Tooth Crown Research Articles

Clinical experience of tooth replantation

Relevance. Modern dental practice strives, above all, to preserve teeth. A variety of operations aimed at this include dental replantation. Replantation is used in cases where there are difficulties with the root canals, such as their pathological bending or previous treatment with the resorcinol-formalin method, and also when root resection is impossible due to the risk of damage to surrounding structures, for example, the maxillary sinus or the inferior alveolar nerve.The purpose of this study was to study the osseointegration of a replanted tooth subjected to coronoradicular separation. Materials and methods. Thirty-one-year-old patient K. came to the dental clinic with the problem of pain in the projection of tooth 4.6, which occurs during chewing. A detailed examination revealed that the crown of tooth 4.6 had previously undergone restoration using a filling material that had defects. It was decided that tooth 4.6 should be removed and subsequently replanted. The tooth was extracted according to established procedures, while maximally preserving the surrounding periodontal and periosteal tissues. To preserve periodontal tissues, alveolar curettage was carefully performed. During the extraction of the tooth, it was longitudinally divided into two parts – the medial and distal roots. After this, the root canals were treated using extraoral therapy. The roots of tooth 4.6, treated with an antiseptic, were returned to their anatomical positions in the alveolus. The final stage was the creation of a control x-ray to verify the correctness of the replantation. Conclusions. After two years of observation of tooth 4.6, which was subjected to replantation, no pathological changes in root stability were detected. It was reported that the soft tissue surrounding the roots of the tooth formed a structure similar to the periodontal sulcus, which facilitated the use of retraction cord during tooth preparation.

Automatic 3-dimensional quantification of orthodontically induced root resorption in cone-beam computed tomography images based on deep learning

Orthodontically induced root resorption (OIRR) is a common and undesirable consequence of orthodontic treatment. Traditionally, studies employ manual methods to conduct 3-dimensional quantitative analysis of OIRR via cone-beam computed tomography (CBCT), which is often subjective and time-consuming. With advancements in computer technology, deep learning-based approaches have gained traction in medical image processing. This study presents a deep learning-based model for the fully automatic extraction of root volume information and the localization of root resorption from CBCT images. In this cross-sectional, retrospective study, 4534 teeth from 105 patients were used to train and validate an automatic model for OIRR quantification. The protocol encompassed several steps: preprocessing of CBCT images involving automatic tooth segmentation and conversion into point clouds, followed by segmentation of tooth crowns and roots via the Dynamic Graph Convolutional Neural Network. The root volume was subsequently calculated, and OIRR localization was performed. The intraclass correlation coefficient was employed to validate the consistency between the automatic model and manual measurements. The proposed method strongly correlated with manual measurements in terms of root volume and OIRR severity assessment. The intraclass correlation coefficient values for average volume measurements at each tooth position exceeded 0.95 (P<0.001), with the accuracy of different OIRR severity classifications surpassing 0.8. The proposed methodology provides automatic and reliable tools for OIRR assessment, offering potential improvements in orthodontic treatment planning and monitoring.

