Clinical performance of direct composite resin restorations in a full mouth rehabilitation for patients with severe tooth wear: 5.5-year results

Clinical performance of minimally invasive full-mouth rehabilitation using different materials and techniques for patients with moderate to severe tooth wear: a systematic review and meta-analysis

OBJECTIVE

To evaluate short, mid and long-term clinical outcomes and patients' satisfaction of minimally invasive full-mouth rehabilitation using different materials and techniques for patients with moderate to severe tooth wear. Furthermore, materials were analyzed to identify their influences on clinical results.

MATERIALS AND METHODS

Search was conducted in PubMed, Cochrane Central Register of Controlled Trial, Embase, Web of science and Scopus until December 19, 2024. Randomized clinical trials (RCT), cohort studies and case series with at least mean period of 3 years were included. The revised Cochrane risk of bias tool, Newcastle-Ottawa scale and Joanna Briggs Institute Critical Appraisal were used to evaluate the quality of RCT, cohort studies and case series. Meta-analysis and Poisson regression were conducted.

RESULTS

Ten studies in this review included three case series, six cohort studies and one RCT with three low, six moderate risks and one some concerns. Annual failure rates (AFRs) and annual complication rates (ACRs) of direct composite restorations were 0-6.2% and 1.0%-4.2%, respectively. AFRs of indirect restorations were 0%-0.5%. Overall ACRs of indirect restorations fabricated by traditional indirect resin composites, polymer-infiltrated ceramic-network, resin nanoceramics and ceramics were at 1.6%-15.1%, 0.7%-4.8%, 0.5%-5.0% and 0.2%-1.1%, respectively. The estimated AFRs of direct composites, resin nanoceramics and ceramics were 0.64%, 0.13% and 0.04% respectively. Significantly lowest AFRs of ceramic was found after mid-term follow-up with incidence rate ratios of direct composites, resin nanoceramics and ceramics being 1: 0.68 (P = 0.60): 0.001 (P < 0.05). The estimated ACRs of the three materials were 2.16%, 2.14% and 0.62%. Overall AFRs of restorations using different techniques were 0%-0.5%. Overall ACRs of direct and indirect techniques were 1.1%-2.2% and 0.2%-4.8%, respectively. Overall ACRs of hybrid technique were 0.5% to 15.1%. Restoration fracture was the most predominant complication regardless of materials. High appreciation was expressed by patient reported outcomes measures.

CONCLUSIONS

Minimally invasive full-mouth rehabilitation for patients with moderate to severe tooth wear presented good clinical performance apart from traditional indirect resin composite used in posterior teeth.

CLINICAL RELEVANCE

Minimally invasive full-mouth rehabilitation should be strongly advocated for the patients with moderately and severely worn dentition.

The One-step No-prep technique for non-invasive full-mouth rehabilitation of worn dentition using PICN CAD-CAM restorations: Up to 9-year results from a prospective and retrospective clinical study

OBJECTIVES

To report up to 9-year results of a prospective and retrospective study on non-invasive full-mouth rehabilitation of worn dentition with PICN CAD-CAM restorations using the One-Step No-Prep technique. The secondary objective is to evaluate the influence of restoration thickness on fracture of restorations.

METHODS

A total of 580 Vita Enamic restorations (218 anterior and 362 posterior; 260 monoblock (MO) and 320 multiColor (MC)) in 24 patients were clinically evaluated once a year (up 9 months to 9 years) according to FDI criteria. Patient data and prosthetic parameters were registered. The minimum thickness of restorations was measured in 15 patients.

RESULTS

The Kaplan-Meier survival rate of restorations at 9 years was 98.4 % (100 % for anterior and 96.7 % for posterior) and the success rate was 79.7 %, while the success rate excluding minor chipping requiring only polishing as failure was 86.7 %. Actually, minor chipping was the leading cause of failure and significantly more fractures were observed in the posterior region (9.2 times higher risk), particularly in the first and second molars or when the restoration thickness was less than 0.56 mm. Except for fracture, FDI evaluation showed clinically acceptable results for all restorations, mostly rated as excellent. Results remained consistent over time, including material luster and color, with no staining. MC showed superior esthetics compared to MO. Patient satisfaction was high.

