Developing diagnostic criteria for tooth wear, a preliminary beta version based on expert opinion, and a narrative literature review.

BACKGROUND: Tooth wear is a multifactorial condition, leading to the irreversible loss of dental hard tissues. The availability of an unambiguous, universally applicable assessment protocol remains lacking. OBJECTIVES: The goal of the authors is to develop a set of diagnostic criteria for the assessment of tooth wear (DC-TW). A two-step approach will be used to achieve this objective: (1) to develop a preliminary beta version of the DC-TW, based on the authors' clinical experience and their shared expertise and supported by a narrative review of the existing literature, and (2) to develop the final DC-TW, with input from a larger group of experts using an international Delphi process. This paper relates to the first step. METHODS: The authors outlined the components that should be incorporated into the DC-TW. The literature search was performed to investigate if their concept was in line with the available literature. The search was conducted to identify eligible publications from inception to July 11, 2022. Two authors independently screened all publications, and differences in judgements were resolved through a consensus procedure. RESULTS: The search yielded 5362 publications, resulting in the final inclusion of 383. These publications were divided into four main topics: (1) nomenclature/taxonomies; (2) self-report tools; (3) clinical assessment tools; and (4) clinical decision-making. CONCLUSIONS: The information from the publications was used and fused with the clinical experience and shared expertise of the authors to contribute to the development of a preliminary beta version of the DC-TW.

Randomised controlled trial on testing an increased vertical dimension of occlusion prior to restorative treatment of tooth wear.

BACKGROUND: Evaluation of a new vertical dimension of occlusion (VDO) in complex restorative treatments is considered a necessary step prior to placement of restorations. OBJECTIVES: This randomised controlled trial (RCT) aimed to assess the effects of using an evaluation of a VDO increase before restorative treatment in patients with moderate-to-severe tooth wear, on OHRQoL, freeway space (FWS) and interventions to restorations. METHODS: Forty-two patients with tooth wear were included and randomly allocated to either a test phase with a Removable Appliance (RA) or no test phase. Restorative treatment consisted of restoration of all teeth using composite restorations in an increased VDO. OHIP-score, freeway space (FWS) and clinical acceptability of restorations were assessed at baseline and at recall appointments (1 month and 1 year). Intervention to restoration was scored in case of material chipping or when the abutment tooth had increased sensitivity that could be linked to occlusal overloading. ANCOVA analyses, Univariate Cox regression, t-tests and descriptive analyses were performed (p < .05). RESULTS: Clinical follow-up after 1 year was completed for 41 patients. No significant effect of testing the VDO with a RA could be found on the OHIP-score (p = .14). Reduction of FWS in the RA group, compared to the control group, was significantly lower at 1 year (p = .01, 95% CI -1.09 to -0.15). No effect on early interventions to restorations was found (p = .94). CONCLUSION: This RCT showed that a removable appliance is not indicated to functionally test the increased VDO prior to restorative treatment in patients with tooth wear.

Deterioration of anterior resin composite restorations in moderate to severe tooth wear patients: 3-year results.

OBJECTIVES: Deterioration in anterior resin composite restorations placed in tooth wear patients was investigated after 36 months. MATERIALS AND METHODS: Data collected prospectively for 47 participants of the Radboud Tooth Wear Project were used (41 ± 8 years, 90% male, n = 270 restorations). Restorations were individually evaluated using intraoral photographs and 3D scans to rate modified FDI scores and to record the presence of degradation features. Four groups with distinct combinations of composites and techniques were assessed, and multivariable logistic regression models were used to analyze the data (p < 0.05). RESULTS: For all groups together, early degradation signs were present at 1 month: irregularities (41.5%) and ditching (7.4%) were observed at the surface and adhesive interfaces. The frequency of irregularities decreased in the 36-month evaluation (37%), but ditching (12.2%) and fractures (10.7%) were more common. The most frequent deterioration (based on photographs) was observed for staining (44%) and loss of luster (31%). In 3D scans, the most frequent were for wear (25%), marginal adaptation (24%), and the presence of irregularities (19%). Canines had 5.5 times more chances of deterioration by ditching than incisors (p < 0.001). The differences between composites and restorative techniques were minor. CONCLUSIONS: A continuous degradation process of restorations placed in tooth wear patients was observed in anterior teeth restored with different composites, with a progression of the deterioration over 36 months. CLINICAL RELEVANCE: When placing anterior resin composite restorations in tooth wear patients, it could be important to establish realistic expectations and the need for checkup appointments.

