The quality of ultrasonic root-end preparation: A quantitative study

doi:10.1016/S0099-2399(98)80152-0

Journal of Endodontics

Volume 24, Issue 10, October 1998, Pages 666-670

https://doi.org/10.1016/S0099-2399(98)80152-0 Get rights and content

Ultrasonic root-end preparation techniques have recently been introduced and revolutionized the field of endodontic surgery. The purpose of this study was to compare quantitatively the quality of root-end preparation techniques prepared by a specially designed ultrasonic retrotip with those prepared in a traditional manner by a microhand-piece bur. Twenty roots with two canals and an isthmus from extracted maxillary human molars were selected for this study. After instrumentation, obturation, and root-end resection, root-end preparations were made using either an ultrasonic retrotip or a conventional microhandpiece bur. With the aid of the image processing and analysis system, the specimens were inspected under a stereomicroscope for further evaluation of the quality of the shape and size of preparation. The results of this investigation showed that the ultrasonic rootend preparations produced more conservative and less perforated cavities than those made with conventional microhandpiece bur preparations.

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Cited by (24)

The influence of an isthmus on the outcomes of surgically treated molars: A retrospective study
2016, Journal of Endodontics
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Eight of the 9 had an isthmus preparation. Ultrasonic root-end preparations produce more conservative and less perforated cavities than those produced with conventional microhandpiece bur preparations (19). However, despite the procedural advances, there is no avoiding root weakening because of the reduction in the thickness of the remaining dentin after an isthmus preparation.
The purpose of this study was to investigate the effects of an isthmus on the success rate of surgically treated molars.
The study included 106 maxillary and mandibular first molars with endodontic lesions limited to the periapical area. Endodontic microsurgical procedures were performed according to the Yonsei protocol reported in a previous study. When an isthmus was observed after a high-magnification inspection, it was included in the retrograde preparation design. When an isthmus was not observed, only the main root canal space was prepared. The patients were followed up periodically every year after treatment. Success was defined as the absence of clinical signs and symptoms and radiographic evidence of complete or incomplete healing.
Of the 106 teeth included in the study, 72 teeth had an isthmus, and 34 did not. Kaplan-Meier analysis revealed that the cumulative survival rate after surgery was 61.5% and 87.4% for 4 years when an isthmus was present and absent, respectively. A multivariate Cox proportional hazards regression analysis showed that the adjusted hazard ratio for failure was 6.01 times higher for the isthmus-present teeth than for the isthmus-absent teeth (P < .05).
In this study, the success rate for endodontic microsurgery on isthmus-absent teeth was higher than that for isthmus-present teeth. Considering the success rate and potential risk of weakening the root after preparation, the techniques of isthmus preparation need to be improved.
Periradicular Surgery
2010, Cohen's Pathways of the Pulp, Tenth Edition
Microscope versus endoscope in root-end management: a randomized controlled study
2008, International Journal of Oral and Maxillofacial Surgery
The purpose of this prospective, randomized, clinical study was to monitor the outcome of periradicular surgery, in which either a surgical microscope or an endoscope was used as a magnification device. A total of 113 teeth in 70 patients were included in the study, according to specific selection criteria. The choice of endoscope or surgical microscope was made using a randomized table. One hundred cases were followed for at least 2 years. Of these, 59 root-end management procedures were performed using a microscope and 41 using an endoscope. At the 2-year follow-up they were classified into three groups (success, uncertain healing and failure) according to radiographic and clinical criteria. After a 2-year follow-up, 91 teeth (91%) healed successfully. In the group using an endoscope 90% of successful healing was achieved, while 92% of success was recorded for the group using a microscope. No statistically significant difference was found in the treatment results relating to the type of magnification device.
The type of magnification device used did not seem to affect the outcome of endodontic surgery.
Ultrasonics in Endodontics: A Review of the Literature
2007, Journal of Endodontics
Citation Excerpt :
Furthermore, the geometry of the retrotip design does not require a beveled root-end resection for surgical access (232), thus decreasing the number of exposed dentinal tubules (20, 239–241) and minimizing apical leakage (242–245). They also enable the removal of isthmus tissue present between two canals within the same root (234, 236, 246–248). It is considered a timesaving technique (234) that seems to have a lower failure rate (20).
During the past few decades endodontic treatment has benefited from the development of new techniques and equipment, which have improved outcome and predictability. Important attributes such as the operating microscope and ultrasonics (US) have found indispensable applications in a number of dental procedures in periodontology, to a much lesser extent in restorative dentistry, while being very prominently used in endodontics. US in endodontics has enhanced the quality of treatment and represents an important adjunct in the treatment of difficult cases. Since its introduction, US has become increasingly more useful in applications such as gaining access to canal openings, cleaning and shaping, obturation of root canals, removal of intracanal materials and obstructions, and endodontic surgery. This comprehensive review of the literature aims at presenting the numerous uses of US in clinical endodontics and emphasizes the broad applications in a modern-day endodontic practice.
Ultrasonic retrograde preparation
2002, Oral and Maxillofacial Surgery Clinics of North America
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^*: This study was supported in part by a grant (NSC84-2732-B-002-012) from the National Science Council of Taiwan, Republic of China.

¹: Dr. Lin is chairman and associate professor, Department of Endodontics, School of Dentistry, College of Medicine, National Taiwan University, Taiwan, Republic of China.

²: Dr. Chou is a graduate student, Department of Endodontics, School of Dentistry, College of Medicine, National Taiwan University, Taiwan, Republic of China.

⁴: Dr. Kuo is affiliated with the Department of Family Dentistry, National Taiwan University Hospital, Taiwan, Republic of China.

³: Dr. Lan is associate dean and professor, Department of Endodontics, School of Dentistry, College of Medicine, National Taiwan University, Taiwan, Republic of China.

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The quality of ultrasonic root-end preparation: A quantitative study*

J Endodon

Dent Clin North Am

Oral Surg Oral Med Oral Pathol

J Endodon

J Endodon