Bank vole genomics links determinate and indeterminate growth of teeth

BackgroundContinuously growing teeth are an important innovation in mammalian evolution, yet genetic regulation of continuous growth by stem cells remains incompletely understood. Dental stem cells responsible for tooth crown growth are lost at the onset of tooth root formation. Genetic signaling that initiates this loss is difficult to study with the ever-growing incisor and rooted molars of mice, the most common mammalian dental model species, because signals for root formation overlap with signals that pattern tooth size and shape (i.e., cusp patterns). Bank and prairie voles (Cricetidae, Rodentia, Glires) have evolved rooted and unrooted molars while retaining similar size and shape, providing alternative models for studying roots.ResultsWe assembled a de novo genome of Myodes glareolus, a vole with high-crowned, rooted molars, and performed genomic and transcriptomic analyses in a broad phylogenetic context of Glires (rodents and lagomorphs) to assess differential selection and evolution in tooth forming genes. Bulk transcriptomics comparisons of embryonic molar development between bank voles and mice demonstrated overall conservation of gene expression levels, with species-specific differences corresponding to the accelerated and more extensive patterning of the vole molar. We leverage convergent evolution of unrooted molars across the clade to examine changes that may underlie the evolution of unrooted molars. We identified 15 dental genes with changing synteny relationships and six dental genes undergoing positive selection across Glires, two of which were undergoing positive selection in species with unrooted molars, Dspp and Aqp1. Decreased expression of both genes in prairie voles with unrooted molars compared to bank voles supports the presence of positive selection and may underlie differences in root formation.ConclusionsOur results support ongoing evolution of dental genes across Glires and identify candidate genes for mechanistic studies of root formation. Comparative research using the bank vole as a model species can reveal the complex evolutionary background of convergent evolution for ever-growing molars.

MANEJO DO SORRISO GENGIVAL ATRAVÉS DO USO DA TOXINA BOTULÍNICA TIPO A

An aesthetically pleasing smile results from the combination of several factors, such as the position, size, shape, and color of the teeth, as well as the exposure and characteristics of the gingival tissue. When evaluating the gingival tissue in a smile, several important factors must be considered: excessive vertical growth of the maxilla, reduced length of the upper lip, excessive contraction of the upper lip, and disproportion between the length and width of the clinical crown of the anterior teeth. A minimally invasive approach that can be used as a complement to dental treatment is the application of botulinum toxin, a neurotoxin produced by the anaerobic bacterium Clostridium botulinum. This toxin blocks the release of acetylcholine in the presynaptic vesicles of neuromuscular junctions, inhibiting muscle contraction. The aim of this literature review was to analyze the use of botulinum toxin type A (BTX-A) in the management of gummy smile. The search was conducted in the databases Google Scholar, PubMed, Latin American and Caribbean Health Sciences Literature (LILACS), and Scientific Electronic Library Online (SciELO). The descriptors used for the search were "botulinum toxin," "gingiva," "periodontology," and "dental aesthetics," combined using the boolean operators AND and OR. Although the evidence demonstrates favorable results, the use of botulinum toxin to correct gummy smile has limitations. It is a temporary solution, and patients should be informed about the need for periodic reapplications and the potential side effects, such as facial asymmetries. The reviewed studies indicate that this technique is particularly effective in cases of gummy smile resulting from hyperactivity of the upper lip elevator muscle, providing a significant reduction in gingival exposure, with results lasting up to 12 weeks. The combination of different therapeutic approaches, along with a careful evaluation of the causes of gummy smile, allows dental professionals to offer more integrated and personalized solutions for each patient.

Optimizing Treatment for Severe-Early Childhood Caries: The Role of Groper’s Appliance

Severe-Early Childhood Caries (S-ECC), often leading to serious health issues if left untreated, possesses a great restorative challenge to the pediatric dentist. This case report discusses a comprehensive management of S-ECC in a 5-year-old female patient with high dental caries risk. The patient presented with multiple carious lesions, root stumps, and fenestrated roots, necessitating a staged intervention. Treatment involved restorations with glass ionomer cement, pulpectomy followed by omega loop post build-up on anterior tooth and stainless-steel crowns on posterior teeth. Additionally, extractions were performed and Groper’s appliance was inserted for esthetic rehabilitation and space maintenance on maxillary anterior and posterior regions, respectively. Following completion of the planned treatment, overall risk assessment measured low. This case report emphasizes the importance of rehabilitative interventions in S-ECC, showcasing Groper's appliance as a viable and effective treatment option.

