Effect of low-temperature degradation on the fatigue performance of dental strength-gradient multilayered zirconia restorations

OBJECTIVES

Fatigue and low-temperature degradation (LTD) are the main factors contributing to zirconia restoration failure. This study evaluated the effect of LTD on the fatigue performance of the novel "strength & shade-gradient" multilayered zirconia restorations.

METHODS

Discs (15 mm × 1.2 mm) of each yttria content layer from a newly developed strength-gradient multilayered zirconia were fabricated and under accelerated aging in an autoclave at 134℃ for 0 h, 32 h, and 64 h. Then, the phase transformation, microstructure, and mechanical properties after LTD were assessed. In addition, the crown samples, including the multi-Zir, 3Y-Zir, and 5Y-Zir were fabricated, and their monotonic and fatigue load before and after LTD, percentage of fatigue degradation (Sd) and the fracture morphology were investigated. Statistical analyses were performed using paired samples t-test (α' = α/3 = 0.017), one-way ANOVA and Weibull analysis.

RESULTS

After LTD, the phase transformation, surface roughness, depth of transformed zone, and residual stress were increased and inversely associated with the yttria content. The indentation elastic modulus and hardness after LTD decreased; however, there was no significant difference between the different yttria content layers. The monotonic and fatigue load of multi-Zir restorations decreased, but their Weibull modulus increased, and Sd decreased, similar to 3Y-Zir. The crack origin was associated with the cervical region.

CONCLUSION

These results show that although LTD reduces the absolute fatigue strength of strength-gradient multilayered zirconia restorations, it also reduces the effect of cyclic fatigue itself on the strength of zirconia (relative to monotonic strength), which might be due to the increase of residual stress.

CLINICAL SIGNIFICANCE

The novel "strength & shade-gradient" multilayered zirconia restorations show a promising performance during in vitro LTD and fatigue test and their reliability to some extent is comparable to 3Y-Zir. Yet, further in vivo longitudinal studies are warranted to confirm their precise performance.

Comparison of aesthetic treatments for molar-incisor hypomineralisation: Systematic review and meta-analysis

Introduction

Molar incisor hypomineralisation (MIH) is a developmental defect that predominantly targets the first permanent molars and incisors and consists of hypomineralisation of the enamel. A range of treatment options are available to improve aesthetics in this condition, including resin infiltration, bleaching techniques, restorations, microabrasion, and laser therapy.

Objectives

This systematic review and meta-analysis aimed to analyse the effects of treatments on changes in enamel colour in teeth with MIH lesions and determine whether resin infiltration is the most aesthetic treatment.

Material and Methods

A systematic literature search was conducted on PubMed, Web of Science, EBSCO, and Scopus databases until December 2022. The addressed PICO question was: "Is resin Infiltration the most effective treatment for restoring aesthetics in comparison to other treatments in patients with Molar incisor hypomineralisation?''. In addition, a meta-analysis was conducted with the selected studies to integrate the information using R.51 software (R Core Team (2013)).

Results

In total, 678 articles were obtained from the initial search, of which 11 met the inclusion criteria. Seven studies concluded that resin infiltration was the most successful treatment method in the aesthetic rehabilitation of MIH lesions. Six of the eleven articles were included in the meta-analysis, which indicated that the treatments generated substantial colour changes.

Conclusions

This systematic review and meta-analysis provided significant data suggesting that resin infiltration is the most effective treatment for achieving aesthetic improvements in MIH lesions, with the meta-analysis providing a significant result (p = 0.051) in favour of the hypothesis.

Effect of abutment screw-access hole on the fatigue performance of implant-supported lithium-disilicate luted simplified restorations

The present study aimed to evaluate the impact of the existence of an abutment screw-access hole and the filling effects on the fatigue mechanical behavior of a luted lithium-disilicate glass-ceramic. Seventy-two discs (Ø = 10 mm, 1.0 mm in thickness) of lithium disilicate (IPS e.max CAD, Ivoclar AG) were obtained from prefabricated blocks. Thirty-six abutment specimens of an opaque zirconia (Yz - IPS e.max ZirCAD, Ivoclar AG) and titanium (Ti - Luminesse Ti-Cam discs, Talladium Inc.) were confectioned, and allocated according to 6 groups: Yz and Ti rigid (without screw access hole); Yz unfilled, Yz filled, Ti unfilled and Ti filled (with the screw access (Ø = 2.5 mm) in the center). For the unfilled groups, only a polytetrafluoroethylene tape was used. Resin composite (Tetric N-Ceram, Ivoclar AG) was applied to the screw access hole for the filled groups (Yz and Ti). A cyclic fatigue test was carried out (load of 200 N, 10,000 cycles each; 20 Hz of frequency, step size of 100 N until failure detection (radial/cone crack). The fatigue failure load (FFL) and number of cycles until failure (CFF) were recorded for statistical purposes. The stress distribution (MPa) was evaluated by finite element analysis. A statistically positive effect of the abutment material and the presence of the screw access hole was observed (p ≤ 0.05). The rigid groups (without screw access holes) depicted almost 100% of survival after the fatigue tests. Among the other groups, the Yz-filled group showed the best performance (p ≤ 0.05), followed by the Yz unfilled group. The Ti groups depicted lower values of FFL and CFF, with the Ti unfilled group showing the most unfavorable fatigue behavior (p ≤ 0.05). The lowest tensile stress concentration in the restorative material was observed with the use of rigid abutments, the filled groups depicted intermediate values, while unfilled groups showed the highest stress concentration (Yz rigid = 306.3 MPa; Ti rigid = 310.4 MPa < Yz filled = 490.7 MPa; Ti filled = 498.9 MPa < Yz unfilled = 707.6 MPa; Ti unfilled = 719.7 MPa). Therefore, the presence of a screw-access hole decreases the mechanical performance of a lithium disilicate ceramic regardless of the abutment material. In the presence of a screw-access hole, zirconia abutments depicted a higher fatigue failure load when compared with titanium. The filling of the abutment screw-access hole with resin composite increased the mechanical performance of the simulated restoration.

Outcome of chairside CAD/CAM ceramic restorations on endodontically treated posterior teeth: a prospective study

OBJECTIVE

The aim of this study was to evaluate the outcome and risk factors for chairside CAD/CAM full cusp coverage restorations on endodontically treated posterior teeth after 3 years of follow-up.