How to Intervene in the Caries Process in Children: A Joint ORCA and EFCD Expert Delphi Consensus Statement.

This paper provides recommendations for dentists for the treatment of dental caries in children, with an emphasis on early childhood caries (ECC), primary teeth, and occlusal surfaces in permanent teeth. A consensus workshop followed by an e-Delphi consensus process was conducted with an expert panel nominated by the European Organization for Caries Research (ORCA) and European Federation of Conservative Dentistry (EFCD)/German Association of Conservative Dentistry (DGZ) boards. Based on 3 systematic reviews and a nonsystematic literature search, recommendations were developed. The caries decline has led to a more polarized disease distribution in children and adolescents along social gradients which should be taken into account when managing the caries process at all levels, such as the individual, the group, or a population. The control or reduction of caries activity is the basis for successful caries management. In children, caries management requires adequate daily oral hygiene and fluoride application via toothpaste, ensured by caregivers, and especially for ECC prevention an emphasis on sugar intake reduction is needed. These noninvasive interventions are also suitable to arrest or control initial or even cavitated dentine caries lesions in the absence of irreversible pulpitis. Fluoride varnish or silver diammine fluoride can be added as supplementary agents. In pits and fissures, composite resin materials can be used as preventive sealants and for defect-oriented minimally invasive restorations. In primary molars, preformed metal crowns are more successful than multisurface fillings, especially in caries-active patients. With persisting high caries activity, multiple lesions, and limited cooperation, caries control should consist of robust measures with high success rates, even including extraction in selected cases. This applies especially to treatments performed under general anesthesia.

Minimally Invasive Intervention for Primary Caries Lesions: Are Dentists Implementing This Concept?

Contemporary minimally invasive treatment concepts for restorative treatment of primary caries lesions include both delayed intervention and smaller-sized preparations restricted to removal of carious tissue. The aim of this study was to investigate whether these concepts have resulted in a trend towards a more conservative choice made by dentists regarding treatment thresholds and restorative techniques. The results from previously conducted, precoded questionnaires developed by Espelid and Tveit, as well as from a recent Dutch questionnaire, were collected and analysed. A worldwide trend towards more minimally invasive strategies in the operative treatment of caries lesions could not be observed, neither for the initiation of operative treatment nor for the preparation techniques. However, in some countries, changes over time could be assessed, especially in Norway, where a reduction in the proportion of interventions is visible for both occlusal and approximal lesions, indicating that more dentists are postponing interventions until the lesions have progressed to a deeper level. From the Dutch national survey, it could be concluded that operators that intervene at an earlier stage of approximal lesioning (stage ≤4) also intervene at an earlier stage of occlusal caries (stage ≤3) (p = 0.012; OR = 2.52; 95% CI: 1.22-5.22). Generally, it can be concluded that dentists worldwide still tend to operatively intervene at a too early stage of caries, although variations exist between countries. A worldwide shift could be observed in the restorative material applied, since composite resin has almost completely replaced amalgam for restoring primary caries lesions.

Impact of a diagnostic workshop on undergraduate teaching-learning process for the diagnosis and management of tooth restorations-A randomised controlled study.

OBJECTIVE: The aim of this study was to investigate the impact of a diagnostic workshop on undergraduate teaching-learning process for the diagnosis and management of tooth restorations. METHODS: The first stage of the study was a randomised controlled study with two parallel groups: lecture (L) and lecture coupled with a diagnostic workshop (LW). A pool of cases of tooth restorations including secondary caries and marginal defects was used for training. Theoretical knowledge, perception about the activity and practical abilities were evaluated. The second stage of the study assessed students' theoretical knowledge retention six months following intervention. All students included in the first stage of the study were exposed to LW. Hence, a new control group of students not exposed to LW was selected. One-way analysis of variance, Fisher's exact test, Kruskal-Wallis test and multilevel regression analysis were used as part of statistical analysis. RESULTS: The LW group had greater scores for the assignment of lesion severity and activity, presence of marginal defect and treatment indication than the L group (P < 0.05). Multilevel regression analysis showed a positive impact of the workshop diagnosis in the correct assessment of lesion activity (P = 0.03). There was no statistical difference between the LW and L groups in students' perception of the activity. The LW group showed greater knowledge retention after six months than the L group (P = 0.027). CONCLUSION: Lecture coupled with diagnostic workshop improved students' practical skills of diagnosis restorations and knowledge retention in the six months following intervention.

