Comparison of the Accuracy and Efficiency of a 3-Dimensional Dynamic Navigation System for Osteotomy and Root-end Resection Performed by Novice and Experienced Endodontists.

INTRODUCTION: The aim of the study is to investigate whether the 3-dimensional dynamic navigation system (3D-DNS) can improve experienced endodontists' (EEs') and novice endodontists' (NEs') accuracy and efficiency in osteotomy and root-end resection (RER) and to verify that the 3D-DNS enables NEs to perform osteotomy and RER as accurately and efficiently as EEs. METHODS: Seventy-six roots in cadaver heads were randomly divided into 4 groups: 3D-DNS-NE, 3D-DNS-EE, freehanded (FH)-NE, and FH-EE (all, n = 19). Cone-beam computed tomography scans were taken preoperatively and postoperatively. Osteotomy and RER were planned virtually in the X-guided software (X-Nav Technologies, Lansdale). Accuracy was calculated by measuring the 2-dimensional and 3D virtual deviations and angular deflection using superimposing software (X-Nav technologies). Efficiency was determined by the time of operation and the number of mishaps. RESULTS: Accuracy deviations were significantly fewer in the 3D-DNS-EE group than those in the FH-EE group (P < .05). We found less 2-dimensional and 3D accuracy deviations comparing the 3D-DNS-NE group to the FH-NE group (P < .05). The time required for osteotomy and RER with the 3D-DNS was ∼ ½ of that required for the FH method for both EEs and NEs (P < .05). We found no difference in the number of mishaps between the 3D-DNS and FH groups for EEs and NEs (P > .05). CONCLUSIONS: The 3D-DNS improved EEs' and NEs' accuracy and efficiency in osteotomy and RER. The NEs were as efficient as the EEs using the 3D-DNS. Notably, the 3D-DNS improved the NEs' accuracy compared to the FH method, but the 3D-DNS did not enable the NEs to perform osteotomy and RER as accurately as the EEs.

Real-time 3-dimensional Dynamic Navigation System in Endodontic Microsurgery: A Cadaver Study.

INTRODUCTION: This study evaluated the accuracy and efficiency of the 3-dimensional dynamic navigation system (3D-DNS) to perform minimally invasive osteotomy (MIO) and root end resection (RER) in endodontic microsurgery (EMS) and investigated the viability of root end cavity preparation (RECP) and root end fill (REF) in MIO. METHODS: Forty-eight tooth roots were divided in cadaver heads into 2 groups: 3D-DNS (n = 24) and freehand (n = 24). Cone-beam computed tomographic scans were taken before and after surgery. First, virtual 3D-DNS accuracy was verified using 3 outcome measures: 2-dimensional and 3-dimensional virtual deviations and angular deflection. Second, the accuracy of 3D-DNS for performing MIO was investigated in 2 outcome measures: osteotomy size and volume. Third, the 3D-DNS accuracy was determined for RER in 3 outcomes: resected root length, root length after resection, and resection angle. The viability of RECP and REF was investigated and REF depth and volume measured as well, and procedural time and the number of mishaps were recorded. RESULTS: Two- and 3-dimensional virtual deviations and the angular deflection were lower in the 3D-DNS group than the freehand group (P < .05). Osteotomy height, length, and volume were all reduced when using 3D-DNS (P < .05). The resection angle was lower for 3D-DNS (P < .05). RECP and REF were completed in 100% of the roots. The REF depth achieved was ∼3 mm. Osteotomy time, RER time, and the total procedure time were all significantly shortened using 3D-DNS (P < .05). CONCLUSIONS: 3D-DNS enabled our surgeon to perform accurate and efficient EMS with minimally invasive osteotomy and RER. The surgeon was also able to conduct RECP with adequate REF in minimally invasive osteotomy performed using 3D-DNS guidance.

Accuracy and Efficiency of 3-dimensional Dynamic Navigation System for Removal of Fiber Post from Root Canal-Treated Teeth.

INTRODUCTION: The purpose of this study was to investigate the accuracy and efficiency of the 3-dimensional dynamic navigation system (DNS) compared with the freehand technique (FH) when removing fiber posts from root canal-treated teeth. METHODS: Twenty-six maxillary teeth were included. Teeth were root canal treated and restored with Parapost Taper Lux (Coltene/Whaledent, Altstätten, Switzerland) luted with RelyX Unicem (3M ESPE, St Paul, MN). A core buildup was then performed using Paracore (Coltene/Whaledent). Teeth were mounted in tissue-denuded cadaver maxillae. Teeth were divided into 2 groups: the DNS group (n = 13) and the FH group (n = 13). Cone-beam computed tomographic scans were taken pre- and postoperatively. The drilling path and depth were planned virtually using X-guide software (X-Nav Technologies, Lansdale, PA) in both groups. For the DNS group, drilling was guided with X-Nav software and the FH group under a dental operating microscope. Global coronal and apical deviations, angular deflection, operation time, and the number of mishaps were compared between the groups to determine the accuracy and efficiency. The 3-dimensional volume (mm3) of all teeth was calculated before and after post removal using the Mimics Innovation Suite (Materialise NV, Leuven, Belgium). The Shapiro-Wilk, 1-way analysis of variance, and Fisher exact tests were used (P < .05). RESULTS: The DNS group showed significantly less global coronal and apical deviations and angular deflection than the FH group (P < .05). DNS required less operation time than FH. Moreover, the DNS technique had significantly less volumetric loss of tooth structure than the FH technique (P < .05). CONCLUSIONS: The DNS was more accurate and efficient in removing fiber posts from root canal-treated teeth than the FH technique.

