Regenerative Endodontics Shows 98% Tooth Survival—But Is the Pulp Really Regenerating?

Does the size of the apex matter?

The researchers also explored whether initial apical diameter influenced treatment outcomes.

Interestingly, clinical success remained relatively high—above 80%—across different apical diameters. Tooth survival similarly remained above 90%, and neither showed a statistically significant relationship with increasing apical diameter.

This suggests that initial apical maturity may not have as strong an influence on basic clinical success and tooth retention as might be expected.

However, the biological outcomes told a different story.

Complete apical closure appeared to decrease as initial apical diameter increased, with the exploratory analysis suggesting higher closure rates in teeth with narrower apices than those with wider openings.

For pulp vitality recovery, the available evidence was too limited and variable to establish a clear relationship with apical diameter.

The authors caution that these findings should not be treated as definitive. Only 10 studies were included, just two specifically involved mature teeth, and methods used to measure apical diameter varied considerably between studies. The analysis relating apical size to outcomes should therefore be considered exploratory rather than evidence of a causal relationship.

There was another important source of uncertainty: even the definition of “pulp vitality” differed between studies. Some researchers used cold testing, others electric pulp testing and some laser Doppler flowmetry, making direct comparison difficult.

The findings are reassuring when the primary objective is clinical success and tooth preservation. Across the available studies, regenerative endodontic procedures demonstrated high rates of both.

But the review also provides an important reality check for the word “regeneration.”

Successful treatment does not necessarily mean that a functional pulp-dentin complex has been restored. Complete apical closure remains inconsistent, and recovery of pulp vitality appears considerably less predictable than clinical healing or tooth survival.

The authors therefore recommend careful case selection based on apical maturity and realistic communication with patients about what regenerative treatment can currently be expected to achieve.

Regenerative endodontic procedures showed approximately 90% clinical success and 98% tooth survival, but true biological outcomes were far less consistent: complete apical closure occurred in 53% of cases and pulp vitality recovery in only 21%.