Tooth Wear Research Articles

A novel method for early fault diagnosis of planetary gearbox with distributed tooth surface wear

Planetary gearbox (PGB) usually work in harsh working conditions with low speed and heavy load, and they are prone to wear. Different from the local faults, the distributed faults such as tooth surface wear are often weak and difficult to detect in the early stage, and it is difficult to extract fault characteristic. This paper presents an early fault diagnosis method for the distributed tooth surface wear of PGB to solve this problem. The proposed multi-channel optimal maximum correlation kurtosis deconvolution (MCO_MCKD) algorithm is used to extract fault characteristic. In order to enhance the effect of fault characteristic extraction (FCE), the algorithm first uses the sliding window principle to segment the input signal to establishes multiple channels for maximum correlation kurtosis (max_CK) optimization based on all the short signals obtained. The finite impulse response (FIR) filter with the max_CK is selected to filter the input signal, in order to realize FCE. The influence of tooth wear is mainly reflected in the frequency-domain signal amplitude. In order to realize early fault diagnosis, the frequency-domain statistical indicator fault characteristic energy ratio (FCER) is proposed based on this characteristic. The health status of the equipment is monitored by calculating the FCER of the signal after FCE. Early fault diagnosis is realized based on the mutation of the FCER. The simulation results show that MCO_MCKD algorithm has strong robustness. The experimental results show this proposed method is effective and superior.

The Oral Health of a Group of 19th Century South Australian Settlers in Relation to Their General Health and Compared with That of Contemporaneous Samples.

The aims of this study are to determine the oral health status of a rare sample of 19th-century migrant settlers to South Australia, how oral conditions may have influenced their general health, and how the oral health of this group compares with contemporaneous samples in Australia, New Zealand, and Britain. Dentitions of 18 adults and 22 subadults were investigated using non-destructive methods (micro-CT, macroscopic, radiographic). Extensive carious lesions were identified in seventeen adults and four subadults, and from this group one subadult and sixteen adults had antemortem tooth loss. Sixteen adults showed evidence of periodontal disease. Enamel hypoplastic (EH) defects were identified in fourteen adults and nine subadults. Many individuals with dental defects also had skeletal signs of comorbidities. South Australian individuals had the same percentage of carious lesions as the British sample (53%), more than other historic Australian samples, but less than a contemporary New Zealand sample. Over 50% of individuals from all the historic cemeteries had EH defects, suggesting systemic health insults during dental development were common during the 19th century. The overall oral health of the South Australian settlers was poor but, in some categories, (tooth wear, periapical abscess, periodontal disease), better than the other historic samples.

Prevalence of Dentin Hypersensitivity in a Target Subjects in Hanoi, Vietnam

BACKGROUND: Dentin hypersensitivity (DH) is a short pain when dentin is exposed to external stimuli such as: Thermal, vapor, rubbing, osmotic, or chemical stimuli without pathological or any other dental defect and in normal teeth, that level of stimulation is not sufficient to cause pain. Besides tooth decay and periodontal disease, DH is the top concern of Odonto-Stomatology doctors. AIM: The aim of this study was to study the prevalence of DH in Hanoi, Vietnam, in two groups (workers at Hanvico Company and dental students at the University of Medicine and Pharmacy, VNU, Hanoi, Vietnam). MATERIALS AND METHODS: The study was conducted on 500 subjects which consisted of 288 workers at Hanvico Company and 212 Odonto-Stomatology students at the University of Medicine and Pharmacy, VNU. The study subjects were examined intraorally and diagnosed with DH to vapor and tactile stimuli using the Yeaple Probe electronic probe. RESULTS: It was found that the prevalence of DH is 20.4% in Hanoi, Vietnam, with no difference between men and women. The highest prevalence of DH is in group 40–49 years of age group. CONCLUSION: It was found that there is a moderate prevalence of DH in Hanoi, Vietnam. The cervical wear, tooth wear, gingival shrinkage, and a diet high in acid showed a high prevalence of DH.