Effect of Thermal Mismatch on Fracture Characteristics of Porcelain Veneered Lithia-Based Disilicate Posterior Ceramic Crown

(1) Background: Dental glass–ceramics shrink during crystallization, complicating restoration manufacturing. Thermo-pressure molding was introduced to address this, with lithium disilicate crystals providing high strength. Residual tensile stresses can influence the chipping strength of single tooth crowns. (2) Methods: Insync dentine was layered onto three lithia-based disilicate core ceramics (Amber Press, IPS e.max Press) for microtensile bond strength tests. The Vickers test assessed the residual tensile stress and interfacial bonding. Porcelain-veneered posterior ceramic crowns were fabricated and subjected to axial loading, measuring fracture loads (three per group). (3) Results: A chemical bonding layer formed at the interface, which was thicker in the Insync-IPS e.max Press and increased with more firings. The ultimate tensile bond strength was 28.5 MPa for the four-times-fired Insync-Amber Press, similar to the twice-fired Insync-IPS e.max Press. No residual tensile stress was found in the Insync-Amber Press; the Insync-IPS e.max Press showed crack growth within 250 μm of the bonded interface. The average fracture resistance was twice as high for the Insync-Amber Press. (4) Conclusions: The Insync-Amber Press exhibited better thermal harmony with no crack growth, while the IPS e.max Press showed crack growth due to residual tensile stress. Insync-Amber Press posterior ceramic crowns had significantly greater fracture resistance than Insync-IPS e.max Press crowns.

Cisto dentígero pós-traumático: relato de caso

The dentigerous cyst is an odontogenic cyst associated with the crown of unerupted teeth, inflammation or after trauma. It is asymptomatic, unilocular, predominantly in the mandible and male. The objective of this case was to report the diagnosis and treatment of the dentigerous cyst. The anamnesis, clinical examination and complementary tests were carried out in order to obtain a thorough diagnosis and the best possible treatment. The diagnosis through radiographic examinations and CT scans was extremely important, allowing the visualization of anatomical conditions and structures, dental fracture, presence of fixed plates and appearance of the lesion. Surgical treatment by means of enucleation was the most indicated technique according to the conditions presented, considering the circumstances of the patient and the size of the lesion. Complete removal of the lesion, extraction of element 45 and partial removal of the miniplate were performed. Therefore, the biopsy is essential to corroborate a differential diagnosis, the excisional type is recommended for small and benign lesions.

Orthodontic management of severe inversely impacted maxillary central incisors: a case series.

Abnormal positioning and dislocation of the central incisor can disturb tooth eruption. Generally, inversely impacted maxillary central incisors do not erupt naturally. Performing traction and applied extrusion of an inversely impacted maxillary central incisor with a high inclination angle of the crown is challenging. This study aimed to examine the possibility of orthodontic treatment for severely inversely impacted maxillary central incisors in a series of case studies. The inclination angle of the tooth crown, curvature of the tooth root, and length of the formed tooth root were measured using radiography. The teeth were then fenestrated and traction was applied using a lingual arch appliance with elastics. The average crown axis inclination was 113°, the degree of root curvature was 97.3°, and the root formation was 36.1%. Although the crown axis inclination and root curvature were severe, all the incisors were aligned in the correct position as vital teeth through surgical and orthodontic treatments. Traction should be performed in the early period of incisor development when root formation is not progressing, regardless of the tooth angle.

A conservative treatment of an involved molar tooth associated with dentigerous cyst: a case report and literature review

BackgroundDentigerous cysts (DCs) are among the most frequently odontogenic cysts in young and middle-aged individuals. Marsupialization and enucleation are the main treatment options in clinical practice. However, there are few reports on preserving molars severely involved by the cyst.Case presentationA 35-year-old male patient with a large odontogenic cyst that was successfully treated using a multidisciplinary approach. The patient’s chief complaint was discomfort during mastication in the lower left molar region for a month. Clinical examination revealed that teeth 36 and 37 were intact without pain upon percussion, while tooth 38 was unerupted. The radiology examination illustrated a typical well-defined oval radiolucent lesion surrounding the crown of unerupted tooth 38, extending to the distal root of tooth 37. The treatment was divided into two parts: removal of the cyst and the impacted third molar, followed by filling with collagen bone particles; and preserving the tooth 37 via hemisection, root canal treatment and crown restoration. Pathological examination indicated a dentigerous cyst. After 18 months of treatment, the bone defect completely recovered and tooth 37 functioned well following the hemisection.ConclusionsHemisection effectively preserves the cyst-associated molars and maintains oral function. This article underscores the significance of collaboration among various departments in the treatment of odontogenic cysts, ultimately aiming to achieve minimally invasive and functional surgery.