Survival and Associated Risk Factors of Selective Caries Removal Treatments in Primary Teeth: A Retrospective Study in a High Caries Risk Population.

OBJECTIVE: The aim of this retrospective study was to analyze the survival probability of selective caries removal (SCR) treatments in the primary teeth of children with high caries experience and factors potentially associated with treatment failure. METHODS: The sample included SCR treatments conducted in anterior and posterior teeth without sedation or general anesthesia among children attending a university dental service. Kaplan-Meier survival analysis was used to estimate the longevity of restorations and multivariate Cox regression with shared frailty was used to assess risk factors. RESULTS: A total of 284 SCR treatments in 88 children (aged 5.2 ± 1.91 years) with high caries experience (mean dmft/DMFT = 11.1 ± 5.04) were analyzed. The 3-year survival reached 48.8%, with an annual failure rate of 21.2%. Restorative failures (n = 60) were found more frequently compared to pulp complications (n = 12). SCR performed in anterior primary teeth were more prone to failure (hazard ratio = 3.6, 95% CI: 1.94; 6.71). Patients with a higher amount of visible plaque experienced more failures in SCR treatments (hazard ratio 3.0, 95% CI:1.27; 7.07). CONCLUSIONS: In this retrospective study, SCR showed restricted survival when compared to other prospective clinical trials. Patient-related factors, especially the young age and high caries experience of the children, may represent a challenge for restoration survival. Regardless of the caries removal technique or restorative material, cariogenic biofilm has a negative effect on the survival of restorations, probably by acting directly on material deterioration and, particularly, on the development of new caries lesions of rapid progression.

Bonding Efficacy and Fracture Pattern of Adhesives Submitted to Mechanical Aging with the Rub&Roll Device.

PURPOSE: To evaluate the effect of water storage and cyclic loading on the microtensile bond strength (µTBS) and fracture pattern of adhesives to dentin. MATERIALS AND METHODS: Midcoronal dentin surfaces (n = 36) were prepared and composite restorations were built up using two adhesives (self-etch and etch-and-rinse). The specimens were randomly divided into 3 groups according to the aging conditions (n = 6): 1. CONTROL: storage in water for 24 h (CO); 2. water storage: storage in water for 6 months (WS); 3. mechanical loading: 750,000 mechanical cycles (ML) using the Rub&Roll loading device. Specimens were sections into beams and the µTBS was tested. Fracture patterns were analyzed using stereomicroscopy and fractographic analysis was performed using SEM. µTBS data (n = 53-72 specimens) were subjected to two-way ANOVA and Tukey's post-hoc test. The chi-squared test was used to compare the distribution of failure modes (p < 0.05). RESULTS: Aging conditions and adhesives significantly affected µTBS (p < 0.01). The CO group showed no difference between materials and had highest µTBS. After WS, the self-etch adhesive showed higher µTBS than did the etchand- rinse adhesive. ML resulted in lower µTBS for both adhesives. Materials (p < 0.01) and aging (p < 0.01) significantly influenced the distribution of failure modes. SEM analysis showed that specimens submitted to WS or ML showed features of degradation and fatigue at the fractured interface, depending on the adhesive. CONCLUSION: Mechanical loading had a negative effect on the bonding efficacy of both adhesives and influenced the fracture pattern, with specimens presenting a different fracture surface from that observed in water-stored specimens.

Occlusal Caries Management: Preferences among Dentists in Norway.

The aim was to measure variations in the threshold for operative treatment of occlusal caries in permanent teeth and the use of dental materials, compared with results from a similar study conducted in Norway in 1995. In 2009, a precoded questionnaire was sent electronically to 3,654 dentists with E-mail addresses in the member register of the Norwegian Dental Association. The questions were related to caries, treatment strategies and choice of dental materials. Replies were obtained from 61.3% respondents after two reminders. Restorative treatment of occlusal lesions confined to enamel was proposed by 12% of the dentists, compared with 18% in 1995 (p < 0.01). Older dentists more often than younger dentists would operatively treat enamel lesions (p < 0.01). Most dentists preferred to drill only the carious part of the fissure rather than the whole fissure both in 2009 (78.8%) and 1995 (68.3%; p < 0.01). In 2009, 91.9% preferred composite as the restorative material of choice, compared to only 39.1% in 1995. Logistic regression analyses identified higher age of the dentist as the only variable significantly associated with higher risk of restoring occlusal enamel lesions operatively. The authors conclude that especially young dentists appear to be more reluctant to remove tooth substance in 2009 compared with 1995. Composite is the dominating material of choice in 2009 and seems to have substituted the use of most other filling materials in occlusal restorations in permanent teeth.

