Three-Armed Trials Including Placebo and No-Treatment Groups May Be Subject to Publication Bias: Systematic Review

Background: It has been argued that placebos may not have important clinical impacts in general. However, there is increasing evidence of a publication bias among trials published in journals. Therefore, we explored the potential for publication bias in randomized trials with active treatment, placebo, and no-treatment groups. Methods: Three-armed randomized trials of acupuncture, acupoint stimulation, and transcutaneous electrical stimulation were obtained from electronic databases. Effect sizes between treatment and placebo groups were calculated for treatment effect, and effect sizes between placebo and no-treatment groups were calculated for placebo effect. All data were then analyzed for publication bias. Results: For the treatment effect, small trials with fewer than 100 patients per arm showed more benefits than large trials with at least 100 patients per arm in acupuncture and acupoint stimulation. For the placebo effect, no differences were found between large and small trials. Further analyses showed that the treatment effect in acupuncture and acupoint stimulation may be subject to publication bias because study design and any known factors of heterogeneity were not associated with the small study effects. In the simulation, the magnitude of the placebo effect was smaller than that calculated after considering publication bias. Conclusions: Randomized three-armed trials, which are necessary for estimating the placebo effect, may be subject t

Cross-contamination and infection control in intraoral digital imaging: a comprehensive review

Dental health care workers are subjected to various infectious disease agents that are present in patients' saliva and blood which make infection control and universal prevention methods indispensable to the dental practice given that some of these diseases cause loss of work and time for dental staff and patients; some of them cause serious morbidity; and some of them currently have a poor prognosis and no effective treatments. Although dental radiographic procedures are not invasive, and there are no incidents such as injuries caused by dental instruments, they are a potential infection source because of contamination with saliva and blood, and comprehensive infection control procedures also apply to the radiology clinic. In addition, contact with a large number of patients in dental schools and clinics in a short period of time, and the fact that radiographic procedures are performed in the same environment as other dental procedures in dental offices increase the significance of infection control in dental radiology. Major advances in computer technology have enabled digital imaging systems to develop rapidly and to become common in dental practice as an alternative to conventional film-based imaging. The use of digital sensors in dental radiology introduced unique infection control challenges and required the revision and modification of existing infection control techniques. In this review, studies concerning the risk of cross-contamination and challenges of infection control with digital image sensors are comprehensively reviewed and infection control protocols that should be followed in intraoral digital imaging using both direct and indirect systems are thoroughly examined

Assessment of the periapical health of abutment teeth: A retrospective radiological study

Aim: The aim was to examine the technical quality of root fillings and periapical status of root-filled and nonroot-filled teeth restored with crowns and bridge retainers through a retrospective analysis of orthopantomographs (OPTGs) in an adult Turkish subpopulation. Materials and Methods: In this study, the digital OPTGs of adult patients between the ages of 20 and 70 who appealed to the Endodontics Endodontics Department of the Dentistry Faculty at Marmara University (Istanbul, Turkey) for the first time to have their endodontic treatment needs met were used. The periapical health of all teeth restored with crowns and bridge retainers, and the technical quality of the root fillings on abutment teeth were evaluated by radiographic criteria. Results: The survey was carried out using the OPTGs of 1000 adult patients composed of 590 (59.0%) women and 410 (41.0%) men. 4656 (20.9%) of the totally examined 22280 teeth were with crowns and bridge retainers. 986 of the total abutment teeth were root-filled and 458 (46.5%) of them had apical periodontitis (AP) while 3670 of the total abutment teeth were nonroot-filled and 930 (25.3%) of them were with AP. The most commonly treated teeth were premolars (33.8%), followed by molars (26.2%), incisors (23.3%) and canines (16.7%). Technical quality was proved to be adequate in 27.5% of the root fillings. A higher frequency of AP was related to inadequate root fillings (P < 0.01). Conclusion: The frequency of root-filled abutment teeth with AP, nonroot-filled abutment teeth with AP, and technically inadequate root-fillings among teeth with crowns and bridge retainers was high in the selected adult population

