Current concepts on the management of tooth wear: part 2. Active restorative care 1: the management of localised tooth wear

Biomechanical impact of labiolingual diameter on endodontically treated anterior teeth with crown restoration under occlusal loading

OBJECTIVE

To evaluate the effect of the labiolingual diameter and construction of an endodontically treated (ET) anterior tooth with crown restoration on stress distribution and biomechanical safety under occlusal loading.

METHODOLOGY

Three-dimensional finite element models were generated for maxillary central incisors with all-ceramic crown restorations. The labiolingual diameters of the tooth, defined as the horizontal distance between the protrusion of the labial and lingual surfaces, were changed as follows: (D1) 6.85 mm, (D2) 6.35 mm, and (D3) 5.85 mm. The model was constructed as follows: (S0) vital pulp tooth; (S1) ET tooth; (S2) ET tooth with a 2 mm ferrule, restored with a fiber post and composite resin core; (S3) ET tooth without a ferrule, restored with a fiber post and composite resin core. A total of 12 models were developed. In total, two force loads (100 N) were applied to the crown's incisal edge and palatal surface at a 45° oblique angle to the longitudinal axis of the teeth. The Von Mises stress distribution and maximum stress of the models were analyzed.

RESULTS

Regardless of the loading location, stress concentration and maximum stress (34.07~66.78MPa) in all models occurred in the labial cervical 1/3 of each root. Both labiolingual diameter and construction influenced the maximum stress of the residual tooth tissue, with the impact of the labiolingual diameter being greater. A reduction in labiolingual diameter led to increased maximum stress throughout the tooth. The ferrule reduced the maximum stress of the core of S2 models (7.15~10.69 MPa), which is lower compared with that of S3 models (19.45~43.67 MPa).

CONCLUSION

The labiolingual diameter exerts a greater impact on the biomechanical characteristics of ET anterior teeth with crown restoration, surpassing the influence of the construction. The ferrule can reduce the maximum stress of the core and maintain the uniformity of stress distribution.

Treatment of Tooth Wear Using Direct or Indirect Restorations: A Systematic Review of Clinical Studies

Tooth wear is considered a well-developed issue in daily clinical practice; however, there is no standard protocol for treatment. The aim of this manuscript was to systematically review the literature to evaluate the clinical outcomes of direct or indirect restorations for treating tooth wear. A literature search was conducted through the PubMed MedLine, Scopus, ISI Web of Science, Scielo, and EMBASE databases up to 29 April 2022. Clinical studies evaluating the clinical performance of direct or indirect restorations for treating tooth wear for a minimum follow-up of 6 months were included in the review. A total of 2776 records were obtained from the search databases. After full-text reading, 16 studies were included in the qualitative analysis. Considering the high heterogenicity of the studies included, a meta-analysis could not be performed. All studies included the rehabilitation of anterior and posterior teeth with extensive wear, using both indirect and direct restorations for a maximum follow-up of 10 years. Restoration materials included ceramo-metal crowns, full gold crowns, lithium disilicate ceramic, zirconia, polymer infiltrated ceramic networks, and resin composites. Most of the reports assessed the survival rate of the restorations and the clinical features using the United States Public Health Service (USPHS) Evaluation System criteria. Contradictory discoveries were perceived concerning the type of restoration with better clinical performance. Considering the current literature available, there is no evidence in the superiority of any restoration technique to ensure the highest clinical performance for treating tooth wear.

The dental demolition derby: bruxism and its impact - part 1: background

Bruxism may lead to changes or damage to the oral and perioral tissues. Bruxism may occur during sleep or when awake. Many patients will not require active management; however, for some, intervention is required. Control of bruxism may be difficult, if not impossible, but the need exists for preservation of the dentition and quality of life. A prediction of risk to the tissues for the planning of interventions is difficult and relies upon evidence of past damage and assessment of future risks. Treatment options may need to be imaginative and rescuable. This series of papers will review the aetiology of bruxism, its impacts and treatment strategies for persistent bruxers who are at risk of, or suffering, tissue damage.

Minimally Invasive Rehabilitation of Posterior Erosive Tooth Wear: Two Case Reports of the One-Stage Dahl Approach

Rehabilitation of posterior erosive tooth wear can be especially challenging in the presence of substantial tooth structure loss and limited inter-occlusal space. This article describes two case reports illustrating a conservative approach using the one-step Dahl approach in the management of localized posterior erosive tooth wear. The occlusal surfaces of worn teeth in both cases were successfully restored using direct composite resin and gold onlay, respectively. The material was placed in supra-occlusion during the initial stage. This technique enables intrusion of affected worn teeth and the opposing counterpart. Eruption of the remaining dentition will occur after two to three months to re-establish a complete occlusal relationship. With proper treatment planning, the one-step Dahl approach offers a simpler and predictable positive outcome in restoring structurally compromised posterior worn teeth.

