Radiation dose and protection in dentistry

Associated risks with periodontal x-rays or CBCT scans: Are there any?

Periodontal and implant radiography, mainly including intra-oral peri-apical and cone beam computed tomography images, are crucial in the diagnosis and treatment planning process. However, radiation safety concerns have been a chronic concern over the years, leading to uncomfortable situations. It is therefore crucial to understand the actual radiation exposure to determine if the patients' fear of necessary diagnostic exams is justified. In this perspective article, we aimed to provide concise information on dental imaging exposure, risks, and benefits, comparing them to that of absorbed radiation from daily life activities; and secondarily, to help periodontists choose the best option for each case and become more confident in addressing patients' concerns and providing a summary of safety guidelines as a reference for them.

Efficacy of hydroxyapatite and fibrin sealant as carriers for bone morphogenetic protein-2 in maxillary sinus floor augmentation: a retrospective study

The aim of this retrospective study was to assess the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) with hydroxyapatite (HA) granules and fibrin sealant (FS) in maxillary sinus floor augmentation (MSFA), with a focus on the volume change. Fifty-two of 137 patients who underwent MSFA with rhBMP-2/HA grafting between June 2016 and December 2022 met the study inclusion criteria; 25 had received rhBMP-2/HA without FS and 27 had received rhBMP-2/HA with FS. Computed tomography (CT) images were obtained preoperatively, immediately following the operation, and at 6 months postoperative. These images were three-dimensionally reconstructed to measure the volumetric and height changes following MSFA. The mean ± standard deviation percentage of volumetric change at 6 months was 48.75 ± 37.44% in the group with FS and 29.77 ± 13.42% in the group without FS (P = 0.019). The vertical height measured at a specific site of the grafted area showed a mean percentage change at 6 months of 4.05 ± 12.08% in the group with FS and 6.07 ± 10.15% in the group without FS (P = 0.518). The additional use of FS as a carrier for rhBMP-2/HA in MSFA was found to improve surgical convenience and bone regeneration ability.

Prescription of panoramic radiographs in children using age-based prevalence of dental anomalies and pathologies

BACKGROUND

Panoramic radiographs (PRs) are used in the detection and diagnosis of developmental dental anomalies and pathologies (DDAPs) in children.

AIM

The primary objective of this observational cohort study was to evaluate the age-based prevalence of DDAP on PRs, whereas the secondary objective was to determine a threshold age for the detection of DDAP to provide supportive evidence for the prescription of PR in paediatric dental practice.

DESIGN

The study examined diagnostic PRs from 581 subjects aged 6 to 19 years. All PRs were reviewed by experienced, calibrated, masked examiners for the identification or presence of anomalies in size, shape, position, structure, and other developmental anomalies and pathologies (ODAP) of the face-neck region in a standardized condition. The data were statistically analyzed for interpretation.

RESULTS

Overall, 74% (n = 411) of the cohort had at least one anomaly (shape anomaly: 12%, number anomaly: 17%, positional anomaly: 28%, structural anomaly: 0%, and ODAP: 63%). The optimal Youden index cutoff for any anomaly was 9 years. Twelve and 15 years also showed predictive ability.

CONCLUSION

The results suggest that PRs should be prescribed at ages 9, 12, and 15 years for the diagnosis of DDAP.

Unfavourable beliefs about oral health and safety of dental care during pregnancy: a systematic review

BACKGROUND

Oral conditions such as gingivitis and periodontitis are correlated with adverse pregnancy outcomes such as preeclampsia, preterm birth and low birth weight. Oral health-related unfavourable beliefs can have negative influences on oral health behaviours including hesitation in accessing preventative dental treatments and dental service utilization. The objective of this systematic review was to examine unfavourable beliefs that expectant or new mothers frequently hold about oral health and the safety of dental care during pregnancy.

METHODS

An electronic database search on PubMed, Scopus, CINAHL, and MEDLINE (Ovid) followed by forward and backward citation tracing of the included studies was conducted. All English primary studies regardless of the year of publication were independently screened by two reviewers to identify studies addressing unfavourable beliefs about oral health and dental care during pregnancy. The CLARITY tool was applied to assess the risk of bias in the included studies.

RESULTS

Out of a total of 5766 records, 39 quantitative and six qualitative studies met the inclusion criteria. The commonly held unfavourable beliefs were regarding the safety of dental services utilization and dental treatment procedures, the adverse impacts of pregnancy on oral health, and oral hygiene necessity during pregnancy. The most discussed unfavourable beliefs included "pregnant women lose their teeth because of pregnancy" (n = 18), "dental treatments are not safe and harm the fetus" (n = 17), and "the developing baby absorbs calcium from the mother's teeth" (n = 14).

CONCLUSIONS

Unfavourable beliefs about oral health and dental care utilization are common among pregnant women and new mothers. The literature suggests that a low level of oral health knowledge and seeking information from social networks can contribute to such beliefs. This has implications for health promotion.

Caries-preventing effect of a hydroxyapatite-toothpaste in adults: a 18-month double-blinded randomized clinical trial

Background

Dental caries is a worldwide challenge for public health. The aim of this 18-month double-blinded, randomized, clinical trial was to compare the caries-preventing effect of a fluoride-free, hydroxyapatite toothpaste (test) and a toothpaste with sodium fluoride (1450 ppm fluoride; positive control) in adults.

Methods

The primary endpoint was the percentage of subjects showing no increase in overall Decayed Missing Filled Surfaces (DMFS) index. The study was designed as non-inferiority trial. Non-inferiority was claimed if the upper limit of the exact one-sided 95% confidence interval for the difference of the primary endpoint DMFS between test and control toothpaste was less than the predefined margin of non-inferiority (Δ ≤ 20%).