SIGNIFICANCE

The One-Step No-Prep technique exhibits successful long-term outcomes, and PICN (hybrid ceramic) is an appropriate material for this non-invasive treatment of tooth wear. Nevertheless, the minimum thickness of posterior restorations should be 0.6 mm, particularly at occlusal contact points. MultiColor blocks are recommended for esthetics.

Rehabilitation of the Worn Dentition With Direct and Indirect Minimally Invasive Concepts-A Systematic Review and Meta-Analysis

OBJECTIVE

To report and compare the survival of minimally invasive direct and indirect restorations of different materials for restoring the worn dentition.

MATERIAL AND METHODS

A systematic search was conducted in six databases: MEDLINE, Web of Science, Scopus, CENTRAL, VHL, and EMBASE. The eligibility criteria of this systematic review used the PICO framework to address the following research question: "In dentate patients with a worn dentition (P), does rehabilitating their lost tooth structure with indirect restorations (I) or direct (C) effect the survival and success of treatment (O)?". Study characteristics, survival rates of the restorations were extracted from each article. No language restrictions were applied. Survival and prevalence estimates were calculated using random-effect models.

RESULTS

The electronic search yielded 5009 entries, resulting in 14 publications selected for full-text analysis. These included 2 RCTs, 7 prospective, and 5 retrospective studies, with a varying level of methodological quality. This included 52% direct and 48% indirect restorations, using varying materials and follow-up periods. The survival of direct composite resin restorations versus indirect manually processed composite resin restorations showed no significant difference (n = 2; OR, 1.79 [95% CI, 0.64-5.05]; p = 0.270). For the prospective articles, the pooled prevalence estimates of the survival restorations were; direct (n = 3; 99% [95% CI, 0.97-1.00]) and; indirect (n = 5; 100% [95% CI, 0.99-1.00]). Lithium disilicate recorded the least amount of failures at 1.8%.

CONCLUSIONS

Although the survival estimates of indirect manually processed and direct composite resins were not significantly different, indirect restorations-especially those made of lithium disilicate ceramic-may offer better survival rates, compared to direct resin restorations in patients with worn dentition.

CLINICAL SIGNIFICANCE

Despite the limited evidence, indirect ceramic restorations appear to be well-suited for long-term treatment of worn dentition, whilst direct composite resin restorations are more suited as an medium-term solution.

Changes in Oral Health-Related Quality of Life after (non-)restorative treatment of tooth wear in adult patients: A systematic review

OBJECTIVE

Literature was systematically reviewed to determine the impact of tooth wear management on the Oral Health Related Quality of Life (OHRQoL) amongst adult patients with tooth wear.

DATA

A protocol was developed, a priori (PROSPERO CRD42022343108) following the PRISMA guidelines. To assess risk of bias and certainty of evidence the RoB2-tool, JBI-tool, and GRADE were used.

SOURCES

PubMed, Scopus, Cochrane Library, Embase and Web of Science were searched. The first search took place on 21.10.2022, subsequently updated in May 2024.

STUDY SELECTION

Inclusion criteria were RCT's, quasi-RCT's, prospective- or retrospective-studies with adult patients with moderate to severe tooth wear, treated restoratively and/or with counseling and monitoring that were also assessed for OHRQoL during at least two time points. Exclusion criteria were, studies with children, OHRQoL only measured once, narrative and systematic reviews, conference abstracts, technical reports, consensus papers, and any other type of non-clinical study.

RESULTS

Six papers were included in this review. Overall, qualitative analysis revealed an increase in OHRQoL after restorative treatment, and no change in OHRQoL after one year of counseling and monitoring. Some studies showed a slightly negative effect on esthetics in the years post-treatment, and some of the dimensions of the Oral Health Impact Profile (OHIP) did not change or demonstrated minor change only. For the RCT's, blinding of participants and operators was not possible, as the participants had an awareness of the treatment. For the non-RCT's, the primary issue was the lack of control, with a general high risk of bias.

