Evaluation of VGG-16 deep learning algorithm for dental caries classification

Min-Ji Byon , Eun-Joo Jun , Ji-Soo Kim , Jae-Joon Hwang , Seung-Hwa Jeong

Abstract : Objectives: Diagnosis of dental caries is based on the dentist’s observation and subjective judgment; therefore, a reliable and objective approach for diagnosing caries is required. Intraoral camera images combined with deep learning technology can be a useful tool to diagnose caries. This study aimed to evaluate the accuracy of the VGG-16 convolutional neural network (CNN) model in detecting dental caries in intraoral camera images. Methods: Images were obtained from the Internet and websites using keywords linked to teeth and dental caries. The 670 images that were obtained were categorized by an investigator as either sound (404 sound teeth) or dental caries (266 dental caries), and used in this study. The training and test datasets were divided in the ratio of 7:3 and a four-fold cross validation was performed. The Tensorflow-based Python package Keras was used to train and validate the CNN model. Accuracy, Kappa value, sensitivity, specificity, positive predictive value, negative predictive value, ROC (receiver operating characteristic) curve and AUC (area under curve) values were calculated for the test datasets. Results: The accuracy of the VGG-16 deep learning model for the four datasets, through random sampling, was between 0.77 and 0.81, with 0.81 being the highest. The Kappa value was 0.51- 0.60, indicating moderate agreement. The resulting positive predictive values were 0.77-0.82 and negative predictive values were 0.80-0.85. Sensitivity, specificity, and AUC values were 0.66-0.74, 0.81-0.88, and 0.88-0.91, respectively. Conclusions: The VGG-16 CNN model showed good discriminatory performance in detecting dental caries in intraoral camera images. The deep learning model can be beneficial in monitoring dental caries in the population.

Metaverse and changes in oral health

A step-by-step guide to random forest model using orange data mining in the field of periodontitis

Hoi-Jeong Lim

Abstract : Objectives: The purpose of this study was to show a procedure for a random forest (RF) analysis which predicts periodontal disease status by using R and Orange Data Mining software, and helps us to understand how to apply the RF technique for dental research. Methods: Oral examination data of the 7th Korea National Health and Nutrition Examination Survey were used. A RF model was adopted to analyze the data where the target variable was periodontal disease status and the features were gender, age, education level, marital status, alcohol consumption level, smoking status, brushing before sleep, hypertension, and diabetes-related variables. Results: The important features of the RF analysis were in the order of age, marital status, and prevalence of hypertension and diabetes. The accuracy of the RF analysis was 73% which is not high enough for use in the clinical field. Conclusions: The RF technique is an ensemble method used to predict periodontal disease status which produces higher accurate outputs than a single method. This study provides a step-by-step guide using Orange Data Mining for researchers who want to study machine learning techniques.

The effects of commercial liqueur on bovine enamel surface with incipient dental caries

Su-Na Lee , Na-Yeoung Kim , Ji-Eun Kim , Choong-Ho Choi , Ki-Ho Chung

Abstract : Objectives: The purpose of this study was to evaluate the tooth erosion potential of liqueur and to confirm the anti-erosive effect of calcium. Methods: After purchasing commercially available liqueur in Korea and measuring the pH, products with low pH and high consumption were selected and used as experimental beverages. Calcium (1%) was added to the selected beverages. Chamisul was used as a negative control, and Coca Cola was used as a positive control. Healthy bovine teeth samples were soaked in the selected beverages for 1, 3, 5, 10, 15, and 30 minutes. The changes in the tooth surface after beverage treatment were observed and analyzed using microhardness (VHN, Vickers hardness number) and scanning electron microscopy. Results: Jinro Grapefruit (-88.03±13.05) had the highest surface microhardness difference (ΔVHN) before and after 30 minutes of treatment in each group, followed by Coca Cola (-61.31±21.90) (P0.05). When comparing changes in surface microhardness over time, Jinro Grapefruit+Calcium (pH 3.75) had slightly lower surface microhardness than Chamisul, but the difference was not statistically significant. Jinro Grapefruit+Calcium has a lower surface microhardness change value than Coca-Cola and grapefruit dew group (P

Impact of COVID-19 on dental technicians

Eun-Jeong Bae

Abstract : Objectives: The purpose of this study is to investigate the impact of COVID-19 on dental technicians and dental laboratories. Methods: In June 2020, self-reported questionnaires were distributed to and completed by dental technicians who attended the Seoul Dental Technologist Association’s academic conference (n=210). The responses were cross analyzed with frequency analysis (α=0.05). Results: Due to COVID-19, the number of employees has decreased to less than 20%, and sales of dental laboratories have decreased by 21-40%. On the Likert 5-point scale for individual precautions, ‘I wear a mask when using public transportation’ was the highest at 4.80. If infected with COVID-19, ‘my family’s infection is most concerned’ was the highest 3.89, but there was no significant difference between having children under the age of 13 in the family and having an elderly family over 65 years old (P>0.05). Conclusions: To prevent infection by dental technicians, it is mandatory to check body temperature when going to work and refrain from eating while working. As COVID-19 continues for a long time, it is necessary to continuously investigate the status of infected persons among dental technicians and vaccination rates as health care workers.

