[Post-endodontic restoration: a direct or indirect restoration?] / De coronale afsluiting: een directe of indirecte restauratie?

When restoring an endodontically treated tooth, it is important to preserve the pericervical dentin so it is resistant especially to lateral forces occurring during mastication. When little pericervical dentin is seen to be present, an adhesive restoration is indicated. Tooth survival of endodontically treated teeth restored with adhesive direct and indirect restorations varies between 90.5% and 95.0% after 5 years. Deciding between a direct or an indirect restoration depends above all on the possibility to predictably restore the anatomy and on gloss retention. Because endodontically treated teeth are vulnerable to lateral forces, control of these forces after direct or indirect restoration is important. This can be achieved by a reduction in the steepness of the cuspal slope and/or by covering the cusps with the restorative material.

Clinical longevity of intracoronal restorations made of gold, lithium disilicate, leucite, and indirect resin composite: a systematic review and meta-analysis.

OBJECTIVES: The aim of this systematic review and meta-analysis is to assess the comparative clinical success and survival of intracoronal indirect restorations using gold, lithium disilicate, leucite, and indirect composite materials. MATERIAL AND METHODS: This systematic review and meta-analysis were conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. The protocol for this study was registered in PROSPERO (registration number: CRD42021233185). A comprehensive literature search was conducted across various databases and sources, including PubMed/Medline, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, and gray literature. A total of 7826 articles were screened on title and abstract. Articles were not excluded based on the vitality of teeth, the language of the study, or the observation period. The risk difference was utilized for the analyses, and a random-effects model was applied. All analyses were conducted with a 95% confidence interval (95% CI). The calculated risk differences were derived from the combined data on restoration survival and failures obtained from each individual article. The presence of heterogeneity was assessed using the I2 statistic, and if present, the heterogeneity of the data in the articles was evaluated using the non-parametric chi-squared statistic (p < 0.05). RESULTS: A total of 12 eligible studies were selected, which included 946 restorations evaluated over a minimum observation period of 1 year and a maximum observation period of 7 years. Results of the meta-analysis indicated that intracoronal indirect resin composite restorations have an 18% higher rate of failure when compared to intracoronal gold restorations over 5-7 years of clinical service (risk difference = - 0.18 [95% CI: - 0.27, - 0.09]; p = .0002; I2 = 0%). The meta-analysis examining the disparity in survival rates between intracoronal gold and leucite restorations could not be carried out due to methodological differences in the studies. CONCLUSIONS: According to the currently available evidence, medium-quality data indicates that lithium disilicate and indirect composite materials demonstrate comparable survival rates in short-term follow-up. Furthermore, intracoronal gold restorations showed significantly higher survival rates, making them a preferred option over intracoronal indirect resin-composite restorations. Besides that, the analysis revealed no statistically significant difference in survival rates between leucite and indirect composite restorations. The short observation period, limited number of eligible articles, and low sample size of the included studies were significant limitations. CLINICAL SIGNIFICANCE: Bearing in mind the limitations of the reviewed literature, this systematic review and meta-analysis help clinicians make evidence-based decisions on how to restore biomechanically compromised posterior teeth.

Clinical survival and performance of premolars restored with direct or indirect cusp-replacing resin composite restorations with a mean follow-up of 14 years.