CONCLUSION

The provision of restorative treatment in patients with moderate to severe tooth wear frequently results in a positive impact on OHRQoL. Further research is required to substantiate the importance of OHRQoL for the treatment of (tooth wear) patients.

CLINICAL SIGNIFICANCE

The outcomes may help dentists and researchers better understand the advantages of using PROMS in their clinical work or research as valuable outcomes.

Direct ink writing with dental composites: A paradigm shift toward sustainable chair-side production

OBJECTIVES

To evaluate the dimensional accuracy of occlusal veneers printed using a novel direct ink writing (DIW) system and a clinically approved dental composite.

METHODS

A novel three-dimensional printer was developed based on the extrusion-based DIW principle. The printer, constructed primarily with open-source hardware, was calibrated to print with a flowable resin composite (Beautifil Flow Plus). The feasibility of this technology was assessed through an evaluation of the dimensional accuracy of 20 printed occlusal veneers using a laboratory confocal scanner. The precision was determined by pairwise superimposition of the 20 prints, resulting in a set of 190 deviation maps used to evaluate between-sample variations.

RESULTS

Without material waste or residuals, the DIW system can print a solid occlusal veneer of a maxillary molar within a 20-minute timeframe. Across all the sampled surface points, the overall unsigned dimensional deviation was 30.1 ± 20.2 µm (mean ± standard deviation), with a median of 24.4 µm (interquartile range of 22.5 µm) and a root mean square value of 36.3 µm. The pairwise superimposition procedure revealed a mean between-sample dimensional deviation of 26.7 ± 4.5 µm (mean ± standard deviation; n = 190 pairs), indicating adequate precision. Visualization of the deviation together with the nonextrusion movements highlights the correlation between high-deviation regions and material stringing.

SIGNIFICANCE

This study underscores the potential of using the proposed DIW system to create indirect restorations utilizing clinically approved flowable resin composites. Future optimization holds promise for enhancing the printing accuracy and increasing the printing speed.

An in vitro evaluation of the fatigue behavior of resin composite materials as part of a translational research cycle

PURPOSE

This study aimed to reproduce and translate clinical presentations in an in vitro set-up and evaluate laboratory outcomes of mechanical properties (flexural strength, fatigue resistance, wear resistance) and link them to the clinical outcomes of the employed materials in the Radboud Tooth Wear Project (RTWP).

MATERIALS AND METHODS

Four dental resin composites were selected. 30 discs (Ø12.0 mm, 1.2 mm thick) were fabricated for each of Clearfil TM AP-X (AP), Filtek TM Supreme XTE (FS), Estenia TM C&B (ES), and Lava Ultimate (LU). Cyclic loading (200 N, 2 Hz frequency) was applied concentrically to 15 specimens per group with a spherical steatite indenter (r = 3.18 mm) in water in a contact-load-slide-liftoff motion (105 cycles). The wear scar was analysed using profilometry and the volume loss was digitally computed. Finally, all specimens were loaded (fatigued specimens with their worn surface loaded in tension) until fracture in a biaxial flexure apparatus. The differences in volume loss and flexural strength were determined using regression analysis.

RESULTS

Compared to AP and FS, ES and LU showed a significantly lower volume loss (p < 0.05). Non-fatigued ES specimens had a similar flexural strength compared to nonfatigued AP, while non-fatigued FS and LU specimens had a lower flexural strength (p < 0.001; 95 %CI: -80.0 - 51.8). The fatigue test resulted in a significant decrease of the flexural strength of ES specimens, only (p < 0.001; 95 %CI: -96.1 - -54.6).

CLINICAL RELEVANCE

These outcomes concur with the outcomes of clinical studies on the longevity of these composites in patients with tooth wear. Therefore, the employed laboratory test seems to have the potential to test materials in a clinically relevant way.

Effect of acidic media on surface characteristics of highly filled flowable resin-based composites: An in vitro study

OBJECTIVE

To analyze and compare the impact of acidic media on the surface characteristics of highly filled flowable resin-based composites.