An Analysis of Electronic Primary Dental Practice Tooth Wear Referrals

We evaluated the quality of general dental practitioner (GDP) tooth wear (TW) referrals to secondary care services in Kent, Surrey and Sussex.Prospective consecutive referrals received via an electronic pathway were assessed from 1 June to 30 October 2019. Reasons for referral, patient demographics, quality of referral, opinion of the triaging clinician and outcome were assessed.Of 671 referrals, 32% were for TW. Males were referred more commonly (1.7:1.0). The median age was 52. Patients were more likely to be referred from distant locations than places closer to the referral centre (p<0.001). Only 55% of referrals suggested a cause for the TW, 33% provided a clinical photograph and 1% recorded a tooth wear index of any type. Referring clinicians most commonly cited attrition as reason for referral (p<0.001). Those under 40 years were referred for erosion (p=0.001) and those over 40 years, attrition (p=0.019). The triaging clinician was more likely to allocate a tooth wear score of three for those under 40 years and a score of four for over 40 years (p<0.001). 47% of referrals were rejected. Males and referrals with photographs were more likely to be accepted for treatment (p=0.017 and p<0.001, respectively).There is a high demand for specialist TW services. The number of referrals being rejected has not changed using the electronic referral system. We advocate the inclusion of mandatory fields for completion by GDPs as well as compulsory clinical photographs and tooth wear indices (Smith and Knight Tooth Wear Index or a basic erosive wear examination - BEWE index).

Long-term results of a randomized clinical trial of 2 types of ceramic crowns in participants with extensive tooth wear

STATEMENT OF PROBLEM

Evidence is sparse regarding the long-term outcomes of restorative treatment of patients with extensive tooth wear.

PURPOSE

The purpose of this long-term prospective randomized clinical trial was to evaluate the performance and success rate of pressed lithium disilicate (LD) and translucent zirconia (TZ) crowns in participants with extensive tooth wear.

MATERIAL AND METHODS

A total of 62 participants with extensive tooth wear (17 women, 45 men; mean age 44.8 years; range 25-63 years) received a total of 713 crowns, LD=362 and TZ=351. Both types of crowns had chamfer preparations and were adhesively luted with dual-polymerizing composite resin cement (PANAVIA F 2.0; Kuraray Noritake Dental Inc). The restorations were clinically reevaluated on average 14, 31, 39, 54, and 65 months after insertion of the crowns according to the modified United States Public Health Service (USPHS) criteria.

RESULTS

After an observation period of up to 6 years, the survival rate for both types of crowns was 99.7%, with 1 lost LD crown after 1 year as a result of loss of retention and 1 lost TZ crown after 3 years because of tooth fracture at the cemento-enamel junction. The success rates were similar for both types of crowns: 98.6% for LD and 99.1% for TZ. Reasons for failures were that 3 participants in each group developed apical lesions, minimal ceramic fractures, or their crowns were rebonded after loss of adhesion. Assessment of color at baseline was significantly different with a better match for LD (84.8% Alfa, 15.2% Bravo) than for TZ crowns (36.5% Alfa, 63.5% Bravo), including TZ crowns with veneered porcelain (P<.001). Secondary caries and cracks did not occur. A post hoc analysis of clinical performance did not indicate any significant differences between extensive tooth wear with primarily mechanical or chemical factors.

CONCLUSIONS

No differences were found between the 2 types of ceramic materials concerning the long-term success and clinical performance, except that TZ crowns were rated by a blinded clinician as less esthetic than LD crowns. The use of high-strength ceramic materials, as well as reliable adhesive bonding, are probably the key factors in the long-term success of ceramic crowns in participants with extensive tooth wear independent of the specific etiology.

Awareness and Treatment Decisions on Tooth Wear among Jordanian Dentists and Prosthodontists: A Cross-Sectional Survey Study

Objectives

To assess the awareness, knowledge, and treatment decisions by dentists in Jordan regarding tooth wear.

Materials and Methods

A questionnaire was disseminated to a random sample of 200 general dentists and 100 prosthodontists working in the Ministry of Health, academia, private practices, and military services. Chi square and independent t-tests were performed for statistical analysis.