What every dentist needs to know about electronic cigarettes.

Electronic cigarette (EC) use is on a steady rise, leading to increased concerns about its efficacy with regard to tobacco cessation goals and safety with regard to systemic and oral health. Recent studies have shown that EC flavoring agents can have adverse effects similar to those of combustible tobacco products. Evidence is mounting that EC use should not be considered a healthier alternative to tobacco smoking. The aerosols produced by ECs have been associated with respiratory, cardiac, and central nervous system disease as well as oral mucosal alterations. In addition, ECs can affect kidney and liver function. Their use has also resulted in EC explosions and burn injuries, some of which have been fatal. The aim of this article is to review the systemic and oral health concerns associated with EC use.

Guided Endodontic Access in a Maxillary Molar Using a Dynamic Navigation System.

The treatment of calcified root canals is challenging in endodontic practice. A 63-year-old man was referred to the postgraduate endodontic clinic at the University of Maryland School of Dentistry, Baltimore, MD, for the treatment of tooth #3. Because of the patient's history of head and neck radiation and the high risk of developing osteoradionecrosis, a nonsurgical endodontic approach was found to be the most reasonable treatment option despite the questionable prognosis of the tooth. During the endodontic treatment, the distobuccal canal appeared to be partially calcified and was not possible to be located freehand even with use of the dental operating microscope and cone-beam computed tomographic approximated approach. Therefore, the dynamic navigation system using the X-Guide system (X-Nav technologies, LLC, Lansdale, PA) was used, which allowed for the successful location of the canal. Conventional endodontic treatment was completed following standardized instrumentation, irrigation, and obturation. Details on how to use the dynamic navigation system are described including its advantages, disadvantages, and limitations.

Accuracy and Efficiency of a Dynamic Navigation System for Locating Calcified Canals.

INTRODUCTION: Calcified canals present a challenge during endodontic treatments. The purpose of this study was to compare the accuracy and efficiency of a dynamic navigation system (DNS) to the freehand (FH) method for locating calcified canals in human teeth. METHODS: Sixty human single-rooted teeth with canal obliteration were selected and mounted in dry cadaver jaws. Based on cone-beam computed tomographic scans of the jaws, the drilling path and depth were virtually planned to use X-Guide software (X-Nav Technologies, LLC, Lansdale, PA). Access preparation was made with navigation in the DNS group and without guidance in the FH group by 2 operators with different levels of experience. Postoperative cone-beam computed tomographic scans were taken of all teeth. Linear and angular deviations and reduced dentin thickness at 2 levels were measured. The time for locating the canal, the number of mishaps, and the unsuccessful attempts were determined and analyzed. RESULTS: The mean linear and angular deviations, reduced dentin thickness (at both levels), the time for access cavity preparation, and the number of mishaps in the DNS group were significantly less than the FH group (P ≤ .05). The unsuccessful attempts were not different between the 2 groups (P > .05). The time for access preparation was significantly shorter for the board-certified endodontist in the FH group (P ≤ .05). CONCLUSIONS: The DNS was more accurate and more efficient than the FH technique in locating calcified canals in human teeth. This novel DNS can help clinicians avoid catastrophic mishaps during access preparation in calcified teeth.

Central xanthoma of the mandible associated with hyperlipidemia: A rare presentation.

Xanthoma is a common, self-limiting cutaneous lesion of non-Langerhans cell, lipid-laden foamy histiocytes that is often concomitant with hyperlipidemia. The intraosseous counterpart is rarely encountered and typically presents as a painless, expansile osteolytic process in the context of hyperlipidemia or normolipidemia. Only a scant number of gnathic xanthomas have been reported in the otolaryngologic literature. We report the clinical, laboratory, radiographic, histopathologic, immunohistochemical, and ultrastructural studies of a mandibular lesion discovered in an asymptomatic 16-year-old male, and associated with 2 previously unreported comorbidities, namely hyperlipidemia and vitamin D deficiency.

Large Cell Transformation of Oral Mycosis Fungoides.

Mycosis fungoides (MF) accounts for approximately 50% of all primary cutaneous lymphomas. MF occurrence in the oral cavity is extremely rare with approximately 45 cases reported to date. We present a case of a 68 year-old man with a raised nodular lesion of the ventral tongue with clinical impression of irritational fibroma. Histopathologic and immunohistochemical (IHC) examination revealed a phenotype consistent with MF with large cell transformation in the context of Sezary syndrome. The histological diagnosis of oral MF requires a high index of suspicion and IHC panel to rule out large cell transformation. To our knowledge, only four cases of large cell transformation of oral MF have been reported in the English literature. The clinical and histopathologic features of a rare case of intra-oral MF with large cell transformation are exemplified in this article.