Search Results (157)

Introduction: Digital planning and evolution of technology is allowing dentistry to be more efficient in time than before. In orthodontics the main purpose is to obtain fewer patient visits and to reduce the bonding time. For that, indirect bonding planned with CAD-CAM softwares is used to obtain a shorter treatment period, in general, and less chair-time. This waste of chair-time should also be reduced in other fields of dentistry such as endodontics, surgery, prosthodontics, and aesthetics. Methods: A total of 504 teeth were embedded into epoxy resin models mounted as a dental arch. Customized lingual multibracket appliances were bonded by a current adhesion protocol. After that, they were debonded, the polishing of cement remnants was performed with three different burs and two drills. The polishing time of each group was recorded by an iPhone 14 chronometer. Results: Descriptive and comparative statistical analyses were performed with the different study groups. Statistical differences (p < 0.005) between diamond bur and tungsten carbide and white stone burs and turbine were obtained, with the first being the slowest of them. Discussion: Enamel roughness was widely studied in orthodontics polishing protocol as the main variable for protocols establishment. However, in lingual orthodontics, due the difficulty of the access to the enamel surfaces, the protocol is not clear and efficiency should be considered. It was observed that the tungsten carbide bur is the safest bur. It was also recommended that a two-step protocol of polishing by tungsten carbide bur be followed by polishers. Conclusions: A tungsten carbide bur mounted in a turbine was the most efficient protocol for polishing after lingual bracket debonding. Full article

This study aims to evaluate the feasibility and accuracy of 3D printing-guided endodontics in the maxillary teeth of dogs. CT data from a Beagle dog were processed to create a 3D model of the maxilla, and virtual root canal pathways were established using SOLIDWORKS software (version 29.0.0.5028). Guided endodontic templates were 3D printed and tested in vitro on 20 maxillary teeth (excluding the third molars), with 36 root canals treated using both guided and conventional methods. Results indicated that 3D printing-guided endodontics provided accurate root canal pathways, with minimal deviations in length (average 3.08 ± 1.75%) and angular alignment (average 2.06° ± 0.5°) compared to conventional methods. This research represents a significant step forward in the application of 3D printing technology in veterinary endodontics, offering a promising alternative to traditional methods for treating complex dental conditions in dogs. Full article

Background: Reaction time is analyzed in various situations in sporting events and is reported to be so important that it can make the difference between victory and defeat. This study focused on teeth clenching resulting in remote muscle activation, and examined whether it improves performance of reaction time. This study examined the effects of clenching and clenching strength on the systemic simple reaction time. Methods: This study included 20 healthy adults with normal clenching and a right dominant foot. The task movement for the systemic simple reaction time measurement was a 30 cm forward step. The following three clenching conditions were used: no clenching without dental contact (no-bite condition), a condition in which the participants were instructed to clench with moderate strength (moderate condition), and a condition in which the participants clenching with maximum effort (max condition). The analysis items were release time, grounding time, soleus muscle (Sol) reaction time, and masseter muscle activity. Results: The max condition significantly reduced the reaction time compared with the no-bite condition. Sol reaction and grounding times showed a negative correlation between clenching strength under moderate conditions and the rate of change in reaction time under no-bite and moderate conditions. Release time exhibited no significant correlation between clenching strength under the moderate condition and the rate of change in reaction time under the no-bite and moderate conditions. The remote facilitation effect of clenching improved the systemic reaction time by producing immediate muscle activity. Conclusions: Clenching shortens the systemic simple reaction time. This finding highlights the potential importance of clenching in enhancing performance during sporting events. Full article

