Light-curing units used in dentistry: factors associated with heat development – potential risk for patients

Source: doi: 10.1007/s00784-016-1962-5Objectives:To investigate how heat development in the pulp chamber and coronal surface of natural teeth with and without cusps subjected to irradiance using light-emitting diode (LED)–light-curing units (LCUs) is associated with (i) irradiance, (ii) time, (iii) distance, and (iv) radiant exposure. Materials and methods:Three different LED-LCUs were used. Their irradiance was measured with a calibrated spectrometer (BlueLight Analytics Inc., Halifax, Canada). An experimental rig was constructed to control the thermal environment of the teeth. The LED-LCU tip position was accurately controlled by a gantry system. Tooth surface temperature was measured by thermography (ThermaCAM S65 HS, FLIR Systems, Wilsonville, USA) and pulp chamber temperature with a thermocouple. LED-LCU tip distance and irradiation times tested were 0, 2, and 4 mm and 10, 20, and 30 s, respectively. Ethical permission was not required for the use of extracted teeth. Results:Maximum surface and pulp chamber temperatures were recorded in tooth without cusps (58.1 °C ± 0.9 °C and 43.1 °C ± 0.9 °C, respectively). Radiant exposure explained the largest amount of variance in temperature, being more affected by time than irradiance. Conclusions:At all combinations of variables tested, repeated measurements produced consistent results indicating the reliability of the method used. Increased exposure time seems to be the factor most likely to cause tissue damage. Clinical relevance:Risk of superficial tissue damage at irradiances >1200 mW/cm2 is evident. There is a risk of pulp damage when only thin dentin is left at higher irradiances (>1200 mW/cm2). Clinicians should be aware of LED-LCU settings and possible high temperature generated

The educational gradient in dental caries experience in Northern- Norway: a cross-sectional study from the seventh survey of the Tromsø study

Background Although, studies from Norway indicate a reduction in dental caries experience, in Northern-Norway this non-communicable oral condition is still prevalent. There is conflicting evidence of presence of social inequalities in dental caries in an adult population. Therefore, the aim of this study was to assess an association between educational level and dental caries experience in adults in urban Tromsø municipality, Northern-Norway, using The World Health Organization (WHO) Commission on Social Determinants of Health (CSDH) framework of health determinants. Methods Data from 3752 participants having recorded dental caries status and educational level in the seventh survey of the Tromsø Study: Tromsø7 were included. Dental status was examined clinically as decayed-, missing-, filled-teeth (DMFT score). For statistical analyses DMFT score was grouped into lower (DMFT<19) and higher (DMFT≥20). Educational level was obtained from a questionnaire and categorized as primary/partly secondary education, upper secondary education, tertiary education, short and tertiary education, long. Data on social and intermediary determinants was also self-reported. Univariable and multivariable binary logistic regression analyses were applied. Result This study included 1939 (52%) women and the mean age of the participants was 57.11. The mean DMFT score was 18.03. The odds of having higher DMFT score followed a gradient based on educational level. Participants who reported lower than secondary education had 2.06 -fold increased odds of having higher DMFT score than those with tertiary education, long (OR: 2.06, 95% CI: 1.50–2.83). Those with upper secondary education had 60% higher odds of having higher DMFT score (OR: 1.60, 95% CI: 1.21–2.11), and those with tertiary education, short had 66% higher odds of having higher DMFT score (OR: 1.66, 95% CI: 1.24–2.22). Conclusion The current cross-sectional study suggested an educational gradient in dental caries experience in an adult population of Northern- Norway. Further studies validating our results and investigating mechanisms of educational inequalities in oral health are warranted

Changes in management preference of deep carious lesions and exposed pulps: questionnaire studies with a 10-year interval among dentists in Lithuania