Elemental analysis and micromorphological patterns of tooth/restoration interface of three ion-releasing class V restorations

ObjectivesTo evaluate and compare the ion-releasing capability of three different restorative systems at the restoration/tooth interface elemental analysis using energy-dispersive X-ray technique. Additionally, micromorphological patterns of the restoration/tooth interfaces was investigated.Materials and methodsEighteen freshly extracted sound human premolars were collected for the study. The premolars were randomly assigned into 3 groups (n = 6) based on the type of restorative materials used: Giomer (Beautifill II), ion-releasing composite (Activa Presto), and RMGI (Riva Light Cure). Half of the specimens in each group were tested after 24 h (the “immediate group”), while the remaining half were tested after 6 months of storage in deionized water (the “delayed group”). Standardized box-shaped cavities along the cervical area of teeth crowns and restored them with the assigned restorative material following manufacturers’ instructions. The specimens were sectioned buccolingually into 2 halves. One half of each specimen was subjected to elemental analysis using energy-dispersive X-ray technique (EDX), while the remaining half was sputter coated and underwent micromorphological analysis of the restoration/tooth interface using a scanning electron microscope (SEM). The collected data from elemental analysis test were tabulated and subjected to statistical analysis.ResultsThe two-way ANOVA test showed significant differences in both phosphorus and calcium levels among the tested restorative systems (p < 0.05). In the immediate subgroup, RMGI recorded the highest phosphorus level (0.1527), followed by the ion-releasing composite (0.1172), while Giomer exhibited the least levels (0.0326) (p < 0.05). The ion-releasing composite group had the highest calcium level (0.2797), followed by RMGI (0.248), and Giomer (0.2385) respectively (p < 0.05). In the delayed subgroups, Giomer recorded the highest phosphorus level (0.1526), followed by the ion-releasing composite (0.1058), and RMGI group (0.0466) respectively (p < 0.05). RMGI had the highest calcium level (0.2801), followed by the ion-releasing composite (0.2659), and Giomer had the lowest level (0.1792) (p < 0.05). The micromorphological analysis of the restoration/tooth interfaces showed good adaptation between the composite and tooth substrate in different restorative groups.ConclusionsThe ion-releasing capability of the three restorative systems appears to be comparable. The rate of mineral release and diffusion is affected by time and composition.

Evaluation of Wear on Primary Tooth Enamel and Fracture Resistance of Esthetic Pediatric Crowns Manufactured from Different Materials

Background and Objectives: Advances in dental materials and CAD-CAM technology have expanded crown options in primary teeth due to their improved appearance and mechanical properties. Thus, this study aimed to assess the enamel wear and fracture resistance of prefabricated, milled, and 3D-printed esthetic pediatric crowns. Materials and Methods: The study involved 60 extracted maxillary second primary molars and 60 3D-printed resin dies, divided into six groups based on different crown materials (n = 10): prefabricated zirconia, prefabricated composite, milled composite, milled resin matrix ceramic, milled PEEK, and 3D-printed resin. Prefabricated crowns were selected after the preparation of the typodont mandibular second primary molar tooth, while milled and 3D-printed crowns were custom produced. The specimens underwent mechanical loading of 50 N at 1.6 Hz for 250,000 cycles with simultaneous thermal cycling. The 3D and 2D wear amounts were evaluated by scanning the specimens before and after aging. Then, the fracture resistance and failure types of the restorations were recorded. Results: The results showed that the milled PEEK group had superior fracture resistance compared to the other groups, while prefabricated zirconia crown group had the lowest value. Milled resin matrix ceramic crown group displayed the lowest 3D wear volume, while 3D-printed crown group showed the highest 2D wear. Conclusions: The restorative material type did not have a significant effect on the wear of primary tooth enamel. The fracture resistance of the tested materials differed according to the material type. Although the milled PEEK group showed the highest fracture resistance, all tested materials can withstand chewing forces in children.