Secondary Caries Development in in situ Gaps next to Composite and Amalgam.

This in situ study investigated the secondary caries development in dentin in gaps next to composite and amalgam. For 21 days, 14 volunteers wore a modified occlusal splint containing human dentin samples with an average gap of 215 µm (SD=55 µm) restored with three different materials: Filtek Supreme composite, Clearfil AP-X composite and Tytin amalgam. Eight times a day, the splint with samples was dipped in a 20% sucrose solution for 10 min. Before and after caries development, specimens were imaged with transversal wavelength independent microradiography, and lesion depth (LD) and mineral loss (ML) were calculated. The LD and ML of the three restoration materials were compared within patients using paired t tests (α=5%). In total 38 composite samples (Filtek n=19 and AP-X n=19) and 19 amalgam samples could be used for data analysis. AP-X composite presented the highest mean values of LD and ML of the three restorative materials. Amalgam showed statistically significantly less ML (Δ=452 µm×vol%) than the combined composite materials (p=0.036). When comparing amalgam to the separate composite materials, only AP-X composite showed higher ML (Δ=515 µm×vol%) than amalgam (p=0.034). Analysis of LD showed the same trends, but these were not statistically significant. In conclusion, amalgam showed reduced secondary caries progression in dentin in gaps compared to composite materials tested in this in situ model.

Long term clinical performance of 'open sandwich' and 'total-etch' Class II composite resin restorations showing proximal deterioration of glass-ionomer cement.

OBJECTIVES: To compare clinical performance of resin composite posterior Class-II restorations placed with etch-and-rinse adhesive or open sandwich technique using glass-ionomer cement. METHODS: Data on Class II restorations placed by one dentist between 1990 and 2016 were collected from patient files, including caries risk, tooth related variables, applied materials and dates of last check-up visit and restoration placement. Open sandwich restorations were placed before 2001, while after 2001, a total-etch technique using etch-and-rinse 3-step adhesive was used when placing a Class II composite restoration. For statistical analysis, Kaplan-Meier statistics and a multilevel Cox-Regression was conducted (p < 0.05). Annual Failures Rates (AFR) were calculated. RESULTS: 675 Class II restorations were placed in 91 patients, 491 total-etch restorations (observation time 2-18 y), and 184 open sandwich restorations (observation time 19-29 y) showing AFRs at 15 years as 2.9 % for total-etch and 9.7 % for open sandwich restorations. Secondary caries as failure was equally distributed among the 2 groups and 27 % of the failures in the open sandwich group were due to proximal deterioration of glass-ionomer cement. The Cox-regression showed a significant higher risk for failure for the open sandwich technique compared to total-etch class-II composite restorations (HR = 2.9; p < 0.001). SIGNIFICANCE: Application of glass-ionomer cement using the open sandwich technique cannot be recommended for class-II restorations as being more complex and showing poorer clinical performance.

Longevity of composite restorations is definitely not only about materials.

OBJECTIVES: This review study provides an overview of factors that influence the longevity of all types of direct resin composite restorations. METHODS: A systematic search was performed in PubMed, Scopus, and Web of Science databases for articles reporting data from primary longitudinal clinical studies on composite longevity published 2011-2021. Prospective or retrospective studies with restorations in permanent dentition, with follow-up periods of at least 5 years were included. RESULTS: In total, 33 articles were included with different study designs, practice settings, datasets, countries of origin, and sample sizes. Annual failure rates of restorations ranged from 0.08% to 6.3%. Survival rates varied between 23% and 97.7%, success rates varied between 43.4% and 98.7%. Secondary caries, fractures, and esthetic compromise were main reasons for failures. Risk factors for reduced restoration durability included patient-level factors (e.g., caries risk, parafunctional habits, number of check-ups per year, socioeconomic status), dentist factors (different operators, operator's experience), and tooth/restoration factors (endodontic treatment, type of tooth, number of restored surfaces). Patient gender and the composite used generally did not influence durability. SIGNIFICANCE: A number of risk factors are involved in the longevity of composite restorations. Differences between composites play a minor role in durability, assuming that materials and techniques are properly applied by dentists. Patient factors play a major role in longevity. The decision-making process implemented by dentists relative to the diagnosis of aging or failed restorations may also affect the longevity of restorations. Clinicians should treat patients comprehensively and promote a healthy lifestyle to ensure longevity.

