Teaching Cariology in Asia and Arabia.

The European Organisation for Caries Research education platform 2020 had the aim to assess the undergraduate curriculum in cariology in Asian and Arabian countries in order to support structured teaching of cariology in these countries with about almost half of the global population. Representatives of 4 Asian and 4 Arabian countries completed a comprehensive questionnaire on structure of dental education in their country in general and the extent, the content, the responsibilities, structure and standardization regarding cariology in particular. In spite of a wide range from very few universities (Lebanon 3) to larger numbers of dental schools (India 313, China 121, Russia 52) there were similar statements on the list of content for cariology teaching. Often the catalogue was close to the Undergraduate Core Curriculum in Cariology (UCCC) covering most of the 5 domains from basic science to dental public health, but a national curriculum for cariology or dentistry was mostly missing. With various departments being involved, a need of coordination is obvious. Most representatives thought it possible and feasible to teach a standardized curriculum in cariology on the basis of the UCCC. In conclusion, many Arabian and Asian countries have implemented modern, evidence-based curricula in their universities, but an obligatory national curriculum in cariology would be advisable to standardize the quality in teaching.

Simple oral exercise with chewing gum for improving oral function in older adults.

BACKGROUND: As general and oral health are closely interrelated, promoting oral health may extend a healthy life expectancy. AIMS: To evaluate the long-term effects of simple oral exercise (SOE) and chewing gum exercise on mastication, salivation, and swallowing function in adults aged ≥ 65 years. METHODS: Ninety-six participants were assigned to control, SOE, and GOE (chewing gum exercise with SOE) groups. The SOE comprised exercises to improve mastication, salivation, and swallowing function. Control group participants performed no exercises. The intervention period was 8 weeks, followed by a 3-week maintenance period. The Mixing Ability Index (MAI), occlusal force, unstimulated saliva, and repetitive saliva swallowing test were evaluated at baseline and 2, 5, 8, and 11 weeks later. Self-reported discomfort was re-evaluated after 8 weeks. RESULTS: After 8 weeks, mean MAI differences from baseline significantly increased in both groups; the increase in the GOE group was largest and four times higher than in the control group. Mean differences of occlusal force from baseline increased by 56 N (SOE group) and 60 N (GOE group). The increase of salivation was greater in the SOE (3.6-fold) and GOE (2.2-fold) groups than in the control group. Furthermore, 27% and 18% of SOE and GOE group participants, respectively, were re-categorized as having good swallowing function. Participants reported less discomfort as oral functions improved. DISCUSSION: These findings may facilitate the development of clinical practice guidelines for optimal oral care in older adults. CONCLUSION: While both SOE and GOE may improve oral function in older adults, GOE is recommended for those with impaired mastication. TRIAL REGISTRATION: KCT0003305, retrospectively registered 31/10/2018.

Antimicrobial activity of Curcuma xanthorrhiza nanoemulsions on Streptococcus mutans biofilms.

In this study, an optimal nanoemulsion formulation for Curcuma xanthorrhiza oil (Xan) was investigated using different sonication times. The antimicrobial effects of the nanoemulsion, the original emulsion, distilled water (DW), and Listerine, on Streptococcus mutans biofilms were compared. The optimum ultrasonic time, determined in terms of droplet size and stability, was found to be 10 min. Cell viability was the lowest on exposure to the nanoemulsion, and significantly different compared with exposure to DW or Listerine. The emulsion's effect was similar to that of the nanoemulsion, but was non-uniform with a high interquartile range. Confocal microscope analysis revealed that the live/dead cell ratio in the nanoemulsion was 50% and 40% less than those in DW and Listerine, respectively. Biofilm treated with the nanoemulsion was thinner than biofilms exposed to the other treatments. Xan nanoemulsions exhibited stable and strong antimicrobial effects due to nano-sized particles, highlighting their potential use in oral health treatment.

Unilateral Mastication Evaluated Using Asymmetric Functional Tooth Units as a Risk Indicator for Hearing Loss.

