• Medical Lasers
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• v.10 no.4
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• pp.214-219
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• 2021

Background and Objectives To evaluate the difference in near-infrared (810 nm) laser energy transmission through teeth with and without cracks. Materials and Methods Extracted teeth were sectioned and examined visually for the presence of cracks with the aid of photographs and a trans-illuminator. Fourteen sections, each with cracks (Group A) and no cracks (Group B) were identified and placed 15 mm from the tip of a 300 micron fiber, prior to activation with an 810 nm diode laser (0.1W, 50 ms interval,100 ms duration). A power meter positioned behind the tooth recorded the average energy that was transmitted through the samples. Unpaired t-test analysis was used to determine if the tooth sections with cracks allowed higher power passage compared to sound teeth. Results The mean power recording for the cracked teeth (Group A) was significantly greater (p = 0.0005) than that for the non-cracked teeth (Group B). Conclusion Within the limitations of this study, it is evident that significantly higher laser energy passes through teeth with cracks in comparison to teeth without cracks. A recent clinical study has also shown that lasers could be used to assess symptomatic cracked teeth. Hence, further research is required to determine the relative increase in energy required to identify symptomatic cracked teeth.

• The Journal of the Korean dental association
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• v.57 no.7
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• pp.403-411
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• 2019

A cracked tooth is defined as an incomplete fracture initiated from the crown and extending subgingivally and usually directed mesiodistally. Cracked teeth were most frequently involved in mandibular and maxillary molars at the age of 50s. Cracks occurred mainly in nonbonded restorations such as gold and amalgam, and majority of cracks were found in intact teeth. A pulpal and periapical diagnosis is dependent on the extent of the crack and duration of the symptom. The pulp of a cracked tooth might become inflamed because of microleakage, which induces thermal sensitivity. Once the crack has extended and exposed the pulp, severe pulp and periapical pathosis will likely be present. In addition, the extended crack can cause a bony dehiscence with a resulting narrow and deep periodontal pocket. Therefore, early diagnosis of the cracked tooth and proper treatment planning are important for clinician.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.3
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• pp.305-316
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• 2011

Cracked teeth are a common problem with incomplete fracture that typically shows pain on biting and temperature stimuli. The most common cause of crack is known to be the masticatory accident. Predisposing factors were aging, old restoration, and iatrogenic stress concentration, etc. Accurate diagnosis is needed for detecting the extent of crack and pulp vitality. There are many diagnostic tools like bite test, direct observation with transillumination, dye penetration, and radiographs. Immediate treatment for pain relief and occlusal adjustment would be needed. Composite resin and bonded amalgam showed favorable prognosis. Moreover, cusp protection is reliable permanent treatment for cracked teeth. The purpose of this article is to review the literature about the prevention, diagnosis, and treatment for cracked teeth.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.3
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• pp.271-280
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• 2021

Purpose. The aim of this study was to evaluate the relationship between the patient's occlusion and a cracked tooth by using T-scan occlusal analysis and a quantitative light-induced fluorescence (QLF) technology. Materials and methods. This study was carried out on 51 patients having cracked teeth between January, 2019 and December, 2020. The tooth crack was determined with a Q-ray pen and QLF parameters (ΔF_max and ΔR_max) were obtained by a Q-ray software. T-scan tests were conducted to all subjects and then, the occlusal force and disclosing time were analyzed. Mann-Whitney U test was performed to compare the occlusal force and disclosing time between cracked teeth groups and contra-lateral normal teeth groups (α = .05). Mann-Whitney U test was performed to compare ΔF_max and ΔR_max according to the results of cold/bite tests (α = .05). A Spearman correlation analysis was run to determine the relationship between ΔF_max or ΔR_max and occlusal force or disclosing time (α=.05). Results. The mean occlusal force and disclosing time were significantly higher on cracked teeth than on normal teeth (P < .05). The ΔF_max or ΔR_max were not significantly different according to the results of cold/bite tests (P > .05). There was no correlation between ΔF_max or ΔR_max and occlusal force or disclosing time (P > .05). Conclusion. There was a significant relationship between occlusion and cracked tooth syndrome. QLF has the potential to be a valuable tool for the diagnosis of tooth crack in clinical practice.