A Cross-Sectional Study On Determination Of Age From Third Molar Tooth Eruption In The Population Of Telangana.

Age has got significant role in Forensic medicine. It helps in identification and correlates various civil and criminal related issues. A cross sectional study on age determination from eruption of third molar tooth was conducted at Malla Reddy Institute of Medical sciences Hyderabad Telangana for a period of one year in the age group between 18 years to 25 years. A total of 160 medical students were participated in which 80 males and 80 females were participated in the study. Each individual was examined for physical dental examination in each quadrant of the jaw, mere appearance of crown of the third molar tooth was considered as erupted. A space between the second molar tooth and the ramus of the mandible without any evidence of the crown of the 3rd molar tooth was considered as not erupted. Statistical results reveal 54.2% of the study population third molar teeth eruption was observed first in the lower left quadrant. 96.2% in male and 98.4% in female individuals third molar was erupted at 22 years of age and at 23 years third molar was completely erupted in all the quadrants of the jaw in both male and female population.

Calcifying epithelial odontogenic tumour with an atypical clinical presentation in a paediatric patient: A case report and literature review

AbstractAimWe report a rare case of a calcifying epithelial odontogenic tumour with atypical clinical presentation in an adolescent and present a literature review of this tumour in paediatric patients.Materials and MethodsA 12‐year‐old female patient presented with a painless swelling of the left mandible, with a history of 6 months. Clinical examination revealed a sessile mass with a reddish‐pink colour and firm consistency. Tomographic images showed a hypodense, unilocular lesion involving unerupted tooth #34, with a hyperdense focus in contact with the tooth crown disrupting the buccal cortex.ResultsEnucleation, curettage and peripheral osteotomy of the lesion were performed, and the impacted tooth was removed, followed by the application of autologous leucocyte and platelet‐rich fibrin matrices to the region. The patient evolved favourably with good clinical healing and evidence of new bone formation.ConclusionsDespite its aggressive potential, the conservative approach for CEOT in paediatric patients proved to be effective. Our review found reports of recurrence up to 13 years after surgery. Therefore, long‐term clinical and radiographical follow‐up is indicated.

A novel diode laser intervention in the management of external invasive cervical resorption

Abstract “Invasive cervical resorption (ICR)” is a rare category of “external root resorption.” It is a progressive and destructive condition with an unclear cause. Managing external “ICR” presents a significant challenge, even to the most seasoned dental professionals. The removal of excessively vascularized granulation tissue is viewed as a pivotal step. This case report highlights the use of a diode laser to excise granulation tissue, by achieving optimal tissue ablation, promoting better healing, and subsequently restoring the severely damaged crown of the external ICR tooth with an intracanal fiber post.

Prefabricated Zirconia Crowns for Primary Anterior Teeth: Case Series

Prefabricated Zirconia Crowns for Primary Anterior Teeth: Case Series

Impact of vertical facial type on alveolar bone thickness and tooth morphology: A retrospective CBCT-based clinical study

