and the pontic contour may become visible over time as the ridge changes. A bridge restores function and appearance, but it does not restore the biological root.
Crown vs Bridge: The Core Difference
A dental crown restores a single tooth that remains in the mouth, while a dental bridge replaces a tooth that is missing. The tooth count and the preparation burden follow from that single fact.
A one-sentence decision rule helps at the consultation: if the tooth is present, the choice is usually a crown; if the tooth is missing, the choice is a bridge or an implant, and the abutment teeth and bone volume decide between them. A bridge is not a crown on a missing tooth. A crown is not a bridge on a present tooth.
When a Crown Is the Right Restoration
A dental crown fits a tooth with structural damage that a direct filling cannot safely restore. The threshold is usually more than 50 percent of the coronal tooth structure lost to decay, fracture, or previous restorative work. A tooth that has had root canal treatment also fits a crown because the access opening and the loss of internal moisture increase fracture risk. A tooth with a crack that reaches dentin fits a crown because the crack can propagate under chewing load without full-coverage protection.
Situations where a crown is overtreatment
A healthy tooth with a small chip or a cosmetic concern does not need a crown. A veneer or composite bonding preserves more enamel and achieves the esthetic goal with less tooth removal. A tooth with adequate structure and a modest filling does not need a crown unless the filling fails or the remaining walls flex under load. The presence of a crown on a mostly healthy tooth is a warning sign, not a standard of care. Modern preparation guidelines favor the least invasive restoration that meets the structural requirement.
When a Bridge Is the Right Restoration
A dental bridge fits a patient with one or more adjacent missing teeth when the bordering teeth already need crowns or when an implant is not feasible. The abutment teeth must have enough bone support and healthy periodontal tissue. A bridge also fits a patient who wants to avoid surgery, who has a medical condition that complicates implant placement, or who prefers a shorter treatment sequence.
Situations where a bridge is the wrong choice
A bridge is the wrong choice when the adjacent teeth are healthy and intact. Preparing two sound teeth to replace one missing tooth removes enamel from teeth that did not need restoration. A bridge is also the wrong choice when the abutment teeth have untreated gum disease or when the missing tooth site has enough bone for an implant. In those cases, an implant-supported crown replaces the tooth without preparing the neighbors.
A resin-bonded bridge offers a more conservative alternative for a single missing tooth. The design uses wing-like retainers bonded to the lingual surfaces of the adjacent teeth and removes 0.3 to 0.5 millimeters of enamel rather than full crown preparation. Systematic reviews place five-year survival for resin-bonded bridges near 87.7 percent as of 2024, which is lower than conventional bridges but useful when preserving abutment structure matters more than maximum longevity.
Crown and Bridge Materials
Crown and bridge materials fall into three main groups: porcelain-fused-to-metal, lithium disilicate, and zirconia. Each material balances strength, appearance, and the amount of tooth reduction required. The material also changes how the restoration wears against opposing teeth and how it handles a heavy bite.
Lithium disilicate remains the preferred material for many anterior single crowns because it transmits light in a way that mimics natural enamel. Zirconia handles posterior load and multi-unit bridge spans with a higher flexural strength. Porcelain-fused-to-metal retains a role when the abutment tooth is dark and needs masking or when a patient prefers a material with a long clinical track record.
The Treatment Process: Traditional and Same-Day
A traditional crown or bridge requires two appointments separated by a laboratory phase of one to two weeks. The first appointment prepares the tooth or teeth, records an impression or digital scan, and places a temporary restoration. The second appointment tries in the final restoration, adjusts the bite, and cements or bonds it.
Chairside CAD/CAM workflow
A same-day crown uses an intraoral scanner, design software, and a chairside milling unit to produce a ceramic restoration in one visit. The dentist scans the prepared tooth, designs the crown on screen, and mills it from a ceramic block. The restoration is then crystallized or finished and bonded. A 2024 systematic review found that a fully digital workflow provides clinically acceptable accuracy for single crowns and shortens chair time compared with the traditional method.