• The Journal of Korean Society for School & Community Health Education
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• v.8 no.2
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• pp.49-59
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• 2007

Objectives: This study was designed to understand the oral health fact of high school students, search for an education method and learning goal appropriate for the subjects, and utilize them as basic data to think of effective solutions for oral health care. Methods: The samples to achieve the purpose of this research are composed of 386 students in J industrial high school, OO city, Kyounggido, the number of male students 286, and female students 100. Data were statistically analyzed by frequency analysis, cross tabulation by using SPSS WIN Ver. 12.0. Results: First, The answers in terms of oral symptoms were in the order of 31.8% for gum hurt and bleeding, 31.4% for pain in teeth by drinking or eating hot and cold drinks or food, 27.1% for broken or cracked teeth, 25.7% for aching and throbbing teeth, 20.6% for unpleasant mouth smell, and 5.7% for pain of tongue and soft oral tissues. Second, In terms of behavior for oral health, 88.4% answered that they consume cariogenic snacks, while 29.2% of them, 2.5% of male and 6.3% of female enjoy consuming them but hardly brush their teeth after consumption. Third, In terms of timing for brushing teeth, the results show that 50.0% do so before breakfast, 47.9% after breakfast, 15.2% after lunch, 36.9% after dinner, 65.5% before going to sleep, and 3.5% after consuming snacks, whereas 64.2% answered that they are not aware of fluorine mouthwash. Fourth, In terms of oral health condition. proportion of children with one or more caries in permanent teeth was 71.0%, while 51.4% have $2{\sim}3$ cariogenic teeth, and 16.8% have more than 4 cariogenic teeth. Considering sex, female students have somewhat higher ratio showing 68.5% for male and 78.0% for female, but the ratio was 53.1% for male and 46.7% for female in case of $2{\sim}3$ cariogenic teeth, and 17.5% for male and 15.8% for female in case of more than 4 cariogenic teeth. 9.3% of students turned out to have decayed teeth. Fifth, In terms of oral hygiene condition, only 7.9% of them had excellent condition, and 38.4% need to improve. More specifically, 41.1% of male students and 30.6% of female students need to improve their oral hygiene condition. Conclusions: The study results suggest that School Dental health programs increase and need to be community-incorporated and comprehensive from elementary to high school.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.508-515
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• 2011

Bovine incisor was investigated using active infrared thermography(IRT) to visualize crack on bovine teeth. An artificial crack was carefully created in bovine incisor sample by compression load of universal tensile machine. While applying a sinusoidal heat wave to the cracked bovine incisor through halogen lamp, consecutive digital infrared images was captured from the sample surface at a frequency synchronized with heat excitation. Phase information of thermal image was calculated by four-point correlation method and processed to produce the phase image of bovine incisor. This phase image showed clearly the crack on the incisor, which was hardly detected in traditional passive thermography.

• Journal of Periodontal and Implant Science
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• v.47 no.1
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• pp.41-50
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• 2017

Purpose: The aims of the present study were to compare the image quality and visibility of tooth cracks between conventional methods and swept-source optical coherence tomography (SS-OCT) and to develop an automatic detection technique for tooth cracks by SS-OCT imaging. Methods: We evaluated SS-OCT with a near-infrared wavelength centered at 1,310 nm over a spectral bandwidth of 100 nm at a rate of 50 kHz as a new diagnostic tool for the detection of tooth cracks. The reliability of the SS-OCT images was verified by comparing the crack lines with those detected using conventional methods. After performing preprocessing of the obtained SS-OCT images to emphasize cracks, an algorithm was developed and verified to detect tooth cracks automatically. Results: The detection capability of SS-OCT was superior or comparable to that of trans-illumination, which did not discriminate among the cracks according to depth. Other conventional methods for the detection of tooth cracks did not sense initial cracks with a width of less than $100{\mu}m$. However, SS-OCT detected cracks of all sizes, ranging from craze lines to split teeth, and the crack lines were automatically detected in images using the Hough transform. Conclusions: We were able to distinguish structural cracks, craze lines, and split lines in tooth cracks using SS-OCT images, and to automatically detect the position of various cracks in the OCT images. Therefore, the detection capability of SS-OCT images provides a useful diagnostic tool for cracked tooth syndrome.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.298-305
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• 2016