Talon cusp on a maxillary central incisor: a case report with clinical and radiological findings, and management

Dens evaginatus (DE) is a developmental dental anomaly and is defined as a tubercle-like structure that may contain pulp tissue as well as enamel and dentin. Although it is usually associated with premolars, it is also seen in incisors (talon cusp). This anomaly, which is more common among Asians, may affect both genders and may be observed unilaterally or bilaterally. Clinically, it may cause complications such as caries, malocclusion, occlusal trauma, and pulp necrosis. Radiologically, the V-shaped radiopaque structure superimposed over the affected crown may mimic the appearance of a mesiodens, compound odontoma, or supernumerary tooth. Clinical and radiological examination of a 16-year-old male patient who admitted to our clinic with aesthetic concerns and treatment of decayed teeth was performed. In the intra-oral examination, a conical accessory cusp was noted on the lingual surface of the left maxillary central incisor. A typical V-shaped radiopaque structure superimposed on the affected crown was observed on the periapical radiograph taken from the relevant area. Cone beam computed tomography (CBCT) imaging was used to evaluate the restorative treatment options by examining the pulp extension in the relevant tubercle. The patient was referred to the Department of Restorative Dentistry for restoration of the retentive areas and caries. DE, which is a rare anomaly, should be evaluated together with clinical and radiological findings. Consideration of genetic transmission is quite important for early diagnosis. CBCT imaging will provide significant advantage to the clinician in preventive and minimally invasive applications.Dens evaginatus (DE) gelişimsel bir dental anomali olup, mine ve dentin dokusunun yanı sıra pulpa dokusunu da içerebilen tüberkül benzeri yapı olarak tanımlanmaktadır. Genellikle premolar dişlerle ilişkilendirilmekle birlikte, kesici dişlerde de görülmektedir (talon tüberkülü). Asya kökenlilerde daha sık rastlanan bu anomali, her iki cinsiyeti de etkileyebilmekte ve unilateral veya bilateral olarak izlenebilmektedir. Klinik olarak; çürük, maloklüzyon, oklüzal travma ve pulpa nekrozu gibi komplikasyonlara sebep olabilir. Radyolojik olarak, etkilenen kuron üzerine süperpoze olan “V” şeklindeki radyo-opak yapı mesiodens, kompound odontoma veya sürnumerer diş görüntüsünü taklit edebilir. Estetik kaygılar ve çürük dişlerinin tedavisi için kliniğimize başvuran 16 yaşındaki erkek hastanın klinik ve radyolojik muayenesi gerçekleştirilmiştir. İntra-oral muayenede, sol maksiller santral kesici dişin lingual yüzeyinde konik şekilli aksesuar tüberkül saptanmıştır. İlgili bölgeden alınan periapikal radyografide, etkilenen kuron üzerine süperpoze olmuş tipik “V” şekilli radyo-opak yapı izlenmiştir. İlgili tüberküldeki pulpa uzantısının incelenmesi ve restoratif tedavilerin bu doğrultuda şekillendirilmesi için konik ışınlı bilgisayarlı tomografi (KIBT) görüntülemeye başvurulmuştur. Hasta, retantif alanların ve çürüklerin restorasyonu için Restoratif Diş Tedavisi Anabilim Dalı’na sevk edilmiştir. Nadir rastlanan bir anomali olan DE, klinik ve radyolojik bulgularla birlikte değerlendirilmelidir. Genetik aktarımın göz önünde bulundurulması erken tanı açısından oldukça önemlidir. Koruyucu/önleyici ve minimal invaziv uygulamaların KIBT görüntüleme ile desteklenmesi klinisyene önemli avantaj sağlayacaktı

Are Bismuth Shields Useful in Dentomaxillofacial Radiology Practice for the Protection of Eyes and Thyroid Glands from Ionizing Radiation?

