Use of Cone Beam Computed Tomography in Endodontics

Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imaging adjunct for endodontics

Određivanje dužine korijenskog kanala: procjena CDR® intraoralnog radiografskog sustava in vivo

The Computed Dental Radiolography System® (CDR: Schick Technologies, Long Island City, NY) is a CCD-based digital intraoral radiographic device which possesses a measurement software algorithm that can be adjusted with respect to an object of known dimension. This “calibration ” algorithm was compared to the CDR® preset mode and analog film using 30 root canals in vivo. The three measurement methods differed significantly from each other for 40% o f the canals sampled. Two o f the three differed significantly for 50% o f canals. No difference existed between the methods for 10% o f the canals. Estimates of tooth length using the calibrated mode differed from those obtained using a conventional radiographic technique by an average o f 1.2 mm, while those using the calibrated mode differed by 1.9 mm. The 1.2 mm average for the calibrated CDR® was judged to be an acceptable degree o f clinical error for most root canal procedures and indicates that the calibration function of the CDR® system should be used when measuring endodontic working lengths. The results demonstrated that calibration to a 15 mm probe when using the Schick CDR® system is more consistent with a comparable measurement, if film is used as the “gold standard”, than are measurements of the tooth length using the CDR® without calibration.Sustav "Kompjuterizirane dentalne radiografije" (CDR: Schick Technologies. Long Island City. NY) je na CDD-u zasnovan uređaj za digitalnu intraoralnu radio grafiju koji posjeduje "Software-ski algoritam" za mjerenja koji se može prilagoditi prema objektu poznate veličine. Ovaj "kalibracijski" algoritam uspoređen je sa sustavom CDR (kompjutorizirane dentalne radiografije) bez mjernog algoritma i analognim filmom rabeći 30 korijenskih kanala in vivo. Tri postupka mjerenja značajno su se razlikovali u 40% mjerenih korijenskih kanala. Dva od tri postupka razlikovala su se u 50% mjerenih kanala. Nikakve razlike između postupaka nije bilo u 10% mjerenih korijenskih kanala. Procjena duljine zuba korištenjem kalibriranog načina razlikovala se od procjene dobivene konvencionalnom (analognom) radio grafskom tehnikom za otprilike 1,2 mm, dok se od digitalnog sustava bez mjernog algoritma razlikovala za prosječno 1,9 mm. Razlika od 1,2 mm za "kalibrirani CDR" se procjenjuje kao prihvatljiva klinička greška za većinu endodontskih postupaka i ukazuje da bi se "kalibracijski sustav CDRa" trebao rabiti pri mjerenju radne duljine korijenskog kanala. Rezultati ukazuju da je kalibracija sonde do 15 mm kad se rabi Schch-ov CDR sustav postojanija s usporednim mjerenjem ako se film koji se mjeri uzme kao "zlatni standard", nego je mjerenje duljine CDR sustavom bez kalibracije

Određivanje dužine korijenskog kanala: procjena CDR® intraoralnog radiografskog sustava in vivo