BACKGROUND: Some previous studies reported hearing ability can be reduced by impaired masticatory ability, but there has been little evidence reported of an association between hearing loss and unilateral mastication. Therefore, this study aimed to investigate the relationship between unilateral mastication (UM), estimated from individual functional tooth units (FTUs), and hearing loss in a representative sample of Korean adults. METHODS: The analyzed data were obtained from 1,773 adults aged 40-89 years who participated in Korean national survey. Hearing loss was defined as a pure-tone average of >25 dB at frequencies of 0.5, 1, 2, and 4 kHz in either ear. In each subject, UM was calculated as the difference in the sums of the FTU scores, which is an index of posterior tooth occlusion, on the two sides of the oral cavity. The scores were used to classify the UM into low, moderate, and high. The adjusted odds ratios (aORs) and their 95% confidence intervals (CIs) were calculated in multivariable logistic regression analyses. RESULTS: When controlling for sociodemographic factors, the aOR for hearing loss was 3.12 (95% CI, 1.21-8.03) for high UM relative to low UM. This association remained in a fully-adjusted model containing factors related to noise exposure (aOR 2.88; 95% CI, 1.12-7.46). CONCLUSION: Adults with high UM as measured using FTUs showed a higher occurrence of hearing loss than those with low UM.

Does the national dental scaling policy reduce inequalities in dental scaling usage? A population-based quasi-experimental study.

BACKGROUND: In 2013, the national dental scaling insurance policy was introduced in South Korea. The purpose of this study is to determine the impact of the policy on inequalities in dental scaling usage. METHODS: Data of a nationally representative sample of 1,517,097 people over the age of 20 were obtained from the 2010-2016 Community Health Survey. Respondents who reported that they had not received dental scaling in the past year were defined as dental scaling non-users. The excess prevalence and relative prevalence ratio of dental scaling non-users were calculated for the pre-policy (2010-2012) and post-policy periods (2014-2016) using monthly household income levels. Additionally, trends of dental scaling inequalities were shown as concentration indexes. RESULTS: The prevalence of dental scaling non-users declined from 58.0 to 48.7% in the highest income group and from 86.3 to 78.8% in the lowest income group. However, the adjusted excess prevalence for the lowest income group compared with the highest had increased from 11.9 (95% CI: 11.9-11.9) to 15.5 (95% CI: 15.5-15.5)%, and the adjusted prevalence ratio increased from 1.19 (95% CI: 1.19-1.20) to 1.29 (95% CI: 1.29-1.30). Absolute and relative concentration indexes of dental scaling non-users increased after policy implementation. CONCLUSIONS: The national dental scaling insurance policy has increased socioeconomic inequalities in dental scaling usage. Because dental care access generally requires high individual agency, expanded dental coverage may have had limited effects in attenuating inequalities and inadvertently widened the gap. To reduce dental care inequalities, universal access with universal dental coverage should be considered.

Photodiagnosis of White Spot Lesions after Orthodontic Treatment with a Quantitative Light-induced Fluorescence-Digital System: A Pilot Study.

PURPOSE: To confirm that the quantitative light-induced fluorescence-digital (QLF-D) system is an adequate tool for monitoring changes in the mineral contents of white spot lesions. MATERIALS AND METHODS: Twenty-three anterior teeth from five orthodontic patients were selected for the samples. Initial fluorescent images were taken with the QLF-D system immediately after removing the fixed orthodontic appliances, and the white spot lesions were visualised in the fluorescent images that were selected. Subsequently, a fluoride varnish containing 0.1% fluoride was applied to all white spot lesions, and the final QLF-D images were taken two weeks after fluoride treatment. Finally, the following four parameters were compared between the images taken at baseline and two weeks after the treatment with paired t-tests: the mean fluorescence loss (∆F), maximum fluorescence loss (∆Fmax), lesion area (area), and lesion volume (∆Q). RESULTS: All the parameters obtained by QLF-D after two weeks had improved significantly when compared with baseline (p < 0.01). The recovery rates of the ∆F, ∆Fmax, area, and ∆Q were 11.4%, 17.1%, -37.5%, and 42.1%, respectively. Shallow lesions (∆Fi ≥ -15%) were better remineralized than deep lesions (∆Fi < -15%). The ratios of the ∆F, ∆Fmax, area, and ∆Q parameters between the shallow and deep lesions were 2.86, 3.30, 2.20, and 1.88, respectively. CONCLUSION: The QLF-D system is a sensitive tool for the assessment of small levels of mineral changes in carious lesions after the removal of orthodontic appliances.