METHODS

A total of 245 endodontically treated posterior teeth of 224 patients were included and restored with CAD/CAM full cusp coverage all-ceramic restorations according to a standardized protocol. Patients were recalled after treatments 1 to 3 years and underwent clinical and radiological examinations. At recall, modified FDI criteria were used to determine treatment outcomes by 2 evaluators. Success was determined when FDI scores were 1-2, and failure was indicated when FDI scores were 5. Logistic regression analysis was performed to evaluate potential risk factors.

RESULTS

A total of 183 patients presented at recall, and the clinical outcomes of 201 teeth were analyzed with a recall rate of 82.0% for teeth and 81.7% for patients after 1-3 years of follow-up.185 of 201 teeth were found to have FDI scores of 1-2, and the success rate was 92%. No teeth were extracted during the follow-up period. Fourteen failed cases with an FDI score of 5 presented restoration dislocation, fracture of restoration or/and tooth. Logistic regression analysis revealed that oral parafunction (OR 2.281, 95% CI 2.2 ~ 47.5, P value 0.01) was a risk factor for success rate.

CONCLUSION

Chairside CAD/CAM all-ceramic full cusp coverage restoration was (could be) a promising alternative for restoring endodontically treated posterior teeth.

Comparative Evaluation of Fluoride Release from Four Commercially Available Pediatric Dental Restorative Materials

Objectives

The aim of this study was to evaluate the fluoride-releasing abilities of commercially available restorative materials such as-Activa™ BioActive-restorative™ material, Zirconomer (Shofu Inc), Beautifil® II (Shofu Inc), GC Gold Label 9 high strength posterior restorative glass ionomer cement (GIC Corp).

Materials and methods

A total of 40 disk specimens (10 of each material) were placed into distilled/deionized (DI) water and the fluoride release was measured for 30 days. Fluoride ion measurement was performed at the end of the 1st, 3rd, 7th, 15th, and 30th day under normal atmospheric conditions by fluoride ion selective electrode (F-ISE) (Orion 9609 BNWP, Ionplus SureFlow fluoride electrode, Thermo Scientific, United States of America) coupled to a benchtop analyzer (Hachsen Ion+).

Results

All the materials included in the study exhibited fluoride release. Although there were differences in the amounts of fluoride released between Activa™, Zirconomer, and GC Gold Label 9 the mean difference between these three groups was not found to be statistically significant. Beautifil® II showed low amounts of fluoride released at all time intervals.

Conclusion

Among the above-compared materials Activa™ and Zirconomer exhibit both improved mechanical properties as well as they have fluoride-releasing ability so can be preferred over conventional glass ionomer restorations.

How to cite this article

Dhumal RS, Chauhan RS, Patil V, et al. Comparative Evaluation of Fluoride Release from Four Commercially Available Pediatric Dental Restorative Materials. Int J Clin Pediatr Dent 2023;16(S-1):S6-S12.

Restorative Treatment in a Patient with Chronic Obstructive Pulmonary Disease, Ischemic Heart Disease, and Arrhythmia

Cardiovascular diseases are among the most common medical problems in the general population. Individuals with underlying cardiac conditions require special considerations with regard to appropriateness of dental treatment and precautions needed to deliver safe and effective care. Patients with unstable cardiac disease are at higher risk of developing complications during dental treatment. Similarly, comorbid conditions among patients with ischemic heart disease, such as chronic obstructive pulmonary disease, can further affect dental health and treatment, and they often require more individualized dental approaches.

How long does it take for the occlusion to re-establish following the placement of restorations at an increased occlusal vertical dimension? A literature review

Purpose This literature review aimed to investigate predictability of re-establishment of the occlusion following placement of restorations at an increased OVD, duration and to assess the quality of the available evidence.Methods An electronic search of articles using MEDLINE (1946-01/2019), EMBASE (1974-01/2019) and the Cochrane databases was undertaken. Search terms included dental restoration, vertical dimension and time. Studies involving placement of restorations at an increased OVD and recorded the time taken for the occlusion to re-establish were included. Eligibility assessments were carried out independently by two reviewers who also undertook independent extraction of predefined data fields, including study quality indicators.Results The search provided 61 results with 11 being relevant. A further 5 papers were identified for full text analysis. 4 papers used similar data from previous studies and 3 were excluded after full text assessment.. A final total of 9 papers were included in the review. It was indicated that the technique of placing restorations at an increased OVD appears to be clinically predictable in terms of re-establishment of occlusion and appears to occur most rapidly in younger patients.Conclusions The time taken for the occlusion to re-establish was between 15 days to 24 months. However, there is a need for prospective studies to evaluate the process in terms of success, predictive variables and specifically how long the process takes and this information would be helpful for both clinicians and patients, so that they know what to expect before embarking on a treatment.

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.

Comparison of two clinical approaches based on visual criteria for secondary caries assessments and treatment decisions in permanent posterior teeth

Background

This cross-sectional study aimed to compare two clinical approaches based on visual criteria for secondary caries assessments and treatment decisions in permanent posterior teeth.

Methods

The two clinical visual criteria tested for the assessments of restored teeth were: FDI criteria—based on the caries presence, marginal adaptation and staining criteria, adapted from the FDI (International Dental Federation) criteria and CARS criteria—"Caries Associated with Restorations or Sealants" (CARS) criteria described by the International Caries Classification and Management System. Adults were randomized according to the criteria. One calibrated examiner assessed the restorations and assigned the treatment according to the criteria. The primary outcome was replacement indication.

Results

A total of 185 patients were included, totalling 718 restorations. The strongest correlation founded between the methods was for the presence of caries lesions (Rho = 0.829). A moderate correlation (Rho = 0.420) was founded between the treatment decisions proposed by the CARS and by the FDI criteria. The multilevel regression analysis showed that the FDI criteria indicated five times more replacements when compared to the CARS (< 0.001). Also, using the FDI criteria restorations were 2.7 times more related to caries around restorations (p < 0.001) compared to the other criterion.

Conclusions

The visual criteria used on the restoration's assessment directly influences the treatment decision to intervene or not on the restoration. The use of a minimally invasive based approach for assessing secondary caries may prevent overtreatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02112-6.

A novel workflow for indirect cobalt-chromium restorations using additive manufacturing without digital design

This preliminary investigation explored additive manufacturing to fabricate cobalt-chromium onlay restorations without the use of digital design. Extracted molars were prepared for four-surface onlays followed by the conventional approach for the fabrication of provisionals. The provisionals were digitized with an intraoral scanner, and stereolithography (STL) files were fabricated with additive manufacturing in cobalt-chromium, utilizing selective laser melting (SLM). Onlays were bonded to the corresponding tooth. Restorations were polished after cementation and assessed with photography, radiography, and a clinical post-cementation checklist. Cementation was unremarkable; marginal adaption and surface finish were generally acceptable. A simple, efficient, and inexpensive alternative workflow for the fabrication of indirect restorations without using the digital design is proposed.