Results

In total, 189 adults were included in the intention-to-treat (ITT) analysis; 171 subjects finished the study per protocol (PP). According to the PP analysis, no increase in DMFS index was observed in 89.3% of subjects of the hydroxyapatite group and 87.4% of the subjects of the fluoride group. The hydroxyapatite toothpaste was not statistically inferior to a fluoride toothpaste with regard to the primary endpoint.

Conclusion

Hydroxyapatite was proven to be a safe and efficient anticaries agent in oral care.

Clinical trial registration

NCT04756557.

Radiation Exposure and Frequency of Dental, Bitewing and Occlusal Radiographs in Children and Adolescents

Dental radiographs are valuable diagnostic aids for oral healthcare, but exposure to ionizing radiation carries health risks, especially in children due to their high radio-sensitivity. Valid reference values for intraoral radiographs in children and adolescents are still missing. This study aimed to investigate the radiation dose values and underlying justifications of dental, bitewing and occlusal X-rays in children and adolescents. Data from routinely executed intraoral radiographs between 2002 and 2020 with conventional and digital tube-heads were extracted from the Radiology Information System. The effective exposure was calculated from technical parameters and statistical tests performed. A total number of 4455 intraoral (3128 dental, 903 bitewing and 424 occlusal) radiographs were investigated. For dental and bitewing radiographs, the dose area product (DAP) was 2.57 cGy × cm² and the effective dose (ED) 0.77 µSv. For occlusal radiographs, the DAP was 7.43 cGy × cm² and the ED 2.22 µSv. Overall, 70.2% of all intraoral radiographs were dental, 20.3% bitewing and 9.5% occlusal radiographs. The most frequent indication for intraoral radiographs was trauma (28.7%), followed by caries (22.7%) and apical diagnostics (22.7%). Moreover, 59.7% of all intraoral radiographs were taken in boys, especially for trauma (66.5%) and endodontics (67.2%) (p ≤ 0.00). Girls were significantly more frequently X-rayed for caries diagnostics than boys (28.1% vs. 19.1%, p ≤ 0.00). The average ED of 0.77 µSv for intraoral dental and bitewing radiographs in this study was within the range of other reported values. The technical parameters of the X-ray devices were found at the lowest recommended levels to best limit the radiation exposure and to assure acceptable diagnostic efficacy. Intraoral radiographs were performed predominantly for trauma, caries and apical diagnostics-reflecting general recommendations for the use of X-rays in children. For improved quality assurance and radiation protection, further studies are necessary to determine the meaningful dose reference level (DRL) for children.

Fenestration and dehiscence defects in maxillary anterior teeth using two classification systems

BACKGROUND

The primary objective of the study was to assess the buccal bone thickness (BT), evaluate and compare the prevalence of bone fenestration and dehiscence in anterior maxillary teeth using cone-beam computed tomography (CBCT).

METHODS

Images of 300 maxillary anterior teeth were investigated. The BT was measured at the bone crest, 3, 6 and 9 mm from the bone crest, and apical. Fenestration and dehiscence were recorded according to Yang and Pan's classification. Student's t-test and one-way ANOVA were performed for statistical analysis.

RESULTS

Fenestration and dehiscence rates were 35.66% and 20%, respectively. Type III fenestration was higher in group 3 (>65 years) (P = 0.028). Type I and IV fenestration and CII DII dehiscence were more common in canines (P > 0.05). Fenestration involving two-thirds (46.76%) and one-third (44.84%) of the root length was more common. Fenestrations involving the entire root were 8.4%. Most of the dehiscence (63.3%) involved one-third of the root length. Dehiscence involving two-thirds of the root length and the entire root was 5% and 9.95%, respectively. The coexistence of fenestration and dehiscence was 8.3%. Dehiscence on the palatal aspect was detected in 1.65% of the anterior maxilla.

CONCLUSIONS

The rate of BT ≤1 mm was 80.08%, and ≥2 mm was 3.66%. Fenestration was most common in canines. Fenestration was mostly located in the apical third, while dehiscence was mostly located in the coronal third. © 2022 Australian Dental Association.

Evaluation of Radiation Exposure Due to Dental Radiographs Taken during Endodontic Treatment Sessions in Young Permanent Teeth

Background and Objectives: The aim of this study was to retrospectively analyze the duration of treatment and the number of dental radiographs taken during endodontic treatment (endo-t) of young permanent teeth (YPT). Materials and Methods: Age, gender, affected tooth number, apex status, duration of treatment and dental radiographs taken during this period were retrospectively evaluated in pediatric patients aged 6−15 years who presented to the pedodontic department for endo-t of anterior YPT. Data were analyzed with Kruskal Wallis H, Dunn and Pearson chi-square tests. p < 0.05 was accepted as statistically significant in all analyses. Results: Anterior endo-t was initiated in 471 of 9,200 pedodontic patients between the ages of 6 and 15 years who applied to our university. The reason for seeking treatment was caries (8.1%) and trauma (91.9%). It was observed that 59% of the teeth had an open apex and 45.7% had a closed apex. A total of 1893 periapical radiographs (Per-R) and 245 panoramic radiographs (Pan-R) were taken from 471 pediatric patients during the treatment period. Total number of dental radiographs was 2138 with 4.5 per patient. Number of Per-R was lower in patients whose treatment was completed in a single session (p < 0.001). There was no difference in the number of Pan-R with respect to duration of treatment (p = 0.560). Conclusions: In children, the number of Per-R significantly increased with prolonged duration of treatment encompassing multiple sessions for endo-t procedures of anterior YPT, decided based on the apex and lesion status of the affected tooth. Especially in long-term traditional apexification treatments, treatment should be carried out in children with the ALADAIP (As Low As Diagnostically Achievable being Indication-oriented and Patient-specific) principle in mind.

