Conservative Dentistry – Part I · MU Plovdiv

25. Fabrication of class I and class II composite restorations – stages, instruments, matrix systems. Occlusal contacts.

Inside: 14 sections · 2 labelled pictures · 2 tables · 34 flashcards · 14 min

Topic 25 of 53 in the MU Plovdiv syllabus for Conservative Dentistry – Part I (Dental Medicine, Year 3). The free AceMed note covers it in 12 sections, about 1,730 words (14 min of reading), with 34 flashcards.

In this note

  1. Introduction
  2. Principles of the adhesive preparation
  3. Class I and Class II designs
  4. C-factor and polymerisation shrinkage
  5. Clinical steps
  6. Main mistakes
  7. Key points
  8. Armamentarium
  9. Shade selection and placement steps
  10. Incremental technique and polymerisation stress
  11. Curing, finishing and polishing
  12. Typical mistakes

Introduction

Direct composite is now the usual material for Class I and Class II cavities in premolars and molars. Because it is bonded to enamel and dentin, the cavity no longer has to hold the filling: the preparation removes caries, gives access and is shaped to limit polymerisation-shrinkage stress. The classical (amalgam) designs are topics 6–11.

Principles of the adhesive preparation

Retention comes from micromechanical bonding – etched enamel and the hybrid layer in dentin – not from the shape of the cavity. The preparation for composite is dictated by the lesion: caries and weakened tooth are removed, and nothing more.

  • No extension for prevention: the outline stops where caries and unsupported enamel end; sound fissures are sealed, not cut.
  • No mechanical retention: no dovetail, undercuts or retention grooves. Walls need not converge occlusally; they may be parallel or slightly flared.
  • Depth set by the caries: pulpal and axial walls follow the excavated lesion, not a fixed level, and need not be flat.
  • Rounded internal angles: less stress concentration, better adaptation without voids. Use round-ended burs (pear-shaped No. 330 or 245, round-ended diamonds).
  • Minimal width: isthmus and box as narrow as the lesion and the bur allow; cusps and marginal ridges kept wherever possible.

Continue reading free

The whole note, all 12 sections, is free with an AceMed account, with its 34 flashcards. Premium adds flashcard recall, highlights and Ask AI.

Start freeAlready a member? Open the note