Use of Restorative Full Crowns Made with Zirconia in Children: A Systematic Review

Aim and objective

The purpose of this systematic review is to analyze the suitability of the zirconia crowns for restoration of damaged primary teeth in children.

Background

This systematic review has been conducted in line with the preferred reporting items for systematic reviews (which is also called as PRISMA) guidelines. A search for the relevant articles of zirconia crowns in deciduous teeth has been made in electronic database of PubMed and a study design (meta-analysis), i.e., PICOS framework. The words used in the search are “zirconia crowns” and “primary molars,” “zirconia crowns” and “primary incisors,” “zirconia crowns” and “children,” “zirconia crowns” and “primary teeth.”

Review results

The database search showed 44 studies of which 20 articles were excluded as they were irrelevant, duplicates, and data were not available. In the present systematic review, the remaining 24 articles were included.

Conclusion

Zirconia crowns have been proved with better results than other crowns in terms of gingival and periodontal health, esthetics, and crown fractures. However, the quantity of tooth preparation and the wear of antagonist tooth are reported to be more in case of zirconia crowns. Future randomized control studies should be carried out in primary teeth due to less number of randomized studies on this topic.

Clinical significance

Zirconia crowns are now widely used in dentistry and there is an increase in the number of studies, so a systematic review evaluating and comparing results is warranted.

How to cite this article

Ajayakumar LP, Chowdhary N, Reddy VR, et al. Use of Restorative Full Crowns Made with Zirconia in Children: A Systematic Review. Int J Clin Pediatr Dent 2020;13(5):551–558.

Secondary caries risk of different adhesive strategies and restorative materials in permanent teeth: Systematic review and network meta-analysis

OBJECTIVES

Secondary caries is a major long-term complication of dental restorations. Different adhesive strategies and restorative materials may affect secondary caries risk. We aimed to systematically review and synthesize the secondary caries risk of different adhesive strategies and restorative materials.

SOURCES

Medline via PubMed 01/2005-10/2019.

STUDY SELECTION

Randomized controlled studies with minimum 2 years follow-up, comparing different adhesive strategies and/or restorative materials in permanent teeth were included. Our outcome was the occurrence of secondary caries. Bayesian pairwise and network-meta-analysis were conducted.

DATA

We included 50 trials; 19 assessing secondary caries depending on different adhesive strategies, 31 on restorative materials. Studies were published between 2005 and 2017, largely of unclear risk of bias, and included a mean of 40 (range: 8-90) participants and 46 (range: 14-200) placed restorations. Mean follow-up was 43 (range: 24-180) months. Secondary caries was a rare event; the majority of studies did not find any lesions. Network meta-analysis found great uncertainty. 3-step etch-and-rinse adhesives showed the lowest risk of secondary caries, 2-step etch-and-rinse the highest. For restorative materials, resin-modified glass ionomer showed the lowest risk of secondary caries. Most resin composites showed similar risks.

CONCLUSION

Data from randomized trials comparing different adhesive strategies or restorative materials are extremely scarce. The differences between materials were limited over the observational period of the included studies. The yielded rankings should be interpreted with caution.

CLINICAL SIGNIFICANCE

Despite often claimed to be a major complication of restorations, there is surprisingly little data on secondary caries from randomized trials. Longer-term studies may be needed to identify differences in secondary caries risk between materials.

Study protocol for a diagnostic randomized clinical trial to evaluate the effect of the use of two clinical criteria in the assessment of caries lesions around restorations in adults: the Caries Cognition and Identification in Adults (CaCIA) trial

Background

The assessment of restored teeth in dentistry remains a challenge, mainly related to the detection of caries around restorations. There is a diversity of clinical criteria available to assess the caries lesions, resulting in differences in the dentists’ diagnosis and treatment decisions. In addition, there is a lack of evidence regarding the best criteria to detect caries lesions around the restorations. Thus, the present protocol aims to evaluate the effect of using 2 visual criteria to assess restored teeth on the outcomes related to oral health in adults.

Methods

The design protocol of the Caries Cognition and Identification in Adults trial correspond to a triple-blind randomized, controlled clinical trial with parallel-groups. Two groups will be compared: patients who will receive the diagnosis and treatment decision according to FDI (World Dental Federation) criteria—FDI group; and patients who will receive diagnosis and treatment decision according to the “Caries Associated with Restorations or Sealants” criteria defined by the International Caries Classification and Management System (ICCMS group). The participants will be followed up after 6, 12, 18, 24, and 60 months, and the restoration failure will be the primary outcome. The analysis will be conducted through Cox regression with shared frailty. The impact of oral health on quality of life and the cost-effectiveness of the methods used will be the secondary outcomes. Two-tailed analyzes will be used, considering a level of significance of 5%.

Discussion

This is the first clinical trial to assess the effect of using two visual methods to detect caries lesions around restorations on the outcomes related to oral health in adults. The findings of this study will define what is the best diagnostic strategy for the assessment of caries around restorations in permanent teeth.

Trial registration NCT03108586 (registered 11 April 2017).

Long-term costs of post-restorations: 7-year practice-based results from Germany

Objectives

We evaluated the initial and follow-up treatment costs of different post-restorations in a practice-based German healthcare setting.

Methods

A total of 139 incisors, canines, or premolars received post-restorations placed by eight general dental practitioners in Germany, and were followed over a mean ± SD 7.1 ± 4.5 years. Preformed metal (MP, n = 68), glass-fiber (GF, n = 28), or cast post-and-core buildups (MC, n = 23) had been used to retain crowns or bridge anchors. Preformed metal and glass-fiber had also been used to retain directly built up post-retained composite restorations (PC, n = 20). Material and treatment costs for the initial post-restorations as well as restorative, endodontic, or surgical re-treatments were estimated from a public-payer-perspective in Germany. Associations between total and annualized total costs and covariates were assessed using generalized linear modeling. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00012938).

