Official Announcement: ORAL → BRUSH Token

Nov 9

Back

Dental Crowns and Bridges: Materials, Procedures, and Clinical Outcomes
Jul 20

Jul 20

Introduction

Dental crowns and bridges are among the most frequently performed fixed prosthodontic procedures worldwide. A crown (or cap) covers an individual tooth to restore its shape, size, strength, and appearance. A bridge replaces one or more missing teeth by anchoring artificial teeth (pontics) to adjacent natural teeth or implants. With advances in material science and digital dentistry, clinicians today have an unprecedented range of options for delivering durable, aesthetic restorations.

Dental Crowns: Indications and Material Selection

Clinical Indications

Extensive caries or fracture: When tooth structure loss exceeds 50%, direct restorations (fillings) become inadequate. A crown provides circumferential protection against further fracture.
Root canal treated teeth: Endodontically treated posterior teeth have increased fracture risk. Full-coverage crowns are recommended, particularly for molars and premolars.
Severe attrition or erosion: Crowns restore vertical dimension and protect against further wear.
Aesthetic improvement: Discolored, malformed, or severely misaligned teeth can be restored with all-ceramic crowns for optimal aesthetics.
Implant restoration: Crowns are the final prosthetic component for single-tooth implants.

Crown Material Options

Material	Advantages	Disadvantages	Best For
Full Metal (Gold, Base Alloys)	Exceptional durability, minimal tooth reduction, no ceramic fracture risk	Poor aesthetics, metal allergy risk	Posterior teeth, heavy bruxers
Porcelain-Fused-to-Metal (PFM)	Good strength, acceptable aesthetics, proven long-term track record	Metal margin display, gingival discoloration, ceramic chipping	Posterior and anterior, budget-conscious
Lithium Disilicate (e.max)	Excellent aesthetics, high flexural strength (360–400 MPa), adhesive bonding	Higher cost, technique-sensitive cementation	Anterior and posterior, aesthetic zone
Zirconia (Monolithic)	Extreme strength (1000+ MPa), tooth-colored, minimal antagonist wear (polished)	Opacity challenges for anterior, limited translucency in early generations	Posterior bridges, bruxers, full-arch
Zirconia (Layered / High-Translucency)	Improved aesthetics, strength 600–900 MPa	Potential for veneering ceramic chipping	Anterior and posterior, aesthetic bridges
Composite Resin	Lowest cost, easy repair, minimal antagonist wear	Lower strength, higher wear rate, staining	Temporary crowns, budget-limited cases

Dental Bridges: Classification and Design Principles

Traditional Fixed Bridges

Conventional bridge: Pontic suspended between two or more abutment crowns. Requires preparation of adjacent healthy teeth. The most common design.
Cantilever bridge: Pontic supported by a single abutment crown on one side only. Suitable when only one adjacent tooth is available. Higher leverage forces limit its use to areas of low occlusal load.
Maryland bridge (resin-bonded): Pontic with metal or ceramic wings bonded to the lingual surfaces of adjacent teeth. Minimally invasive, preserves enamel. Single-wing designs show better survival than two-wing. 5-year survival approximately 87% in anterior applications.

Implant-Supported Bridges

When multiple teeth are missing, implant-supported bridges provide a fixed solution without involving natural teeth. Two or more implants support a connected prosthesis. This approach preserves adjacent tooth structure and provides superior long-term survival (10-year survival >95%). Compared to traditional bridges, implant-supported restorations show lower annual failure rates and better patient satisfaction.

Pontic Design Considerations

Sanitary (hygienic) pontic: Easy to clean but poor aesthetics. Used in non-aesthetic posterior regions.
Modified ridge-lap pontic: Slight tissue contact on the buccal aspect only, T-shaped cross-section. Good compromise between aesthetics and hygiene.
Ovate pontic: Concave tissue surface extending into a prepared socket. Best aesthetics for anterior regions. Requires excellent oral hygiene.

Clinical Procedure: From Preparation to Cementation

Step 1: Tooth Preparation

Tooth reduction follows material-specific guidelines. All-ceramic crowns require 1.5–2.0 mm occlusal reduction and 1.0–1.5 mm axial reduction. PFM requires 1.5–2.0 mm occlusal and facial reduction, 1.0–1.5 mm lingual. Full metal requires least reduction (0.5–1.0 mm). Chamfer or rounded shoulder finish lines are preferred. Sharp line angles and undercuts must be eliminated.

