Endodontic Clinical Outcome after Separated Instrument Removal Using a Spinal Needle Technique: A Retrospective Study of Thirty Years of Clinical Experience.

INTRODUCTION: Current methods for the removal of separated endodontic instruments (RSI) are not predictable. METHODS: The primary outcome of this retrospective study was to assess the clinical and radiographic success (CRS) of teeth in case of RSI after a 5-year follow-up. Secondary outcomes were to evaluate (1) the effectiveness in RSI and (2) the risk of root fracture after RSI. The study protocol was registered at ClinicalTrials.gov (ID: NCT05128266). The patients were treated by the same endodontist between January 1991 and December 2019. The RSI was performed under the operative microscope as follows: first, the dentine surrounding the coronal part of the broken instrument was selectively removed by using a small ultrasonic tip to loosen the fragment; then, a modified spinal needle was used to catch and remove the instrument. The 1-, 3-, 5-, and >5-year CRS were recorded. Logistic regression analysis was performed to determine independent predictors of failure (ie, tooth number, type of root canal, shape of the root canal, type of broken instrument, apicocoronal level of the separated instrument, presence of periapical lesions, and root perforations). RESULTS: A total of 158 teeth were included in this study. Finally, 131 instruments underwent RSI (82.9%). RSI was an independent predictor of CRS after 1-year of treatment (odds ratio: 58.3; 95% confidence interval: 27.42-95.73, P < .05). At the 5-year follow-up, only 10 of 131 teeth (7.6%) failed. All failures were caused by root fracture (10/10) (χ2 test, P < .05). Separated instruments located in the apical third of the root were more difficult to remove (13/49 cases, 26.5%; χ2 test, P < .05). CONCLUSIONS: The proposed technique can achieve excellent effectiveness in RSI, can achieve a high CRS rate when a periapical lesion is present, is not associated to a significant increase in root fracture incidence, and should be performed with the help of an operative microscope.

Lingual Flap Protection during Third Molar Surgery: A Literature Review.

The purpose of this review was to analyze how the retraction and protection of lingual flap (LF+) could influence the incidence of lingual nerve injury (LNI) during third molar extraction, as compared with protocols that do not involve handling of lingual tissue (LF). A literature review was performed from the "Medline" and "Scopus" medical databases, using the keywords "lingual nerve" and "third molar surgery." From the selected articles, the mean values for transitory and permanent LNI's incidence were elaborated, taking into account the group treated with LF+ technique and the group treated with LF technique. Of 480 articles, 11 studies were included in the review. The LF+ group counted 3,866 surgeries and it resulted in a transitory LNI's mean incidence of 2.98 ± 0.03% and a mean incidence of 0.1 ± 0.003% for permanent LNI. The LF group counted 5,938 surgeries with, respectively, 1.92 ± 0.02 and 0.49 ± 0.006% of transitory and permanent LNI's incidence mean values. The results of this study suggest that the application of LF+ techniques reduces the risk of damage and injuries of lingual nerve.

Repair of teeth with cracks in crowns and roots: An observational clinical study.

AIM: This retrospective observational study investigated the survival rate of teeth with radicular cracks that were restored using composite materials. METHODOLOGY: The study was approved by the Ethical Committee of Sistema Sanitario Nazionale (prot. N°2370CELazio1), Clinicaltrials.gov identifier: NCT04430205. Between 1991 and 2019, 87 teeth with radicular cracks (87 patients [46 men, 41 women, mean age 50.2 years]) were treated with adhesive composite restorations. Forty-five cracks were observed in the maxillary posterior teeth (molars and premolars), 40 in the mandibular posterior teeth and only two cracks in the anterior teeth, both in maxilla. Based on the depth of the crack, teeth were categorized as proximal radicular cracked teeth (PRCT), in which the fracture line was restricted within the pulpal floor or the coronal one-third of the root and deep radicular cracked teeth (DRCT), in which the fracture line extended to the middle and apical thirds of the root canal up to the apex. Bone loss/recovery was evaluated radiographically at 1-year follow-up. All patients were treated using surgical microscopy by the same operator. Logistic regression analysis was performed to determine independent predictors of extraction. Kaplan-Meier survival curves were used to analyse PRCT and DRCT. RESULTS: Among 87 cracked teeth, 66 were molars, 19 premolars and 2 incisors. Fifty-two were DRCT, 35 were PRCT, 46 had a periodontal probing defect. Patients were followed up for a mean of 66.9 months (standard deviation 44.6, min 1 to max 172). Lack of probing depth was a significant protective factor against extraction (odds ratio [OR] 0.027, 95% confidence interval [CI] 0.003-0.27, p < .05), whereas further bone loss (OR 10.63, 95% CI 2.08-54.36, p < .05) was a risk factor for extraction. More than 50% of teeth treated with the adhesive protocol were functional (46 of 87 teeth [χ2 test], p < .05) at 5-year follow-up. Among the PRCT group, a 78% survival rate at 5 years was found, while among the DRCT group, a 58% survival rate was found. CONCLUSION: Composite resin restorations resulted in tooth survival in >50% of patients; 85.4% of PRCT and 61.5% of DRCT were functional after 5 years of follow-up.