Posterior Dahl: A Minimally Invasive Method for the Treatment of Localized Posterior Tooth Wear.

PURPOSE: This retrospective case series of 9 patients aimed to describe clinical outcomes and patient satisfaction following the implementation of the posterior Dahl concept to manage localized posterior tooth wear. MATERIALS AND METHODS: Localized occlusal space was created in the posterior dentition. Supra-occluding direct restorations were placed bilaterally for the restoration of molars. Intraoral scans were taken at the pre-treatment stage, immediately post-restoration, and during follow-up appointments. Scans were used to undertake analysis of any occlusal changes and re-establishment of the occlusion. A questionnaire was used to assess patient satisfaction, alleviation of any pre-treatment concerns, and evaluation of post-treatment complaints. RESULTS: Immediately post-treatment, all patients showed an increase in the vertical dimension. Opening of the bite in the untreated areas following restoration of worn posterior molars resulted either in a tendency towards or the actual reestablishment of the occlusion. One patient completely lacked compensatory vertical tooth movement in the untreated areas, culminating in the persistence of a vertical open bite. One restoration displayed cohesive fracture after 4 months. Pre-treatment problems (eg, sensitivity) were fully resolved amongst all patients after 6 months. Post-treatment complaints were minor and demonstrated resolution within a relatively short period of time. Eight patients reported being "very satisfied" with their treatment outcomes. CONCLUSION: Application of the posterior Dahl concept appears to offer a promising, relatively simple, minimally invasive and effective approach for the management of localized posterior tooth wear, which is well accepted by patients.

Proximal marginal overhang of composite restorations in relation to placement technique of separation rings.

The aim was to investigate in vitro the marginal overhang in Class II composite restorations placed with various separation rings and placement techniques. A total of 180 Mesial-Occlusal [MO] preparations in artificial molar teeth were divided into nine groups (n=20). After placement of the sectional matrix, one of three ring systems was applied: Contact Matrix System (Danville Materials), Composi-Tight Gold (Garrison), and V-Ring (Triodent). In each group, rings were placed according to four different techniques (V-Ring placed with technique no. 2 only): 1) occlusally of the wedge, 2) on back end of the wedge, 3) between adjacent tooth and wedge, and 4) between treated tooth and wedge.After application of the adhesive resin, preparations were restored with composite Clearfil AP-X (Kuraray) and polymerized in increments. After matrix removal, overhang was measured on a standardized digital macroscopic image in millimeters squared. For analysis, analysis of variance and Tukey B were used (p<0.05).For the Contact Matrix System and Composi-Tight Gold ring, the different placement techniques had a statistically significant effect on the amount of marginal overhang (p<0.031). The V-Ring resulted in the least marginal overhang (p<0.001).None of the placement techniques and separation rings could completely prevent marginal overhang, and the placement technique has a significant influence on its occurrence.

Rehabilitation of Worn Dentition with CAD-CAM Restorations: A Case Report.

PURPOSE: To describe the digital workflow applied for restoring a severely worn dentition with minimally invasive CAD/CAM resin nano-composite restorations. MATERIALS AND METHODS: A 40-year-old male in good general health and with full-arch dentition suffered from dentin hypersensitivity and wanted to improve the esthetics of his worn anterior teeth. The dental wear can be described as general, grade 3, according to the Tooth Wear Index,27 with more wear in maxillary than in mandibular teeth. Signs and symptoms were typical for a chemical type of wear, with some mechanical wear also apparent. No functional problems, eg, impaired chewing, were present. On the OHIP-49 questionnaire, the patient expressed a reduced quality of life. The goal of the treatment was to reconstruct the anatomical form of the teeth as far as possible, thereby also improving quality of life. Due to the rather large volume of lost tooth tissue per tooth, indirect treatment using CAD/CAM resin nano-composite restorations (LAVA Ultimate, 3M Oral Care) was applied. RESULTS: The seating of the CAD/CAM resin nano-composite restorations (LAVA Ultimate, 3M Oral Care) restorations was considered precise. CONCLUSION: In the treatment of severe tooth wear, the described digital workflow using CAD/CAM restorations for occluding restorations and direct composite materials in the esthetic zone is a potential treatment modality that is workable and minimally invasive.