OBJECTIVES: The objective is to evaluate the long-term clinical survival and performance of direct and indirect resin composite restorations replacing cusps in vital upper premolars. METHODS: Between 2001 and 2007, 176 upper premolars in 157 patients were restored with 92 direct and 84 indirect resin composite restorations as part of an RCT. Inclusion criteria were fracture of the buccal or palatal cusp of vital upper premolars along with a class II cavity or restoration in the same tooth. RESULTS: Forty patients having 23 direct and 22 indirect composite restorations respectively, were lost to follow-up (25.6%). The cumulative Kaplan-Meier survival rates were 63.6% (mean observation time: 15.3 years, SE 5.6%) with an AFR of 2.4% for direct restorations and 54.5% (mean observation time: 13.9 years, SE: 6.4%) with an AFR of 3.3% for indirect restorations. The Cox regression analysis revealed a statistically significant influence of the patient's age at placement on the survival of the restoration (HR 1.036, p = 0.024), the variables gender, type of upper premolar, type of restoration, and which cusp involved in the restoration had no statistically significant influence. Direct composite restorations failed predominantly due to tooth fracture, indirect restorations primarily by adhesive failure (p < 0.05). SIGNIFICANCE: There was no statistically significant difference in survival rates between direct and indirect composite cusp-replacing restorations. Both direct and indirect resin composite cusp-replacing restorations are suitable options to restore compromised premolars. The longer treatment time and higher costs for the indirect restoration argue in favor of the direct technique.

[Online survey on adhesive dentistry: the results]. / Online enquête over adhesieve tandheelkunde: de resultaten.

In the months leading up to this special issue on adhesive dentistry, an online survey was conducted on various aspects of this. This survey was completed by 133 people, with a similar number of men and women. The results show that half of the oral care providers apply a rubber dam for adhesive restorations. The vast majority prefer to manufacture partial indirect restorations and the majority apply an IDS layer during dentine exposure. The choice of adhesive is not determined by time savings, but the dental technician often pre-treats the indirect restorations.

[Attitude of graduate dental students in The Netherlands towards rubber dam use]. / Rubberdamgebruik onder vijfde- en zesdejaars tandheelkundestudenten in Nederland.

The use of rubber dam isolation during restorative procedures is often used. This survey study analyzed several aspects of the use of rubber dam isolation of fifth and sixth year's dental students at three Dutch universities using the COM-B model. This model explains behavior (B) from 3 factors: capacity (C), opportunity (O), and motivation (M). In the period of February-August 2022, a total of 81 students completed the survey (Academic Center for Dentistry Amsterdam, ACTA, n = 25; Radboud University, RU, n=28; Center for Dentistry and Oral Hygiene, CTM, n = 28). There were significant differences on all 3 factors between universities. RU students felt more confident than CTM students in applying the rubber dam in the anterior zone. At RU, teachers were significantly less likely to encourage the use of rubber dams. CTM students were more likely to assess the use of rubber dams as more important in the longevity of direct restorations (motivation). Students struggled the most with rubber dam use in subgingival cases and would like that their teachers were more adept in manipulation of soft tissues. Within the Netherlands, the education in rubber dam use should focus more on practical skills in these subgingival cases, including soft tissue handling.

[The digital impression under rubber dam: clinical insights for an accurate scan]. / Digitaal afdrukken onder rubberdam: klinische inzichten voor een nauwkeurige scan.

During the past 15 years, the advent of digital innovations has completely changed the dental practice. Tools like intraoral scanners, computer-aided design (CAD) and computer-aided manufacturing (CAM) are considered perfectly reliable and affordable, today. The use of these digital techniques greatly facilitates restorative and prosthetic treatment. It is particularly interesting to combine isolation under the rubber dam with digital impressions in adhesive restorative dentistry. In this article, a clinical protocol is given on the basis of a case for making a digital impression under the rubber dam.

[Is Immediate Dentin Sealing of added value in partial indirect restoration?] / Is Immediate Dentin Sealing van meerwaarde bij partieel indirect restaureren?

Full crowns/rebates are based on the principle of macro-mechanical retention. Nowadays, indirect partial restorations can also be bonded predictably to tooth tissue, just like direct restorations. Therefore, adapting the preparation form to the restoration is unnecessarily invasive. Partial ceramic restorations are mainly used if the morphology cannot be properly restored with direct restorations. In case of exposed dentin, an immediate dentin sealing (IDS) can prevent failures. An IDS gives a significantly higher bond strength and therefore a longer survival of partial glass-ceramic restorations.

[Deep Margin Elevation for adhesive indirect restorations]. / De coronaalwaarts verplaatste preparatiegrens voor adhesieve indirecte restauraties.