Results

MC showed highest initial treatment costs (557.23 Euro), but the least re-treatments (6/23, 26%), while PC showed lowest initial costs (203.52 Euro) but the most re-treatments (11/20, 55%). Costs for MP/GF post-crowns were initially similarly costly (496.47/496.87 Euro), and both also showed similar re-treatments (35%/36%). The overall annual failure rate was 5.2% (MC: 3.5%, MP: 4.6%, GF: 5.3%, PC: 10.3%). Including costs for the resulting re-treatments, mean total costs were 591.66 Euro (MC), 548.31 Euro (MP), 526.37 Euro (GF), and 361.81 Euro (PC). Annualized total costs were 171.36 Euro (MC), 141.75 Euro (MP), 146.12 Euro (GF), and 135.65 Euro (PC). Total and annualized total costs were highest for MC, with PC being the significantly less costly option (p < 0.001).

Conclusions

Within German healthcare, both initial and follow-up costs for post-restorations were considerable. Saving costs initially may, at least partially, be offset by more complications long-term.

Clinical relevance

Dentists need to be aware that the placement of posts is not only initially costly but also comes with significant long-term costs for treating occurring complications. This should be communicated with patients and considered during treatment planning.

Electronic supplementary material

The online version of this article (10.1007/s00784-020-03529-5) contains supplementary material, which is available to authorized users.

How to intervene in the caries process in adults: proximal and secondary caries? An EFCD-ORCA-DGZ expert Delphi consensus statement

OBJECTIVES

To provide consensus recommendations on how to intervene in the caries process in adults, specifically proximal and secondary carious lesions.

METHODS

Based on two systematic reviews, a consensus conference and followed by an e-Delphi consensus process were held with EFCD/ORCA/DGZ delegates.

RESULTS

Managing an individual's caries risk using non-invasive means (oral hygiene measures including flossing/interdental brushes, fluoride application) is recommended, as both proximal and secondary carious lesions may be prevented or their activity reduced. For proximal lesions, only cavitated lesions (confirmed by visual-tactile, or radiographically extending into the middle/inner dentine third) should be treated invasively/restoratively. Non-cavitated lesions may be successfully arrested using non-invasive measures in low-risk individuals or if radiographically confined to the enamel. In high-risk individuals or if radiographically extended into dentine, for these lesions, additional micro-invasive (lesion sealing and infiltration) treatment should be considered. For restoring proximal lesions, adhesive direct restorations allow minimally invasive, tooth-preserving preparations. Amalgams come with a lower risk of secondary lesions and may be preferable in more clinically complex scenarios, dependent on specific national guidelines. In structurally compromised (especially endodontically treated) teeth, indirect cuspal coverage restorations may be indicated. Detection methods for secondary lesions should be tailored according to the individual's caries risk. Avoiding false positive detection and over-treatment is a priority. Bitewing radiographs should be combined with visual-tactile assessment to confirm secondary caries detections. Review/refurbishing/resealing/repairing instead of replacing partially defective restorations should be considered for managing secondary caries, if possible.

CONCLUSIONS

An individualized and lesion-specific approach is recommended for intervening in the caries process in adults.

CLINICAL SIGNIFICANCE

Dental clinicians have an increasing number of interventions available for the management of dental caries. Many of them are grounded in the growing understanding of the disease. The best evidence, patients' expectations, clinicians' expertise, and the individual clinical scenario all need to be considered during the decision-making process.

Secondary caries: what is it, and how it can be controlled, detected, and managed?

OBJECTIVES

To assess how to control, detect, and treat secondary caries. This review serves to inform a joint ORCA/EFCD consensus process.

METHODS

Systematic and non-systematic reviews were performed or consulted and narratively synthesized.

RESULTS

Secondary (or recurrent) caries is defined as a lesion associated with restorations or sealants. While the restorative material itself has some influence on secondary caries, further factors like the presence and size of restoration gaps, patients' caries risk, and the placing dentist's experience seem more relevant. Current detection methods for secondary caries are only sparsely validated and likely prone for the risk of over-detection. In many patients, it might be prudent to prioritize specific detection methods to avoid invasive overtreatment. Detected secondary caries can be managed either by repair of the defective part of the restoration or its complete replacement.

CONCLUSIONS

There is sparse data towards the nature of secondary caries and how to control, detect, and treat it.

CLINICAL SIGNIFICANCE

Despite often claimed to be a major complication of restorations, there is surprisingly little data on secondary caries. Longer-term studies may be needed to identify differences in secondary caries risk between materials and to identify characteristic features of progressive lesions (i.e., those in need of treatment).

Cavity treatment in primary molars and malocclusion: quasi-randomised clinical trial

Background

An innovative caries treatment protocol for primary teeth, termed Ultra-Conservative Treatment (UCT), restores small cavities through the Atraumatic Restorative Treatment (ART) protocol and cleans medium to large open cavities with toothbrush and fluoride toothpaste. However, UCT-treated primary molars were found to exfoliate earlier than amalgam (CRT) and ART-restored cavities, which may lead to unacceptable loss of space for normal eruption of permanent successors. The null-hypothesis tested was that there is no difference between the three treatment protocols and the intra-arch distances, and index of orthodontic treatment need (IOTN) after 4 years.

Methods

Dental casts were taken at baseline (T0) and four (T4) years. The space of the premolars (D + E space), arch perimeter, anterior and total arch depth were measured using a morphometric computer programme. The presence and level of malocclusion were assessed according to the IOTN index. Dependent variables were all intra-arch distances and the IOTN while the independent variable was treatment protocol (CRT, ART and UCT). Data were analysed using linear and logistic regression.

Results

The sample consisted of 867 pairs of casts of 272 initial 6–7-year-olds. No difference was observed between the UCT protocol and the two restorative protocols for the intra-arch variables in both maxilla and mandible over the 4 year period. There was no difference between the UCT and the CRT and ART protocols regarding the occurrence of orthodontic treatment need (malocclusion). In conclusion, the UCT treatment protocol does not differ significantly from the traditional amalgam (CRT) and ART restorative protocols with respect to intra-arch distances and malocclusion. The earlier exfoliation of UCT-treated primary molars does not lead to a worsening of the eruption pattern of permanent successors.

Edge chipping test in dentistry: A comprehensive review

OBJECTIVE

Literature on edge chipping test applied to dental materials and structures has been systematically reviewed with regard to the evaluation methods and parameters used.

DATA

A systematic search of the literature retrieved 3484 relevant studies. After removing duplicates, 1848 records were screened by titles and abstracts and 1797 were excluded; 51 papers were assessed full text for eligibility. Twenty papers were included in this study and they were organized according to the dental materials and structures tested as follows: 2 studies on human tooth, 9 on dental ceramics, 5 on polymer-based composites, and 4 studies evaluated both ceramic and polymer-based materials.