Ionizing radiation protection and the linear No-threshold controversy: Extent of support or counter to the prevailing paradigm

This study has developed a relationship that categorized radiation protection and allows for a proper, clear, and concise review of the different classifications in terms of principles of protection, dose criteria, categories, fundamental tools, exposure situations, applications and control measures. With the groundwork laid, advances of the linear no-threshold (LNT) model which has attracted attention in the field of radiobiology and epidemiology were examined in detail. Various plausible dose-response relationship scenarios were x-rayed under low-dose extrapolation. Intensive review of factors opposing the LNT model involving radiophobia (including misdiagnosis, alternative surgery/imaging, suppression of ionizing radiation (IR) research); radiobiology (including DNA damage repair, apoptosis/necrosis, senescence protection) and cost issues (including-high operating cost of LNT, incorrect prioritization, exaggeration of LNT impact, risk-to-benefit analysis) were performed. On the other hand, factors supporting the use of LNT were equally examined, they include regulatory bodies' endorsement, insufficient statistical significance, partial DNA repair, variability of irradiated bodies, different latency periods for cancer, dynamic nature of threshold and conflicting interests. After considering the gaps in the scientific investigations that either support or counter the scientific paradigm on the use of LNT model, further research and advocacy is recommended that will ultimately lead to the acceptance of an alternative paradigm by the international regulators.

Knowledge, attitude, and behavior of Turkish dentists about radiation protection and radiation safety

OBJECTIVES

Dentists use dental imaging methods frequently in the diagnosis and treatment of dental diseases. This study aimed to determine dentists' knowledge, attitudes, and behaviors about radiation protection during dental imaging procedures.

METHODS

Dentists from two major dental health centres in İzmir province were asked to participate in this study. The participants replied to a questionnaire that consisted of questions on the use of radiographic devices, knowledge on the radiation protection of patients and staff, and attitudes and behaviors regarding radiation protection. The questionnaire also included questions about the socio-demographic characteristics of the participants. Descriptive statistics of data were performed using the SPSS software program.

RESULTS

Sixty-six dentists participated in the survey. The mean knowledge score of dentists on dental imaging, radiation, and radiation protection was 8.3 ± 2.6 out of 17, while the mean attitude and behavior score was 8.3 ± 2.1 out of 27.97% of the participants stated that medical imaging technicians should carry out imaging procedures. The use of rectangular collimators was 9.1%, and using E/F film was 56.3% among dentists. 23.3% of participants stated that they applied the bisecting angle technique during dental imaging, 23.8% stated that they wear a lead apron during imaging, and 37.8% stated that they always used thyroid shields on the patients. In addition, 37.2% of the dentists stated that the patient holds the film during preapical radiography, and 81.5% used the same imaging parameters for adult and pediatric patients. 62% of dentists stated that they question the pregnancy of female patients before imaging.

CONCLUSION

Findings of the study suggest that the knowledge of dentists about dental imaging procedures and radiation protection needs to be improved. The implementation and the follow-up of quality training programs in accordance with the standards set by the national authority will be of great importance.

Diagnostic Reference Levels for Common X-ray Procedures in Peru

Diagnostic reference levels (DRLs) for X-ray procedures have been established in many countries since 1996. In Peru, data from the literature are used as guidelines as DRLs research is limited. The objective of this study is to analyze the parameters and variables which are used in radiological techniques such as kV, mAs, and type of machine (conventional or digital); study the geographical distribution of radiological X-ray machines, and establish DRLs in Peru. Two radiological procedures were considered, general X-rays (fixed and mobile) and intraoral X-rays (fixed, mobile, and portable). An Unfors RaySafe Xi detector (Unfors RaySafe AB, Billdal, Sweden) was used; air kerma was measured at a source to image distance that varied depending on the procedure, and the entrance skin dose was subsequently calculated using the Arcal XLIX formalism. The data were collected over a period of three years (2015-2017). Only results from the last evaluation during this period were taken into consideration for each X-ray machine. DRLs were calculated at 0.21 mSv, and 0.25 mSv for posterior-anterior chest examinations in conventional and digital machines, respectively; 4.39 mSv and 6.01 mSv for conventional and digital antero-posterior lumbar spine examinations, respectively; and at 4.21 mSv for the dental intraoral procedure. The largest amount of X-ray machines is concentrated in the city of Lima. These results reflect the standard of practice in Peru.