Deep subgingival margin elevation is a much-debated topic in adhesive and restorative dentistry. The hydrophobic trait of adhesive materials challenges the restorative procedure of cavities with deep subgingival margins since bonding and isolation by means of rubber dam is complicated. By relocating the deep subgingival preparation outline to epigingival, or supragingival with a direct composite restoration, the impression procedure and the use of rubber dam is simplified and the bonding of an indirect adhesive restoration can be performed more reliably. In the English-language literature, the term 'Deep Margin Elevation' is reserved for this approach. This article discusses the rationale and clinical implementation of Deep Margin Elevation. The current knowledge about the coronal relocated preparation margin is growing and is tersely summarized in this article with special attention to adhesive bonding between dentine, composites, and ceramic.

Dimensional changes of CAD/CAM polymer crowns after water aging - An in vitro experiment.

Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) polymers can potentially replace traditional materials used for manufacturing indirect restorations. In 2012, Lava Ultimate (LU) was introduced as a highly suitable material for implant-supported single crowns. Three years after its introduction, the manufacturer issued a change in indication for the material, implying that they no longer considered the material to be suitable for crown indications due to debonding issues. A clinical trial with implant-borne Lava Ultimate crowns bonded to zirconia abutments revealed that 80 percent of the LU crowns showed debonding from the abutment within one year, whereas no debonding occurred when an alternative full-ceramic restoration material was used. These results suggest that the material itself had been the cause of the debonding. However, the exact reason for the debonding remained unclear. Water uptake in resin methacrylates like LU is known to cause dimensional changes resulting in mechanical stress on the RelyX Ultimate (RU) cement. The purpose of this study is to quantify the dimensional changes in LU caused by water uptake and relate these dimensional changes to the failure of the RU cement. Twenty-five identical LU-crowns were divided into three groups. 10 LU-crowns with abutment and 10 crowns without abutments were stored in water for 23 days and were only removed for measurement. Five crowns served as a control to calibrate the measurements. The internal diameter was measured eight times with a TS 460 Heidenhain touch probe. For visualization purposes, one crown was also 3D scanned before and after water treatment. The results showed that after 23 days in water the mean increase in diameter for the groups with and without abutment was 36.6 µm (SD = 35,1) and 36.7 µm (SD = 26,5) respectively. Mixed effects modelling indicated no significant between-group differences at any time point. Exposure of LU to water results in dimensional changes causing mechanical stress on the crown-abutment complex. It can be estimated that RU cement fails after an expansion of more than 4 µm. Within the limitations of this in vitro study, it can be concluded that the dimensional changes induced by water uptake can cause debonding issues. As more CAD/CAM polymers for restorative purposes are expected to be developed, the results of this study should stimulate manufacturers to quantify their products' dimensional changes in a wet environment before market release.

[Restoration choices for endodontically treated posterior teeth]. / Restauratieve keuzes voor endodontisch behandelde gebits-elementen in de posterieure zone.

There aren't any generally accepted guidelines for the restoration of an endodontically treated tooth. With a questionnaire among dental general practitioners and endodontists, several restorative treatment options for endodontically treated molars and premolars were identified. The questionnaire inventoried the influence of various parameters on treatment preferences. For each case, additional questions were put about material choice, cuspal coverage and the use of root canal posts. Both groups identified the vertical root fracture as the most common reason for extraction. The dentist general practitioner waited longer than the endodontist to make a permanent restoration in the case of apical periodontitis. Treatment preferences were found to be the same for premolars and molars. In the case of premolars, a root canal post was indicated more often and the location of the wall (bearing/non-bearing) influenced the choice of cuspal coverage. Of the dentist general practitioners and endodontists, 51-53% and 75-94%, respectively, preferred a partial over a full crown preparation in the case of single-walled teeth.

Influence of Deep Margin Elevation and preparation design on the fracture strength of indirectly restored molars.

