Use of the metal artefact reduction tool in the identification of fractured endodontic instruments in cone-beam computed tomography.

AIM: To evaluate the influence of the metal artefact reduction (MAR) tool in the diagnosis of fractured instruments in root canals of extracted mandibular molars, with or without root canal fillings. METHODOLOGY: The root canals of 31 mandibular molars were divided into four groups: (i) the control group, without root fillings; (ii) the fracture group, without fillings and with fractured files; (iii) the fill group, with root filling; and (iv) the fill/fracture group, root filled and with fractured files. The following instruments were used as fractured endodontic instruments: stainless steel hand files, NiTi reciprocating files and NiTi rotary files. Each tooth was inserted in a dry mandible to obtain cone-beam computed tomography (CBCT) images using a CBCT OP300 3D Maxio (Instrumentarium Dental, Tuusula, Finland) and Picasso Trio (Vatech, Hwaseong, Republic of Korea), with and without application of the MAR tool. All images were evaluated by three radiologists for the presence or absence of fractured files on a 5-point scale. The diagnostic accuracy (area under ROC curve) was calculated. Image noise was measured in regions of trabecular and cortical bone and soft tissue. The comparison between the ROC curve values with the MAR tool enabled or disabled was performed using a t-test. A t-test was also employed for comparing image noise when the MAR tool was enabled and disabled. The significance level was set at 5%. RESULTS: The use of the MAR tool did not influence the diagnostic accuracy for identifying fractured endodontic instruments in root canals with and without fillings in both CBCT systems (P > 0.05), nor did it influence the image noise (P > 0.05). CONCLUSIONS: The MAR tool on these two devices did not increase the detection of fractured endodontic instruments and did not reduce image noise using extracted mandibular molars. Therefore, the MAR tool is not recommended for evaluation of fractured endodontic instruments in teeth with and without root fillings in mandibular molars.

The clinical outcome of skeletal anchorage in interceptive treatment (in growing patients) for class III malocclusion.

A systematic review of the literature was performed regarding the clinical outcome (effectiveness) of bone anchorage devices in interceptive treatment for class III malocclusion. A search of Embase, PubMed and Web of Science databases yielded 285 papers. An additional two articles were retrieved through manual searching of the reference lists. After initial abstract selection, 32 potentially eligible articles were screened in detail, resulting in a final number of eight articles included in this review. Insufficient evidence was found regarding the effects of skeletal anchorage in interceptive class III treatment to support definitive conclusions on long-term skeletal effects and stability. In the short term, it seems that bone anchors can provide more skeletal effect with less dentoalveolar compensations and less unwanted vertical changes. This does not always exclude the use of a face mask. The use of miniscrews as skeletal anchorage device does not seem to provide more skeletal effect, although it could minimize the unwanted dental effects in the upper jaw. No information regarding the need for orthognathic surgery, orthodontic treatment time or patient compliance and complications was found in the selected articles.

Efficacy of lead foil for reducing doses in the head and neck: a simulation study using digital intraoral systems.

OBJECTIVES: To assess the efficacy of lead foils in reducing the radiation dose received by different anatomical sites of the head and neck during periapical intraoral examinations performed with digital systems. METHODS: Images were acquired through four different manners: phosphor plate (PSP; VistaScan(®) system; Dürr Dental GmbH, Bissingen, Germany) alone, PSP plus lead foil, complementary metal oxide semiconductor (CMOS; DIGORA(®) Toto, Soredex(®), Tuusula, Finland) alone and CMOS plus lead foil. Radiation dose was measured after a full-mouth periapical series (14 radiographs) using the long-cone paralleling technique. Lithium fluoride (LiF 100) thermoluminescent dosemeters were placed in an anthropomorphic phantom at points corresponding to the tongue, thyroid, crystalline lenses, parotid glands and maxillary sinuses. RESULTS: Dosemeter readings demonstrated the efficacy of the addition of lead foil in the intraoral digital X-ray systems provided in reducing organ doses in the selected structures, approximately 32% in the PSP system and 59% in the CMOS system. CONCLUSIONS: The use of lead foils associated with digital X-ray sensors is an effective alternative for the protection of different anatomical sites of the head and neck during full-mouth periapical series acquisition.