MATERIALS AND METHODS

Two hundred fifty-six specimens were divided into four groups: GUF (G-aenial Universal Flo), GUI (G-aenial Universal Injectable), TEF (Tetric EvoFlow), and FSF (Filtek Supreme Flowable Restorative). Surface characteristics were analyzed before (T0) and after specimens immersion in different media, such as gastric juice (GJ), fizzy drink (FD), citric juice (CJ), or artificial saliva (AS), for 9 h (T1) and 18 h (T2). The analyses included surface roughness (SR) measurements, where average roughness (Ra) was obtained, scanning electron microscopy (SEM) analysis, and surface hardness (SH) evaluation, with Vickers numbers (HV) reported. The differences in values among groups/subgroups within the same stage were assessed using two-way ANOVA and Tukey's post hoc test, whereas repeated measures ANOVA with Bonferroni post hoc test was performed to compare the changes in values through the stages. Data were presented as mean ± standard deviation (SD).

RESULTS

At T0, GUI and GUF revealed lower Ra values (p < 0.05), more evenness in SEM micrographs, and higher HV values (p < 0.05) than FSF and TEF. At T1 and T2, specimens of all groups/subgroups demonstrated an increase in Ra and a decrease in HV compared with T0 (p < 0.05), as well as the changes in surface morphology on SEM micrographs. The lowest Ra and highest HV values were observed in GUI group, in contrast to FSF group, and in specimens immersed in GJ.

CONCLUSIONS

GUI revealed lower SR and higher SH compared to GUF and FSF both before and after exposure to acidic media. The presence of acidic media, especially GJ, significantly increases SR and decreases SH of tested materials.

CLINICAL SIGNIFICANCE

Information on the changes in the surface characteristics of highly filled resin-based composites after exposure to acidic media may be essential for the longevity of restorations like composite veneers fabricated from these materials.

5.5-year-survival of CAD/CAM resin-based composite restorations in severe tooth wear patients

OBJECTIVES

Aim of this prospective study was to assess full mouth rehabilitation of severe tooth wear patients using minimally invasive CAD/CAM resin-based composite (RBC) restorations and direct veneers by evaluating restoration survival up to 5.5-years.

METHODS

Twenty-two patients with generalized severe tooth wear with functional and/or esthetic problems were included. Following minimally invasive preparation, CAD/CAM RBC restorations (LAVA Ultimate,3M) were adhesively luted, direct RBC veneers (Filtek Supreme XTE, 3M) were applied in the aesthetic region. Patients were recalled after 1m,1y,3y,5y and seen in between recalls by their general dentists or at the clinical study center if complaints occurred. Failures were categorized as F1 (severe deficiencies requiring replacement/extraction), F2 (localized deficiencies requiring re-cementation/repair) and F3 (small chippings requiring refurbishment/monitoring). Survival of indirect restorations was evaluated using lifetables and Kaplan-Meier-graphs, distinguishing between failure categories and tooth type (front teeth=FT, premolars=PM, molars=M). F1 + F2 and F1 + F2 + F3 failures were analyzed using Cox regression on the variables tooth type/ location, age, gender and VDO increase (p < 0.05).

RESULTS

568 indirect restorations and 200 direct veneers in 21 patients evaluated for up to 5.5-years. For indirect restorations, 96 failures were recorded (F1:6;F2:41;F3:49) and annual failure rates were 0.29%(FT), 1.56%(PM), 2.93%(M) for F1 +F2 and 0.53%(FT), 2.42%(PM), 6.11%(M) for F1 + F2 + F3. Reasons for failure were chipping fracture (48), adhesive fracture (32), complete debonding (7), caries (4), endodontic treatment (1) and reasons unknown (documentation general dentists, 4). Molar tooth type had a statistically significantly increased probability of failure compared with front teeth and premolars for F1 + F2 + F3 (p < 0.006). Direct veneer restorations showed 18 failures (F1:2;F2:9;F3:7).

