Available online 6 March 2023

After endodontic treatment, teeth may require additional treatment. Data regarding the number of treatments up to extraction after endodontic treatment are lacking.

The purpose of this retrospective study was to evaluate the number of consecutive restorative procedures performed on a specific tooth starting from endodontic treatment up to extraction. A comparison was made between crowned and uncrowned teeth.

A retrospective study was conducted using 28 years of data from a private clinic. The total number of patients was 18 082 and included 88 388 treated teeth. The data were collected for permanent teeth that received at least 2 consecutive retreatments. The data included tooth number, procedure type, date of procedure, total number of procedures conducted during the study period, extraction date, time from endodontic treatment to extraction, and whether the tooth had been crowned or not. Endodontically treated teeth were divided into 2 groups: extracted and nonextracted. In each group, a comparison was made between crowned and uncrowned teeth and between anterior and posterior teeth by using the Student t test (α=.05).

In the non extracted group, teeth that were crowned required significantly (P<.05) fewer restorative treatments (mean ±standard deviation 2.9 ±2.1) than uncrowned teeth (5.01 ±2.98). For extracted teeth, the mean time from endodontic treatment until extraction was 10.39 years. Crowned teeth were extracted after a mean of 11.06 years and 3.98 treatments, while uncrowned teeth were extracted after a mean of 9.96 years and 7.22 treatments (P<.05).

Endodontically treated teeth that were crowned required significantly fewer subsequent restorative procedures than uncrowned teeth and exhibited higher survival rates up to extraction.

A retrospective study was conducted from 28-year data obtained from a private clinic in Rehovot, Israel. A total of 18 082 patients and 88 388 teeth were included. Data were collected for the 3 dentists operating in the clinic and for all patients treated in the clinic during the study period (1993-2020). The signed permission of the clinical staff was obtained as requested by the institutional ethical committee. Data were extracted from the clinic patient management software program into a

A total of 18 082 patients and 88 388 teeth were surveyed, 2765 of which were endodontically treated and had not been extracted during the study period (Fig. 1). Of those, 514 were anterior teeth (290 incisors and 224 canines) and 2251 posterior teeth (1308 premolars and 943 molars) (Table 1).

The number of additional consecutive procedures performed on endodontically treated teeth during the study period was significantly lower (P<.05) in the group that had been crowned: mean ±standard

The study purpose was to evaluate the number of consecutive restorative procedures performed on teeth after endodontic treatment while examining the effect of crowning. The results supported the hypothesis that crowned endodontically treated teeth required significantly fewer consecutive restorative procedures and exhibited better survival rates than uncrowned teeth. For crowned teeth, the mean time from endodontic treatment up to extraction in the current study was 11 years, consistent with

Based on the findings of this retrospective clinical study, the following conclusions were drawn:

Crowning of endodontically treated teeth was associated with a decrease in the number of consecutive treatments required to maintain the same tooth.

Uncrowned endodontically treated teeth were extracted earlier than crowned teeth.

The authors thank Dr Kles Joel, Dr Katz Eran, and Dr Ofer Valter for assistance in supplying the clinic data. The authors also thank Mr Or Kles for data processing and help with data analysis.

© 2023 by the Editorial Council for the Journal of Prosthetic Dentistry.