SOURCES

MEDLINE/PubMed, Scopus and Web of Science databases were searched up to June 2019 without restriction on date and language.

STUDY SELECTION

In vitro studies using edge chipping test on dental materials and structures were included.

CONCLUSIONS

Different methods have been used for edge chipping test, regardless of reported parameters. There is significant evidence that edge chipping test is a relevant approach to predict chipping behavior of dental materials and tooth tissues because chips produced from most edge chipping studies are similar to clinically reported chipping failures.

Households' age, country of birth, and marital status, stronger predictor variables than education in the prevalence of dental sealants, restorations, and caries among US children 5-19 years of age, NHANES 2005-2010

Background

The aim of this study is to use data representative of the U.S. population to determine if households (HHs) age, birth country, and marital status, are strong predictors as HHs education for dental sealants, restorations, and caries in children 5 to 19 years of age.

Methods

A cross sectional analysis was performed with oral health data from three waves of the National Health and Nutrition Examination Survey (NHANES 2005 to 2010). The sample size consisted of children 5 to 19 years of age (n = 9151) and households > 18 years of age (n = 31,034). Dependent variables included the number of children with dental sealants, restorations, and caries. HHs independent variables consisted of gender, age, race, country of birth, HHs education level, marital status, and HHs spouse education. Multivariate regression analysis models were adjusted for HHs citizenship, health insurance, family size, and children age categories.

Results

The prevalence of children 5–19 years of age with dental sealants, restorations, and caries was 31.3, 43, and 15.8% respectively. The odds of children having sealants were higher among HHs with a college education or above OR 2.05 [1.54.-2.73] vs. HHs with a < 9th grade, in HHs ages 39–49 (OR 1.78 [1.41–2.24) vs. 18–29 years of age, and in HHs spouses with a college education and above OR 1.71 [1.14–2.56] vs. HHs with a < 9th grade. The odds of having at least one restored tooth were higher in children from HHs born in Mexico 1.74 [1.44–2.10] vs. US born. The highest odds for caries were among children from HHs that were never married 1.91 [1.47–2.48] vs. married HHs. In HHs with a college education the odds for caries in children were 0.31 (0.22–0.43) for college and above, and 0.78 (0.60–1.01) for some college.

Conclusions

The odds of children having dental sealants were higher in HHs with a college education, however, HHs ages 30–49 provided higher odds for sealants than spouses with college education. HHs birth place increased the odds of children with restorations more than HHs education. Children from HHs that never married had higher odds of experiencing dental caries. Recognizing the impact of these HHs characteristics could augment efforts in the prevention of adverse oral health outcomes in U.S. children.

Households’ age, country of birth, and marital status, stronger predictor variables than education in the prevalence of dental sealants, restorations, and caries among US children 5–19 years of age, NHANES 2005–2010.

When to intervene in the caries process? An expert Delphi consensus statement

OBJECTIVES

To define an expert Delphi consensus on when to intervene in the caries process and on existing carious lesions using non- or micro-invasive, invasive/restorative or mixed interventions.

METHODS

Non-systematic literature synthesis, expert Delphi consensus process and expert panel conference.

RESULTS

Carious lesion activity, cavitation and cleansability determine intervention thresholds. Inactive lesions do not require treatment (in some cases, restorations will be placed for reasons of form, function and aesthetics); active lesions do. Non-cavitated carious lesions should be managed non- or micro-invasively, as should most cavitated carious lesions which are cleansable. Cavitated lesions which are not cleansable usually require invasive/restorative management, to restore form, function and aesthetics. In specific circumstances, mixed interventions may be applicable. On occlusal surfaces, cavitated lesions confined to enamel and non-cavitated lesions radiographically extending deep into dentine (middle or inner dentine third, D2/3) may be exceptions to that rule. On proximal surfaces, cavitation is hard to assess visually or by using tactile methods. Hence, radiographic lesion depth is used to determine the likelihood of cavitation. Most lesions radiographically extending into the middle or inner third of the dentine (D2/3) can be assumed to be cavitated, while those restricted to the enamel (E1/2) are not cavitated. For lesions radiographically extending into the outer third of the dentine (D1), cavitation is unlikely, and these lesions should be managed as if they were non-cavitated unless otherwise indicated. Individual decisions should consider factors modifying these thresholds.

CONCLUSIONS

Comprehensive diagnostics are the basis for systematic decision-making on when to intervene in the caries process and on existing carious lesions.

CLINICAL RELEVANCE

Carious lesion activity, cavitation and cleansability determine intervention thresholds. Invasive treatments should be applied restrictively and with these factors in mind.

The effects of household corrosive substances on silver amalgam and porcelain-fused-to-metal restorations and non-restored teeth

This study examines the effects of household corrosive products on 105 restored (silver amalgam and porcelain-fused-to metal) and non-restored teeth. Five household products were utilized, including hydrochloric acid, sulfuric acid and detergent. Teeth were radiographed before and after exposure and were submerged for 120 or 264h. Documentation included weight, mesiodistal and buccolingual crown measurements, ordinal scores, and photography at specific hours of exposure. Results indicate that 81.9% of the teeth could be positively matched by radiographs. Hydrochloric acid had the most destructive effects mainly to non-restored and silver amalgam teeth followed by sulfuric acid. Porcelain samples were more resistant to the effects of acid and conferred protection to the underlying teeth. Acid type, acid concentration and the restoration type are statistically significant contributors to alterations and in radiographic matching. Household corrosive substances may affect the morphology of teeth, and in some cases completely destroy teeth, which could conceal identifications.

Longevity of defective direct restorations treated by minimally invasive techniques or complete replacement in permanent teeth: A systematic review

OBJECTIVES

This systematic review aimed to verify if there is difference in the longevity of minimally invasive techniques compared to the complete replacement for the treatment of defective direct restorations in permanent teeth.

DATA

The data included randomized controlled clinical trials comparing the clinical performance of defective dental restorations treated by a complete replacement technique or minimally invasive techniques on permanent teeth. Evaluation of the risk of bias was performed using the Cochrane Collaboration common scheme for bias and the evidence was qualified using the GRADE tool.

SOURCE

A comprehensive search was performed in the electronic databases: PubMed, Scopus, ISI Web of Science, The Cochrane Library, LILACS, BBO, SIGLE, followed by manual search in the reference lists of the included studies, without any restrictions.