Results

Hundred and seventy-nine dentists and prosthodontists responded (59.7% response rate), of which 71.5% was females. 83.8% of the dentists reported they see patients with tooth wear. 61.5% registered wear lesions in the patient file, and 68.2% reported they find a probable cause of tooth wear. 87.2% of the dentists reported that bruxism is the most common cause in Jordan. 63.3% dentists treated their patients. 46.4% reported they “always” record a dietary history. 77.7% did not think that tooth wear is linked to caries. Low confidence levels were demonstrated among general practitioners in diagnosing and treating tooth wear. Regarding treatment decisions, most dentists decided to restore worn teeth with composite and to construct a night guard. Minimally affected anterior teeth were mostly treated with fluoride. Restoration of posterior worn teeth with overlay was suggested by one-third of the dentists.

Conclusion

The dentists and prosthodontists in Jordan are aware of tooth wear. However, examination and documentation were given a little priority by general dentists. On the other hand, there was an agreement among the dentists and prosthodontists on applying the minimally invasive approach. Clinical Significance. It is challenging for dentists to make the best treatment decision for tooth wear especially as no standard treatment is available. Therefore, this study investigated the awareness and treatment decisions of a sample of dentists and prosthodontists in Jordan.

Fracture Resistance of Monolithic Zirconia Crowns in Implant Prostheses in Patients with Bruxism

The aim of this study is to determine the minimum required thickness of a monolithic zirconia crown in the mandibular posterior area for patients with bruxism. Forty-nine full zirconia crowns, with seven different occlusal thicknesses of 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 mm, were made by using a computer-aided design/computer-aided manufacturing system (CAD/CAM). Seven crowns in each group were subjected to cyclic loading at 800 N and 5 Hz in a servohydraulic testing machine until fracture or completion of 100,000 cycles. Seven finite element models comprising seven different occlusal thicknesses of 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 mm were simulated using three different loads of vertical 800 N, oblique 10 degrees 800 N, and vertical 800 N + x N torque (x = 10, 50, and 100). The results of cyclic loading tests showed that the fracture resistance of the crown was positively associated with thickness. Specimen breakage differed significantly according to the different thicknesses of the prostheses (p < 0.01). Lowest von Mises stress values were determined for prostheses with a minimal thickness of 1.0 mm in different loading directions and with different forces. Zirconia specimens of 1.0 mm thickness had the lowest stress values and high fracture resistance and under 800 N of loading.

Restorative Management of Severe Localized Tooth Wear Using a Supraoccluding Appliance: A 5-Year Follow-Up

This case report illustrates a novel conservative restorative management of a patient with bulimia nervosa who presented with severe localized upper palatal tooth wear and an anterior reverse overjet. This was achieved by using a localized bite raising or supraoccluding appliance, cemented on the lingual side of the lower anterior teeth to create interocclusal space, obviating the need for tooth reduction of the eroded upper palatal and incisal tooth surfaces. Surgical crown lengthening was performed to create a better aesthetic gingival architecture. All-ceramic restorations were provided on the upper anterior teeth to restore the tooth surface loss and provide a positive overbite and overjet. There was no complication or other observable biological change detected at the 5-year follow-up. The use of an appliance applying the supraoccluding technique, or Dahl concept, is a safe, conservative, and useful treatment option in the management of localized tooth wear.

In-vitro analysis of maxillary first molars morphology using three dimensional Micro-CT imaging: considerations for restorative dentistry

PURPOSE

The aim of this study was to determine the differences between the positional relationship of the crown contour and the pulp chamber of left and right maxillary first molars, as well as their morphological characteristics by using micro-CT system with reconstruction from a volumetric rendering software.

MATERIALS AND METHODS

In total, 21 extracted maxillary first molars, including 11 left and 10 right teeth, were used. The positional relationship between the crown contour, pulp chamber and morphology of the teeth were investigated three-dimensionally by means of micro-CT imaging.

RESULTS

Closest distance of mesio-buccal pulp horn to enamel surface in mm was calculated as 2.5±0.20 mm for right and 2.29±0.17 mm for left teeth. This difference was statistically significant (p=0.017). The means of closest distance of disto-buccal pulp horn to enamel surface were also significantly different between left and right teeth (p=0.001). The mean pulp volumes of right side and left side teeth were, respectively, 32.94±3.19 mm³ and 33.71±2.82 mm³ but this difference was not statistically significant.

CONCLUSION

These results suggest that right and left maxillary first molars should be treated differently during preparation of cavities. Further studies must be done with larger samples as well as for other molar teeth in different populations to reveal the morphology of the molar for further considerations in restorative dentistry.

