anterior proximal caries

Restorative dentistry plays a crucial role in preserving tooth structure, restoring aesthetics, and maintaining proper oral function. Among the most common challenges in clinical practice are the management of anterior proximal (Class III), incisal (Class IV), cervical (Class V), and root surface caries. Each of these lesion types presents with unique etiological factors, diagnostic considerations, and clinical techniques. This comprehensive educational article expands upon the foundational principles of managing these lesions, offering a detailed and practical guide suitable for dental students, new clinicians, and any practitioner seeking to strengthen their understanding of restorative dentistry.

Understanding the Lesion Types

Before diving into the intricacies of preparation design and restorative approaches, it is essential to understand the differences between these types of lesions:

  1. Class III Caries (Anterior Proximal Caries):
    Occur on the proximal surfaces of anterior teeth without involving the incisal edge.
  2. Class IV Caries (Incisal Angle Fractures or Large Proximal Lesions):
    Involve the incisal edge of anterior teeth, often due to trauma or extensive decay.
  3. Class V Caries (Cervical Caries):
    Located on the gingival third of the facial or lingual surfaces of teeth.
  4. Root Surface Caries:
    Develop on exposed root surfaces, typically in older adults with gingival recession.

Each type of lesion requires a tailored approach in terms of diagnosis, cavity preparation, and material selection.

 

Advertisements

Anterior Proximal Lesions (Class III Caries)

Class III lesions commonly affect the proximal surfaces of maxillary and mandibular incisors and canines. These lesions may not be visible clinically and often rely on radiographic detection.

Diagnosis

Diagnosis typically involves:

  • Radiographs (bitewings) to detect proximal radiolucencies.
  • Transillumination, which is particularly helpful for anterior teeth.
  • Visual-tactile exams aided by tooth separation when necessary.

 

Access and Preparation

Access can be gained from either the buccal or lingual aspect, depending on:

  • Esthetic considerations
  • Proximity of the lesion
  • Tooth morphology

 

Most clinicians prefer the lingual approach to preserve facial enamel, which is crucial for esthetics, translucency, and shade-matching.

Since resin composite is adhesive, cavity preparations tend to be conservative. The main goals are:

  • Remove all carious tissue
  • Preserve as much healthy enamel as possible
  • Ensure access for proper visualization and composite placement

 

Unsupported enamel may sometimes remain on the labial surface if it does not compromise strength, but margins must be smooth and properly planed.

Beveling

Margins, especially in enamel, are often bevelled to:

  • Increase the bonding surface area
  • Enhance the blending of composite with the surrounding tooth structure
  • Reduce marginal staining

 

A typical bevel is 0.5–1.0 mm wide at a 45-degree angle.

Matrixing and Insertion

A mylar strip is traditionally used for Class III composites because it:

  • Helps contour the proximal surface
  • Prevents the formation of an overhang
  • Provides a smooth, glossy surface due to intimate contact

 

A small wedge may be placed cervically to:

  • Ensure adequate separation
  • Prevent gingival overhangs
  • Improve the seal at the gingival margin

 

Finishing and Polishing

Once the material is placed and light-cured:

  • Check occlusion
  • Remove excess composite
  • Polish using systems like Sof-Lex™ discs or Enhance® points for high-luster finishes

 

Polishing is essential because smoother surfaces decrease plaque retention and prolong restoration longevity.

 

Incisal Lesions (Class IV Caries or Fractures)

Class IV lesions are often more extensive, involving the incisal edge due to:

  • Trauma (e.g., sports injuries, falls)
  • Large proximal caries that have undermined the incisal angle
  • Developmental defects

 

Restoration of Choice: Resin Composite

Composite resin is ideal due to:

  • Excellent esthetics
  • Layering capabilities to mimic natural enamel and dentin
  • Strong adhesion when using the acid-etch technique

 

When Composite May Not Be Sufficient

For very large incisal and proximal defects, especially in adults, alternative options may include:

  • Porcelain veneers
  • Crowns with dentine bonding
    These options provide superior:
  • Strength
  • Longevity
  • Color stability

 

Such choices are particularly useful when the remaining structure is severely compromised.

Technique Considerations

Class IV restorations are esthetically demanding. Successful outcomes depend on:

  • Shade selection (using multiple shades to mimic natural layering)
  • Building anatomical contour
  • Proper beveling of enamel margins
  • Incremental layering
  • Adequate curing through different angles

 

Achieving a natural transition between composite and tooth requires skill and attention to detail.