The objectives of this in-vitro study were to investigate the influence of Deep Margin Elevation (DME) and the preparation design (cusp coverage) on the fracture strength and repairability of CAD/CAM manufactured lithium disilicate (LS2) restorations on molars. Sound extracted human molars (n = 60) were randomly divided into 4 groups (n = 15) (inlay without DME (InoD); inlay with DME (IWD); onlay without DME (OnoD); onlay with DME (OnWD)). All samples were aged (1.2 × 106 cycles of 50N, 8000 cycles of 5-55 °C) followed by oblique static loading until fracture. Fracture strength was measured in Newton and the fracture analysis was performed using a (scanning electron) microscope. Data was statistically analyzed using two-way ANOVA and contingency tables. DME did not affect the fracture strength of LS2 restorations to a statistically significant level (p = .15). Onlays were stronger compared to inlays (p = .00). DME and preparation design did not interact (p = .97). However, onlays with DME were significantly stronger than inlays without DME (p = .00). More repairable fractures were observed among inlays (p = .00). Catastrophic, crown-root fractures were more prevalent in onlays (p = .00). DME did not influence repairability of fractures or fracture types to a statistically significant level (p > .05). Within the limitations of this in-vitro study, DME did not statistical significantly affect the fracture strength, nor the fracture type or repairability of LS2 restorations in molars. Cusp coverage did increase the fracture strength. However, oblique forces necessary to fracture both inlays and onlays, either with or without DME, by far exceeded the bite forces that can be expected under physiological clinical conditions. Hence, both inlays and onlays are likely to be fracture resistant during clinical service.

[Fracture strength of various types of direct and indirect restorations in the functional repair of endodontically treated molars]. / Breuksterkte van verschillende types directe en indirecte restauraties bij het functioneel herstel van endodontisch behandelde molaren.

The fracture strength of endodontically treated molars restored by means of various types of direct and indirect materials was studied in vitro. 105 sound molars were endodontically treated and randomly assigned to 1 control group (endodontic access cavity only) and 6 experimental groups (n = 15) with restorations of the following materials: glass fibre reinforced composite (GFRC); microhybrid composite (C); microhybrid composite restoration with glass fiber post (CP); full-contour lithium disilicate crown (LDS); full-contour lithium disilicate crown with glass fiber post (P-LDS); and an endocrown (EC). Specimens were thermo-mechanically aged and axially loaded until failure. Data were analysed using ANOVA and Tukey's post hoc test (α = 0.05). Fracture strength was significantly affected by the type of restoration (p = 0.000). LDS had significantly higher fracture strength than the control group and GFRC, C and CP groups. Groups EC, LDS and P-LDS were not statistically different from each other in fracture strength. This was also the case with EC, P-LDS and all composite groups. The glass fibre strength of composite restoration resulted in significantly fewer fatal fractures.

Up to 12 years clinical evaluation of 197 partial indirect restorations with deep margin elevation in the posterior region.

OBJECTIVES: Deep margin elevation (DME) relocates the cervical outline of large-sized cavity dimensions in the posterior area supragingivally, using a resin composite in a direct technique. The aim of this study is to evaluate the clinical performance of partial indirect restorations with DME and compare the effects of selected baseline variables on the (quality of) survival of the restorations. METHODS: All teeth that were restored in combination with indirect restorations and DME between 2007 and 2016 were eligible for inclusion. Overall cumulative survival rates were calculated (Kaplan-Meier estimates) and compared among subsets of variables. Qualitative evaluation of all surviving restorations was performed using the modified United States Public Health Service (USPHS) criteria using Chi-square tests. RESULTS: A total of 197 indirect restorations in 120 patients could be included. Restorations or teeth presenting with secondary caries, fracture of the restoration/tooth, debonding of the indirect restoration, root caries, severe periodontal breakdown or pulpal necrosis were considered as absolute failures (n = 8) leading to an overall cumulative survival rate of 95.9% (SE 2.9%) up to 12 years, with an average evaluation time of 57.7 months. Some indication of degradation of the restorations was seen over time. Indirect composite restorations showed more degradation compared to ceramic restorations (p = 0.000). More wear of the antagonist was observed when teeth were opposed to ceramic restorations (p = 0.04). Endodontic treatment negatively impacted the occurrence of fracture of restorations and teeth (p = 0.000). CONCLUSIONS: Indirect restorations with DME have a good survival rate in this study, however longer follow-up is needed as degradation of the restorations is seen over time. CLINICAL SIGNIFICANCE: This long-term study shows the possible clinical applicability of deep margin elevation.