Background: Adhesive systems are important for achieving reliable and durable bracket bonding in orthodontic treatments. The purpose of this study is to compare the outcomes of a new one-step orthodontic bonding system that combines the primer and adhesive solutions. Methods: In this study, four groups were formed, each consisting of 20 first premolar teeth. Acid etching was applied to all teeth for 30 s, except in Group II. Group I included teeth where a single layer of primer was applied using the Transbond XT system before bracket bonding. Group II consisted of teeth bonded with brackets after using a self-etching primer with the Transbond XT system. Group III used GC Ortho Connect, a single-step adhesive that incorporates the primer within the adhesive itself. Group IV, a single layer of primer was applied before bonding with GC Ortho Connect. Shear bond strength (SBS) was assessed using one-way ANOVA and the Tukey-HSD test, while Adhesive Remnant Index (ARI) scores were analyzed using the Chi-square test at a significance level of p < 0.05. Results: SBS measurements were recorded as 13.28 ± 2.15 MPa for Group I, 11.06 ± 2.26 MPa for Group II, 10.37 ± 1.92 MPa for Group III, and 16.02 ± 2.17 MPa for Group IV. Statistical analysis using the Tukey test revealed significant differences in SBS values between Groups II and IV, as well as Groups III and IV (p < 0.05). All groups showed clinically acceptable bond strength, with Group IV demonstrating superior adhesion. Additionally, the chi-square test indicated a statistically significant variation in the ARI scores across all four groups (p < 0.05). Conclusions: The adhesive performance of the one-step GC Ortho Connect system is clinically comparable to Transbond XT. However, primer application is necessary to achieve optimal bond strength. Full article

Approximately 72% of older adults in residential care have dementia and present with different levels of functioning. People living with dementia (PLwD) may not always be facilitated to independently carry out activities of daily living (ADLs) in care, increasing the likelihood of excess disability. This study incorporated Behavioural Skills Training (BST) to train healthcare staff how to increase opportunities for independence for PLwD by using task analyses and least-to-most (L-M) prompting procedures during ADLs. Three healthcare staff, two female and one male (mean age = 42.67, SD = 16.82), participated in the intervention. The What Works Clearinghouse (WWC) Single-Case Design Technical Documentation guided the study’s design. A randomised single-case experimental (N-of-1) design was employed, using a multiple-baseline design (MBD) across participants (n = 3) for three separate ADLs. The dependent variable (DV) was the percentage of correct staff responses when implementing the L-M prompting procedure for each step during ADLs. Visual and statistical analyses demonstrated an increase in the correct use of a task analysis and L-M prompting for all three participants during the intervention compared to the baseline: for ADL1 (assistance to stand), effect sizes were d = 5.39, d = 9.38, and d = 6.79 for the three participants, respectively; for ADL2 (assistance with drinking), effect sizes were d = 3.27, d = 8.55, and d = 3.67; and for ADL3 (assistance to brush teeth), effect sizes were d = 5.99, d = 12.93, and d = 9.39. Maintenance data ranged from 70% to 100% correct responses at follow-up (mean = 93.11% SD = 7.85). Participants successfully generalised skills learned to two new ADLs (PLwD eating a meal and putting on a jumper). BST was demonstrated to be an effective training strategy to increase opportunities for independent responding for PLwD in care environments. The contingencies influencing staff behaviour require attention within the healthcare environment. Full article

Oral hygiene practices are vital for maintaining health, yet many adults do not engage in daily teeth cleaning. This study aimed to assess the prevalence and determinants of non-daily teeth cleaning among adults in Rwanda using data from the 2022 Rwanda Non-Communicable Diseases (NCD) STEPS Survey which used a cross-sectional design and multistage cluster sampling. Weighted prevalence estimates and logistic regression models were used to examine associations between non-daily teeth cleaning and key demographic, socioeconomic, behavioral, and oral health factors. The prevalence of non-daily teeth cleaning was 33.1% (95% CI: 31.0–35.2). Rural residence (AOR = 2.5, 95% CI: 1.5–4.1), lower education (AOR = 0.3, 95% CI: 0.2–0.6), lower income (AOR = 2.0, 95% CI: 1.3–3.2), and not using toothpaste (AOR = 1.3, 95% CI: 1.0–1.7) were significantly associated with increased odds of non-daily teeth cleaning. These findings underscore the need for targeted oral health promotion strategies that address socioeconomic disparities and improve access to affordable hygiene products. Full article