The Computed Dental Radiolography System® (CDR: Schick Technologies, Long Island City, NY) is a CCD-based digital intraoral radiographic device which possesses a measurement software algorithm that can be adjusted with respect to an object of known dimension. This “calibration ” algorithm was compared to the CDR® preset mode and analog film using 30 root canals in vivo. The three measurement methods differed significantly from each other for 40% o f the canals sampled. Two o f the three differed significantly for 50% o f canals. No difference existed between the methods for 10% o f the canals. Estimates of tooth length using the calibrated mode differed from those obtained using a conventional radiographic technique by an average o f 1.2 mm, while those using the calibrated mode differed by 1.9 mm. The 1.2 mm average for the calibrated CDR® was judged to be an acceptable degree o f clinical error for most root canal procedures and indicates that the calibration function of the CDR® system should be used when measuring endodontic working lengths. The results demonstrated that calibration to a 15 mm probe when using the Schick CDR® system is more consistent with a comparable measurement, if film is used as the “gold standard”, than are measurements of the tooth length using the CDR® without calibration.Sustav "Kompjuterizirane dentalne radiografije" (CDR: Schick Technologies. Long Island City. NY) je na CDD-u zasnovan uređaj za digitalnu intraoralnu radio grafiju koji posjeduje "Software-ski algoritam" za mjerenja koji se može prilagoditi prema objektu poznate veličine. Ovaj "kalibracijski" algoritam uspoređen je sa sustavom CDR (kompjutorizirane dentalne radiografije) bez mjernog algoritma i analognim filmom rabeći 30 korijenskih kanala in vivo. Tri postupka mjerenja značajno su se razlikovali u 40% mjerenih korijenskih kanala. Dva od tri postupka razlikovala su se u 50% mjerenih kanala. Nikakve razlike između postupaka nije bilo u 10% mjerenih korijenskih kanala. Procjena duljine zuba korištenjem kalibriranog načina razlikovala se od procjene dobivene konvencionalnom (analognom) radio grafskom tehnikom za otprilike 1,2 mm, dok se od digitalnog sustava bez mjernog algoritma razlikovala za prosječno 1,9 mm. Razlika od 1,2 mm za "kalibrirani CDR" se procjenjuje kao prihvatljiva klinička greška za većinu endodontskih postupaka i ukazuje da bi se "kalibracijski sustav CDRa" trebao rabiti pri mjerenju radne duljine korijenskog kanala. Rezultati ukazuju da je kalibracija sonde do 15 mm kad se rabi Schch-ov CDR sustav postojanija s usporednim mjerenjem ako se film koji se mjeri uzme kao "zlatni standard", nego je mjerenje duljine CDR sustavom bez kalibracije

In vivo Accuracy of CCD-based Radiography for the Estimation of Periapical Lesion Dimensions

Ciljevi: Ova je klinička studija provedena da bi se usporedile točnosti procjena stomatologa o dimenzijama periapikalnih prosvjetljenja temeljenih na primjeni elektroničkoga slikanja uporabom sustava za intraoralnu radiografiju tipa RVG® 32000, te filma tipa Ektaspeed. Metode: Držeći se dozvole Nadzornoga tijela Institucije i informacija o uvjetima, napravljene su bile predoperacijske slike periapikalnih oštećenja 12 redom pridošlih pacijenata kojima je bio potreban kirurški zahvat. Slike su napravljene na oba načina: sustavom RVG® 32000, i filmom Ektaspeed. Stvarna veličina oštećenja bila je ustanovljena izradom otisaka od koštanoga voska tipa Ethicon®, tijekom same operacije. Skupina od pet stomatologa postigla je konsenzus u procjeni superiornih - inferiornih i mezio-distalnih dimenzija periapikalnih prosvjetljenja ustanovljenih iz predoperacijskih slika, odvojeno i neovisno za dva modaliteta. Rezultati: Procjene dimenzija oštećenja izrađene sustavom RVG® 32000 i filmom Ektaspeed znatno su se među se razlikovale. Odstupanje od stvarnih izmjerenih vrijednosti bilo je znatno veće za procjene temeljene na filmskim radio grafijama od odstupanja procjena na temelju slika sustava RVG® 32000. Općenito uzevši, dimenzije oštećenja bile su na osnovi filmskih slika precijenjene, a malo podcijenjene na osnovi slika snimljenih sustavom RVG® 32000. Zaključci: Digitalno intraoralno slikanje sustavom RVG® 32000 daje moguće prednosti pred konvencionalnom radiografijom time što stomatolozima omogućuje u prosjeku točnije procjene veličina periapikalnih prosvjetljenja.Objectives: This clinical study was performed to compare the accuracy of endodontists ’ assessment o f the sizes o f periapical radiolucencies using electronic imaging with the RVG® 32000 intraoral radiographic system and Ektaspeed film. Methods: Following Institutions Review Board approval and informed consent, presurgical images were made both with the RVG® 32000 and Ektaspeed film for periapical lesions in 12 consecutive patients requiring endodontic surgery. Actual lesion size was determined by making impressions with Ethicon® bone wax at the time of surgery. A panel o f five endodontists reached consensus in estimation of the superior- inferior and mesio-distal dimensions of the periapical radiolucencies from the presurgical images, separately and independently for two modalities. Results: Lesion dimension estimates were significantly different between images made with the RVG® 32000 Ektaspeed film. There was a much greater deviation from the measured actual values for estimates using film radiographs than for those for the RVG® 32000 images. Generally, there was an over-estimation o f lesion size with film, and a slight under-estimation with RVG® 32000 images. Conclusions: Digital intraoral imaging with the RVG® 32000 offers potential advantages over conventional radiography in permitting endodontists on average to more accurately estimate the size of periapical radiolucencies

hENT1 Predicts Benefit from Gemcitabine in Pancreatic Cancer but Only with Low CDA mRNA