Randomized clinical trial on indirect resin composite and ceramic laminate veneers: Up to 10-year findings.

OBJECTIVES: In this randomized split-mouth clinical trial the survival rate and quality of survival of indirect resin composite and ceramic laminate veneers were evaluated. METHODS: A total of 48 indirect resin composite (Estenia; n = 24) and ceramic laminate veneers (IPS Empress Esthetic; n = 24) were placed on maxillary anterior teeth. Veneer preparations with incisal overlap were performed using a mock up technique. Survival of the restoration was considered the primary outcome measure and reported using Kaplan-Meier statistics and survival curves compared by means of Log Rank (Mantel-Cox) test. After luting, restorations were evaluated by calibrated operators at baseline and every year thereafter, using modified USPHS criteria and compared by means of Mann-Whitney U test. RESULTS: In total, 6 failures were observed, consisting of debonding (n = 3) and fracture (n = 3), all in the group of the indirect resin composite laminate veneers. Cumulative chance on survival after 10 years of the indirect resin composite and ceramic veneers was 75% (se 3,8%) and 100% respectively (p = 0.013). Of the surviving 42 laminate veneers, the variables 'color match' (p = 0.002), 'surface roughness' (p = 0.000), 'fracture of the restoration' (p = 0.028), and 'wear of the restoration' (p = 0.014), were significantly less favourable among the composite laminate veneers as well. CONCLUSIONS: The ceramic veneers on maxillary anterior teeth in this study performed significantly better compared to the composite indirect laminate veneers after a decade, both in terms of survival rate and in terms of quality of the surviving restorations. CLINICAL RELEVANCE: When indicated, anterior ceramic laminate veneers may be preferred over indirect composite laminate veneers.

Randomized clinical trial on the survival of lithium disilicate posterior partial restorations bonded using immediate or delayed dentin sealing after 3 years of function.

OBJECTIVES: The survival and success rate and the quality of survival of partial ceramic restorations bonded employing Immediate (IDS) or Delayed Dentin Sealing (DDS) in vital molar teeth were evaluated in a randomized clinical trial with within-subject comparison study. MATERIALS AND METHODS: 30 patients received two lithium disilicate ceramic (IPS-e.max press, Ivoclar Vivadent) partial restorations on vital first or second molar teeth (N = 60). The two teeth randomly received either IDS (test group, n = 30) or DDS (control group, n = 30). Partial ceramic restorations were luted (Variolink Ultra, Ivoclar Vivadent) two weeks after preparation. Evaluations were performed at 1 week, 12 months and 36 months post-operatively, using qualitative (FDI) criteria. Representative failures were evaluated microscopically (SEM) and by means of simplified qualitative fractography analysis. RESULTS: One absolute failure occurred in the DDS group due to (secondary) caries. The overall survival rate according to Kaplan-Meier after 3 years was 98.3% (FDI criteria score 1-4, n = 59) and the overall success rate was 85% (FDI criteria score 1-3, n = 51), with no significant difference between restorations in the IDS and DDS group (p = 0.32; Kaplan-Meier, Log Rank (Mantel-Cox), CI = 95%). For the quality of the survival, no statistically significant differences were found between IDS and DDS (p = 0.7; Kaplan-Meier, Log Rank (Mantel-Cox), CI = 95%) restorations on any follow-up timepoints for any of the FDI criteria (Wilcoxon, McNemar, p > 0.05). CONCLUSION: Adhesively luted partial ceramic restorations in vital molar teeth have a good prognosis, however IDS did not show any differences in success and survival rates after 3 years of function.