Background: In recent years, thanks to the improvement of adhesive techniques, patients affected by tooth wear, related to erosion and/or parafunctional habits, can undergo restoration by adding only what has been lost of their dentition (additive approach). However, since not all clinicians are convinced that dental rehabilitation should be proposed in the early stages of exposed dentin, several treatments are often postponed. It is important to emphasize that, in the early stages, the clinical approach should remain conservative, focusing on dietary counseling, the modification of harmful habits, fluoride application, and risk factor management. Only when these preventive and non-invasive strategies prove insufficient, and the condition continues to progress, should invasive restorative treatments be considered. Unfortunately, epidemiological studies are reporting an increase in the number of young patients affected by erosive tooth wear, and not intercepting these cases earlier could lead to a severe degradation of the affected dentition. In addition, parafunctional habits are also becoming more frequent among patients. The combination of erosion and attrition can be very destructive, and may progress rapidly once dentin is exposed and the risk factors remain unaddressed. The aim of this report was to present a conservative full-mouth rehabilitation approach for severe erosive lesions and to provide a 10-year follow-up assessing the biological, functional, and esthetic outcomes. Methods: In this article, the postponed restorative treatment of a patient, suffering from severe tooth wear, is illustrated. The patient had sought dental treatment in the past; however, due to the already very compromised dentition, a conventional but very aggressive treatment was proposed and refused. Four years later, when the patient finally accepted an alternative conservative therapy, the tooth degradation was very severe, especially at the level of the maxillary anterior teeth. The combination of three different approaches, Speed-Up Therapy, BOPT (Biologically-Oriented Preparation Technique), and the 3 Step Technique, however, improved the capacity to successfully complete the difficult therapeutic task. Results: The biological goals (maintenance of the pulp vitality of all of the teeth and the minimal removal of healthy tooth structure) were accomplished, relying only on adhesive techniques. Conclusions: The overall treatment was very comfortable for the patient and less complicated for the clinician. At 10-year follow-up, biological, functional, and esthetic success was still confirmed. Full article

Background: The segmentation of individual teeth in three-dimensional (3D) dental models is a key step in orthodontic computer-aided design systems. Traditional methods lack robustness when handling challenging cases such as missing or misaligned teeth. Objectives: to semantically segment maxillary teeth and palatal rugae in 3D textured scans using Convolutional Neural Networks (CNNs) and assess tooth movement after orthodontic treatment using stable rugae references. Methods: Building on the robustness of two-dimensional image semantic segmentation, we developed a method to convert 3D textured palate scans into two-dimensional images for segmentation, then back projected them onto the original 3D meshes. A dataset of 100 textured scans from 100 patients seeking orthodontic treatment was manually segmented by orthodontic experts. The proposed 3D segmentation method was applied to these scans. Finally, each pair of segmented 3D scans from the same patient, before and after treatment, was aligned by superimposing them on the stable rugae region. Results: The 3D segmentation method achieved an accuracy of 98.69% and an average Intersection over Union (IoU) of 84.5%. The common stable coordinate frame for both scans using the rugae area as a stable reference enabled the computation of the 3D translational and rotational motions of each maxillary tooth. Neither pre- nor post-processing of the data was required to enhance segmentation. Conclusions: The proposed method enabled successful motion measurement of teeth using the rugal area as a stable reference and providing rotation and translational measurements of the maxillary teeth. Full article

Although the manual classification of microfossils is possible, it can become burdensome. Machine learning offers an alternative that allows for automatic classification. Our contribution is to use machine learning to develop an automated approach for classifying images of Pectinodon bakkeri teeth. This can be expanded for use with many other species. Our approach is composed of two steps. First, PCA and K-means were applied to a numerical dataset with 459 samples collected at the Hanson Ranch Bonebed in eastern Wyoming, containing the following features: crown height, fore-aft basal length, basal width, anterior denticles, and posterior denticles per millimeter. The results obtained in this step were used to automatically organize the P. bakkeri images from two out of three clusters generated. Finally, the tooth images were used to train a convolutional neural network with two classes. The model has an accuracy of 71%, a precision of 71%, a recall of 70.5%, and an F1-score of 70.5%. Full article