STUDY SELECTION

From 5554 retrieved studies, 10 met the eligibility criteria and were submitted to data extraction and quality assessment. The repair technique presented similar results to replacement and superior results when compared to sealing. In addition, refurbishment demonstrated to be a useful treatment for localized anatomical form defects. All the studies presented low risk of bias and high quality evidence for repair and refurbishment and moderate for the sealing technique.

CONCLUSIONS

The direct restorations treated by the repair, seal and refurbishment techniques did not present a significant difference in clinical longevity in comparison to the replacement technique in permanent teeth with overall moderate quality of evidence.

CLINICAL SIGNIFICANCE

The present findings demonstrated that the best treatment for defective restorations is conservative management. The evidence demonstrated here helps and encourages clinicians during the decision-making process. Moreover, it suggests not replacing imperfect restorations, but to managing them in a minimally invasive way, allowing the structure to be preserved.

Restoring root-canal treated molars: Cost-effectiveness-analysis of direct versus indirect restorations

OBJECTIVES

Root-canal treated molars can be directly restored, usually using resin-based-composite restorations (RBCs), or indirectly restored using full or partial crowns (FCs/PCs). Both the initial treatment costs and the risks of restorative and endodontic complications differ between RBCs and FCs/PCs. We aimed to assess the cost-effectiveness of RBCs versus FCs/PCs for restoring root-canal treated molars.

METHODS

A mixed public-private payer's perspective within German healthcare was taken. Risks of complications were extracted from large cohort studies or systematic reviews. Costs were estimated using fee-items catalogues of public and private German insurance. A Markov-model was constructed to follow up a root-canal treated molar receiving different restorations in an initially 50-year-old patient over his lifetime. Monte Carlo-microsimulations were performed to assess lifetime costs and effectiveness (tooth retention time), and the resulting cost-effectiveness.

RESULTS

RBCs were less costly than FCs/PCs (749 Euro versus 782 Euro), but also less effective (22 years versus 24 years), the incremental-cost-effectiveness-ratio was 10.80 Euro/year. This ratio increased if costs for direct restorations decreased, or costs for indirect restorations increased. If no teeth were replaced, RBC was far more cost-effective (the incremental cost-effectiveness ratios was 52.95 Euro/year). If all teeth were replaced, FC was both more effective and less costly.

CONCLUSIONS

RBCs showed lower costs, but also lower effectiveness than FCs/PCs. Consequently, the cost-effectiveness of both strategies depended on the willingness-to-pay of patients or other payers, i.e. their willingness to invest in higher effectiveness. Clinically, a large number of tooth, patient and dentist-related factors will impact on decision-making and should be considered.

CLINICAL SIGNIFICANCE

We found composite restorations to be less costly, but also less effective than indirect restorations for root-canal treated teeth. Over a long-term period, the initial treatment costs and associated cost-differences between strategies may be outweighed by costs of follow-up treatments.

Decision-making of general practitioners on interventions at restorations based on bitewing radiographs

OBJECTIVE

The aim of this study was to compare decision-making based on bitewing analysis of restored proximal surfaces by general dental practitioners (GDPs) with diagnossis and clinical decisions made by experts in cariology and restorative dentistry.

METHODS

This practice-based study used a database of 7 general dental practices. Posterior bitewing radiographs were selected from the electronic patient files of patients, and 770 cases of proximal restored surfaces were selected. Fifty percent of the cases which lead to the restorative decision, and the other half were cases decided for monitoring by the GDPs. Three experts performed radiographic assessment. The outcome variables were agreement of diagnosis and decision of treatment. Cohen's kappa statistic was used.

RESULTS

For the experts, moderate to substantial intraexaminer agreement was observed for the diagnostic criteria, and kappa values of 0.77, 0.79, and 0.88 were obtained for each expert regarding the treatment assignment. Agreement between GDPs and the majority of experts for secondary caries varied between 67 and 83%. One hundred seventy-three out of 385 cases that were treated by GDPs were decided for monitoring by the experts, while 8 cases that were decided for monitoring by the GDPs were decided for treatment. The agreement between experts and GDPs was moderate for secondary caries detection, and fair for treatment decision.

CONCLUSION

The GDPs tend to have a less conservative approach regarding the decision to intervene or not concerning the reassessment of restorations, showing moderate agreement with the experts for secondary caries detection and fair agreement regarding the treatment decision.

CLINICAL SIGNIFICANCE

This study highlights that GDPs tend to have a less conservative approach to the decision to intervene or not in posterior restorations, compared to experts in cariology and restorative dentistry. Efforts should be made to reduce these differences based on minimally invasive dentistry.

Outcomes in randomised controlled trials in prevention and management of carious lesions: a systematic review

Background

Inconsistent outcome reporting is one significant hurdle to combining results from trials into systematic reviews. Core outcome sets (COS) can reduce this barrier. The aim of this review was to map outcomes reported in caries prevention and management randomised controlled trials (RCT) as a first step to COS development. We also investigated RCT characteristics and reporting of primary outcomes and sample size calculations.

Methods

PubMed, Embase, Web of Knowledge and Cochrane CENTRAL were systematically searched (1 January 1968 to 25 August 2015). Inclusion criteria: RCTs comparing any technique for prevention or management of caries with another or placebo and RCTs comparing interventions to support patients undergoing treatment of caries (without setting, dentition or age restrictions). Categories were developed through piloting and group consensus and outcomes grouped accordingly.

Results

Of 4773 search results, 764 were potentially relevant, full text was available for 731 papers and 605 publications met the inclusion criteria and were included. For all outcomes across the time periods 1968–1980 and 2001–2010, reporting of outcome ‘caries experience’ reduced from 39% to 18%; ‘clinical performance of the restoration’ reporting increased from 33% to 42% although there was a reduction to 22% in 2011–2015. Emerging outcome domains include ‘lesion activity’ and ‘pulp health-related outcomes’, accounting for 1% and 0%, respectively, during 1968–1980 and 10% and 4% for 2011–2015. Reporting ‘resource efficiency’ and ‘quality of life measures’ have remained at a low level. No publications reported tooth survival independent of an index such as DMFT or equivalent. Primary outcomes were only identified as such in 414 (68%) of the reports.

