Post-Operative Hypersensitivity in Dentistry

Post-Operative Hypersensitivity and Pain

• Post-operative pain, often of dentinal origin, is linked to intraoperative procedures.
• Pain can occur due to cutting and exposing healthy dentin, dentin dehydration, or improper application of dental tools during cavity preparation.
• Excessive cutting pressure without adequate cooling, and the use of dull burs/stones, increase the risk for frictional heat, dentin dehydration and a painful pulp response.
• Replacing diamond burs after the fourth use, and discontinuing their use after the fifth, is recommended.

Causes of Post-Operative Sensitivity

Pre-Operative Causes

• Improper Diagnosis: Accurate diagnosis is crucial to rule out pre-existing issues (e.g., tooth fractures, dentinal sensitivity, reversible/irreversible pulp conditions) that could be causing pain.
• Contaminated Armamentarium: Contamination of instruments (e.g., handpieces) by oral streptococci and staphylococcus aureus can affect pulp health and potentially lead to post-operative sensitivity.

Intra-Operative Causes

• Cavity Preparation: Inadequate cavity prep techniques, including potentially cutting or exposing healthy dentin or using improper application of dental cutting tools during cavity preparation, can cause post-operative pain.
• Improper Isolation: Inadequate isolation allows saliva containing microorganisms and humidity into the operative field, risking pulp inflammation and marginal leakage. A study showed no correlation between the type of isolation and post-operative pain.
• Material Manipulation (Direct Resin Composite): Focus on bonding protocols to manage resin composite post-operative sensitivity. The type of etchant, concentration, etching time, and tissue to be etched are key factors to consider during the etching procedure in order to effectively prepare dental tissue for hybridization. Increased etching time is a common clinical error linked to post-operative sensitivity.
• Material Manipulation (Amalgam): Inadequate lining of amalgam restorations (especially in deep cavities) often leads to thermal changes affecting the dentin-pulp complex, triggering post-operative sensitivity.
• Bonding (hybridization): Correct dentin hybridization procedure is essential for creating a mixed resin-monomer/collagen-fibril layer that alters the physical and chemical properties of the tissue. Optimizing bond interfaces to ensure minimal or zero bacterial fluid contact improves resin composite longevity. Adhesive application steps are critical for minimizing sensitivity.
• Polymerization Shrinkage: Resin polymerization forces can potentially rupture the bond interface, increasing the risk of bacterial entry, and contributing to caries, stains, and post-operative pain. A previous study suggested small incremental restorations and base materials with low modulus of elasticity as possible solutions.
• Incomplete Polymerization: Incomplete polymerization is a common cause of post-operative resin composite sensitivity.

Post-Operative Causes

• Finishing and Polishing: Excessive material insertion during restoration finishing or inappropriate brushing techniques increase the risk of frictional heat, potential pulp injury, and post-operative sensitivity. Careful instrumentation and attention to cervical margins are crucial.
• Faulty Occlusal and Proximal Relationships: Improper adjustment of a new restoration's occlusal interface may alter the dimensional changes in the corresponding area, causing potential fluid movement in dentinal tubules and leading to post-operative pain, especially temperature sensitivity. Thorough evaluation and removal of occlusal interferences/high spots prevents such occurrences.