Background: The eye lens and thyroid gland are sensitive to radiation and have a risk of being exposed to primary beams and scattered radiation during dental radiographic examinations. Objectives: The present study was aimed to evaluate the effectiveness of bismuth shielding in decreasing eye lens and thyroid radiation dose in periapical radiography (PR), orthopantomography (OPTG), and cone beam computed tomography (CBCT) examinations. There is no information in relevant literature regarding the use of bismuth shielding in dental radiology. Materials and Methods: Dose measurements for PR, OPTG and CBCT were conducted by placing thermoluminescent dosimeter chips on the eye and thyroid location in a standard head phantom. Each one of the scan techniques was performed without any bismuth shielding, and they were then repeated with bismuth shielding in place. The percent dose reduction from bismuth shielding was calculated by dividing the dose measured with bismuth shielding by the dose measured without bismuth shielding. Results: The eye dose was observed to decrease in bismuth shielding group in PR, however it was not statistically significant. The thyroid dose was found to be significantly decreased in PR (P 0.05). Conclusion: This study demonstrated higher thyroid and eye lens dose with the use of bismuth shielding in OPTG and CBCT scanning. However, due to the significantly decreased thyroid dose in PR, it may be recommended as an alternative to leaded shielding in periapical radiographic examinations

Evaluation of cone beam computed tomography referral profile: Retrospective study in a Turkish paediatric subpopulation

Aim Increasing use of cone beam computed tomography (CBCT) for dentomaxillofacial diagnosis raises concerns about radiation dose which is known to be higher compared to conventional dental imaging methods. This retrospective study investigated the CBCT referrals in a Turkish paediatric subpopulation in terms of referring department, field of view (FOV), and findings. Materials and methods A total of 8,880 CBCT images were reviewed retrospectively and images of paediatric patients (<= 14 years old) were selected. In paediatric patients; data related to patient age and gender, referring department, FOV, region of interest for localised applications, and reason for CBCT referral were recorded. FOVs of CBCT scans were classified as face, jaws (maxilla and mandible), maxilla, mandible, and tooth. CBCT indications were categorised based upon an adaptation of the European DIMITRA (dentomaxillofacial paediatric imaging: an investigation towards low-dose radiation induced risks) multicenter and multidisciplinary project recommendations as impacted teeth, trauma, orofacial clefts, dental anomalies, bone pathology, syndromes, and other. Patients undergoing consecutive CBCT examinations for follow-up were also recorded. In order to record the incidental findings noticed in the CBCT evaluation, the radiological report prepared by the radiologist was used. The results were analysed statistically with a significance level set at p<0.05. Results Four hundred forty-nine of the 8880 CBCT scans were taken from paediatric patients under the age of 14, representing approximately 5% of all scans. Most of the referrals were from Department of Paediatric Dentistry (36.3%), followed by Department of Orthodontics (25.6%). The most frequently imaged region was the maxilla (33.4%), followed by the face (20.5%). The most common region of interest for localised applications was the maxillary canine/incisor region (85.55%). The most common indication was impacted teeth (41.4%) followed by bone pathology (31%) and dental anomalies (29.6%); 11.6% of the patients underwent follow-up CBCT examinations especially for orofacial clefts and syndromes. Conclusions This retrospective study investigating CBCT indications in a Turkish paediatric subpopulation and comparing existing applications with DIMITRA project recommendations can guide dental professionals in referring paediatric patients for CBCT

The effect of zirconia thickness on the biaxial flexural strength of zirconia-ceramic bilayered discs

The aim of this study was to assess the effect of zirconia core thickness on the biaxial flexural strength values of zirconia-porcelain bilayered discs. A total of 60 discs with 0.3, 0.4, and 0.5 mm thickness were obtained from a fully sintered zirconia block. A 1.5-mm thick layer of veneer porcelain was fired on the zirconia specimens and biaxial flexural strength tests were performed on the bilayered discs. In each group, the loading surface was the veneer porcelain in half of the specimens (core in tension) and the zirconia core surface in the other half (core in compression). The zirconia core thickness had no effect on the biaxial flexural strength of zirconia-porcelain bilayered discs when the core was in tension (p>0.05). Whereas, when the core was in compression, an increase in the zirconia core thickness resulted in an increase in the biaxial flexural strength (p<0.05)