IntroductionThe relationship between vertical facial patterns and the morphology of the alveolar bone and teeth is crucial for successful orthodontic treatment planning. This study aimed to evaluate the relationship between vertical facial patterns, bone thickness, and root-crown dimensions in the maxillary anterior teeth. MethodsThis retrospective study screened 300 cone-beam computed tomography (CBCT) scans of orthodontic patients between December 2022 and November 2023, with 115 meeting the inclusion criteria. Buccal and lingual alveolar bone thickness, along with crown and root lengths of maxillary anterior teeth, were measured and compared across short, normal, and long facial types, classified according to the Frankfort-Mandibular Plane Angle. One-way ANOVA, independent-samples Kruskal-Wallis, and post-hoc tests were used for statistical analysis. ResultsSignificant differences in alveolar bone thickness were observed across facial types, with short facial types showing consistently greater thickness in the apical and mid-palatal regions compared to normal and long facial types (p < 0.05). No significant differences in crown or root lengths were found among the facial types. ConclusionFacial type significantly influences alveolar bone thickness, particularly in short facial types, which demonstrate greater bone support. These findings underscore the importance of considering facial type in orthodontic treatment planning to minimize complications.

МЕТОДИКА КОМПЛЕКСНОЙ ОЦЕНКИ ИСКУССТВЕННЫХ КОРОНОК В ПОЛОСТИ РТА

According to statistics collected by domestic and foreign authors, the number of patients in need of orthopedic treatment is increasing every year. [7,8] Modern dental prosthetics includes not only an integrated approach to rehabilitation and restoration of lost functions, but also a high level of aesthetics of the prostheses themselves, which has a significant impact on the comfort and quality of life of dental patients [7,8,15]. The patient's subjective satisfaction with the result of treatment is one of the main tasks of an orthopedic dentist, no less important than rational prosthetics itself. Thus, in order to achieve success, it is necessary to carefully analyze the initial clinical situation, draw up a comprehensive treatment plan, perform dental prosthetics and evaluate the results obtained. The purpose of the work: to propose a fast and effective method for the comprehensive assessment of an artificial tooth crown, which would have practical application by dentists, would not require significant efforts to interpret the results, and also took into account the general subjective assessment of the patient's quality of life. We have created a web page on the Internet where the proposed two-stage questionnaire is posted. The following technologies and libraries were used to implement the project: HTML5: The main markup language for creating the structure of a web page, including a table with evaluation parameters. CSS: A style language used for the visual design of a table and other elements of a web page to provide a user-friendly and intuitive interface for users. JavaScript: A scripting programming language used to implement the logic of calculating the W coefficient and dynamically displaying the results on the page. The first part is an assessment of artificial crowns according to the method of patent No. 2619386 From the Russian Federation, IPC A61B 10/00 [3], supplemented by an assessment of galvanosis phenomena. The second part is presented by the standardized questionnaire OHIP-14RU [1]. The proposed technique allows for a quick, effective, comprehensive and unified assessment of artificial crowns and their impact on the comfort of the patient's quality of life. Conclusions. This work is aimed at improving the results of comprehensive orthopedic treatment and rehabilitation of patients. The technique allows for a comprehensive assessment, is fast and effective, and is suitable for direct use at a clinical appointment and in research activities in the field of medicine.

Examining gaze behavior in undergraduate students and educators during the evaluation of tooth preparation: an eye-tracking study

BackgroundGaze behavior can serve as an objective tool in undergraduate pre-clinical dental education, helping to identify key areas of interest and common pitfalls in the routine evaluation of tooth preparations. Therefore, this study aimed to investigate the gaze behavior of undergraduate dental students and dental educators while evaluating a single crown tooth preparation.MethodsThirty-five participants volunteered to participate in the study and were divided into a novice group (dental students, n = 18) and an expert group (dental educators, n = 17). Each participant wore a binocular eye-tracking device, and the total duration of fixation was evaluated as a metric to study the gaze behavior. Sixty photographs of twenty different tooth preparations in three different views (buccal, lingual, and occlusal) were prepared and displayed during the experimental session. The participants were asked to rate the tooth preparations on a 100 mm visual analog rating scale and were also asked to determine whether each tooth preparation was ready to make an impression. Each view was divided into different areas of interest. Statistical analysis was performed with a three-way analysis of the variance model with repeated measures.ResultsBased on the participants’ mean rates, the “best” and the “worst” tooth preparations were selected for analysis. The results showed a significantly longer time to decision in the novices compared to the experts (P = 0.003) and a significantly longer time to decision for both the groups in the best tooth preparation compared to the worst tooth preparation (P = 0.002). Statistical analysis also showed a significantly longer total duration of fixations in the margin compared to all other conditions for both the buccal (P < 0.012) and lingual (P < 0.001) views.ConclusionsThe current study showed distinct differences in gaze behavior between the novices and the experts during the evaluation of single crown tooth preparation. Understanding differences in gaze behavior between undergraduate dental students and dental educators could help improve tooth preparation skills and provide constructive customized feedback.