Occupational and patients effective radiation doses in dental imaging

Ionizing radiation exposure from medical applications is increasing annually worldwide. It was estimated that 325 million dental procedures were performed in the United States. Radiation exposure from dental radiography consists of intraoral, panoramic, and 3D imaging cone-beam computed tomography (CBCT) imaging. Recent studies reported an association between dental imaging procedures and increased cancer probability of brain and thyroid. Previous studies showed that some dental imaging practices exposed patients and staff to unnecessary radiation doses due to incorrect image acquisition and insufficient radiation protection measures. This study aims to (i) measure the occupational and patients doses during dental procedures and (ii) assess the current imaging techniques and radiation protection practices. Two hundred fourteen patients were evaluated for periapical, bitewing, cephalometric, occlusal, and panoramic procedures. Organ equivalent doses were quantified for the breast, eye lens, and thyroid gland during CBCT procedure. Occupational and ambient dose assessment were assessed using calibrated thermoluminescent dosimeters (TLD-100(LiF: Mg. Ti). Ambient doses were measure at different locations at the department using TLDs. Patients' radiation doses were quantified using kerma area product (PKA (mGy.cm) and the entrance surface air kerma (ESAK (mGy). Fixed tube voltage (65 kVp) and tube current-time product (7 mAs) were used. The overall mean, sd, and range of patients dose values during intraoral (mGy), panoramic and CBCT examinations were 4.6 ± 0.7 (1.4-7.1), 135 ± 45 (75.2-168.5), and 215 ± 165 (186-2115), respectively. The mean and range of the annual occupational doses (mSv) were 1.4 (0.6-3.7), which below the annual dose limits for radiation workers (20 mSv/y). The study showed that inadequate radiation protection for patients existed in terms of the use of the thyroid shield, the technologist's presence inside the room during radiation exposure. Patients' radiation doses were comparable with the international diagnostic reference level (DRL). Staff education and training in radiation protection aspects are highly recommended.

Effect of Implant Surface Modification on Bone Mineral Density and Survival Rate in the Maxilla After a Short Period Using Cone Beam Computed Tomography

ABSTRACT

This study was aimed to objectively measure the changes in bone density amount obtained through cone-beam computed tomography around dental implants after a short period of time in the maxilla. Thirty-two SLActive Straumann implants were inserted into 12 healthy patients. Changes in bone density were measured at the surgery time (Bone mineral density (BMD)0) and 60 days after investment (Bone mineral density (BMD)60). Statistically, significant differences were observed between traumatic and sinus zones at the time of surgery and after 60 days respectively (P ≤ 0.05). For each group, a significant decrease in density was observed with the following variables (male, age of 18-40 years, sinus zone, and implant diameter of 4.1 mm). The survival rate was 83.8% after 60 days. Implant surface modification has no significant effect on bone mineral density after a short period of time in the sinus zone. Early loading of the prosthesis can be performed in the traumatic zone only.

Public Perception and Viewpoints of Dental Radiograph Prescriptions and Dentists' Safety Protection Practice

Purpose

The exposure of patients to ionizing radiation used in dentistry comes with a subtle risk of a stochastic effect, but there is tremendous benefit obtained from radiographic investigation for diagnosis, management, and monitoring of the treatment offered.

Aim

The aim of this study was to assess the viewpoint of the population concerning the prescriptions and practices in dentistry associated with dental radiographs and the safe use of ionizing radiation in dental clinics.

Patients and Methods

Validated and pretested structured self-administered questionnaires with 11 items were used. An electronic version of the questionnaire was created using Google Forms and distributed online through social media outlets. A total of 437 patients completed the questionnaire which contains questions about their demographic data and their perception of the practice of dentistry regarding hazard from dental radiographs. The collected data were analyzed statistically.

Results

Up to 88.6% of the study participants underwent dental radiography for various dental treatments. A majority of them relied on the dentist for the type of requested radiograph, 40% of them reported that dentist never explained the hazards associated with radiography. More than half of the participants (55%) never or hardly ever asked about safety measures before undergoing radiography. Most of the participants approved of radiography and never refrained.

Conclusion

There is a spectrum of perceptions by the population. Continuous patient education is recommended to enhance awareness regarding this matter. Community perception assists in correcting wrong beliefs and ensuring improvement.

Effects of scanning parameters reduction in dental radiographs on image quality and diagnostic performance: A randomised controlled trial

OBJECTIVES

To investigate the effect of reducing scanning parameters of digital dental panoramic tomogram (DPT) and lateral cephalometric (LC) radiographs on quality and diagnostic performance of the images.

DESIGN

Single-centre prospective two-arm parallel randomised controlled trial.

SETTING

Orthodontic Clinic, Faculty of Dentistry, Universiti Teknologi MARA, Selangor, Malaysia.

PARTICIPANTS

Adult orthodontic patients aged 18-35 years, indicated for DPT and LC, who were fit and healthy with a body mass index of 18.5-25.0, not contraindicated to radiographic examination, not pregnant, and did not have a history of facial or skeletal abnormalities or bone diseases were included.

METHODS

Thirty-eight adult orthodontic patients were randomised into control and intervention groups. DPT and LC radiographs in the control group were obtained using standard scanning parameters as prescribed by the manufacturer using Orthopantomograph® OP300 by Instrumentarium. Scanning parameters in the intervention group were reduced by 60% for DPT (60 kV, 3.2 mA) and 30% for LC (85 kV, 8 mA). A five-point rating scale was used for the assessment of image quality. Images were evaluated for diagnostic performance by detection of anatomical landmarks. Mann-Whitney test was performed to compare the quality and diagnostic performance of the images and the observer agreement was assessed using the intraclass correlation coefficient (ICC).

RESULTS

For image quality, the control group produced slightly lower median scores (DPT 2.0, LC 2.0) compared to the intervention group (DPT 2.0, LC 3.0). For diagnostic performance, both groups showed similar median scores (DPT 21.0, LC 32.0). The differences between control and intervention groups for both modalities were not statistically significant. The average scores for intra-observer agreement were excellent (ICC 0.917) and inter-observer agreement was good (ICC 0.822).

CONCLUSION

Minimising radiation exposure by reducing scanning parameters on digital DPT by 60% and LC by 30% on Intsrumentarium 300 OP did not affect the quality and diagnostic performance of the images. Thus, scanning parameters on digital DPT and LC should be reduced when taking radiographs.

