From the Guidelines
When assessing existing dental crowns, a comprehensive clinical and radiographic evaluation is essential to determine their integrity and need for replacement or maintenance, as evidenced by the most recent guidelines 1. This evaluation should include examining the crown margins for gaps, discoloration, or decay, which may indicate failure.
- Check for recurrent decay underneath the crown using bitewing radiographs, as this is a common reason for crown replacement.
- Evaluate the integrity of the crown material for chips, cracks, or excessive wear.
- Assess the gingival health around the crown, looking for inflammation, bleeding, or recession which may expose crown margins.
- Test for mobility of the crown which could indicate cement failure or underlying tooth fracture.
- Evaluate the occlusion to ensure proper bite relationship. Consider the age of the crown, as most crowns have a lifespan of 5-15 years depending on material and oral hygiene, as well as patient symptoms such as pain, sensitivity, or esthetic concerns, which should be documented, as recommended by recent studies 1. The goal of this systematic approach is to balance the risks of unnecessary replacement against the potential complications of maintaining a failing restoration, ultimately prioritizing the patient's oral health and quality of life, in line with the latest evidence-based recommendations 1.
From the Research
Assessment of Existing Dental Crowns
The assessment of existing dental crowns involves evaluating their condition, functionality, and impact on oral health. Several studies have investigated the effects of different types of crowns and cementing agents on the retention and periodontal condition of crowned teeth.
- The study by 2 found that replacing swaged crowns with metal ceramic crowns improves gingival health and leads to better long-term prognosis for restored teeth.
- Another study by 3 discussed the advantages and disadvantages of all-ceramic crowns, including their bonding and cementing properties.
- The effects of desensitizing agents on the retention of crowns cemented with luting agents were evaluated in studies by 4 and 5, which found that certain desensitizing agents can affect the retentive strength of different types of cements.
- A study by 6 reviewed the current status of dentin-bonded all-ceramic crowns, highlighting their advantages and disadvantages, and emphasizing the need for long-term clinical studies to fully assess their performance.
Factors Affecting Crown Retention
Several factors can affect the retention of dental crowns, including:
- Type of cementing agent used, such as zinc phosphate, glass ionomer, or resin modified glass ionomer cement 4, 5
- Use of desensitizing agents, such as GC Tooth Mousse or GLUMA desensitizer 4, 5
- Type of crown material, such as all-ceramic or metal ceramic 2, 3
- Periodontal condition of the crowned tooth, including presence of inflammation and pocket depth 2