We aimed to investigate changes in management preferences for deep carious lesions and pulps exposed during carious tissue removal that occurred during the last 10 years and identify associated dentists’ background factors. The data were collected among dentists registered with the Lithuanian Dental Chamber at two time points using a similar questionnaire. In 2011, 400 randomly selected dentists received a questionnaire by mail, and 153 (38.3%) responded. In 2021, an electronic invitation to an online questionnaire was sent to all members of the Lithuanian Dental Chamber, and 213 (8.9%) dentists responded. The questionnaire included the definitions of management options, a radiograph, and a clinical picture of a deep carious lesion reaching to the inner fourth of dentine in a mature permanent tooth, asked management preferences in four different scenarios, as well as participants’ background characteristics, reasons for management, and procedural preferences. Data were analyzed using bivariate and multivariable analyses. Compared to 2011, participants in 2021 had 60% lower odds of preferring nonselective versus selective caries removal (OR 0.4, 95% CI 0.2–0.7) and endodontic treatment versus nonselective and selective caries removal (OR 0.4, 95% CI 0.2–0.6) in the scenario of asymptomatic and symptomatic (indicating reversible pulpitis at most) deep lesions, respectively. For exposed pulp, participants in 2021 had lower odds than in 2011 of preferring endodontic treatment versus vital pulp therapy (direct pulp capping and pulpotomies) for both scenarios without symptoms (OR 0.4, 95% CI 0.2–0.7) and with symptoms (OR 0.2, 95% CI 0.1–0.4). A higher proportion of respondents in 2021 reported using rubber dam (44% vs. 17% in 2011, p < 0.001) and hydraulic calcium silicate cements as a capping material (68% vs. 40% in 2011, p < 0.001). The management preferences were associated with the university of graduation and the number of years in dental practice, indicating “recommended in textbooks” and “recommended in scientific publications” as reasons for management preferences. To conclude, a change toward less invasive management options was observed. To a certain extent, dentists have implemented evidence-based recommendations in dental practice. To ensure further adoption of scientific evidence, dentists should be encouraged to update themselves on the newest evidence-based practices

How does indirect air-cooling influence pulp chamber temperature in different volume teeth and absence/presence of resin-based composite during light curing?

Background Light-curing of materials during restorative dental procedures poses a risk for pulp tissue overheating. Therefore, the aim of this study was to investigate the effect of indirect air-cooling on pulp chamber temperatures during light-curing of varying volume teeth and absence/presence of resin-based composite (RBC) at different exposure time. Methods The volume of 11 human teeth was measured by micro computed tomograph. An experimental rig controlled the thermal environment of the teeth and a thermocouple inserted retrograde into the root canal measured temperature changes. Pulp chamber temperature was measured with and without air-cooling on teeth without and with RBC at 15 s, 30 s and 60 s intervals. Generalized estimating equations were used for statistical analysis. Results The temperature increase with air-cooling (versus no air-cooling) was lower in teeth despite absence/presence of RBC (β = − 4.26, 95%CI − 5.33 and β = − 4.47, 95%CI − 5.60, respectively). With air-cooling, the temperature increase in teeth with RBC was lower compared to teeth without RBC (β = − 0.42, 95%CI -0.79; − 0.05). Higher teeth volume resulted in lower temperature increase with air-cooling than without air-cooling (β = − 0.04, 95%CI -0.07; − 0.01 and β = − 0.17, 95%CI -0.30; − 0.05, respectively). Conclusions Air-cooling resulted in lower pulp chamber temperature increase. Using air-cooling, the temperature increase was lower in teeth with RBC compared to teeth without RBC. Lower volume teeth resulted in higher temperature increase, thus they seemed to benefit more from air-cooling compared to higher volume teeth. Air-cooling could be an effective tool in controlling pulp temperature increase during light-curing, especially when the tooth volume is small

Association between Carbonic Anhydrase VI (CA VI) gene copy number and dental caries experience

The current study examined the association between the carbonic anhydrase VI (CA VI) copy number variations (CNVs) and dental caries experience in adults. In total, 202 of 35-72 years old subjects participating in the Lithuanian National Oral Health Survey (LNOHS) agreed to provide saliva samples, thus their data were included in the current study. Information about sociodemographic, environmental, and behavioural determinants was acquired via the self-administered World Health Organisation (WHO) questionnaire. Fluoride levels in the drinking water were recorded based on information provided by water suppliers. Dental caries experience was recorded by one calibrated examiner using the WHO criteria for recording caries on smooth (including proximal, buccal, and oral) or occlusal surfaces. Caries experience was measured as the total number of decayed (D3), missing (M), filled (F) surfaces (D3MFS). DNA was extracted from saliva samples to examine CA VI CNVs using the QX200 droplet digital PCR system. Negative binomial regression and Poisson regression analyses were employed for data analyses. Based on multivariable regression analyses, higher copy number of CA VI were associated with higher caries experience on smooth surfaces (IRR 1.04, 95% CI 1.005 - 1.08) and occlusal surfaces (IRR 1.02, 95% CI 1.003 - 1.04). Positive associations between higher copy number of CA VI and higher caries experience on smooth and occlusal surfaces were found, suggesting that the CA VI coding gene may be associated with caries development. Future studies are needed to validate our results and to examine the underlying mechanisms of such associations

European student wellness, stress, coping, support and perceptions about remote dental training during COVID-19