Same-day fabrication fits single crowns and some small bridges. Multi-unit bridges, complex esthetic cases, and teeth with deep subgingival margins still require a laboratory phase. The workflow changes the appointment count, not the biological requirements. The tooth still needs adequate preparation, the bite still needs adjustment, and the restoration still needs maintenance.
Longevity, Failure Modes, and Maintenance
A dental crown survives at rates near 90 to 95 percent at five years and 80 to 88 percent at ten years, depending on material and patient factors. Zirconia crowns show survival near 94 percent at ten years in some clinical protocols. Porcelain-fused-to-metal crowns show ten-year survival in the high 80s to low 90s. Lithium disilicate single crowns perform well in anterior sites, with systematic reviews reporting ten-year survival above 90 percent in selected studies.
Bridge survival and abutment risk
A conventional three-unit bridge survives at rates near 90 percent at five years and 80 to 88 percent at ten years. Abutment tooth fracture, caries at the margin, and loss of pulp vitality account for most failures. A bridge concentrates force on the abutment teeth, and the pontic creates a hygiene challenge that increases caries risk at the connectors. Resin-bonded bridges show lower survival than conventional bridges but preserve more abutment structure.
Cleaning under a pontic
A bridge requires a floss threader, super floss, or an interdental brush to clean beneath the pontic and around the abutment margins. Normal floss cannot pass under the pontic because the connectors block the path. Plaque that remains under the pontic inflames the gum and demineralizes the abutment teeth. A single-tufted brush reaches the connector areas, and a water flosser adds another route for plaque removal. Daily cleaning under the pontic is not optional. It is the maintenance step that separates a bridge that lasts from one that fails at the margin.
Cost Factors and Coverage
A dental crown or bridge fee reflects the material, the number of units, the laboratory work, and any preparatory procedures such as core buildup, root canal treatment, or gum treatment. A single crown costs less than a three-unit bridge because the bridge includes two abutment crowns and a pontic. A same-day crown can cost more than a laboratory-fabricated crown at some practices because the chairside workflow uses a different material block and a single extended appointment.
Dental insurance usually classifies a crown as a restorative procedure when it restores a damaged tooth. Most plans cover a percentage of the fee after a deductible. A bridge is also typically covered as a restorative prosthesis, but the plan may apply a missing tooth clause or a frequency limitation. Veneers and purely cosmetic crowns usually receive no coverage. A patient should confirm the plan’s classification before treatment, because the same crown can be covered as restorative in one plan and excluded as cosmetic in another.
Decision Framework for Patients
A patient deciding between a crown and a bridge should confirm four facts before choosing: whether the tooth is present, how much healthy structure remains, whether the adjacent teeth need treatment, and whether an implant is feasible. Those four facts answer most of the decision without a sales conversation.
- Confirm the tooth status. A present tooth points to a crown. A missing tooth points to a bridge or an implant.
- Ask how much structure remains. More than 50 percent loss supports a crown. Less loss may support a smaller restoration first.
- Ask about the adjacent teeth. A bridge makes sense when the neighbors already need crowns. A bridge is hard to justify when the neighbors are intact.
- Ask about bone and implant feasibility. Adequate bone and no medical contraindication make an implant a strong alternative to a bridge.
- Ask about cleaning access. A bridge requires floss threaders or interdental brushes daily. A patient who will not clean under a pontic should weigh that against the longevity of the bridge.
The tradeoff summary is short. A crown preserves one tooth and removes structure from that tooth. A bridge replaces a missing tooth and removes structure from at least two teeth. An implant replaces the root and crown without preparing the neighbors, but it requires surgery and healing time. No option is universally superior. The correct option matches the tooth count, the bone, the gum health, and the patient’s willingness to maintain the restoration.
Frequently Asked Questions
Is a crown the same as a bridge? A crown and a bridge are different restorations. A crown covers one present tooth, and a bridge replaces one or more missing teeth by connecting a pontic to abutment crowns.
