Introduction

Minimally invasive treatment aims to preserve the structural integrity of the tissue, alleviate patient harm, and enhance the natural self-healing ability to combat the disease. There has been marked development in the techniques and materials used for minimally invasive endodontic treatment, yet the clinical outcomes associated with the procedure have not been explored to the fullest.  

Aim

To compare the outcomes at 2 years following the use of two distinct root canal treatment (RCT) protocols: conventional treatment protocol (CP) vs minimally invasive protocol (MP), with a focus on the amount of root canal preparation

Patient Profile

• Adult patients (age ≥18 years) with mature permanent teeth requiring RCT.

  Methods

  Study Design

• A randomized prospective clinical trial

  Treatment Strategy

• A total of 175 mature permanent teeth were randomized 1:1 to CP group or MP group.

  175 mature permanent teeth were randomly assigned to one of two groups.

  The CP group was treated using ProTaper Gold systems and the continuous wave condensation technique

  The MP group underwent treatment with TruNatomy, ultrasonic-associated irrigation, calcium hydroxide (Ca[OH]₂), and a sealer-based obturation technique. The patients were recalled after a minimum of 2 years,

  Outcomes

  Healing Outcomes

• Periapical index (PAI) score, assessed as: Strict criteria (asymptomatic tooth with no apical radiolucency), loose criteria (asymptomatic tooth showing reduction in apical radiolucency size), and failure (symptomatic tooth with no change or increased periradicular radiolucency)

  Results

• The final analysis included 125 teeth, with a recall rate of 67.4% and an average follow-up period of 36 months (24–46 months).
• The overall success rate for RCT based on the loose criteria was 84.8% and based on the strict criteria was 80.8%. The success rates were significantly higher in the CP group, as compared to the MP groups for both the criteria (Fig. 1).

Fig. 1: The success rate in the study groups

• As per a multivariable analysis, MP group [odds ratio (OR) = 7.59, p = 0.009), the absence of sealer extrusion (OR = 0.09, p = 0.012), and the presence of a sinus tract (OR = 7.14, p = 0.021) were associated with a significantly increased risk of failure based on the loose criteria.
• Based on the strict criteria, the MP group (OR = 6.75, p = 0.002), presence of a sinus tract (OR = 6.59, p = 0.007, and being male (OR = 3.27, p = 0.022) were associated with a significantly increased risk of failure.

Conclusions

• Amongst patients undergoing RCT, those in the MP group exhibited significantly lower success rates, as compared to the CP group. Nevertheless, MP seemed to offer benefits in terms of structural preservation.
• Practitioners should weigh the benefits of dentin preservation against the need for effective disinfection while deciding on the endodontic treatment strategies.

Sci Rep. 2025 Jul 2;15(1):23260.  doi: 10.1038/s41598-025-02905-z.