Objectives: The aim of this study was to compare wellness, stress, ability to cope, social support and perceptions about remote training amongst European dental students during COVID-19. Methods: 1795 undergraduate dental students from six countries and eight dental schools participated. The anonymous survey collected data about different aspects in each of the following domains: wellness, stress, ability to cope, social support and perceptions about remote training. Complex multi-item scales were used for all domains. Results: There were differences amongst countries in all the domains. Overall, student stress scores were lower than either their coping or support scores. The highest wellness score (mean ±sd) was observed in Romania: 62.5% ± 11.2% whilst the highest mean stress scores were observed in Albania: 46.3% ± 11.7% and Lithuania: 42.2% ± 13.8%. Overall, student stress and coping ability scores were lower and their support scores higher. About 10% of students did not have any support. In the linear multivariable regression analysis, significant predictors of wellness were being female (β = 0.073), not being in a graduating year (β = 0.059), having less stress (β = 0.222), ability to cope (β = 0.223) and having support (β = 0.179). The student positive perceptions about remote training were predicted by less stress (β = 0.080), coping (β = 0.182) and support (β = 0.057). Conclusions: Students varied in wellness, stress, coping, social support and perceptions of remote training. Also, there were significant differences amongst students from different countries. Coping was the best predictor of both student wellness and their positive perceptions about remote training

Hvordan har tannhelsetjenesten i Norge håndtert pasienter og smittevern under den mest akutte fasen av covid-19-pandemien?

Source at https://www.tannlegetidende.no/i/2020/9/m-1912. The original research paper that is discussed is available in Munin at https://hdl.handle.net/10037/18994.Tannhelsetjenestens kompetansesenter Øst (TkØ) har gjennomført en spørreundersøkelse om tannhelsepersonells erfaringer under nedstenging i perioden 13. mars–17. april 2020. Første del av studien er nå publisert i International Journal of Environmental Research and Public Health og er den første norske studien som omhandler håndtering av covid-19-pandemien i tannhelsetjenesten

Restorative treatment decisions for carious lesions: Do Russian dentists and dental students apply minimal intervention dentistry?

Background - The concept of minimal intervention dentistry (MID) includes both delayed restorative treatment and conservative caries removal, and is now recognised as an evidence-based approach for dental caries management. In order to determine if dental professionals in Russia are incorporating this concept into their clinical practice, we investigated the restorative treatment decisions of Russian dentists and dental students, and the factors associated with these decisions. Methods - We included 171 general dental practitioners and dental therapists (collectively referred to here as “dentists”) from North-West Russia, and 76 dental undergraduate students from the Northern State Medical University in Arkhangelsk (response rate of 11.5% and 67.9%, respectively). Participants completed a questionnaire, which collected background information (sex, region of work, place of dental school graduation, practice type, years of working experience, working in an urban or rural area, and specialisation in restorative dentistry) and information on restorative treatment decisions for proximal and occlusal carious lesions of permanent teeth. Treatment options in accordance with MID were defined as intervention at dentin level and minimally invasive cavity preparation. Multinomial logistic regression was used for statistical analysis. Results - For the proximal carious lesion, 9.4% of participants said they would employ both MID treatment options; 60.7% said they would choose only one; and 29.9% said they would use neither option. For the occlusal carious lesion, the corresponding figures were 37.2%, 52.1%, and 10.7%. No differences in restorative treatment options were observed among general dental practitioners, dental therapists, and dental students. For the proximal carious lesion, dentists from regions outside Arkhangelsk had 4.15 (95% confidence interval [CI] 1.13–15.27) times higher odds of following one versus both MID treatment options. For the occlusal carious lesion, working experience above 15 years was associated with higher odds of using only one versus both MID treatment options (adjusted odds ratio = 3.04, 95% CI 1.33–6.91). Almost all respondents preferred tooth-coloured materials for restorations; more than 75% chose resin-based composite. Conclusions - The majority of Russian dentists and dental students do not apply the MID concept when treating dental caries in permanent teeth. Clinical protocols on dental caries treatment and dental school curriculums should be updated to place an enhanced focus on evidence-based practice and preventive strategies. Further studies with larger samples of Russian dentists and dental students and alternative methods of recruitment are needed to validate our results

The "deep caries" challenge. Prevalence and management of deep carious lesions in Northern Norway.