The maxillary anteriors play an important role in esthetics. Therefore after extraction, it is crucial to preserve the hard tissue and soft tissue in order to promote esthetics of restoration. There are several challenges when restoring the maxillary anteriors via implant. Some of the challenges are be maintaining consistency with neighboring teeth in terms of shade, form, and texture : as well as having harmonious emergency with the gingival margin. In this case, a traumatized patient with crown-root fracture of the maxillary central and lateral incisors is presented. The cracked teeth were extracted, and implants were inserted with bone grafts to compensate the volume of damaged area of the maxillary anterior. Cantilever implant prosthetics were planned while precise adjustments to the gingival area were made using customized impression coping to perform the esthetic restorations. The final outcome of the treatment was satisfying in both esthetic and utilitarian perspective.

• Imaging Science in Dentistry
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• v.53 no.4
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• pp.345-353
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• 2023

Purpose: The objective of this study was to propose a method for developing a clinical phantom to reproduce various diseases that are clinically prevalent in the field of dentistry. This could facilitate diverse clinical research without unnecessarily exposing patients to radiation. Materials and Methods: This study utilized a single dry skull, which was visually and radiographically examined to evaluate its condition. Existing lesions on the dry skull were preserved, and other relevant lesions were artificially created as necessary. These lesions were then documented using intraoral radiography and cone-beam computed tomography. Once all pre-existing and reproduced lesions were confirmed by the consensus of 2 oral and maxillofacial radiologists, the skull was embedded in a soft tissue substitute. To validate the process, cone-beam computed tomography scans and panoramic radiographs were obtained of the fabricated phantom. All acquired images were subsequently evaluated. Results: Most lesions could be identified on panoramic radiographs, although some sialoliths and cracked teeth were confirmed only through cone-beam computed tomographic images. A small gap was observed between the epoxy resin and the bone structures. However, 2 oral and maxillofacial radiologists agreed that this space did not meaningfully impact the interpretation process. Conclusion: The newly developed phantom has potential for use as a standardized phantom within the dental field. It may be utilized for a variety of imaging studies, not only for optimization purposes, but also for addressing other experimental issues related to both 2- and 3-dimensional diagnostic radiography.

• Applied Microscopy
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• v.30 no.3
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• pp.285-293
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• 2000

The present study has been carried out to investigate the effect of fluoride toxicity on the morphology as well as inorganic chemical constituents of rat teeth. Rats were administered sodium fluoride at dose of 0 ppm, 100 ppm, 200 ppm and 300 ppm at the beginning of pregnancy. Animals were perfused intravascularly with glutaraldehyde and the incisors were removed. Changes in the protein composition of the secretory and maturation enamel were investigated using polyacrylamide gel electrophoresis (SDS PAGE). And the enamel surface of incisors was examined under scanning electron microscope (SEM). Changes of protein quantities were found significantly in high levels fluoride administration for experimental groups compared with control. The SDS PAGE analysis demonstrated as follows In control group, secretory phase enamel protein, amelogenins, was detected more quantities than experimental group. The enamelin, presence in maturation phase enamel , showed more quantifies than control enamel with an increasing fluoride concentration in the drinking water. Also, the scanning electron micrographic data showed hypoplastic, tough, uneven, pitted and cracked enamel surfaces covered with granular deposits as a result of excessive intake of fluoride. From these results we conclude that high dose of fluoride administration leads to severe structural alterations on the enamel surface and these structural changes could be through defective mineralization.