SIGNIFICANCE

Minimally invasive CAD/CAM RBC restorations combined with direct RBC veneers showed an acceptable clinical mid-term survival for restorative rehabilitation of severely worn dentitions.

Longevity of Anterior Composite Restorations for Localized Tooth Wear: A Scoping Review

(1) Objective: This scoping review evaluates composite restorations as a treatment modality for anterior tooth surface loss and investigates the longevity of the direct and indirect composites used herein. (2) Method: The search encompassed Medline, Embase, Web of Science, the Cochrane Library, and hand search utilizing the PICO framework. (3) Results: Eight studies were included in this review, comprising one randomized controlled trial, one retrospective, and six prospective studies. Some studies reported favorable outcomes for composite restorations in anterior teeth. Although not statistically significant, evidence supported the anterior composite as a viable short- to medium-term solution for managing tooth wear. Direct resin composites were deemed clinically and cost-effective when managing localized anterior tooth wear. However, limitations and inconsistencies in this scoping review limited definitive clinical recommendations. (4) Conclusions: Further research, including well-managed randomized controlled trials using standardized protocols and longer follow-up periods, is essential to reconfirm the long-term efficacies of anterior composite restorations when managing tooth wear. A robust research design and exacting protocols could facilitate more meaningful clinical conclusions.

Perception of oral health related quality of life and orofacial aesthetics following restorative treatment of tooth wear: A five-year follow-up

OBJECTIVES

Non-carious tooth wear often has a multifactorial etiology and may lead to functional or aesthetically related problems. The most common complaints associated with tooth wear are dissatisfaction with dental appearance and a negative impact on the experienced Oral Health Related Quality of Life (OHRQoL). The aim of this study was to investigate the change in OHRQoL and the perception of aesthetics, following restorative treatment of moderate to severe tooth wear patients, with a five-year follow-up.

METHODS

An explorative study, based on prospective data, was performed. OHRQoL and the perception of aesthetics were measured with the OHIP-NL and OES-NL. These questionnaires were completed before treatment, one month after treatment, and at 1-, 3- and 5-years post-treatment. Treatment involved full mouth reconstruction with composite resin restorations. The data was analysed as repeated measures by using a linear mixed-effects model.

RESULTS

One hundred and twenty-three tooth wear patients that received restorative rehabilitation were included (97 males, 26 females, 37.5 ± 8.8 years-old). Data showed a statistically significant increase in both experienced OHRQoL and orofacial appearance after restorative treatment. The OHIP-scores remained stable over time, while the OES-scores slightly decreased during the years after treatment. Regarding the seven domains of the OHIP, the largest difference in OHIP-score was found in the domain of 'Psychological Discomfort'. The mean overall OHIP-score was 1.8 at baseline and 1.3 at the 5-years recall. The mean OES score increased from 41.8 at baseline to 66.1 at the 5-years follow-up.

CONCLUSIONS

Tooth wear patients reported significant improvements in their OHRQoL and their perception of orofacial aesthetics after restorative treatment. This increase remained at least five years post-treatment.

CLINICAL SIGNIFICANCE

The clinical impact of restorative treatment for tooth wear patients is considerable. This paper emphasizes the need to include a discussion of the patient related outcome measures when planning care.

The longevity of tooth-coloUred materials used for restoration of tooth wear: an evidence-based approach

Patients with tooth wear are commonly encountered in general dental practice. When indicated, restorative rehabilitation is often accompanied by a request from the patient for an aesthetic, tooth-coloured outcome. This article seeks to provide an evidence-based approach, focussing on the longevity of the materials which can be used for the restorative treatment of tooth wear, as well as their modes of failure and observed performance.

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.

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.

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.

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.

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.

Wear behaviour of direct composite restorations in tooth wear patients: a 5-year clinical study

OBJECTIVE

This study aimed to investigate the wear behaviour of direct composite restorations after 5 years and associated patient factors.