Impact of the Coronavirus on Providing Oral Health Care in the Netherlands.

OBJECTIVE: Transmission of SARS-CoV-2 during oral health care is potentially increased compared to regular social activities. Specific amendments to the Dutch national infection control guidelines were promulgated. This study aimed to map the impact of the coronavirus pandemic on providing oral health care during the first wave of the coronavirus pandemic in 2020 in the Netherlands. METHODS: A cross-sectional web-based survey was sent via email to a representative sample of dental hygienists and dentists in the Netherlands. RESULTS: Of the 1700 oral health care practitioners approached, 440 (25.9%) responded to the survey. Patient access to oral health care was severely restricted during the lockdown in the spring of 2020. A total of 1.6% of the oral health care practitioners had laboratory-confirmed COVID-19 during the study period, although this is likely to be an underrepresentation due to limited access to testing at that time. Over half of the participants perceived an increased risk of virus transmission during aerosol-generating treatments in their practices. A large majority (65.0%-87.1%) of the oral health care practitioners followed the COVID-19-specific amendments to the national infection control guidelines. Compared to the pre-pandemic period, additional personal protective equipment and protocols were applied. Factors related with compliance with the additional recommendations were age, employment status, and occupation. CONCLUSIONS: The pandemic had a profound impact on both the accessibility and practice of oral health care. This survey study found that most Dutch oral health care practitioners paid extra attention to hygiene and infection control. Also, a low number of COVID-19 infections detected amongst Dutch oral health care practitioners was reported in the Netherlands. These overall outcomes suggest that safe oral health care can be provided when following the current infection control recommendations.

The Ability of Two Chewing Simulation Devices in Emulating the Clinical Deterioration of Anterior Composite Restorations in Severely Worn Teeth.

PURPOSE: This study investigated the ability of two chewing simulation devices to emulate in vitro the clinical deterioration observed in anterior composite restorations in severe tooth-wear patients. MATERIALS AND METHODS: Advanced tooth wear was simulated in bovine incisors, which were restored with palatal and buccal direct composite veneer restorations. The incisal edges of restorations were subjected to 960K cycles of either compressive loading (Biocycle-V2; 125 N at 2 Hz) or wear and mechanical loading (Rub and Roll; 30 N at 20 rpm). Surface degradation was rated using FDI scores to compare the chewing devices (Fisher's test, a = 0.05). Topography and deterioration of restorations was analyzed using SEM. The ability to emulate the deterioration was investigated by comparing the surface degradation observed in vitro with the clinical degradation observed in restorations placed in severe tooth-wear patients after 3.5 years. RESULTS: Distinct degradation patterns were observed between the simulation devices: Biocycle-V2 generated deterioration that was not comparable to the clinical situation, including contact damage, minor wear, and localized roughening. The degradation caused by Rub and Roll was more similar to the in vivo situation, including wear facets, chipping, delamination, staining, and marginal ditching. The FDI scores were different between the chewing devices for surface/marginal staining, material/retention, and marginal adaptation (p = 0.003). SEM analysis showed microcracking at the interface between composite layers at the incisal edges. CONCLUSIONS: The Rub and Roll chewing device was able to emulate the clinical deterioration observed in anterior restorations in severe tooth-wear patients and thus may be used as an oral-cavity simulation method, contributing to translational research.

Prospective Study on CAD/CAM Nano-Ceramic (Composite) Restorations in the Treatment of Severe Tooth Wear.