Analysis of Orange/Red Fluorescence for Bacterial Activity in Initial Carious Lesions May Provide Accurate Lesion Activity Assessment for Caries Progression.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Orange/Red Fluorescence of Active Caries by Retrospective Quantitative Light-Induced Fluorescence Image Analysis. Gomez GF, Eckert GJ, Zandoná AF.Caries Res 2016; 50(3):295-302. SOURCE OF FUNDING: The study was partially supported by a grant from NIH/NIDCR (R01DE017890) TYPE OF STUDY/DESIGN: Retrospective case-control design using the data collected in a longitudinal study.

The New Marginal Plaque Index May Allow a More Valid Assessment of Gingival Plaque Level Than the Turesky Modification of the Quigley and Hein Index.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Establishment of a new marginal plaque index with high sensitivity for changes in oral hygiene. Deinzer R, Jahns S, Harnacke D. J Periodontol 2014; 85(12):1730-8. SOURCE OF FUNDING: The study was supported by a sponsorship from GABA International, Therwil, Switzerland. TYPE OF STUDY/DESIGN: Observational case-control study.

Measures of Dynamic Chewing Function, Rather than the Number of Teeth, are a Better Predictors of the Elderly's Ability to Intake Food and Nutrients.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Dietary intake is associated with occlusal force rather than number of teeth in 80-y-old Japanese. Inomata C, Ikebe K, Okubo H et al. J Dent Res 2016;2(2):187-97. SOURCE OF FUNDING: The study was supported by a Grant-in-Aid for Scientific Research (Nos. 23390440 and 25293394) from the Japan Society for the Promotion of Science TYPE OF STUDY/DESIGN: Cross-sectional study.

Explaining the Red Fluorescence Evident on the Surface of Failed Dental Implants: Case Reports.

INTRODUCTION: It is important to identify the reasons for implant failure when planning future dental treatment. No studies have distinguished the factors that affect implant failure by evaluating the appearance of failed fixtures. PURPOSE: This study investigated these factors by evaluating the surface of implant fixtures using quantitative light-induced fluorescence-digital (QLF-D), which involves detecting the red fluorescence emitted by porphyrin metabolized by oral bacteria in a mature biofilm. MATERIALS AND METHODS: The areas of red fluorescence in QLF-D images obtained from all aspects of the fixture surface were then analyzed using quantitative analysis software. RESULTS: Red fluorescence was evident on the surface of implants that failed after at least 2 years of occlusal loading and exhibited severe bone loss. Implants with no fluorescence exhibited a clean surface in blue-light images, and the bone loss could not be observed radiographically. CONCLUSIONS: The cases presented that failed dental implant surfaces caused by periimplantitis can be detected by the red fluorescence evident as QLF-D.

Can the Application of Fluoride Iontophoresis Improve Remineralisation of Early Caries Lesions?

PURPOSE: To determine the optimal electric current intensity of fluoride iontophoresis (FI) for remineralisation of early caries lesions in vitro. MATERIALS AND METHODS: Sixty specimens were made from bovine incisors and immersed in a demineralising gel for 96 h. Specimens were divided into control (conventional fluoride application) and experimental (FI) groups. All of the specimens were covered with fluoride for 4 min every day. Different electric current intensities (100, 200, 300 and 400 µA) were applied in the FI groups using the FI device. The concentration of KOH-soluble fluoride was determined to evaluate the amount of CaF2 formed on the tooth surface. The reduction in lesion depth was measured by polarised light microscopy. RESULTS: The concentration of KOH-soluble fluoride was the highest in the specimens of the 300 µA FI group. However, there was no significant difference in the reduction of lesion depth between the experimental groups and the control group. CONCLUSION: Variations in the electric current intensity influenced the amount of CaF2 formed on the enamel surface, with the greatest amount found for 300 µA.

Clinical Assessment of a New Caries Activity Test Using Dental Plaque Acidogenicity in Children under Three Years of Age.