METHODS

38 patients (6 females, 32 males; 35.2 ± 7.6y) from the Radboud Tooth Wear Project with generalized moderate to severe tooth wear were treated with direct composite restorations on all teeth. Ethical approval was sought and granted before the study was undertaken. Intraoral 3D scans were recorded at 1 month (baseline) and 5 years (recall) after treatment. The amount of height loss was measured at six index teeth (first molars and upper central incisors). Patient factors (age, vertical dimension of occlusion increase, bite force, aetiology score, jaw position and bearing/ non-bearing cusps) were included in the analysis. Multilevel multiple regression with bootstrapping was used to analyse the influence of these factors on wear behaviour of restorations. Observer reliability was tested by paired t-tests and Band-Altman plots (p<0.05) RESULTS: After 5 years, the mean height loss was 0.23± 0.19 mm for incisors and 0.43± 0.24 mm for molars (p≤0.001). Patient factors did not show any significant influence on height loss of the composite restorations, while bearing cusps showed significant more wear compared to non-bearing cusps (p≤0.001). The observer reliability tests confirmed the repeatability (correlation of 0.809, DME 0.103).

CONCLUSIONS

Wear of composite restorations is a significant and relevant factor over time in patients treated with severe tooth wear. Within the limitations of this clinical study, patient factors were found not to have a significant effect on wear behaviour of direct composite restorations.

Effect of roughness and acidic medium on wear behavior of dental resin composite

Background

The aim of the study was to investigate whether the citric acid and rough surface have a synergistic effect leading to severe wear behavior of resin composite.

Materials and methods

Disk-shaped (Ø15 × 1.5 mm) specimens of resin composite (n = 12) with different initial roughness were prepared. Reciprocating ball-on-flat wear tests were performed under distilled water and citric acid (pH = 5.5) respectively. The coefficient of friction (COF), wear volume loss, and duration of the running-in period were quantified to assess the wear performance. And the values were analyzed with one-way ANOVA (α = 0.05). Regression analysis was applied to examine the influence of Ra values and mediums on the wear data. The wear morphology was analyzed by scanning electron microscopy and a 3D profilometer.

Results

The average COF was higher in distilled water than in citric acid but was independent of the surface roughness. For the composite, the volume loss of worn area and running-in period increased with surface roughness when tested under distilled water. However, these increasing trends were not found in citric acid. All specimens exhibited mild wear behavior with low COF and less superficial abrasion in acidic medium.

Conclusions

The effect of initial roughness on wear behavior depends on the medium. In distilled water, resin composites with high initial roughness exhibit a longer running-in time, which eventually leads to a significant increase in material loss. The adverse effects of high roughness can be alleviated by the lubrication of citric acid, which can maintain a mild wear behavior regardless of initial surface roughness.

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.

Longevity of Polymer-Infiltrated Ceramic Network and Zirconia-Reinforced Lithium Silicate Restorations: A Systematic Review and Meta-Analysis

The purpose of this study was to systematically review the existing literature to assess the clinical survival and success of PICN and ZLS indirect restorations as the clinical evidence for them remains lacking. PubMed, SCOPUS, Embase, Cochrane Library, Web of Science, LILACs, and SciElo databases were searched from 1 January 2000 to 1 February 2021. Clinical trials and cohort studies published in English were included while case studies, case series, and in vitro studies were excluded. Results were analyzed qualitatively and a meta-analysis using a random effects model was performed. A strength of recommendation taxonomy (SORT) analysis was conducted and risk of bias (RoB) was assessed using the Newcastle-Ottawa scale and Cochrane RoB tools. An electronic search through the databases yielded 2454 articles, of which 825 remained after duplicate removal. Five studies investigating PICN and four investigating ZLS indirect restorations remained after assessing for eligibility. The overall survival rate of PICN over 1 year was 99.6% and 99.2% over 2 years. The overall survival rate of ZLS over 1 year was 99%. The main mode of failure for both materials was catastrophic fracture. One study had a high RoB, four had a moderate RoB, and four had a low RoB. Both materials demonstrated moderate strength of recommendation at a level 2 evidence for all studies based on SORT analysis. PICN and ZLS show promising short-term clinical performance as full and partial coverage indirect restorations, but longer follow-up studies are required to confirm their long-term performance.