PURPOSE: The aim of this prospective study was to evaluate the clinical performance of minimally invasive, CAD/CAM nano-ceramic (composite) restorations in patients with severe tooth wear, the effect of the restorative treatment on the oral health-related quality of life (OHRQoL), and the etiology of tooth wear as a risk factor for restoration failure. MATERIALS AND METHODS: Patients with generalized severe tooth wear were included. Restorations (LAVA Ultimate, 3M Oral Care) were cemented (RelyX Ultimate, 3M Oral Care) on all teeth and were evaluated after 1 month and 1 year. OHRQoL was assessed via questionnaires at baseline and after 1 year. Differences were evaluated (paired t-test). Two mechanical tooth-wear lesions resulting from tooth-tooth contact, and 3 chemical tooth wear lesions resulting from intrinsic or extrinsic acids dissolving natural hard tooth substance, were evaluated to assess the etiology of tooth wear in association with restoration failure using multilevel logistic regression analyses (p < 0.05). RESULTS: Twenty-one patients (age: 41.7 ± 10.4 years) were evaluated after 1 year (13.5 ± 1.2 months). 568 indirect CAD/CAM restorations were placed. None were replaced or lost. Twelve were repaired and 10 were refurbished. Success rates were 100% to 97.2%. Questionnaires showed a significant positive impact of the treatment on OHRQoL (p < 0.001). The presence of mechanical lesions did not pose a higher risk for restoration failure (p = 0.78). The presence of chemical lesions showed a lower risk of restoration failure (p = 0.002). CONCLUSION: The use of minimally invasive, CAD/CAM nano-ceramic (composite) restorations in the restorative treatment of severely worn dentitions showed satisfactory results in the short term.

Clinical performance of posterior resin composite restorations after up to 33 years.

OBJECTIVES: This retrospective study evaluated the performance of posterior composites after up to 33 years of clinical service and investigated factors associated with the risk of failures over time including patient- and tooth-related variables. METHODS: Patients who received at least one Class I or Class II direct composite restoration in a private office in 1986-1992 and had follow-up appointments were included. Failures and interventions over time were investigated using the dental records. A follow-up clinical recall was carried out in 2020. Two scenarios were considered: restorations that did not require any intervention (success) or restorations that were repaired and still functional (survival). Multivariate Cox regression analyses and Kaplan-Meier curves were performed using success and survival rates (p < 0.05). RESULTS: One hundred patient records and 683 restorations were included. A total of 353 failures were reported (success rate= 48%). Main reasons for failure were fracture and secondary caries. Most interventions after failures were repairs. Replacements were registered in 183 cases (survival rate= 73%). Annual failure rates were below 2.5% (success) and 1.1% (survival). Larger restorations and maxillary molars had higher failure risks. No significant differences in success rates among different resin composites was observed. A typical observation in this sample of restorations was the presence of moderate to advanced signs of aging, including marginal and surface staining, wear, chipping, changes in anatomical shape and translucency. Clearly aged restorations were still clinically satisfactory. SIGNIFICANCE: This long-term, practice-based study indicates that resin composites can be used to restore posterior teeth with a long-lasting durability.

The effect of pre-treatment levels of tooth wear and the applied increase in the vertical dimension of occlusion (VDO) on the survival of direct resin composite restorations.

OBJECTIVES: To investigate the effects of the level of pre-treatment tooth wear and increasing the VDO on the performance of direct resin composite restorations for the rehabilitation of pathological tooth wear. METHODS: Full-mouth (pre-treatment) grading was performed on digital greyscale scan records for 34 participants (35.3 ± 8.4 years) with signs of moderate-to-severe generalised tooth wear, using the Tooth Wear Evaluation System and the Basic Erosive Wear Examination. Each participant received full-mouth direct resin composite restorations, with increased VDO. The post-treatment increase in the VDO was determined. Recalls were planned after 1 month, and after 1, 3, and 5 years. Three 'levels' of restoration failure were described. The effects of the variables on the frequencies of restoration failure were calculated with a multivariable Cox regression, (p < 0.05). RESULTS: 1269 restorations were placed with a mean observation period of 62.4 months. Increasing the VDO by 1 mm significantly reduced the risks of all levels of anterior restoration failure (HR ≤ 0.62, p ≤ 0.025). A higher anterior BEWE surface score was associated with increased risks of Level 2- & 3- failures, (HR ≥ 1.29, p ≤ 0.019). Premolar restorations showed lower risks of Level 2- & 3- failure, compared to the molar restorations, (HR ≤ 0.5, p ≤ 0.005). CONCLUSION: Levels of pre-treatment wear and the applied change in the VDO significantly affected failure risk. CLINICAL RELEVANCE: Direct resin composite restorations for the rehabilitation of wear should be made as voluminous as possible, respecting the presenting biological, functional, and esthetic constraints.