 

Cervical Lesions (Class V Caries)

Cervical lesions occur near the CEJ and are influenced by several etiological factors, including:

  • Dental Caries
  • Abrasion (e.g., aggressive brushing)
  • Erosion (dietary acids)
  • Abfraction (occlusal stress-induced lesions)

 

This article focuses primarily on carious cervical lesions.

Prevalence and Demographics

Cervical caries are less common in young people but increase significantly with age due to:

 

Material Choices

Preferred materials include:

  • Flowable composite resin
  • Compomer (polyacid-modified composite)
  • RMGIC (resin-modified glass ionomer cement)

 

These materials offer:

  • Good adhesion to dentin
  • Flexural properties suitable for high-stress cervical areas
  • Fluoride release (RMGIC, compomer)

 

Cavity Preparation

When treating Class V caries:

  • Remove all infected dentin
  • Create a smooth surface for bonding
  • Bevel the occlusal margin to increase enamel bonding area
  • Do NOT bevel the cervical margin due to increased risk of microleakage in dentin/cementum areas

 

Incremental placement of restorative material is recommended, ideally under rubber dam isolation to:

  • Prevent contamination
  • Improve adhesion
  • Ensure moisture control

 

Root Surface Caries

Root surface caries is a growing concern, particularly in aging populations.

Etiology

The primary prerequisite for root caries is gingival recession, which exposes the root surface.

Because cementum and dentin have a higher critical pH than enamel, they are much more prone to:

  • Demineralization
  • Acid attack

 

Other contributing factors include:

Reduced salivary flow

Caused by:

  • Medications (antihistamines, antihypertensives, antidepressants)
  • Diseases (Sjögren’s syndrome)
  • Radiation therapy

 

Reduced saliva decreases:

  • Buffering capacity
  • Mineral availability
  • Natural cleansing

 

Changes in Diet

Individuals with dry mouth often adopt a diet high in:

  • Soft foods
  • Sugary beverages
  • Frequent snacks

 

These habits increase the risk of caries.

Long-Term Sugar-Based Medications

Elderly individuals often take liquid medications or chewable tablets containing sugar, contributing to chronic acid exposure.

Prevention and Control

Management begins with addressing etiological factors:

  • Thorough oral hygiene instruction (OHI)
  • Dietary counselling focused on reducing sugar frequency
  • Using high-fluoride toothpaste (typically 5000 ppm for high-risk patients)
  • Applying fluoride varnish regularly
  • Recommending xylitol-containing products for patients with xerostomia
  • Encouraging saliva substitutes or stimulants (sugar-free gum)

 

Early lesions may undergo remineralization through:

  • Topical fluoride
  • High-fluoride toothpaste
  • CPP-ACP (casein phosphopeptide–amorphous calcium phosphate) products
  • Proper plaque control

 

Restorative Treatment

Active lesions require restorative intervention.

Commonly used materials include:

  • RMGIC, due to its fluoride release and superior bonding to dentin
  • Traditional glass ionomer for high-caries-risk patients
  • Composite resin when greater strength or esthetics is necessary

 

RMGIC is often preferred because it:

  • Bonds chemically to dentin
  • Releases fluoride
  • Has a thermal expansion similar to tooth structure

 

Composite resin may be chosen when esthetics are paramount or when the lesion is well isolated from moisture.

 

Role of Adhesion in Modern Restorative Dentistry

The widespread use of adhesive materials such as composite and RMGIC has dramatically transformed cavity design.

Traditional principles (e.g., mechanical retention through undercuts) are no longer necessary. Today’s goals emphasize:

  • Conservation of tooth structure
  • Maximizing enamel bonding
  • Creating smooth transitions between tooth and restoration

 

Cavity preparations are typically small and minimally invasive.

Adhesion also reduces:

  • Microleakage
  • Postoperative sensitivity
  • Secondary caries

 

Importance of Isolation

Moisture contamination is a major cause of failure, especially for composite restorations.

Rubber dam isolation is strongly recommended for:

  • Predictable bonding
  • Preventing contamination by saliva or blood
  • Keeping the field dry and clean
  • Enhancing visibility

 

In cervical and root surface lesions, isolation can be challenging, but techniques such as:

 

Finishing and Polishing: A Crucial Step

The longevity and esthetics of composite restorations are directly related to surface smoothness.