Step 2: Impression and Temporization

Conventional impression: Polyvinyl siloxane (PVS) or polyether materials for accuracy.
Digital impression: Intraoral scanners (IOS) capture preparation geometry with high accuracy. Benefits include patient comfort, faster workflow, and reduced remakes. Systems such as CEREC, 3Shape TRIOS, and iTero are widely used.
Temporary restoration: Provisional crowns fabricated from bis-acryl composite or PMMA, cemented with temporary (eugenol-free) cement to prevent sensitivity and maintain occlusion.

Step 3: Laboratory or CAD/CAM Fabrication

Conventional fabrication involves wax pattern, investing, casting, and porcelain layering. Digital workflows use CAD software to design the restoration, followed by CAM milling from pre-sintered blocks (lithium disilicate, zirconia) or 3D printing of patterns for casting.

Step 4: Try-In and Cementation

Try-in: Assess marginal fit (<50 μm ideal), proximal contacts, occlusion, and aesthetics.
Cement selection: Resin-modified glass ionomer (RMGI) for conventional cementation. Adhesive resin cement for all-ceramic restorations (especially lithium disilicate). Zirconia can be conventionally cemented with RMGI when retention form is adequate, or adhesively bonded with MDP-containing primers.
Occlusal adjustment: Verify centric and excursive contacts. Polished zirconia causes minimal antagonist wear; unpolished or adjusted surfaces should be repolished.

Longevity and Complications

Systematic reviews report 5-year survival rates: all-ceramic crowns 93–96%, PFM 94–97%, full metal 97%, conventional bridges 88–94%. Common complications include secondary caries, ceramic fracture, loss of retention, endodontic complications, and periodontal issues around abutments. Factors reducing longevity: poor oral hygiene, bruxism, inadequate tooth preparation, and suboptimal cementation technique.

Cost Considerations and Treatment Planning

Crown costs vary by material: composite resin ($300–600), PFM ($600–1000), lithium disilicate ($800–1200), zirconia ($900–1500). Bridge costs multiply per unit. Implant-supported restorations have higher initial costs but lower long-term maintenance. Treatment planning should consider biological cost (tooth structure sacrificed), financial cost, aesthetic demands, and patient preferences.

Conclusion

Dental crowns and bridges remain essential tools in restorative dentistry, offering predictable solutions for tooth restoration and replacement. Material selection should be individualized based on clinical requirements, aesthetic demands, and functional considerations. Digital workflows continue to improve efficiency and precision, while evidence-based cementation protocols enhance longevity.

References

Pjetursson BE, Sailer I, Zwahlen M, Hämmerle CH. A systematic review of the survival and complication rates of all-ceramic and metal-ceramic reconstructions. Dent Mater. 2007;28(1):86–95.
Sailer I, Makarov NA, Thoma DS, et al. All-ceramic or metal-ceramic tooth-supported fixed dental prostheses? A systematic review. Dent Mater. 2015;31(6):624–639.
Raigrodski AJ, Hillstead MB, Meng GK, Chung KH. Survival and complications of zirconia-based fixed dental prostheses: a systematic review. J Prosthet Dent. 2012;107(3):170–177.
Pjetursson BE, Thoma D, Jung R, et al. A systematic review of the survival and complication rates of implant-supported fixed dental prostheses. Clin Oral Implants Res. 2012;23(Suppl 6):22–38.
Edelhoff D, Sorensen JA. Tooth structure removal associated with various preparation designs for anterior teeth. J Prosthet Dent. 2002;87(5):503–509.

Oral Cancer Screening: Why Early Detection Saves Lives

Jul 20

Managing Dental Anxiety: Sedation Options and Psychological Approaches

Jul 20

Official Announcement: ORAL → BRUSH Token

Nov 9

Posts recentes

Management of Traumatic Dental Injuries: Current IADT Guidelines and Clinical Protocols

Traumatic dental injuries constitute a significant public health problem, particularly among children and adolescents, with approximately one-third of individuals experiencing a dental trauma before adulthood. The International Association of Dental Traumatology periodically updates evidence-based guidelines for the management of these injuries. This article synthesizes the current IADT recommendations, covering crown fractures, luxation injuries, root fractures, and avulsion, and discusses emergency management protocols, splinting techniques, follow-up regimens, and factors influencing long-term prognosis.

Contemporary Root Canal Irrigation: Techniques, Irrigants, and Activation Methods

Chemomechanical debridement through irrigation is fundamental to endodontic success, eliminating microorganisms, dissolving organic tissue, and removing the smear layer from the complex root canal system. This article reviews contemporary irrigation protocols, compares the properties and efficacy of sodium hypochlorite, EDTA, chlorhexidine, and newer irrigants, and evaluates activation techniques including passive ultrasonic irrigation, sonic activation, laser-activated irrigation, and negative pressure systems.