Can a bridge be placed on one tooth? A conventional bridge cannot be placed on one tooth because it needs at least two abutments to support the pontic. A cantilever bridge uses one abutment and one pontic, but it places more stress on the single abutment and has lower survival than a fixed-fixed design.
How long do crowns and bridges last? A crown typically lasts 10 to 15 years or longer, and a conventional bridge lasts 10 to 15 years with good maintenance. Material, bite force, hygiene, and the health of the abutment teeth change the actual lifespan.
Does getting a crown or bridge hurt? Crown and bridge preparation uses local anesthesia, so the appointment is usually comfortable. Mild sensitivity after the appointment is common while the tooth adjusts to the temporary or final restoration, and it usually resolves within a few days.
Can a bridge be replaced with an implant later? A bridge can be removed and replaced with an implant-supported crown later if the bone and gum conditions allow it. The abutment teeth that were prepared for the bridge may need crowns or other restoration after the bridge is removed.
People Also Ask
What is the difference between a crown and a bridge? A crown restores a tooth that is still present, and a bridge replaces a tooth that is missing. A bridge uses at least two abutment crowns to support a pontic, while a crown covers one tooth.
How many teeth does a bridge replace? A bridge replaces one or more missing teeth. A three-unit bridge replaces one tooth, and a longer bridge can replace two or more adjacent missing teeth with additional pontics.
Do crowns and bridges need special cleaning? A crown needs normal brushing and flossing around the margin. A bridge needs a floss threader, super floss, or an interdental brush to clean under the pontic and around the abutment connectors.
What happens if a bridge breaks? A broken bridge may be repairable if the fracture is limited to the pontic or a connector, but a fracture that compromises the framework usually requires replacement. The abutment teeth need evaluation before any repair because decay or fracture under the bridge can change the treatment plan.
Is a same-day crown as strong as a traditional crown? A same-day crown made from a modern ceramic block performs similarly to a traditional crown for a single tooth. Systematic reviews report five-year survival near 97 percent and ten-year survival near 89 percent for chairside CAD/CAM restorations, which is comparable to conventional single crowns.
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About the Dentists
Dr. Brett Morgan and Dr. Tim Adamchuk provide restorative dentistry at Morgan Dental Care, 94 Main Street, Gorham, ME 04038, (207) 839-2655. The practice serves Gorham, Westbrook, Portland, South Portland, Windham, Scarborough, Standish, and surrounding Cumberland County communities. Both dentists evaluate crowns and bridges against the condition of the tooth, the health of the adjacent teeth, and the patient’s long-term maintenance plan. The practice offers same-day crown fabrication and conventional laboratory restorations, and it helps patients compare those options during a consultation.
Sources
- American Dental Association (ADA), patient information on crowns and bridges. ada.org
- Centers for Disease Control and Prevention (CDC), Oral Health. cdc.gov/oral-health
- National Institutes of Health (NIH), PubMed, systematic reviews on single crown and fixed dental prosthesis survival. pubmed.ncbi.nlm.nih.gov
- FDI World Dental Federation, clinical criteria for restorations. fdiworlddental.org
- Maine Board of Dental Practice, licensure and consumer information. maine.gov/dental
Conclusion
A dental crown and a dental bridge solve different problems, and the correct choice follows from the condition of the tooth and the number of missing teeth. A crown protects a tooth that remains. A bridge replaces a tooth that is gone. The material, the preparation, the cleaning routine, and the longevity all follow from that first distinction. Patients in Gorham and the surrounding Cumberland County towns can schedule a consultation at Morgan Dental Care to evaluate the tooth, the adjacent teeth, and the bone before choosing a restoration. The goal is not to pick the most expensive option or the fastest option. The goal is to pick the restoration that matches the tooth, the bite, and the maintenance the patient will actually do.
Last reviewed: October 2026