Sinus Floor Augmentation Using Recombinant Human Bone Morphogenetic Protein-2 With Hydroxyapatite: Volume Assessment

INTRODUCTION

The aim of this study was to assess the efficacy of using bone morphogenetic protein-2 with hydroxyapatite granules (BMP-2/hydroxyapatite) during augmentation of maxillary sinus floor, with respect to changes in volume, relative to conventional bone graft materials.

METHOD AND MATERIALS

Twenty of 25 patients in the BMP-2/hydroxyapatite group, and 16 of 33 patients in the conventional materials group met the criteria for inclusion in this study. Computed tomography scans were performed preoperatively, immediately postoperatively, and at follow-up, approximately 6 months postoperatively. Changes in volume and height of both grafted materials were measured using 3-dimensional reconstruction software; these changes were compared between groups.

RESULTS

The mean (standard deviation) volumetric changes were 0.25 (0.11) cc and -0.07 (0.35) cc, and the mean rates of volumetric changes were 26.44% (7.78%) and -2.92% (30.92%) in BMP-2/hydroxyapatite and conventional materials groups, respectively. The mean height changes were 0.34 (0.73) mm and -0.63 (1.07) mm, and the mean rates of height changes were 3.67% (7.57%) and -5.95% (9.98%) in BMP-2/hydroxyapatite and conventional materials groups, respectively.

CONCLUSION

Compared with the conventional materials group, the BMP-2/hydroxyapatite group showed better maxillary sinus floor augmentation results in terms of volumetric changes and grafted material densities, and can provide predictably reliable outcomes.

Label-free quantitative proteomic analysis of gingival crevicular fluid to identify potential early markers for root resorption

Background

Orthodontically-induced root resorption is an iatrogenic effect and it cannot be examined regularly due to the harmful effects of sequential doses of radiation with more frequent radiography. This study aims to compare protein abundance (PA) of pre-treatment and during orthodontic treatment for root resorption and to determine potential early markers for root resorption.

Methods

Ten subjects (n = 10) who had upper and lower fixed appliances (MBT, 3 M Unitek, 0.022″ × 0.028″) were recruited for this study. Human gingival crevicular fluid (GCF) was obtained using periopaper strips at pre-treatment (T0), 1 month (T1), 3 months (T3), and 6 months (T6) of orthodontic treatment. Periapical radiographs of the upper permanent central incisors were taken at T0 and T6 to measure the amount of root resorption. Identification of changes in PA was performed using liquid chromatography-tandem mass spectrometry. Student’s t-test was then performed to determine the significance of the differences in protein abundance before and after orthodontic treatment.

Results

Our findings showed that all ten subjects had mild root resorption, with an average resorption length of 0.56 ± 0.30 mm. A total of 186 proteins were found to be commonly present at T0, T1, T3, and T6. There were significant changes in the abundance of 16 proteins (student’s t-test, p ≤ 0.05). The increased PA of S100A9, immunoglobulin J chain, heat shock protein 1A, immunoglobulin heavy variable 4–34 and vitronectin at T1 suggested a response to stress that involved inflammation during the early phase of orthodontic treatment. On the other hand, the increased PA of thymidine phosphorylase at T3 suggested growth promotion and, angiogenic and chemotactic activities.

Conclusions

The identified proteins can be potential early markers for root resorption based on the increase in their respective PA and predicted roles during the early phase of orthodontic treatment. Non-invasive detection of root resorption using protein markers as early as possible is extremely important as it can aid orthodontists in successful orthodontic treatment.

Does dose optimisation in digital panoramic radiography affect diagnostic performance?

OBJECTIVES

To compare the overall diagnostic performance of digital panoramic radiographs obtained with low-dose protocols and to estimate the absorbed dose in the head and neck.

MATERIALS AND METHODS

Forty-eight panoramic radiographs were obtained from eight imaging phantoms using six exposure protocols of progressively lower tube voltages (kVp) and currents (mA), as follows: (1) 70 kVp and 12.5 mA, (2) 66 kVp and 10 mA, (3) 66 kVp and 8 mA, (4) 66 kVp and 5 mA, (5) 66 kVp and 4 mA and (6) 66 kVp and 3.2 mA. Five oral radiologists independently evaluated the images and reported all detectable radiographic findings. Intra-examiner reproducibility was assessed by re-evaluation of 25% of the images. The data were analysed using the McNemar and weighted Kappa tests. Absorbed doses of the six protocols were obtained from thermoluminescent dosimeters placed inside a Rando phantom and compared using one-way ANOVA with post hoc Tukey (α = 0.05).

RESULTS

The overall diagnostic performance of panoramic radiographs obtained with low-dose protocols did not differ from that of panoramic radiographs obtained with the highest dose (p > 0.05). Moreover, substantial agreement was observed between all protocols. Protocol 1 resulted in the highest absorbed dose and protocols 4, 5 and 6 in the lowest absorbed doses, with the difference being significant (p ≤ 0.05).

CONCLUSION

Although digital panoramic radiography is considered a relatively low-dose examination, the radiation dose can be further reduced without negatively affecting its overall diagnostic performance.

CLINICAL RELEVANCE

Considering the risks associated with X-rays, digital panoramic radiographs can be obtained at even lower exposure levels.