The overall aim of this doctoral thesis was to increase the understanding and knowledge of the prevalence and management of deep carious lesions. The prevalence of dental caries in Norway was among the highest in the world in the middle of 20th century. Though it has significantly declined, there are indications that the prevalence of caries in Northern Norway is higher than in the rest of the country. A higher prevalence of caries might lead to a higher prevalence of deep carious lesions. Study I focused on the prevalence of deep carious lesions and other consequences of caries (DCL-CC) among 18-year-olds enrolled in the Public Dental Health Service in Northern Norway. There were 488 (26%) subjects having at least one molar with DCL-CC. The mean decayed, missing, and filled teeth (DMFT) (SD) score among these 488 subjects was 9.1 (4.6), twice as high as among subjects without DCL-CC (4.5, SD 4.0). The most prevalent modality among untreated deep carious lesions, deep restorations, root canal obturated molars, and molars extracted due to caries were deep restorations, which were observed among 21.5% (n=404) of the age cohort. Root canal obturated molars, molars extracted due to caries, and untreated deep carious lesions were prevalent in 5.1%, 3.6% and 1.6% of this age cohort, respectively. The high prevalence of DCL-CC in Northern Norway is of concern and presents a challenge for dentists, as no treatment guidelines exist for deep carious lesions. Study II was a questionnaire study that investigated the preferred treatment methods of general dental practitioners in Northern Norway for deep carious lesions and carious exposures in mature permanent teeth. Study II underlined the lack of uniformity in preferred treatment methods among the respondents, and the inconsistency of these methods with those suggested in the current literature. For example, in the absence of symptoms, total caries excavation was favored by a majority of respondents (49%), while in presence of symptoms (indicating reversible pulpitis at most), pulpectomy followed by endodontic treatment was the preferred treatment method for 39% of respondents. Direct pulp capping (DPC), mainly with calcium hydroxide (CH), was the most preferred treatment method (51%) for carious exposures in the absence of symptoms, although it is still a controversial treatment method for adults. In Study III, a promising capping material, mineral trioxide aggregate (MTA), was tested against the gold standard material CH for DPC on carious exposures in adults. After 2-3 years of follow-up, the estimated cumulative survival rate for molars capped with MTA was statistically significantly higher (80%) then for molars capped with CH (46%) (p=0.018). The study is still ongoing, but there are indications that it may provide evidence that will change the established recommendations for the treatment of carious exposures in adults

Social gradients in oral and general health among adolescents in Northern Norway. A cross-sectional and longitudinal cohort study.

[Oppgaven fjernet fra Munin etter epost fra forfatter. Legges ut igjen juni 2022. 02.06.2020 LL]Aim: To explore the social gradients in self-perceived oral and general health, caries experience and body mass index (BMI) in a Norwegian adolescent population. Methods: The data was retrieved from a population-based cohort study Fit Futures, which included all first-year high-school students aged 15-19 years, in two municipalities in Troms County, Northern Norway, in 2010-2011 (not including the summer months). Over 90% of the invited participants attended. All the data, except caries experience, BMI and 25(OH)D serum, was collected through the questionnaire. Analyzed sample consisted of 384 girls and 324 boys, with a participation rate of 63%. Multivariable binary logistic regression analysis stratified by gender was used to investigate the association between socioeconomic position indicators (mother’s education, parents’ employment and child’s school program) and outcomes. All models were adjusted for age, country of birth, household with adults, and a combined health variable, which included history of chronic diseases, alcohol consumption, smoking, use of snuff, physical activity, sugar and other unhealthy diet, vitamin D level, oral hygiene, self-esteem, mental health and sleep. Results: Girls attending vocational school program (vs program for specialization in general studies) had more than two times higher odds for being overweight/obese (OR 2.27, 95%CI 1.05-4.91) and for having higher than average DMFT score (OR 2.54, 95%CI 1.30-4.97). Moreover, these girls had more than two and a half times higher odds to perceive their general and oral health at baseline as less good (OR 2.79, 95% CI 1.27-6.12, and OR 2.54, 95%CI 1.30-4.96, respectively). Comparing to boys who attended the program for specialization in general studies, boys in vocational school program had more than three times higher odds to perceive their oral health at baseline as less good (OR 3.39, 95%CI 1.54-7.46), while boys in sports and physical education program had far lower odds to perceive their general health at FF2 as less good (OR 0.11, 95% CI 0.01-0.89). Furthermore, boys having mother with lower education (high school or less and college less than 4 year vs college 4 year or more) had more than three times higher odds to be overweight/obese (OR 3.06, 95% CI 1.05-8.92 and OR 3.59, 95% CI 1.17-11.02, respectively), but lower odds to perceive their general health FF2 as less good (OR 0.37, 95% CI 0.15-0.92 and OR 0.31, 95% CI 0.10-0.94, respectively). Conclusions: The data indicates social gradients among adolescent for general and oral health in Troms, Northern Norway