Conclusions

Over the past 50 years, outcome reporting for trials on prevention and management of carious lesions have tended to focus on outcomes measuring caries experience and restoration material clinical performance with lesion activity and cost-effectiveness increasingly being reported. Patient-reported and patient-focused outcomes are becoming more common (although as secondary outcomes) but remain low in use. The challenge with developing a COS will be balancing commonly previously reported outcomes against those more relevant for the future.

Trial registration

PROSPERO, CRD42015025310. Registered on 14 August 2015, Trials (Schwendicke et al., Trials 16:397, 2015) and COMET initiative online (COMET, 2017).

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2256-1) contains supplementary material, which is available to authorized users.

Cuspal flexure of composite-restored typodont teeth and correlation with polymerization shrinkage values

OBJECTIVE

The relationship between post-gel shrinkage, total shrinkage, and cuspal flexure was examined. Cuspal flexure was measured on restored typodont teeth, which offered a standardized tooth shape for comparison of shrinkage stress effects among restorative composites.

METHODS

Six restorative composites were compared (Filtek LS, Venus Flowable, Tetric EvoCeram, Filtek Flowable, Esthet-X, and Filtek Supreme). Total shrinkage was determined from changes in projected surface area before and after polymerization (n=10). Post-gel shrinkage was determined with a biaxial strain gauge that measured strain development during polymerization (n=10). Cuspal flexure was determined using typodont maxillary second premolars with standard MOD slot preparation (n=10). Flexure was determined by comparing the three-dimensionally scanned cuspal surfaces before and after restoration. Restoration bonding to the typodont cavity was achieved by sandblasting and adhesive application. Bond integrity was verified by measuring dye penetration. Results were analyzed using ANOVA and Student-Newman-Keuls post hoc test (significance level 0.05). Pearson was used for correlations.

RESULTS

Total and post-gel shrinkage were significant different for all composites (t-test; P<0.001). Depending on the composite, only 9-41% of the total shrinkage was recorded as post-gel shrinkage. Bond integrity of restored typodont teeth was 96-99%. Cuspal flexure correlated strongly with post-gel shrinkage, but there was no correlation with total shrinkage.

SIGNIFICANCE

Cuspal flexure of restored typodont teeth showed the effect of shrinkage stress caused by polymerizing composite restorations, ensuring standardization while maintaining the effects of tooth/cavity geometry. Post-gel shrinkage gave a good indication to screen composites for the stress they may generate; total shrinkage had no direct correlation with stress.

Survival of Direct Posterior Composites With and Without a Bulk Fill Base

OBJECTIVES

Direct composite restorations are increasingly popular and a flowable bulk-fill base material (SDR, Dentsply) claims to minimise stress through a more flexible polymerisation process. This retrospective audit of restorations placed in general practice compares SDR based restorations with conventional composite restorations.

METHODS

Restorations were all placed by one operator using a similar clinical technique and were audited as Group G, placed with a conventional layering composite (G-aenial, GC) and Group S which had a bulk-fill base of SDR (Dentsply) and then were covered with G-aenial (GC). Data regarding survival, post-operative sensitivity and mode of failure were recorded and analysed.

RESULTS

In total 54 Group S restorations and 71 Group G restorations were followed for a minimum of 24 months. Group S had a 92.6% survival and Group G 93%. Group S was more prone to failure by tooth fracture (p=0.033). In both groups failure was more likely in larger cavities, in both those with an increased number of surfaces (p⟨0.001) and cuspal coverage (p=0.004).

CONCLUSIONS

There appears to be similar survival of the two techniques in the short-term although there were significantly more tooth fractures in teeth restored with SDR.

CAD/CAM Endocrown Fabrication from a Polymer-Infiltrated Ceramic Network Block for Primary Molar: A Case Report

OBJECTIVE

The aim of this case report is to describe the treatment of a primary molar with a deep carious lesion by pulpotomy and placement of a ceramic endocrown.

CLINICAL CASE

A 7-year-old male patient with profound caries in tooth number 85 was referred to our clinic and underwent a pulpotomy. As the final treatment in tooth restoration, placement of an endocrown was planned, because little more than half of the tooth structure remained. After an additional request from the patient's parents for an advanced and prompt restoration, a computer-aided design/computer-aided manufacturing (CAD/CAM) polymer-infiltrated ceramic network (PICN) block was chosen. A three-dimensional model of the arch was obtained after scanning the dental cast, and the endocrown was designed digitally according to the model. When the design was complete, the endocrown was fabricated with a milling machine. Finally, the endocrown was cemented with self-adhesive resin cement.

RESULTS

Over the 9-month follow-up period, no pulpal or periradicular pathology was observed on radiographs. Regarding the crown, the marginal fit was excellent, the anatomical form was protected, and no discoloration occurred.

CONCLUSION

During follow-up, the CAD/CAM PICN block endocrown proved to be a good material for the short- to long-term treatment of a primary tooth. However, more clinical cases and follow-up are required to investigate the long-term effects of antagonistic tooth wear.

A randomized controlled 27 years follow up of three resin composites in Class II restorations

OBJECTIVE

To evaluate the durability of three conventional resin composites in Class II restorations during 27 years.

METHODS

Thirty participants, 25 female and 5 male (mean age 38.2 years, range 25-63), received at least three (one set) as similar as possible Class II restorations of moderate size. The three cavities were chosen at random to be restored with a chemical-cured (Clearfil Posterior) and two visible light-cured resin composites (Adaptic II, Occlusin). A chemical-cured enamel bonding agent (Clearfil New Bond) was applied after Ca(OH)2 covering of dentin and enamel etch. Marginal sealing of the restorations was performed after finishing. One operator placed 99 restorations (33 sets). Evaluation was performed with slightly modified USPHS criteria at baseline, 2, 3, 10 and 27 years.

RESULTS

Postoperative sensitivity was observed in 5 patients. Three participants with 11 restorations (11%) could not be evaluated at the 27 year recall. Thirty-seven restorations failed (13 AII, 10 CP and 14 O). The overall success rate after 27 years was 56.5% (AII 55.2%, CP 63.0%, O 51.7%; p=0.70), with an annual failure rate of 1.6%. The main reason for failure was secondary caries (54.1%), followed by occlusal wear (21.6%) and material fracture (18.9%). Non-acceptable color match was seen in 24 (28.3%) of the restorations (AII 2, CP 16, O 6). Cox regression-analysis showed significant influence of the covariates tooth type, caries risk, and bruxing activity of the participants.

CONCLUSIONS

Class II restorations of the three conventional resin composites showed an acceptable success rate during the 27 year evaluation.