OBJECTIVES: The aim of this study was to assess the validity of a new caries activity test that uses dental plaque acidogenicity in children with deciduous dentition. STUDY DESIGN: Ninety-two children under the age of three years old underwent clinical examination using the dft index and examinations with two caries activity tests. Plaque samples for the new Cariview(®) test and the saliva sample for the conventional Dentocult SM(®) test were collected, incubated, and scored according to each manufacturers' instruction. The data were analysed using ANOVA and Spearman correlation analyses to evaluate the relationships between the test results and the caries experience. RESULTS: The mean dft index of all of the subjects was 4.73, and 17.4% of the subjects were caries-free. The levels of caries risk based on the new Cariview test score significantly increased with the caries experience (p < 0.01). The test results revealed a stronger correlation with caries indices (dft and dt index) than the conventional SM colony counting method (r = 0.43, r = 0.39, p < 0.01). CONCLUSIONS: The new caries activity test to analyse the acidogenic potential of whole microorganisms from dental plaques can be used to evaluate caries risk in children with deciduous teeth.

Impact of malocclusion and common oral diseases on oral health-related quality of life in young adults.

INTRODUCTION: The aim of this study was to assess the association between malocclusion and oral health-related quality of life in young adults without orthodontic treatment, controlling for sociodemographic factors and common oral diseases. METHODS: The sample consisted of 429 Korean patients (328 men, 101 women) 18 to 32 years of age. They completed the Korean version of the oral health impact profile-14 questionnaire and had a clinical examination, including an assessment with the index of orthodontic treatment need-dental health component. We collected sociodemographic information (age, sex, and education level) and evaluated other common oral diseases (decayed, missing, and filled teeth; periodontal health status; temporomandibular disorder; and oral soft tissue diseases). RESULTS: Multiple logistic regression analysis showed that patients requiring extensive orthodontic treatment were more than 2.7 times as likely to have poor oral health-related quality of life as the corresponding "no treatment needed" reference group (odds ratio, 2.74; 95% confidence interval, 1.60-4.59; P <0.001). Severe malocclusion is significantly associated with functional limitations, physical pain, and social disability in young adults. CONCLUSIONS: Malocclusion is a key factor associated with poor quality of life caused by limited oral function, pain, and social disability in young adults.

Detection of pit and fissure sealant microleakage using quantitative light-induced fluorescence technology: an in vitro study.

This in vitro study aimed to evaluate the feasibility of quantitative light-induced fluorescence (QLF) technology for detecting the presence and severity of microleakage of pit and fissure sealants. The areas of interest (AOIs) were 160 pits and fissures of 40 extracted permanent teeth. Fluorescent images were acquired using a QLF device, and the maximum fluorescence loss ΔFmax of each AOI was analyzed. After staining and cross-sectioning of the teeth, histological dye penetration was scored on a scale of 0 to 3. The relationship between ΔFmax and microleakage depth was analyzed, and the areas under the curve (AUCs) were calculated. The │ΔFmax│ increased as microleakage depth increased. The ΔFmax values of microleakage areas showed a strong significant correlation with the histological scores of dye penetration (r = - 0.72, P = 0.001). AUC analysis showed a high diagnostic accuracy for microleakage depth (AUC = 0.83-0.91). The highest AUC of 0.91 was found when differentiating the outer half microleakage of the sealant (histological score 0 vs. 1-3). QLF technology is effective in assessing the presence and severity of microleakage, suggesting its potential for noninvasive detection and monitoring of sealant microleakage in clinical settings.

Distinguishing discolored caries lesions using biofluorescence and dental bleaching: An in vitro simulation model study.

BACKGROUND: Distinguishing between discoloration caused by caries and organic stains is challenging for dentists in clinical settings. Biofluorescence (BF)-bleaching assesses caries lesions by evaluating BF changes after removing organic stains through dental bleaching, leaving cariogenic discoloration. This study aimed to apply BF-bleaching to a simulation model mimicking cariogenic discoloration and compare the BF color changes between organic staining and cariogenic discoloration. METHODS: Thirty artificial caries lesions in bovine incisors were equally divided into three groups: non-stained (NS), organic-stained (OS), and cariogenic-stained (CS) groups. The specimens were treated with bleaching agent, then BF color of each specimen was evaluated using red BF intensity (ΔR), BF hue angle (h°), and hyperspectral BF spectrum. RESULTS: The ΔR of CS was approximately 2.74 and 1.73 times higher than that of OS, at baseline and after bleaching for 20 min, respectively. After 20 min of bleaching, the h° of CS increased by approximately 8.1° compared to the baseline, while maintaining the red BF hue range (345‒15°). In contrast, the BF hue of OS shifted from orange (15‒45°) to yellow (45‒75°) simultaneously, and the h° change was approximately 21.9°. Both CS and OS exhibited first emission peaks near 515 nm, and CS showed second peaks in the red range (620‒780 nm). After bleaching, the first peaks were restored to the sound enamel direction (peak at 486 nm), whereas the second peaks of red BF in CS were maintained. CONCLUSION: Applying BF-bleaching to discolored caries lesions allowed differentiation between cariogenic discoloration and organic staining based on BF color changes.