A study on the oral environment improvement effect of centella asiaticca extract and dentifrice containing potassium nitrate and potassium glyciric acid

Keum-Sun Lee , Da-Hui Kim , Ja-Won Cho , Chan-Ho Kim , Jin-young Lee , Ji-Hyeon Park

Abstract : Objectives: This study aimed to evaluate the effect of detergents containing a centella quantitative extract and dipotassium glycyrrhizinate and potassium nitrate on patient hygiene performance index, gingivitis index, gingival bleeding index, EPT, and halitosis. Methods: A parallel comparison, randomized, double-blind, controlled trial was conducted for 8 weeks with 60 adult men and women as participants. Results: According to the PMA index, gingival index of Talbott, gingival hemorrhage index, Turesky’s plaque index, and bad breath measurement, there was a statistically significant difference between the experimental group and the control group after 4 weeks (P

Effect of commercial pomegranate drink on the tooth enamel surface

Ka-Young Jung , Ji-Eun Kim , Choong-Ho Choi

Abstract : Objectives: This study examines the pH and titratable acidity of pomegranate drinks sold in Korea to identify the risk of dental erosion, and to provide basic data for oral health when consuming such drinks. Methods: The experiment included 5 groups: As experimental drinks, Sunkist pomegranate (Group A), Beauty liked pomegranate (Group B), Pomegranate juice 100 (Group C) were selected, and Jeju Samdasoo and Coca-Cola were selected for negative and positive controls. The components of the experimental beverage were analyzed, and the degree of erosion was measured using the Vickers hardness number (VHN) and by scanning electron microscope images. Results: When comparing the surface microhardness before and 30 minutes after beverage immersion, there was a significant difference in the positive control group, Group A, Group B, and Group C (P0.05). The difference in surface microhardness (ΔVHN) was found in Group C (-117.33±17.41), Group A (-112.90±15.19), the positive control group (-103.80±13.23), Group B (-90.82±24.60), and the negative control group (-13.44±14.60), in that order. The positive control group, Group A, Group B, and Group C showed a significant difference from the negative control group (P

Changes in the oral health and tooth brushing habits of upper grade primary school children according to the composition of the tooth brushing environment of the school

Su-Kyung Jwa

Abstract : Objectives: This study aimed to provide basic data on the establishment of tooth brushing classrooms in elementary schools in South Korea. The basic data was gathered by investigating the upper-grade children’s oral health and brushing habits according to the tooth brushing environment in their respective elementary schools. Methods: A researcher compared the changes in dental caries and oral hygiene status with the Repeated Measure ANOVA in 137 elementary school students from three elementary schools. Results: The results of oral hygiene status, the Gingivitis Index, the use of the tooth brushing facility, and the number of times students brushed their teeth each day were all compared for all three years of the study. Group A (classroom-type), with a classroom-style tooth brushing facility next to the cafeteria, showed more improvement than Groups B (new classroom-type) and C (corridortype). Conclusions: In order to make tooth brushing a habit, the tooth brushing facility should be constructed in the form of a classroom with good accessibility to the cafeteria. An active and practical form of education will need to be provided by the school teacher to help children form this habit.

Oral disease prevention effect of ginkgo-leaf-extract-containing-dentifrice

Byung-Hoon Kim , Kyong-Hoon Shin , Ja-Won Cho , Ji-Hyeon Park

Abstract : Objectives: The study evaluated the effects of dentifrice with the proper amount of ginkgo biloba extract in the prevention of gum disease through clinical trials. Methods: Total sixty volunteers from the experimental group using experimental dentifrice (30 volunteers) and the control group using control dentifrice (30 volunteers) should use the experimental and control dentifrice for 8 weeks. Before the experiment, and 1, 2, 4, 6, and 8 weeks after the experiment, the papillary marginal attached gingival Index (the PMA index), Talbott’s gingival index, patient hygiene performance index (PHP index), and Tureski’s dental plaque index test were tested six times. Results: As a result of the PMA index measurement, the experimental and control groups showed statistically significant differences after 6 weeks, and the experimental group showed a significant decrease in the PMA index from 4 weeks after the experiment. The patient hygiene performance index measurement results showed a statistically significant difference between the experimental group and the control group after 4 weeks, and the experimental group showed a significant decrease in the PHP index 2 weeks after the experiment. Conclusions: The use of ginkgo-leaf-extract-containing-dentifrice confirmed that improved dental plaque removal, gingivitis relief, and periodontal disease prevention could be expected.

Corrigendum: 3D motion analysis of cervical spine joints of dental hygiene students and dental hygienists during scaling operation