DENTINOGENESIS IMPERFECTA: A CLINICAL CASE REPORT ANTERIOR MOUTH REHABILITATION AND PUBLIC HEALTH ASPECT

The size, shape, number, and tissue structure of teeth in human dentition varies greatly. Dental conditions can run in families. Tooth discoloration caused by DI conditions can range from milky blue-gray to dark tan. Due to the weakening of the dentin structure, DI patients frequently experience severe dentition wear, missing tooth structure, missing teeth, and missing vertical occlusal dimensions. A female patient, age 39, was seen with brown tooth discoloration and wear on all of her front teeth. The patient claimed that her mother was to blame for her dental issue

Advanced Tooth Wear due to Bruxism Associated with Gastroesophageal Reflux Disease: Rehabilitation with Bite Elevators and Single Crowns

Advanced Tooth Wear due to Bruxism Associated with Gastroesophageal Reflux Disease: Rehabilitation with Bite Elevators and Single Crowns

A complete sabertooth cat cranium from the Midcontinent of North America and its evolutionary and ecological context

Outside of Rancho La Brea, southern California, United States, knowledge of the life history, ecology, and extinction of large, late Pleistocene carnivores in North America is frustrated by a scarcity of skeletal material and trustworthy radiocarbon dates. A complete Smilodon fatalis (sabertooth cat) cranium from southwestern Iowa, directly AMS radiocarbon dated to 11,685 ± 40 B.P. (13,605–13,455 cal B.P.), represents an important addition to the inventory of evidence for the taxon in the Midcontinent. Assessment of tooth eruption and wear combined with metric and nonmetric comparisons with coeval crania from Pit 61/67 at Rancho La Brea indicates the specimen belongs to a subadult male 2–3 years of age at death. Craniodental morphology falls within the range of variation in the Pit 61/67 males. Predicted live weight is 251 kg. One C1 has an antemortem bend fracture, and the absence of use-wear on the proximal remnant suggests death ensued within days of the injury. The radiocarbon date centers the animal in the Bølling-Allerød Chronozone (14,640–12,845 cal B.P.). Whereas regional conditions were generally warmer and wetter during this period, southwestern Iowa was a cool, dry non-analog boreal grassland/parkland that supported a diverse, large herbivore community, including Megalonyx jeffersonii (Jefferson's ground sloth), the taxon tentatively identified in this study as the focal prey. Bayesian modeling of 72 direct radiocarbon dates for the taxon suggests extinction of the late Quaternary Smilodon was a hemispheric and geologically synchronic phenomenon that occurred after 13,285 cal B.P.Subjects: vertebrate paleontology, paleoecology, paleozoology.

Influence of different ultra-soft toothbrushes on erosive tooth wear

ObjectiveTo investigate the influence of different ultra-soft toothbrushes on the progression of erosive tooth wear (ETW). MethodsBovine enamel and dentin specimens (n = 10) were submitted to a 5-day erosive-abrasive cycling model (0.3% citric acid for 5 min, artificial saliva for 60 min, 4x/day). Toothbrushing was carried out 2x/day for 15 s, with the different toothbrushes tested (A- Edel White: flexible handle, tapered bristles; B- Oral-B Gengiva Detox: regular handle, criss-cross tapered bristles; C- Colgate Gengiva Therapy: flexible handle, tapered bristles, high tuft density; d- Oral-B Expert Gengiva Sensi: regular handle, round end bristles, high tuft density; E- Oral-B Indicator Plus: soft brush, round end bristles (control). Surface loss (SL, in μm) was assessed by optical profilometry. The toothbrush characteristics were evaluated by a surgical microscope. Data were statistically analyzed (α=0.05). ResultsFor enamel, toothbrush C showed the highest SL (means±SD: 9.86 ± 1.28) and it did not differ significantly from A (8.60 ± 0.50), both with flexible handles. The lowest SL was observed for the toothbrush Control E (6.76 ± 0.63), which differed significantly from A and C, but not from the other toothbrushes. For dentin, the highest SL was found for toothbrush D (6.97 ± 1.05) and it did not differ significantly from E (6.23 ± 0.71). The lowest SL was observed for B (4.61 ± 0.71) and C (4.85 + 0.83), without significant differences from A (5.01 ± 1.24). ConclusionsThe ultra-soft toothbrushes had different impacts on the progression of ETW on the dental substrates. On enamel, higher ETW values were observed for the flexible handle toothbrushes, while for dentin, round-end bristles (ultra-soft and soft) caused more ETW. Clinical significanceKnowledge about the effect of different ultra-soft toothbrushes on ETW can help clinicians to recommend the most suitable types for their patients, bearing in mind that toothbrushes can impact enamel and dentin differently.

Epidemiology, aetiology and prevention of tooth wear.

