Continued root development of immature permanent teeth after regenerative endodontics with or without a collagen membrane: A randomized, controlled clinical trial

Recent studies evaluated the efficacy of a collagen membrane (Bio-Gide) to promote root development in regenerative endodontics (REPs). However, the influence of etiology and tooth type on the results was not assessed.To evaluate the quantitative and qualitative effect of a collagen membrane (Bio-Gide), with and without the effect of etiology and tooth type, in promoting root development in immature teeth after REPs.Eighty nonvital immature teeth were divided randomly into two groups (40 teeth in each group). REPs were performed with (experimental group) and without (control group) a collagen membrane. All teeth were subjected to regular clinical and radiographical follow-up.Seventy-six teeth were included in the final analyses. The average follow-up periods were 33.1 ± 21.8 months for the control group and 28.1± 18.6 months for the experimental group. Quantitative analysis of root development in the experimental group showed a greater increase in dentin wall thickness in the middle one-third of the root compared to the control group, with or without the effect of etiology and tooth type. Six types of root development were observed. There was no significant difference in the type of tooth development between the two groups.The use of a collagen membrane could promote an increase in dentin wall thickness in the middle one-third of the root, and it had no significant effect in terms of the type of subsequent root development.