Drug delivery and antibiofilm efficacy of nano silver fluoride sustained release orthodontic elastomerics against Streptococcus mutans.

We aimed to investigate the chemical and physical properties of nano silver fluoride sustained release orthodontic elastomerics (NSF-RE) and determine their antimicrobial and antibiofilm formation activities against Streptococcus mutans. Orthodontic elastomerics were dip-coated with NSF solution in ethyl cellulose (EC) and polyethylene glycol 6000 (PEG). The studied groups included NSF (no EC/PEG), NSF-E (EC), NSF-EP1 (EC:PEG, 4:1), and NSF-EP2 (EC:PEG, 2:1). The cumulative release of silver nanoparticles (AgNPs) and fluoride, along with the compatibility of the tensile force with orthodontic brackets, was evaluated. The antimicrobial activity was evaluated using an agar diffusion test. The inhibition of biofilm formation was evaluated using colony-forming units (CFUs), biofilm thickness, and the live/dead cell ratio. NSF-RE containing EC sustained the release of AgNPs and fluoride for > 7 days. Tensile forces were not significantly different among the groups. The inhibition zone was 2.64- and 1.31-fold larger with NSF-EP2 than that with NSF and NSF-E, respectively. NSF-EP2 was the most effective in inhibiting biofilm formation with significant reductions in CFUs, biofilm thickness, and live/dead cell ratio by 57, 86, and 96%, respectively, as compared to those in the control group. Overall, sustained release of AgNPs and fluoride by NSF-RE provides antimicrobial and antibiofilm effects against S. mutans.

Anti-biofilm activity of a novel nanoemulsion containing Curcuma xanthorrhiza oil.

OBJECTIVES: We aimed to solubilize Curcuma xanthorrhiza oil (CXO) using nanoemulsification and evaluate its inhibitory effects against biofilm formation. METHODS: The components of CXO were evaluated through high-performance liquid chromatography (HPLC) analysis. Healthy human saliva was inoculated onto hydroxyapatite discs to form microcosm biofilms for four days and treated six times with each antimicrobial agent: distilled water (DW), CXO emulsion (EM), CXO nanoemulsion (NE), and positive controls (Listerine and chlorhexidine). Biofilm fluorescence imaging was performed using quantitative light-induced fluorescence, and cell viability and dry-weight measurements were obtained. We compared the bacterial cell and extracellular polysaccharide (EPS) biovolume and thickness using confocal laser scanning microscopy (CLSM). RESULTS: HPLC analysis revealed that CXO was composed of approximately 47% xanthorrhizol. Compared with DW, NE exhibited significantly lower red fluorescence intensity and area (42% and 37%, p < 0.001 and p < 0.001, respectively), and reduced total and aciduric bacterial cell viability (7.3% and 3.9%, p < 0.001, p = 0.01, respectively). Furthermore, the bacterial cell and EPS biovolume and thickness in NE decreased by 40-80% compared to DW, similar to chlorhexidine. Conversely, EM showed a significant difference only in cell viability against total bacteria when compared with DW (p = 0.003), with EPS biovolume and thickness exhibiting higher values than DW. CONCLUSIONS: Nanoemulsification successfully solubilized CXO and demonstrated superior anti-biofilm effects compared to the emulsion form. CLINICAL SIGNIFICANCE: These findings suggest the potential use of NE as a novel antimicrobial agent for preventing oral diseases.

Real-time optical detection of endodontic infection using bacterial autofluorescence.