SIMPLE SUMMARY: Recent clinical trials suggest that combination therapies that include either gemcitabine or 5-fluorouracil (5-FU) both give significant survival benefits for pancreatic cancer patients. The tumor level of the nucleoside transporter hENT1 is prognostic in patients treated with adjuvant gemcitabine but not adjuvant 5-FU. This work shows for the first time that hENT1 is only predictive of benefit from gemcitabine over 5-FU in patients with low levels of CDA transcript. A choice between adjuvant 5-FU based combination therapies (such as FOLFIRINOX) and gemcitabine-based therapy (e.g., GemCap) could be made based on a combination of hENT1 protein and CDA mRNA measured in a resected tumor. ABSTRACT: Gemcitabine or 5-fluorouracil (5-FU) based treatments can be selected for pancreatic cancer. Equilibrative nucleoside transporter 1 (hENT1) predicts adjuvant gemcitabine treatment benefit over 5-FU. Cytidine deaminase (CDA), inside or outside of the cancer cell, will deaminate gemcitabine, altering transporter affinity. ESPAC-3(v2) was a pancreatic cancer trial comparing adjuvant gemcitabine and 5-FU. Tissue microarray sections underwent in situ hybridization and immunohistochemistry. Analysis of both CDA and hENT1 was possible with 277 patients. The transcript did not correlate with protein levels for either marker. High hENT1 protein was prognostic with gemcitabine; median overall survival was 26.0 v 16.8 months (p = 0.006). Low CDA transcript was prognostic regardless of arm; 24.8 v 21.2 months with gemcitabine (p = 0.02) and 26.4 v 14.6 months with 5-FU (p = 0.02). Patients with low hENT1 protein did better with 5-FU, but only if the CDA transcript was low (median survival of 5-FU v gemcitabine; 29.3 v 18.3 months, compared with 14.2 v 14.6 with high CDA). CDA mRNA is an independent prognostic biomarker. When added to hENT1 protein status, it may also provide treatment-specific predictive information and, within the frame of a personalized treatment strategy, guide to either gemcitabine or 5FU for the individual patient

Radiation Dose, Risks, and Protection in CBCT

status: publishe

Dental Implants

status: publishe

Límites anatómicos del maxilar inferior

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Cone beam computed tomography in implant dentistry: a systematic review focusing on guidelines, indications, and radiation dose risks.

PURPOSE The aim of the paper is to identify, review, analyze, and summarize available evidence in three areas on the use of cross-sectional imaging, specifically maxillofacial cone beam computed tomography (CBCT) in pre- and postoperative dental implant therapy: (1) Available clinical use guidelines, (2) indications and contraindications for use, and (3) assessment of associated radiation dose risk. MATERIALS AND METHODS Three focused questions were developed to address the aims. A systematic literature review was performed using a PICO-based search strategy based on MeSH key words specific to each focused question of English-language publications indexed in the MEDLINE database retrospectively from October 31, 2012. These results were supplemented by a hand search and gray literature search. RESULTS Twelve publications were identified providing guidelines for the use of cross-sectional radiography, particularly CBCT imaging, for the pre- and/or postoperative assessment of potential dental implant sites. The publications discovered by the PICO strategy (43 articles), hand (12), and gray literature searches (1) for the second focus question regarding indications and contraindications for CBCT use in implant dentistry were either cohort or case-controlled studies. For the third question on the assessment of associated radiation dose risk, a total of 22 articles were included. Publication characteristics and themes were summarized in tabular format. CONCLUSIONS The reported indications for CBCT use in implant dentistry vary from preoperative analysis regarding specific anatomic considerations, site development using grafts, and computer-assisted treatment planning to postoperative evaluation focusing on complications due to damage of neurovascular structures. Effective doses for different CBCT devices exhibit a wide range with the lowest dose being almost 100 times less than the highest dose. Significant dose reduction can be achieved by adjusting operating parameters, including exposure factors and reducing the field of view (FOV) to the actual region of interest