Oral Cancer Screening: Adjunctive Diagnostic Tools and Clinical Decision-Making

Conventional oral examination remains the cornerstone of oral cancer screening, but adjunctive diagnostic tools have been developed to improve the detection of potentially malignant disorders and early malignancy. This article evaluates the evidence supporting toluidine blue staining, autofluorescence devices, chemiluminescence, brush biopsy, and salivary biomarkers as adjuncts to visual and tactile examination, discusses their sensitivity and specificity, and provides a practical framework for incorporating these tools into clinical practice while avoiding over-referral and unnecessary patient anxiety.

Digital vs Conventional Impressions: Accuracy and Clinical Efficiency

The transition from conventional elastomeric impressions to digital intraoral scanning represents one of the most significant technological shifts in restorative dentistry. This article compares the accuracy, clinical efficiency, patient acceptance, and cost-effectiveness of digital versus conventional impression techniques across various clinical applications including single crowns, fixed partial dentures, and implant-supported restorations, drawing on recent systematic reviews and clinical studies.

Antibiotic Prophylaxis in Dentistry: Evidence-Based Guidelines and Clinical Decision-Making

Antibiotic prophylaxis in dentistry has undergone substantial re-evaluation over the past two decades, driven by evolving evidence on the risk of distant site infections, growing concerns about antimicrobial resistance, and the recognition of adverse drug reactions. This article reviews current evidence-based guidelines from the American Heart Association, the National Institute for Health and Care Excellence (NICE), and other authoritative bodies regarding prophylaxis for infective endocarditis and prosthetic joint infections, and discusses clinical decision-making in the context of immunosuppression, cardiac devices, and other special patient populations.

Smoking Cessation Interventions in Dental Practice: Evidence and Implementation

Dental professionals are uniquely positioned to deliver smoking cessation interventions due to the frequent and regular nature of dental visits and the visible oral consequences of tobacco use. Evidence demonstrates that even brief advice from a dental practitioner can significantly increase quit rates. This article reviews the current evidence base for smoking cessation interventions in dental settings, outlines the 5As framework, and discusses the integration of pharmacotherapy, behavioral counseling, and referral pathways into routine dental practice.

Removable Partial Dentures: Design Principles and Clinical Outcomes

Removable partial dentures (RPDs) remain a cost-effective and widely used prosthetic solution for partially edentulous patients. Despite the increasing popularity of implant-supported restorations, RPDs continue to serve a substantial patient population. This article examines the fundamental principles of RPD design, including Kennedy classification, biomechanical considerations, and component selection, and reviews long-term clinical outcomes regarding patient satisfaction, abutment tooth survival, and the impact on oral health-related quality of life.

Dental Fear and Anxiety: Behavioral and Pharmacological Management Approaches

Dental fear and anxiety affect approximately 15 to 20 percent of the adult population, with a smaller subset meeting criteria for specific phobia. These conditions lead to avoidance of dental care, deterioration of oral health, and reduced quality of life. This article reviews the epidemiology and etiology of dental fear and anxiety, describes validated assessment tools, and provides an evidence-based framework for behavioral interventions, communication strategies, and pharmacological approaches including nitrous oxide sedation, oral sedation, and intravenous conscious sedation.

Dental Ceramics: From Feldspathic Porcelain to Monolithic Zirconia

The evolution of dental ceramics over the past four decades has transformed restorative dentistry, offering increasingly esthetic, durable, and biocompatible options. From traditional feldspathic porcelain to modern high-translucency zirconia, each ceramic class presents distinct indications, advantages, and limitations. This article traces the development of dental ceramics, compares material properties across glass-based, polycrystalline, and resin-matrix ceramic categories, and discusses clinical selection criteria, bonding protocols, and long-term performance data.

Burning Mouth Syndrome: Etiology, Diagnosis, and Management Strategies

Burning mouth syndrome (BMS) is a chronic intraoral pain condition characterized by a persistent burning sensation in the absence of identifiable mucosal pathology. Affecting predominantly postmenopausal women, BMS presents a significant diagnostic and therapeutic challenge in clinical practice. This article reviews current understanding of its multifactorial etiology, evidence-based diagnostic criteria, and the pharmacological, topical, and psychological management strategies available to dental practitioners.

Popular

Official Announcement: ORAL → BRUSH Token

Dental Crowns and Bridges: Materials, Procedures, and Clinical Outcomes
Jul 20

Introduction