Clinical guidance and an evidence-based approach for restoration of worn dentition by direct composite resin

This paper aims to provide the dentist with practical guidance on the technique for direct composite restoration of worn teeth. It is based on current evidence and includes practical advice regarding type of composite, enamel and dentine preparation, dentine bonding and stent design. The application of direct composite has the advantage of being additive, conserving as much of the remaining worn tooth as possible, ease of placement and adjustment, low maintenance and reversibility. A pragmatic approach to management is advocated, particularly as many of the cases are older patients with advanced wear. Several cases restored by direct composite build-ups illustrate what can be achieved. The restoration of the worn dentition may be challenging for many dentists. Careful planning and simple treatment strategies, however, can prove to be highly effective and rewarding. By keeping any intervention as simple as possible, problems with high maintenance are avoided and management of future failure is made easier. An additive rather than a subtractive treatment approach is more intuitive for worn down teeth. Traditional approaches of full-mouth rehabilitation with indirect cast or milled restorations may still have their place but complex treatment modalities will inevitably be more time consuming, more costly, possibly require specialist care and still have an unpredictable outcome. Composite resin restorations are a universal restorative material familiar to dentists from early-on in the undergraduate curriculum. This review paper discusses the application of composite to restore the worn dentition.

Clinical management of pathological tooth wear in general dental practice

Due to the relatively slow pace and lack of symptoms with which tooth wear develops, patients will often not be aware of the presence of a wearing dentition and often present for treatment at an advanced stage. Thus, it is often challenging for the general dental practitioner to convey the diagnoses, whilst concomitantly emphasising the importance of disease management, as well as the consequences of no care. This article, and the associated session at the 2016 British Dental Conference &Exhibition, review the clinical management of pathological tooth wear in general dental practice.

A Guided, Conservative Approach for the Management of Localized Mandibular Anterior Tooth Wear

The successful management of the worn mandibular anterior dentition may present an awkward challenge to the dental operator. The purpose of this article is to describe a case report illustrating the use of a guided, three-dimensional protocol for the ultra-conservative and predictable restoration of the worn lower anterior dentition using direct resin composite. This technique utilizes information based on established biomechanical and occlusal principles to fabricate a diagnostic wax-up, which is duplicated in dental stone. This is used to prepare a vacuum-formed modified stent, assisting the clinician to place directly bonded resin composite restorations to restore the worn lower anterior dentition. The technique, described in 2012 and referred to as 'injection moulding' has the potential to offer optimal form, function and an aesthetic outcome in an efficient manner. CPD/Clinical Relevance: This article aims to describe an alternative technique to simplify the processes involved with restoration of worn lower anterior teeth.

Effect of placing intentionally high restorations: Randomized clinical trial

OBJECTIVE

The aim of this study was to examine the behavior of posterior teeth restored with single-tooth restorations with intentionally high occlusal contacts.

METHODS

Consent was obtained from 17 patients who were seen a total of 5 times over 3.5 years. The restorations placed were all full occlusal coverage gold restorations. Tooth mobility was recorded using the Periotest device and tooth movement was determined from impressions and 3D imaging. Patients were randomly assigned into two groups, the control group which received restorations with no intentional increase of the occlusal vertical dimension; or the treatment group where they received intentionally high restorations in 0.5mm supraocclusion.

RESULTS

Statistical analysis showed no significant difference in mobility between visits for both the control and the treatment groups while a significant dependency and difference in tooth movement was observed between the subjects of the two groups. Most patients from the treatment group reported discomfort but no pain for the first 7-10 days after the restoration was fitted, which subsided over a period of couple of weeks. At review, 3 years later, no mobility or additional movement was observed.

CONCLUSIONS

Cementation of an intentionally high single-tooth restoration causes no increase in tooth mobility while occlusal adaptation re-establishes and restores the occlusal plane.

Survival rates of anterior composites in managing tooth wear: systematic review

The use of composite restorations for patients with tooth wear is considered as a more conservative treatment option. The aim of this study was to systematically review the literature investigating the survival rates of anterior composite restorations when used in managing tooth wear in patients. PubMed and MEDLINE (Ovid) databases were screened for studies from 1995 to 2015. Cross-referencing was used to further identify articles. Article selection and data extraction were performed in duplication. Languages were restricted to English. A quality appraisal of included studies was carried out using the Strength of Recommendation Taxonomy system. Six hundred and sixty-six articles were initially identified from which eight articles were full-text reviewed. Six articles involving five studies were selected for inclusion. Three studies were prospective and two retrospective. Included studies involved placement of 772 direct and indirect anterior composite restorations in 100 patients with follow-up periods between 5 months and 10 years. The survival rates of anterior composites were >90% and 50% at 2.5 and 5 years, respectively. Posterior occlusion was re-established in 91% of patients within 18 months. Meta-analysis could not be performed due to the heterogeneity of included studies. The systematic review's overall strength of recommendation was graded B. There is evidence to support the use of anterior composite restorations at an increased vertical dimension of occlusion in the short/medium-term management of tooth wear. Long-term reporting of outcomes remains limited. Further research is needed with standardised study design, detailed reporting of outcomes and long-term review.

