Operative II: Common Problems - Causes and Potential Solutions (Reading)

Topic: White Line Adjacent to the Enamel Margin

What causes a white line adjacent to the enamel margin of a direct composite restoration? (2)

-Microseparation (space) between composite and tooth.

-Microfracture within marginal enamel.

Topic: White Line Adjacent to the Enamel Margin

What are microfractures within marginal enamel caused by? (3)

• Inadequate etching and bonding

• High-intensity, fast light curing causing polymerization stresses

• Traumatic finishing techniques

Topic: White Line Adjacent to the Enamel Margin

What are potential solutions for a white line adjacent to the enamel margin? (3)

• Use atraumatic finishing techniques (light intermittent pressure)

• Use proper polymerization techniques (see Chapter 6)

• Seal the gap with adhesive or remove and re-restore if needed

Topic: Voids

What are the causes of voids in composite restorations? (2)

• Spaces left between increments during insertion (lamination defects)

• Adherence of composite to hand instruments during placement

Topic: Voids

How can voids in composite restorations be prevented or repaired? (2)

• Use more careful restorative technique

• Repair marginal voids by preparing area and re-restoring

Topic: Weak or Missing Proximal Contacts

What causes weak or missing proximal contacts in Class II, III, and IV restorations? (6)

• Inadequately contoured matrix band

• Inadequate wedging (preoperative and during insertion)

• Matrix band movement or no direct contact

• Using circumferential matrix when restoring one contact

• Adherence of composite to hand instruments pulling away contact

• Matrix band too thick

Topic: Weak or Missing Proximal Contacts

What are potential solutions for weak or missing proximal contacts? (6)

• Properly contour matrix material

• Ensure matrix contacts adjacent tooth

• Use adequate wedging

• Use matrix system around only the proximal surface

• Hold matrix with hand instrument during curing

• Careful insertion technique

Topic: Inaccurate Shade

What causes inaccurate shade matching in composite restorations? (4)

• Inappropriate operatory lighting while selecting the shade

• Selection of shade after the tooth has dehydrated

• Shade tab not matching the actual composite shade

• Wrong shade utilized

Topic: Inaccurate Shade

What are potential solutions for inaccurate shade matching? (5)

• Use natural light when selecting shade, if possible

• Select the shade before isolating the tooth

• Place some of the selected shade on the tooth and cure preoperatively to verify shade selection

• Do not shine the operator light (overhead or attached to operator loupes) directly on the area during shade selection

• Understand the typical zones of different shades for natural teeth

Topic: Contouring and Finishing Problems

What causes contouring and/or finishing problems in composite restorations? (3)

• Inadequate anatomic tooth form (overcontour or undercontour of the restoration)

• Improper selection of finishing instrument and improper composite placement

• Iatrogenic damage to adjacent unprepared tooth structure

Topic: Contouring and Finishing Problems

What are potential solutions for contouring and finishing problems? (6)

• Have a proper matrix with appropriate axial and line angle contours

• Create embrasures to match the adjacent tooth embrasure form

• Remember the outline form of the preparation

• Use a properly shaped finishing instrument for the area being contoured

• Be careful with the use of rotary instruments to avoid adversely affecting the structure of the adjacent tooth or teeth

• Do not use rotary instruments that leave roughened surfaces

Topic: Postoperative Sensitivity

What causes postoperative sensitivity in composite restorations? (5)

• Aggressive tooth preparation (inadequate use of coolant systems, inefficient cutting instruments)

• Incorrect use of adhesive systems

• Not using a liner/base when indicated

• Formation of microgaps secondary to excessive polymerization shrinkage stress, particularly in situations of high C-factor

• Aggressive finishing of the restoration

Topic: Postoperative Sensitivity

What are potential solutions for postoperative sensitivity? (6)

• Use careful tooth preparation technique

• Use liners/bases properly

• Use adhesive systems properly

• Use a desensitizer solution after dentin acid etching

• Insert and polymerize the composite material properly

• Finish the composite restoration properly