Knowledge, Attitude, and Practice (KAP) of Radiographic Protection by Dental Undergraduate and Endodontic Postgraduate Students, General Practitioners, and Endodontists

The aim of this study is to evaluate the knowledge, attitude, and perception of radiation hazard and preventive measures among dental undergraduate students, general practitioners, endodontic postgraduate students, and endodontists in Saudi Arabia. Multiple choice questions questionnaires were distributed among undergraduate and endodontic postgraduate dental students, general practitioners, and endodontists in the colleges of dentistry in Saudi Arabia, government hospitals, and private clinics. The questionnaire included sociodemographic data, assessment of the knowledge of radiation physics and biology, assessment of the practice of dental radiography, and assessment of knowledge of radiation protection. Chi-square test was used for individual and multiresponse analysis. Level of statistical significance was set at P ≤ 0.05. Three hundred and twenty-nine responded to the questionnaire. More than half of the respondents agreed that dental X-ray is hazardous to health (60.79%), and 68.1% were familiar with ALARA (as low as reasonably achievable) principle. However, only 34% are familiar with the recommendations of the National Council on Radiation Protection (NCRP) and International Commission on Radiological Protection (ICRP). The use of lead apron and thyroid collar for patients' protection from X-ray radiation was practiced among endodontic postgraduate students more frequently as well as those who are proactive in the academic field. Undergraduate students, endodontic postgraduate students, and endodontists in the academic field were the most aware towards radiation reduction measures. The use of the preventive measures needs to be emphasized more among general practitioners, endodontic postgraduate students, and endodontists especially in governmental hospitals and private sectors.

Measuring the dose-width product and proposing the local diagnostic reference level in panoramic dental radiography: a multi-center study from Iran

OBJECTIVE

Although radiation exposure associated with dental radiography is relatively low, patient exposure must be kept practically low. Therefore, it is necessary for each country to establish its own diagnostic reference levels (DRLs) suitable for its equipment and practice. In the present study, dose-width product (DWP) values for panoramic dental radiography were measured and a local DRL was established.

METHODS

Five panoramic devices from five radiology clinics of Kashan, Iran were selected to measure the DWP values of panoramic dental radiography. To investigate the DWP values, the parameters of each patient's exposure (e.g., tube voltage, tube current, and exposure time) at these five radiology clinics were extracted. Then, the dose value received by each patient was measured based on a CT pencil chamber. Finally, the overall median DWP values for the patients with small, medium, and large sizes were obtained, and these values were considered as the local DRLs for panoramic dental radiography.

RESULTS

A total of 99 adult patients were included in the present study. The findings demonstrated that the median and third-quartile DWP values for these five radiology clinics ranged from 42.3 to 94.3 and 49.7 to 142.8 mGy mm, respectively. The local DRL values, which were established as the overall median DWP values, were 43.4, 52.0, and 80.3 mGy  mm for the adults with small, medium, and large sizes, respectively.

CONCLUSION

The local DRL proposed in this study for the adult with standard/medium size was lower than those proposed by other reports and seemed acceptable for panoramic radiography in Kashan, Iran.

Digital reconstruction of teeth using near-infrared light

Cone beam computed tomography has demonstrated value by offering enhanced conceptualization of features of teeth in the 3D space. However, these systems require higher effective radiation doses to image teeth. Previous research from our group has used non-ionizing near-infrared (NIR) light for diagnosing demineralization and caries in human tooth enamel. However, use of safe NIR radiation for rapid, 3D imaging of tooth anatomy has not been described previously. Here we describe a optical setup to rapidly laser scan teeth ex vivo using 1310nm NIR laser diode. We also detail a novel process that uses laser scanning to create stacks of images of extracted teeth, and construct highly accurate 3D models. Our 3D reconstructive models offer promising starting points to recover anatomical details using pixel intensities within these images as projection data to diagnose carious lesions, and can assist in providing rapid and affordable technology-enabled early caries screenings to patients.

CALIBRATION OF LOW ENERGY X-RAY EXPERIMENTAL SETUP WITH STRONGLY FILTERED BEAM USING DATA FROM A SEMICONDUCTOR AND A THERMOLUMINESCENT DETECTORS

The calibration of low energy X-ray experimental setup with strongly filtered beam dedicated to radiobiological research was performed using the absorbed dose calculated from the data collected by two types detectors. For this purpose a semiconductor (Amptek, USA) and a thermoluminescent (Institute of Nuclear Physics, Krakow, Poland) detectors were applied. The absorbed dose in water values estimated by both detectors are in good agreement.

Dental X-Rays and the Risk of Thyroid Cancer and Meningioma: A Systematic Review and Meta-Analysis of Current Epidemiological Evidence

Background: Exposure to moderate-to-high doses of ionizing radiation is the only established environmental risk factor for thyroid cancer and brain and central nervous system tumors. Considering the high lifetime prevalence and frequency of exposure to dental X-rays, the most common source of diagnostic radiation exposure in the general population, even a small associated increase in cancer risk would be of considerable public health importance. With the objective to inform clinical practice and guidelines, we synthesized the current epidemiological evidence on the association between dental X-rays and the risk of thyroid cancer, meningioma, and other cancers of the head and neck region. Methods: The Medline, Embase, and Web of Science databases were searched to identify eligible studies. Summary odds ratio/relative risk estimates and confidence intervals were extracted, and pooled risk ratios (RRs) for each cancer were calculated using random effects meta-analysis. Results: The literature search identified 5537 publications; of these, 26 studies including 10,868 cancer patients were included in the synthesis. The random effects meta-analyses, based on seven studies of thyroid cancer (six case/control, one cohort) and eight studies of meningioma (all case/control), showed that multiple (or repeated) exposures to dental X-rays were significantly associated with an increased risk of thyroid cancer (pooled RR = 1.87 [95% confidence interval, CI 1.11-3.15]) and meningioma (pooled RR = 1.53 [CI 1.26-1.85]). There was no association with glioma, and there were too few studies of other cancers of the head and neck region to conduct a meaningful meta-analysis. Conclusions: Based on a meta-analysis of retrospective case/control studies, these findings provide some support to the hypothesis that multiple (or repeated) exposures to dental X-rays may be associated with an increased risk of thyroid cancer and meningioma. These studies did not include individual organ doses and ages at exposure, and are subject to recall bias and other limitations. Furthermore, the thyroid exposure has decreased dramatically over time from the use of thyroid shields and improved technology/equipment. Prospective studies, based on dental X-ray records and patient follow-up, are needed to test the hypothesis further and clarify the possible cancer risk associated with dental radiography, as although the risk at the individual level, particularly with improved technology/equipment, is likely to be very low, the proportion of the population exposed is high. Considering that about one-third of the general population in developed countries is routinely exposed to one or more dental X-rays per year, these findings manifest the need to reduce diagnostic radiation exposure as much as possible.