In Vitro Fracture Strength of Primary Canine Teeth Reinforced With Prefabricated and Customized Fiber-Reinforced Post Systems.

The demand for esthetics has increased in today's worldand most parents prefer to preserve their children's primary anterior teeth until their natural exfoliation. However, an intracanal post is required to provide retention for reconstruction of severely damaged anterior teeth due to caries or trauma. Various materials and methods may be used for the fabrication of intracanal posts. This study assessed the fracture strength and fracture mode of primary canine teeth reconstructed with prefabricated and customized polyethylene and glass fiber posts. This in vitro study evaluated 60 extracted primary canine teeth in four groups (n = 15). After pulpectomy and post space preparation with 4 mm depth, composite resin post, prefabricated glass fiber post (Whitepost), customized glass fiber post (Interlig), or customized polyethylene fiber post (Ribbond) were placed in the root canals to provide retention, and the tooth crown was restored with bulk-fill composite resin. The fracture strength was then measured in a universal testing machine. The fracture mode was also evaluated visually. The mean fracture strength was 22.45 ± 5.06, 33.10 ± 8.5, 30.20 ± 7.33, and 32.61 ± 5.73 N/mm2 in the composite resin post, Whitepost, Interlig, and Ribbond groups, respectively. The fracture strength was significantly lower in the composite group than in the remaining three groups (p = 0.000). No other significant differences were found (p > 0.05).Also, no significant difference was observed among the study groups in the fracture mode (p = 0.241). The composite resin post yielded a significantly lower fracture strength than the prefabricated and customized glass and polyethylene fiber posts, but the fracture mode was not significantly different among the four groups.

Changes in the Composition and Mechanical Properties of Dentin in Mouse Models of Diabetes

ObjectivesThis study employed mouse models of type 1 (T1D) and type 2 (T2D) diabetes to characterize the changes in tooth dentin composition and its mechanical properties. MethodsThirty-two mice were used in this study and divided into T1D, T2D and corresponding control groups. Mandibles were extracted 12 weeks after the onset of diabetes, and dentin from the first molars was evaluated in varying regions of the root. The composition was assessed using Raman Spectroscopy. Nanoindentation and Vickers indentation were employed to study the mechanical properties of the tissue. Statistical significance was evaluated by two-way analysis of variance with respect to the diabetic group and region of the tooth (p<0.05). ResultsIn the T2D model, the mineral-to-collagen ratio, hardness, and storage modulus of the intertubular dentin were significantly reduced compared to tissue from the controls, especially in the cervical regions of the tooth. The reduction in the mineral-to-collagen ratio was also observed in the T1D model, but changes in nanomechanical properties were not evident. However, the bulk hardness of the teeth in the T1D model was lower than in the littermate controls. Optical microscopy revealed significant wear of the tooth crowns in both models of diabetes, which appear to result from parafunctional activities. ConclusionThis study suggests that both type 1 and type 2 models of diabetes are associated with detrimental changes in dentin. Clinical SignificanceBetter understanding of how diabetes affects dentin and the contributing mechanisms will be key to improving treatments for people with diabetes.