Cracked tooth syndrome is a dental condition where a tooth has an incomplete fracture with vital dental pulp. It is most common in individuals aged between 45 and 60 years, and mandibular molars are often affected. Symptoms include cold pain and biting pain. Treatment options depend on the patient’s symptoms and the condition of the tooth.

Key findings

• Cracked teeth syndrome has a high survival rate if diagnosed and managed appropriately.
• Cracked teeth that underwent root canal treatment (RCT) had slightly lower survival than teeth with vital dental pulp.
• Full crown coverage of cracked teeth with RCT  is crucial for their survival.

Aim

This systematic review and meta-analysis aim to analyse the clinical treatment outcomes of cracked teeth, specifically focusing on those retaining vital dental pulp (CT-VDP) or undergoing root canal treatment (CT-RCT). The study aims to synthesise and analyze the clinical outcomes associated with different treatment options, including monitoring without restorative treatments, direct and indirect restorations, and cracked teeth that received a root canal treatment, across various follow-up periods.

Methods

A systematic search was conducted across multiple databases, including PubMed, Cochrane, Embase, and Web of Science, without language restriction. The search strategy used combinations of medical subject heading terms (MeSH) and non-MeSH terms related to cracked teeth and dental restorations. Two authors independently screened and selected studies according to the inclusion and exclusion criteria. The risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) for cohort observational studies.

Results

Description of Included Studies

The characteristics of the included studies varied, with publications spanning from 1991 to 2021 and follow-up periods ranging from 1 to 14 years. Three studies evaluated cracked teeth with vital dental pulp and those after RCT. Twelve studies focused on cracked teeth with vital dental pulp, while eleven examined cracked teeth after RCT. The studies encompassed various treatments such as direct composite restorations, full crowns, resin composite overlays, and root canal treatments.

Main Findings

The systematic review and meta-analysis on cracked teeth treatment outcomes revealed the following findings:

• Survival Rates of Different Types of Cracked Teeth:
  • Cracked Teeth with Vital Dental Pulp had:
    • decreasing tooth survival rates ranging from 97.8% to 92.8% throughout 1 to 6 years; and
    • notably high pulp survival rates, albeit decreasing, with rates ranging from 92.0 to 85.6% at different follow-up periods.
  • Cracked Teeth that underwent RCT had:
    • slightly lower tooth survival rates, ranging from  91.1% to 83.0% at one to four years,
• Treatment Approaches: 
  • Monitoring without Restorative Treatments:
    • For cracked teeth with vital dental pulp, monitoring without restorative treatments showed a success rate of 80% at three years.
    • Cracked teeth that underwent RCT had a slightly higher survival rate of 91.7% under similar monitoring conditions.
  • Direct Restorations vs. Full Crowns:
    • Full crowns did not show superior results to direct restorations for cracked teeth with vital pulp at one and three years. However, full crowns are recommended when occlusal interference is suspected
    • Cracked teeth that underwent RCT without full-crown restorations had an 11.3-fold higher risk of tooth extraction than those with full-crown restorations.

Study citation: 

Zhang S, Xu Y, Ma Y, Zhao W, Jin X, Fu B. The treatment outcomes of cracked teeth: A systematic review and meta-analysis. J Dent. 2024;142:104843. doi:10.1016/j.jdent.2024.104843

Comments: 

The meta-analysis paper offers a thorough analysis of the clinical effectiveness of various restorative interventions for cracked teeth. The study’s strength lies in its meticulous search strategy and meta-analysis methodology, providing valuable insights into treatment outcomes for cracked teeth over time. However, the study acknowledges some limitations that could impact its findings. One of these issues is the medium risk of bias identified in many included studies, which may affect the overall reliability of the results. The high dropout rates in certain studies could also compromise the robustness of conclusions drawn from those particular studies.

Photo credit

The picture is captured from 

Coronation Dental Specialty Group – own work.  CC BY-SA 3.0