Tooth wear is a commonly reported finding globally; however, many patients are unaware of having tooth wear. Identifying early signs of erosion, abrasion or attrition and determining the risk factors contributing to a patient's tooth wear may help to prevent further loss of enamel and dentine in the future. Appropriate prevention should be instigated, or appropriate referral made to other health professionals, when conditions such as gastroesophageal reflux or eating disorders are suspected. This paper presents the epidemiology and aetiological factors for tooth wear, as well as identifying the common clinical presentations of tooth wear. Patient perspectives on tooth wear and preventive techniques that can be utilised are also discussed.

Monitoring of erosive tooth wear: what to use and when to use it

Although we are increasingly recognising the need to assess patients for accelerated rates of tooth wear progression, it is often difficult to do so within a feasible diagnostic window. This paper aims to provide evidence-based timelines which a diagnosing clinician can expect to assess tooth wear progression in study models, clinical indices, clinical photographs and visually with intraoral scans. It also discusses new technologies emerging for the quantitative assessment of tooth wear, timelines for diagnosis, and caveats in the 3D scan registration and analysis process.

Clinical factors to consider in definitive treatment planning for patients with tooth wear.

Diagnosis, disease control and prevention are the precursors to successful definitive restorative treatment of pathological tooth wear. This case series illustrates how proposed key clinical features can influence treatment complexity and provide the clinician with a logical sequence of treatment options for definitive management of tooth wear.

Managing tooth wear with respect to quality of life: an evidence-based decision on when to intervene

Patients with more severe forms of tooth wear may require restorative rehabilitation. The decision to commence treatment must be taken carefully and there are a multitude of factors to consider. Alongside the clinical signs and symptoms typically associated with tooth wear, there is also the need to assess the impact of the condition on the patient's oral health-related quality of life. As part of the discussions relating to the attainment of informed consent for the restoration of the worn dentition, not only is it relevant to appropriately appraise the risks, benefits, costs, reasonable alternatives and likely prognosis of the proposed treatments, but to also elaborate on the expected impact of the intervention on the patient's oral health-related quality of life. The aim of this article is to review the evidence relating to the impact of the quality of life with the management of tooth wear, with the introduction of the concept of an evidence-based approach to decision-making when planning care.

Relationships between tooth wear, bruxism and temporomandibular disorders.

This article will provide an overview of the diagnosis of common temporomandibular disorders (TMDs) and bruxism, along with their relevance in management of tooth wear. When assessing and managing a tooth wear case, the teeth should not be considered in isolation, but as part of the articulatory system, which has three inter-related elements: the teeth, the temporomandibular joints and the masticatory muscles. The presence/absence of bruxism and TMD are highly relevant, although there may not be a causal relationship between these. A consideration of TMD and bruxism, together with the potential impact these may have on the patient during and after any management of tooth wear, will form part of patient education and the informed consent process.

The opinions of GDPs on the challenges of managing tooth wear in primary dental care.

As patients access most of their dental care within the primary care setting, it is relevant to consider how the experience and opinions of general dental practitioners (GDPs) influence the diagnosis, monitoring and treatment of their patients with tooth wear. This paper records the agreed outcomes of semi-structured discussions with three experienced GDPs. The aim is to continue the broader debate about how patients with tooth wear currently are and ideally could be managed within the primary care settings in England. The outcomes are also likely to be applicable to other countries, regardless of the local funding models for routine patient care.

Digital workflows for the management of tooth wear.

For patients affected by tooth wear who require treatment to restore their dentition, the methods chosen can increasingly involve digital technology, with potentially less use of traditional, analogue treatment methods. Digital technology has transformed clinical photography and dental radiology, and is now available for most of the stages required for managing these patients. Continuous development of these digital technologies, both in the system capability and in the clinician interface, has brought the digital workflow within reach of more clinicians and therefore, for the treatment of more patients. While it is recognised that the comprehensive use of digital technologies is currently most likely to be used in clinical practice by specialist and private practitioners, it is expected that interest in and understanding of digital workflows will increase throughout the dental profession.This paper provides a step-by-step overview of the digital workflow, for both simple and complex cases.

Impact of bariatric surgery on oral health: a systematic review and meta-analysis.