Background: Micro- and macroabrasion represent a minimally invasive treatment approach for stained teeth in the esthetic zone. Diagnosing the type of stain is crucial for selecting the appropriate treatment approach. These clinical procedures involve several meticulous steps that may be confusing for less experienced clinicians. Methods: The objective of this article is to provide an updated review of the literature on the clinical procedures for micro- and macroabrasion and to present a clinical case in which a minimally invasive macroabrasion procedure was applied to treat a female patient seeking to remove stains from her anterior teeth. Preliminary reviews were conducted of existing case reports and reviews evaluating the clinical procedures and outcomes of micro- and macroabrasion. Results: A review of the literature reveals minor differences in how stains on anterior teeth are addressed. Depending on the depth of the stain, microabrasion is typically used for superficial stains, while macroabrasion is employed for deeper stains. Clinicians often combine micro- or macroabrasion with tooth whitening procedures. Literature reviews agree that micro- and macroabrasion techniques are effective minimally invasive approaches that yield high esthetic results. The case study demonstrated each clinical step of microabrasion, achieving results that fully satisfied the patient’s esthetic demands. Conclusions: Micro- and macroabrasion can be effective and minimally invasive methods for treating stained anterior teeth. Superficial stains can be treated with microabrasion, while deeper stains may require macroabrasion. In some clinical scenarios, tooth whitening can also be combined with these treatments. Full article

Background and Clinical Significance: Large extensive intraoral dental swelling is uncommon in adults, and we report a rare case of large exophytic oral granulomatous tissue. A complete explanation of diagnostic steps and surgical treatments is addressed, as well as a thorough review of the literature, and a discussion of this interesting case is provided to underline the need for recognition of these vascular pyogenic proliferative lesions and discuss proper management based on the underlying cause. Case Presentation: A 21-year-old Afghan female patient who presented with an extensive intraoral pale red, friable lesion that bled easily. It was 15 × 15 mm in size related to the lower second molar, and interfered with occlusion and extended to cover the buccal and lingual surfaces of adjacent teeth. Conclusions: The presentation of this rare large reactive vascular proliferative condition of oral posterior gingiva, contribute to a better understanding and the growing body of evidence on the PG. The findings emphasize the importance of early intervention tailored to the patient’s age, lesion location, and underlying causes and patient education to prevent extensive dental tissue destruction. Full article

Background: Dental fluorosis can affect the micromorphology of dentin, a fact that could present constraints relating to the structural, mechanical, and chemical stability of dentin when it is demineralized in operative maneuvers. Introduction: The aim of this article is to quantify the amount of calcium and the microhardness of both a healthy and a fluorotic dentin through conditioning with a two-step self-etching system (Optibond Versa, Kerr, CA, USA). Methods: Dentin samples were obtained from healthy molars diagnosed with mild, moderate, and severe fluorosis. The amount of calcium was quantified utilizing an atomic absorption spectrophotometer. The hardness was evaluated using a Vickers durometer. Two dentin samples from each study group were examined using scanning electron microscopy (SEM). Results: A one-way analysis of variance (ANOVA) and Tukey–Kramer test were applied as post hoc tests for determining the differences in calcium values between the study groups and to show the difference in the hardnesses evaluated. The Student’s t-test was applied to related samples. The level of significance was set at p < 0.05. Statistically significant results were obtained for the amount of calcium and microhardness of the healthy dentin group. The SEM images demonstrated irregular etching patterns in the fluorotic dentin, indicating potential bonding challenges. Conclusion: In conclusion, there is a lower amount of calcium and a significant reduction in microhardness in healthy dentin when applying the self-etching system compared to fluorotic dentin. Fluorotic dentin is more resistant to demineralization, which may influence adhesive bonding strategies. Clinicians should consider adjusting conditioning protocols for optimal adhesion in fluorotic teeth. Full article