A randomized controlled 30 years follow up of three conventional resin composites in Class II restorations

OBJECTIVE

The aim of this 30 year randomized controlled study was to evaluate, by intraindividual comparisons, the durability of three conventional resin composites in Class II restorations.

METHODS

Each of 30 participants, 21 female and 9 male (mean age 30 years, range 20-43), received at least three (one set) as similar as possible Class II restorations of moderate size. After cavity preparation, the three cavities were chosen at random to be restored with two chemical-cured (P10, Miradapt) and one light-cured resin composite (P30). A chemical-cured enamel bonding agent was applied after etching of the enamel. The chemical-cured resin composites were placed in bulk and the light-cured in increments. One operator placed 99 restorations (33 sets). The restorations were evaluated with slightly modified USPHS criteria at baseline, 2, 3, 5, 10, 15, 20 and 30 years. Statistical analyses were performed by the Kaplan-Meier, log-rank test and Cox regression analyses.

RESULTS

After 30 years, 5 participants with 15 restorations (15%) could not be evaluated during the whole evaluation. Seven participants were considered as caries risk and eight participants as having active parafunctional habits. Postoperative sensitivity was observed in 24 teeth. In total 28 restorations, 9 P10, 12 P30 and 7 Miradapt restorations failed during the 30 years. The main reasons for failure were secondary caries (39.2%) and material fracture (35.7%). Sixty-four percent of the secondary caries lesions were found in high caries risk participants and 70% of the material fractures occurred in participants with active parafunctional habits. The overall success rate at 30 years was 63%, with an annual failure rate of 1.1%. 68-81% of the restorations showed non-acceptable color match. No statistical significant difference in survival rate was found between the three resin composites (p=0.45). The variables tooth type, cavity size, age, and gender of the participants did not significantly affect the probability of failure.

SIGNIFICANCE

The three conventional resin composites showed good clinical performance during the 30 year evaluation. The chemical cured resin composites showed better performance than the light-cured composite.

Influence of restoration adjustments on prefrontal blood flow: A simplified NIRS preliminary study

Objective

The aim of this study was to examine, after setting several restorations, the influence of adjusted occlusal interference during gum chewing on blood flow in the prefrontal area as determined using near-infrared spectroscopy.

Material and methods

The physiological rate was assessed using a visual analog scale (VAS) questionnaire. We selected 16 patients who desired prosthetic restorative treatment on the lateral dentition, and eight healthy volunteers. Subjects were divided into three eight-person groups. One group received restorations on the premolar area (PA), another group received restorations on the molar area (MA), and the control group (CT) received no prosthetic restorations. The spectroscope was fastened to the frontal region of the head after placement of the final restoration, but before adjustment.

Results

Pre-adjustment (first gum chewing for CT) blood flow in the prefrontal cortex was measured during gum chewing. Blood flow was again measured during gum chewing after the restoration (second gum chewing for CT) had been adjusted in accordance with the subjective assessment of the patient while wearing the device. The VAS provided quantification of comfort during gum chewing before and after restoration adjustment. For the PA and MA groups, adjusting restorations decreased discomfort significantly during gum chewing. Moreover, in the MA group, prefrontal blood flow was significantly reduced, and blood flow correlated with discomfort.

Conclusions

Activation of the prefrontal area may provide an objective criterion for judging the functionality of occlusion after prosthetic occlusal reconstruction and/or orthodontics.

The decision to repair or replace a defective restoration is affected by who placed the original restoration: findings from the National Dental PBRN

OBJECTIVES

To evaluate how restoration characteristics are associated with the decision to repair or replace an existing restoration. The following hypotheses were studied: dentists who placed the original restoration are more likely to repair instead of replace restorations (H1) that are in molar teeth; (H2) that are in the upper arch; (H3) that have amalgam restorative material; (H4) if a fracture is not the primary reason for the defect; and (H5) when the restoration comprises more than one surface.

METHODS

This cross-sectional study used a consecutive patient/restoration recruitment design. 194 dentists members of a dental practice-based research network recorded data on restorations in permanent teeth that needed repair or replacement.

RESULTS

For 6623 of the 8770 defective restorations in 6643 patients, the treatment was provided by the dentist who had not placed the original restoration (75%). The 2-way interaction revealed that dentists who had placed the original restoration often chose to repair when the defective restoration was in a molar, relative to premolar or anterior teeth (OR=2.2, p<.001); and chose to replace when the restoration had amalgam (OR=0.5, p<.001), and when it was a fracture compared to another reason (OR=0.8, p=001).

CONCLUSION

Most dentists are not conservative when they revisit a restoration that they originally placed regardless of type of failure, number of surfaces or material used. However, dentists who had placed the original restoration were significantly more likely to repair it when the defective restoration was in a molar tooth.

CLINICAL SIGNIFICANCE

Most dentists who placed the original restoration were prone to replace it, however if the defective restoration was located in a molar tooth they would consider repairing it.

Is high-viscosity glass-ionomer-cement a successor to amalgam for treating primary molars?

OBJECTIVES

To assess and compare the cumulative survival rate of amalgam and atraumatic restorative treatment (ART) restorations in primary molars over 3 years.

METHODS

280 children aged 6-7 years old were enrolled in a cluster randomized controlled clinical trial using a parallel group design covering two treatment groups: conventional restorative treatment with amalgam (CRT) and atraumatic restorative treatment (ART) using a high-viscosity glass-ionomer (HVGIC) Ketac Molar Easymix. Three pedodontists placed 750 restorations (364 amalgam and 386 ART in 126 and 154 children, respectively) which were evaluated at 0.5, 1, 2 and 3 years. The proportional hazard rate regression model with frailty correction, ANOVA and Wald tests, and the Jackknife procedure were applied in analysing the data.

RESULTS

The cumulative survival rates over 3 years for all, single- and multiple-surface CRT/amalgam restorations (72.6%, 93.4%, 64.7%, respectively) were no different from those of comparable ART/HVGIC restorations (66.8%; 90.1% and 56.4%, respectively) (p=0.10). Single-surface restorations had higher survival rates than multiple-surface restorations for the both treatment procedures (p<0.0001). A higher proportion of restorations failed because of mechanical reasons (94.8%) than of secondary caries (5.2%). No difference in reasons for restoration failures between all types of amalgam and ART/HVGIC restorations were observed (p=0.24).

SIGNIFICANCE

The high-viscosity glass-ionomer used in this study in conjunction with the ART is a viable option for restoring carious dentin lesions in single surfaces in vital primary molars.