The missing link in image quality assessment in digital dental radiography

Digital radiography is gaining popularity among general dental practitioners. It includes digital intraoral radiography, digital panoramic radiography, digital cephalography, and cone-beam computed tomography. In this study, we focused on the methods to assess image quality of these techniques, except for digital cephalography, in the light of historical issues. We stressed on the importance of the development of a standardized phantom and quantitative analysis of diagnostic image quality using it, especially in the aspect of psychophysical properties of these digital systems. There is no missing link in the image quality assessment in digital intraoral radiography and cone-beam computed tomography in dental use. However, there are missing links between physical and diagnostic image qualities in panoramic radiography. The development of a semi-standardized phantom and the corresponding quantitative analysis method for image quality may be required in digital panoramic radiography. Quantitative image quality assessment using a standardized phantom will also be promising in the future artificial intelligence era.

A comprehensive review of the literature on the biological effects from dental X-ray exposures

PURPOSE

Routine dental X-rays are among the most common sources of ionizing radiation exposure for healthy individuals globally, with 300 examinations/1000 individuals/year as documented by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) global survey of medical radiation usage and exposure. Furthermore, in the United States of America, an increased use of dental radiography is evident. However, with the shift from using film to digital image receptors, the dose of radiation per routine examination has decreased. Despite this, there remains public concern of dental X-rays. This continuing concern highlights the need to review the literature on biological and health effects related to exposure, from dental X-rays.

MATERIAL AND METHODS

This report presents studies investigating biological and health effects related to exposures using dental X-rays in patients and provides a critical evaluation. Relevant studies specific to dental X-rays are reviewed from 1970 and onward with the bulk data in this field resulting from epidemiological and biomonitoring studies.

RESULTS

While, most epidemiological studies suggest a possible correlation between head/neck related tumors and exposure to dental X-rays, evidence for causation is lacking. Biomonitoring studies suggest that exposure to low-level radiation such as that of dental radiography may not be a factor in inducing long-term chromosomal damage, but may result in localized cytotoxicity in the irradiated region of the mouth, with no long-term harm.

CONCLUSIONS

In general, the total number of studies is low and the majority of the data has been generated from poorly designed experiments. This review will highlight shortcomings that could influence outcomes and provide a more balanced interpretation that could impact the public perception and the level of public concern on the health effects resulting from dental X-rays.

Investigation of radiation-protection knowledge, attitudes, and practices of North Queensland dentists

AIM

Queensland has current radiation-protection guidelines; however, with the absence of data exploring compliance and implementation, the efficacy is unknown. The aim of the present study was to investigate the knowledge and attitudes on radiation protection among private North Queensland (NQ) dentists.

METHODS

A quantitative methodology was employed in an observational and descriptive study using questionnaires for data collection.

RESULTS

Of the 154 questionnaires distributed, 63 were completed and returned. The respondents' knowledge concerning the technical details of their equipment was limited, with 31.5% and 47% not knowing the tube voltage and current utilized for their machines, respectively. In total, 23.8% of dentists had limited knowledge about the speed of the conventional film they used, 90.5% of respondents agreed that the role of imaging in dentistry is important, and 75.8% dentists reported the thyroid as the most important organ to protect during dental radiography. Their knowledge regarding position-distance rule was reasonably adequate; 80.3% of the dental practices appeared to follow the Australian Radiation Protection and Nuclear Safety Agency guidelines, 95.2% preferred taking radiographs if it was only urgent, and 69.8% identified a need for spreading awareness regarding radiation protection.

CONCLUSIONS

An opportunity and need for further continuing education was identified among NQ dentists to ensure safety of patients.

Patient radiation doses in intraoral and panoramic X-ray examinations in Sudan

Radiation doses were measured for the first time in intraoral and panoramic dental radiology at Sudanese hospitals. Doses were determined using various exposure settings for adults and children in 8 intraoral and 6 panoramic X-ray devices. The study sample was equally divided between devices using a digital image receptor (DR) and those using conventional screen film (SF). Radiation doses are reported in terms of incident air kerma (IAK) (intraoral radiology) and kerma area product (P_KA) (panoramic radiology). IAK values in intraoral radiology were: 1.45 mGy (DR), 4.45 mGy (SF), and 3.01 mGy (combined). For panoramic radiology, P_KA values ranged: from 35.8 to 103.2 mGy cm² (average: 70.4 mGy cm²) for children and from 65.7 to 151.4 mGy cm² (average: 103.4 mGy cm²) for adults. The results showed that the downward trend in patient doses can be achieved using digital imaging. The study revealed important concerns surrounding radiation protection, such as the lack of regular quality assurance programs and the use of circular collimators.