Benefits of good polishing include:

  • Reduced plaque accumulation
  • Lower risk of gingival inflammation
  • Improved marginal adaptation
  • Enhanced shade and translucency
  • Less discoloration over time

 

Polishing systems vary but typically involve:

  • Sof-Lex™ discs
  • Polishing cups
  • Composite polishing pastes
  • Diamond-impregnated polishers

 

The finishing process gradually progresses from coarse shaping to fine smoothing and final polishing.

 

Patient Education and Prevention Strategies

Restorative dentistry is only one part of managing caries. Effective prevention significantly reduces the incidence of new lesions and improves prognosis.

Essential elements of patient education include:

Oral Hygiene Instruction

Patients must understand:

  • Proper brushing technique
  • The role of fluoridated toothpaste
  • The importance of interdental cleaning

 

Dietary Counselling

Since caries is a diet-mediated disease, patients should be educated to:

  • Limit frequency of sugary foods
  • Avoid sugary drinks between meals
  • Choose tooth-friendly snacks

 

Fluoride Therapy

Topical fluoride promotes:

  • Remineralization
  • Antibacterial effects against cariogenic bacteria
  • Reduced sensitivity

 

Regular Dental Visits

Routine checkups allow for:

  • Early detection of lesions
  • Prophylaxis and fluoride varnish application
  • Monitoring of restorations and gingival health

 

Conclusion

Managing anterior proximal, incisal, cervical, and root surface caries requires a comprehensive understanding of dental anatomy, material science, and adhesive techniques. Modern restorative dentistry emphasizes minimal tooth preparation, strong adhesive protocols, and the use of esthetically pleasing materials like resin composite and RMGIC.

Key principles that underpin successful treatment include:

  • Accurate diagnosis
  • Proper isolation
  • Conservative cavity design
  • Selection of appropriate restorative materials
  • Meticulous placement and finishing
  • Preventive strategies to reduce recurrence

 

By integrating these principles into clinical practice, dentists can provide restorations that are durable, functional, and visually indistinguishable from natural tooth structure—ultimately improving patient satisfaction and long-term oral health.

 

References

  1. Summitt, J. B., Robbins, J. W., Hilton, T. J., & Schwartz, R. S. (Eds.). (2018). Fundamentals of Operative Dentistry: A Contemporary Approach (4th ed.). Quintessence Publishing.
  2. Sturdevant, C. M., Roberson, T. M., Heymann, H. O., & Swift, E. J. (2019). Sturdevant’s Art and Science of Operative Dentistry (7th ed.). Elsevier.
  3. Gilbertson, D., & Sanders, M. (2021). Clinical Operative Dentistry: Principles and Practice. Oxford University Press.
  4. Frenal, S., & Mount, G. J. (2016). Restorative Dentistry: An Integrated Approach (2nd ed.). Churchill Livingstone.
  5. Fejerskov, O., Nyvad, B., & Kidd, E. (2015). Pathology of dental caries. In Dental Caries: The Disease and Its Clinical Management (3rd ed.). Wiley-Blackwell.
  6. Mjor, I. A., & Toffenetti, F. (2000). The clinical relevance of studies on resin-based materials. Dental Materials, 16(1), 1–6.
  7. Burgess, J. O., & Ghuman, T. (2020). Resin-modified glass ionomer restorative materials: A review. Compendium of Continuing Education in Dentistry, 41(7), 406–413.
  8. Hayes, M., & Moran, J. (2017). Caries in the ageing population: root caries. Gerodontology, 34(3), 291–299.
  9. Opdam, N. J., van Dijken, J. W., et al. (2014). Longevity of posterior composite restorations: A systematic review and meta-analysis. Journal of Dental Research, 93(10), 943–949.
  10. Sof-Lex™ Finishing and Polishing System—3M ESPE Clinical Data Summary (2019)
  11. American Dental Association (ADA). (2020). Evidence-Based Clinical Practice Guideline on Nonrestorative Treatments for Carious Lesions.
  12. FDI World Dental Federation. (2017). Caries Classification and Management System (CCMS).
  13. National Institute for Health and Care Excellence (NICE). (2018). Dental checks: intervals between oral health reviews (NG30).
  14. European Federation of Conservative Dentistry (EFCD)—Adhesive Dentistry Guidelines (2021).