OBJECTIVES: For successful root canal treatment (RCT), it is essential to objectively assess the presence and activity of bacteria in the root canal system. However, current methods rely on subjective observations of root canal exudates. This study aimed to confirm whether real-time optical detection using bacterial autofluorescence can evaluate endodontic infection status by assessing the red fluorescence (RF) detected from root canal exudates. METHODS: During RCT, endodontic paper points were used to collect root canal exudates scored using conventional organoleptic tests to assess the severity of root canal infections. RF on the paper points was assessed using quantitative light-induced fluorescence (QLF) technology. RF intensity and area from the paper points were quantified, and their correlations with infection severity were assessed using their organoleptic scores. The oral microbiome composition of RF samples was compared with non-red fluorescent (non-RF) samples. RESULTS: The RF detection rate was nil and >98% in the non-infectious and severe groups. The RF intensity and area significantly increased with infection severity (p<0.001) and showed strong correlations with organoleptic scores (r=0.72, 0.82, respectively). The diagnostic accuracy for detecting root canal infection using RF intensity was good to excellent (AUC = 0.81-0.95) and increased with infection severity. The microbial diversity of the RF samples was significantly lower than that of the non-RF samples. Gram-negative anaerobic bacteria such as Prevotella and Porphyromonas were more predominant in RF samples. CONCLUSIONS: Optical detection using bacterial autofluorescence can objectively evaluate endodontic infection status in real-time by assessing the RF of endodontic root canal exudates. CLINICAL SIGNIFICANCE: This real-time optical technology can be utilised to detect endodontic bacterial infection without conventional incubation, allowing clinicians to determine the endpoint of chemomechanical debridement and increase the positive outcomes of RCTs.

A novel model to predict tooth bleaching efficacy using autofluorescence of the tooth.

OBJECTIVES: We aimed to confirm whether autofluorescence emitted from teeth can predict tooth bleaching efficacy and establish a novel model combining natural color parameters and tooth autofluorescence data to improve the predictability of tooth bleaching. METHODS: A total of 61 tooth specimens were prepared from extracted human molars/premolars and immersed in 35% hydrogen peroxide for 1 h for tooth bleaching. The changes in laser-induced fluorescence (∆LIF) were assessed using Raman spectrometry. Tooth color and autofluorescence data were obtained using quantitative light-induced fluorescence (QLF) technology. Pearson correlation analyses were used to confirm the relationship between ∆LIF and autofluorescence. Intraclass correlation coefficients (ICC) were calculated to compare the conventional and new prediction models. Decision tree analysis was performed to evaluate clinical applicability. RESULTS: The yellowness-to-blueness value from fluorescence imaging showed a moderate correlation with ∆LIF (r= -0.409, p = 0.001). The degree of agreement between the actual efficacy and that predicted by our novel model was high (ICC=0.933, p = 0.002). Decision tree analysis suggested that tooth autofluorescence could be a key factor in prediction of tooth bleaching outcomes. CONCLUSIONS: Our findings showed that autofluorescence detected from QLF images may be used to predict tooth bleaching efficacy. Our proposed model appeared to improve the predictability of tooth bleaching.

Red fluorescence for assessing longitudinal tooth fractures.

BACKGROUND: This study was designed to determine whether autofluorescence emitted from longitudinal tooth fractures (LTFs) differs between fracture types, with the aim of determining which clinical factors are related to red fluorescence at the fracture line. METHODS: Thirty-three extracted teeth were classified into cracked teeth, split teeth, and root fractures using LTF types according to the American Association of Endodontists classification. The types of LTFs were identified using an operating microscope. LTF autofluorescence was captured using a fluorescence technique. Clinical examinations were performed using the preoperative factors from clinical and radiographic findings. RESULTS: Red fluorescence was identified in 82% and 83% of cracked and split teeth, respectively. None of the vertical root fractures exhibited red fluorescence (p<0.001). When red fluorescence was identified on the outer tooth surface, it penetrated into the crack line, but fluorescence that was not red at the tooth surface did not penetrate the fracture line. Among the examined preoperative clinical factors, differences between the presence and absence of red fluorescence were identified for sinus tract formation (p = 0.021), and radiographic features (p = 0.027). Regression analysis revealed a significant factor related to the red fluorescence, with sinus tract formation having a negative effect on red fluorescence (odds ratio [OR]=0.09). The presence of comprehensive periradicular lesions in radiography had a positive effect on red fluorescence (OR=5.04). CONCLUSIONS: Cracks originating from tooth crowns in certain types of LTFs were associated with red fluorescence, and cracks with red fluorescence were associated with extensive periodontal bone resorption around the teeth roots.