To evaluate the impact of bariatric surgery (BS) on the oral health status of obese individuals. The search was performed on the Cochrane Library, Embase, Latin American and Caribbean Literature on Health Sciences (LILACS), LIVIVO, PubMed/Medline, Scopus, and Web of Science databases. Grey literature was also consulted through Google Scholar, OpenGrey, ProQuest, and MedRxiv. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal tool. Pre- and post-surgical moments were compared through random effects meta-analysis. The GRADE (Grading of Recommendations, Assessment, Development and Evaluations) assessment tool was used to judge the certainty of evidence. After searching the databases, 908 references were retrieved, with 30 articles selected for synthesis. When comparing the pre- and postoperative moments, there was no difference in the index of decayed, missing, or filled teeth. Furthermore, salivary flow and probing depth presented a slight increase. Post-surgery patients showed an increase (%) in tooth wear at the dentin level [MD = -6.23; IC95% = -8.45--4.01; I2 = 0%]. Patients undergoing BS show no difference when considering the rate of caries or missing teeth and little to no effect was observed on salivary flow rates and periodontal probing depth. On the other hand, greater attention should be given to dentin wear in post-surgical patients of BS. Patients undergoing BS should receive careful monitoring regarding oral health by doctors, dentists, and the entire multidisciplinary team involved before and after the surgical procedure.

The use of the monolithic ceramic and direct monolithic composite in the aesthetic rehabilitation of tooth wear.

Traditional cold layering composite techniques can have limitations in the aesthetic rehabilitation of advanced tooth wear, with potentially high maintenance/failure rates and compromised aesthetics. This article explores advances in materials and clinical techniques involving monolithic ceramics and direct monolithic composites. These restorations satisfy the most aesthetically demanding patient, providing good to excellent aesthetics and long-term predictability.

Occlusal records in the production of mounted study casts for tooth wear planning and management

This article forms part of a series looking at management of patients with tooth wear. Articulated study casts can be essential in assisting the clinician to plan and communicate proposed treatment to the dental technician and patient. Their production is often seen as straightforward, but a lack of attention to detail can quickly lead to articulated casts that do not replicate the patient clinical presentation. This in turn will lead to inaccurate planning and potentially a suboptimal treatment outcome. This article discusses a collection of the clinical records needed to produce accurate articulated study casts, which can be utilised for tooth wear planning. It also aims to present the evidence base for the recommendations outlined.

Indications for the use of direct composite restorations in the management of tooth wear.

The increasing prevalence of tooth surface loss has been widely reported. Patients present with varying degrees of tooth wear and consideration is given to whether a prevention and monitoring approach, or a treatment and restoration approach, is appropriate. A missed diagnosis or excessively prolonged monitoring risks progression to the detriment of a successful outcome, with the potential compromise on the quality and quantity of tooth structure available for predictable adhesive dentistry. Direct composite resin (DCR) restorations can be considered as a viable treatment option for all extents of tooth wear, including cases that have progressed to a severe degree. This paper aims to review the indications for DCR restorations in the management of tooth wear, using clinical cases to demonstrate their effectiveness.

Gastrointestinal conditions related to tooth wear

Gastro-oesophageal reflux disease (GORD) is a relatively common condition that occurs in adults and less commonly in children. It develops when the reflux of stomach contents into the oesophagus causes troublesome symptoms and/or complications. Signs and symptoms include heartburn, retrosternal discomfort, epigastric pain and hoarseness, dental erosion, chronic cough, burning mouth syndrome, halitosis and laryngitis. A proportion of patients will, however, have silent reflux. Strongly associated risk factors include family history, age, hiatus hernia, obesity and neurological conditions, such as cerebral palsy. There are different treatment options which may be considered for GORD, consisting of conservative, medical and surgical therapy. Dentists should be aware of the symptoms of GORD and dental signs of intrinsic erosion indicative of possible GORD so that they can question patients about this and, if appropriate, initiate a referral to a general medical practitioner.

Rehabilitating a severely worn dentition with removable prosthodontics

In the next part of this series on tooth wear management, we discuss the indications and clinical stages for the provision of removable prostheses for the treatment of severely worn and depleted dentitions. The general design features of a complex prosthesis are described for reorganised occlusal schemes and maintenance guidelines are explained. In addition, the clinical stages for three different situations are described: removable-only approaches, and combined fixed and removable in the same arch and separate arches. The value of providing removable prostheses in worn dentitions allows the immediate rehabilitation of severely worn teeth taking a non-invasive and retrievable approach when the remaining dentition is of poor quality or structure and/or there are missing teeth.