The tooth wear evaluation system: a modular clinical guideline for the diagnosis and management planning of worn dentitions

Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues, viz. enamel and dentine. Tooth wear can be divided into the subtypes mechanical wear (attrition and abrasion) and chemical wear (erosion). Because of its multifactorial aetiology, tooth wear can manifest itself in many different representations, and therefore, it can be difficult to diagnose and manage the condition. A systematic approach is a sine qua non. In the below-described tooth wear evaluation system (TWES), all necessary tools for a clinical guideline are present in different modules. This allows the dental clinician, in a general practitioner setting as well as in a referral practice setting, to perform a state-of-the-art diagnostic process. To avoid the risk of a too cumbersome usage, the dental clinician can select only those modules that are appropriate for a given setting. The modules match with each other, which is indispensable and essential when different modules of the TWES are compared. With the TWES, it is possible to recognise the problem (qualifying), to grade its severity (quantifying), to diagnose the likely causes and to monitor (the progress of) the condition. In addition, a proposal for the classification of tooth wear is made. Further, it is possible to determine when to start a treatment, to make the decision which kind of treatment to apply and to estimate the level of difficulty of a restorative treatment.

Intrusion of supraerupted maxillary molar using a high interim restoration on the defective opposing tooth: a clinical report

Wear, extraction, or fracture of all or part of a mandibular first molar can lead to the supraeruption of the opposing maxillary molar, resulting in occlusal interference and lack of restoration space. This report describes a method to gain sufficient vertical space for permanent restoration. A direct composite resin restoration was placed on the occlusal surface of a lower molar, intentionally making the interim restoration high and intruding the maxillary molar. After 6 weeks, the extruded tooth returned to the desired position, and functional occlusion was restored, enabling a ceramic restoration on the mandibular molar. No marked adverse sensory reaction was reported in this therapeutic process, and no deleterious signs were detected in the teeth, periodontium, or temporomandibular joints. The simple treatment type was effective, noninvasive, and time saving, while also preserving maximum tooth structures.

The management of anterior tooth wear using gold palatal veneers in canine guidance

Localised anterior tooth wear can be managed using minimally invasive techniques with conservation of tooth structure and preservation of pulp vitality. This article describes and illustrates with two clinical cases, the management of localised tooth wear, with the restoration of canine guidance by a combination of gold palatal veneers and direct composite restorations.

Malignant transformation of oral potentially malignant disorders in males: a retrospective cohort study

Background

Oral squamous cell carcinoma could be preceded by clinically evident oral potentially malignant disorders (OPMDs). Transformation of OPMDs to cancer has been studied in several population groups. It is difficult to undertake comparisons across populations due to variations in the methods of computation of malignancy rates among different studies. The aim of our study was to estimate the rate of malignant transformation of OPMDs taking into account the duration of follow-up and to identify the significant factors indicative of malignant potential.

Methods

A total of 148 male patients with OPMDs were included. They were selected among all consecutive subjects registered at the maxillofacial clinic at a medical hospital in Kaohsiung, Taiwan. The mean follow up period was 37.8 months.

Results

The malignant transformation rate was highest in subjects diagnosed with oral epithelial dysplasia. In this group the transformation rate was 7.62 per 100 persons-year. The rate in the group with verrucous hyperplasia (VH) was 5.21 per 100 persons-year, and in those with hyperkeratosis or epithelial hyperplasia was 3.26 per 100 persons-year. The anatomical site of OPMDs was the only statistically significant variable associated with malignancy. The hazard rate ratio (HRR) was 2.41 times for tongue lesions when compared with buccal lesions.

Conclusion

The reported discrepancies of malignant transformation of OPMDs involve the follow-up time to cancer development and hence it is preferable to use a time-to-event estimation for comparisons. We found that malignant transformation of OPMDs involving the tongue was significantly higher than in other anatomical subsites after adjusting for the clinicopathological type or lifestyle factors at diagnosis.