Generation and Role of Reactive Oxygen and Nitrogen Species Induced by Plasma, Lasers, Chemical Agents, and Other Systems in Dentistry

The generation of reactive oxygen and nitrogen species (RONS) has been found to occur during inflammatory procedures, during cell ischemia, and in various crucial developmental processes such as cell differentiation and along cell signaling pathways. The most common sources of intracellular RONS are the mitochondrial electron transport system, NADH oxidase, and cytochrome P450. In this review, we analyzed the extracellular and intracellular sources of reactive species, their cell signaling pathways, the mechanisms of action, and their positive and negative effects in the dental field. In dentistry, ROS can be found—in lasers, photosensitizers, bleaching agents, cold plasma, and even resin cements, all of which contribute to the generation and prevalence of ROS. Nonthermal plasma has been used as a source of ROS for biomedical applications and has the potential for use with dental stem cells as well. There are different types of dental stem cells, but their therapeutic use remains largely untapped, with the focus currently on only periodontal ligament stem cells. More research is necessary in this area, including studies about ROS mechanisms with dental cells, along with the utilization of reactive species in redox medicine. Such studies will help to provide successful treatment modalities for various diseases.

Radiation shielding in dentistry: an update

The purpose of this article was to review the literature and provide guidelines on the use of radiation protection for patients in the dental setting. There are limited published data on the effects of low radiation doses such as those used in dental radiology. Most of the evidence is subject to bias, with risk models extrapolated from higher dose models such as studies of the Hiroshima bomb survivors. However, the lack of evidence does not denote the absence of risk, as there is no established 'safe' level of radiation exposure. All imaging utilizing ionizing radiation carries a risk for the patient. Hence the patient benefits of imaging must outweigh the potential risk. All diagnostic imaging should adhere to three basic principles, these being justification, optimization and application of dose limits. This article discusses dose reduction techniques and shielding of sensitive organs, particularly the thyroid, during procedures such as intraoral imaging, orthopantomograms and imaging of the pregnant patient.

Firearm Projectile in the Maxillary Tuberosity Located by Adjunctive Examination of Wide-Field Optical Fluorescence

OBJECTIVE

Demonstrate the use of wide-field optical fluorescence as an adjunctive examination in a clinical routine to oral diagnosis.

BACKGROUND DATA

Use of wide-field optical fluorescence in the oral cavity has been restricted to topics related to the detection and diagnosis of oral cancer.

MATERIALS AND METHODS

In a regular medical appointment, a 58-year-old female patient, without any complaint or oral symptom, underwent the complementary examination by wide-field optical fluorescence. A device with high-power light-emitting diode emitting light centered at a wavelength of (400 ± 10) nm and maximum irradiance of (0.040 ± 0.008) W/cm² was used for fluorescence visualization.

RESULTS

We report the location of a firearm projectile, intraosseous, in the maxillary tuberosity using wide-field optical fluorescence.

CONCLUSIONS

It is evidenced that wide-field optical fluorescence, within a clinical routine, can provide relevant images and data, with an immediate result, without the use of ionizing radiation, enabling an efficient oral diagnosis.

A cone beam computed tomography (CBCT) study of buccal plate thickness of the maxillary and mandibular posterior dentition

BACKGROUND

Buccal plate thickness is of clinical importance in treatment planning for implants. The purpose of this study was to evaluate the buccal plate thickness in posterior dentate areas of both the maxilla and mandible using cone beam computed tomography in order to estimate the approximate distributions of this anatomic variable.

METHODS

Two hundred and sixty-five subjects were included for a total of nine hundred and thirty-four roots assessed by cone beam computed tomography. CBCT scans were taken and evaluated at the ideal buccolingual cross-sections of each root at 1 mm, 3 mm, and 5 mm apical to the alveolar crest to measure buccal plate thickness. Data are reported by geometric means and 95% confidence intervals.

RESULTS

Both arches demonstrated increasing buccal plate thickness from anterior to posterior. Maxillary teeth had a significant decrease in thickness from coronal to apical along the tooth root (P < 0.001), except at second molars. The first premolar and mesial root of the first molar were significantly thinner than all other roots in the maxilla. Conversely, the mandible demonstrated a significant increase in buccal plate thickness from coronal to apical (P < 0.001). The premolars were significantly thinner than all other roots. Age and sex were found to have limited impact on buccal plate thickness in both arches.

CONCLUSIONS

Buccal plate thickness is highly dependent upon the arch position, tooth location, and measurement point, but age and sex have limited impact.

Endodontic application of cone-beam computed tomography in South Korea

INTRODUCTION

This study aimed to investigate the incidence of cone-beam computed tomography (CBCT) associated with endodontic procedures during 2009 in South Korea and to retrospectively evaluate information from CBCT with large field of view (FOV), which is popular in South Korea.

METHODS

The Health Insurance Review and Assessment agency, which reviews all medical and dental expenses covered under the Korean National Health Insurance (NHI) system, was queried for data on the nationwide number of CBCTs associated with some treatment procedures. To compare digital periapical radiography and CBCT retrospectively, 470 roots of 257 root canal-infected teeth were enrolled.

RESULTS

In total, 13,209 cases of NHI-covered CBCT were performed in South Korea during 2009, excluding cases for implant restoration and orthodontics. In total, 1253 and 95 CBCT cases were combined with root canal length measuring and apicoectomy, respectively. In a retrospective comparison, CBCT with large FOV provided more information about the presence of apical periodontitis, distortion of cortical bone, and identification of root compared with digital periapical radiography.

CONCLUSIONS

CBCT with large FOV is useful in nonsurgical endodontic treatment and provides more information compared with digital periapical radiography.