Noise, vibration and harshness analyses are of great interest for the latest developments of the gearboxes of electric vehicles. Gearboxes are now the main source of vibrations, since electric powertrains are much quieter than internal combustion engines. Traditionally, the simulation of the non-linear gear dynamics is studied by first performing a series of preliminary static analyses to compute the static transmission error (STE). The STE (i.e., in the form of varying mesh stiffness) is then accepted as the system’s excitation source to compute the dynamic transmission error (DTE). This paper presents a novel approach to analyze the non-linear dynamics of gears which does not require any preliminary static analyses. The method consists of a frequency–domain approach based on the Harmonic Balance Method (HBM) and the Alternating Frequency–Time (AFT) scheme, allowing for much faster simulations when compared to the widely used direct–time integration (DTI). The contact between the teeth is modeled as intermittent and penalty based with a varying gap. The time–varying gap between the teeth is initially approximated to a step function that guarantees the design contact ratio. The methodology introduced is tested on a lumped parameter model of a spur–gear pair already proposed and simulated in the literature. The results obtained with the novel approach are compared with the DTI simulation of the model as a reference. The excellent match between the different approaches validates the reliability of developed methodology. Full article

Lop-eared and brachycephalic conformations have inconsistently been associated with dental abnormalities in pet and rescue rabbit populations. We investigated conformational risk factors for dental abnormalities in a pedigree population where conformation could be confirmed. Otoscopic oral examination was performed on breeder-volunteered pedigree rabbits at British Rabbit Council shows and studs. Multivariable models were used for risk factor analysis of 14 possible dental disease signs. In 435 rabbits examined, 68.28% showed no incisor abnormalities and 55.40% showed no cheek teeth abnormalities. Lop-eared rabbits had higher odds than erect-eared rabbits for ocular discharge (odds ratio [OR]: 4.034, p = 0.007) but not for any dental abnormalities. Erect-eared rabbits showed higher odds of reacting to incisor examination than lop-eared rabbits (OR: 1.666, p = 0.003). Brachycephaly showed no associations with dental abnormalities, whilst more dolichocephalic rabbits had increased odds of cheek teeth step or wave mouth (OR: 1.394, p = 0.004). Other conformational and signalment-related risk factor results were mixed. Brachycephaly showed no significant predisposition to dental abnormalities, and the clinical relevance of predisposition to ocular discharge in lop-eared rabbits is unclear. Conformation appears less important than husbandry factors for preventing rabbit dental disease. Generalising the results to companion rabbits is not advised due to husbandry and population differences. Full article

Background/Objectives: Retrospective analysis of long-term periodontal tooth loss (PTL) during supportive periodontal care (SPC) in patients with Stage III/IV periodontitis who received strictly non-surgical periodontal treatment. Methods: Fully documented medical documentation of SPC > 5 years was analyzed at T0 (baseline), T1 (after Steps 1/2), and during SPC (T2). PTL, periodontal pocket depth (PD), bleeding on probing (BOP), tooth mobility (TM), furcation involvement (FI), and frequency of SPC were recorded. Each parameter was tested for significance in a bivariate analysis, before a multilevel logistic regression analysis was performed to identify possible factors with an impact on PTL during SPC. Results: A total of 51 women/64 men (T1 mean age 55.4 ± 10.3 yrs) were surveilled after 9.0 ± 2.4 yrs; 2647 teeth were included. On average, patients attended 10.6 ± 3.8 SPC sessions between T1 and T2; 77 patients (67%) attended at least 1/year. At T1, 68 teeth were lost; 6.1% of the remaining teeth showed FI, and 13.8% showed TM. During SPC, the PTL range was 118 (1.03 ± 1.21/patient). TM, FI, mean PD, and Stage IV periodontitis proved to be statistically significantly associated with increased PTL. Conclusions: PTL was low in this cohort. Nevertheless, at T1, it may be beneficial to focus on stopping TM by splinting the mobile teeth and reducing the PD or treating FI appropriately, understanding that these precise applications of surgical procedures could positively affect long-term tooth retention. Full article