The ultimate guide to restoration longevity in England and Wales. Part 3: Glass ionomer restorations - time to next intervention and to extraction of the restored tooth

Effectiveness of bioactive resin materials in preventing secondary caries and retention loss in direct posterior restorations: A systematic review and meta-analysis

OBJECTIVES

This systematic review aimed to determine whether bioactive resin materials can prevent secondary caries or enhance the longevity of direct posterior restorations.

DATA SOURCES

The protocol was registered in PROSPERO (CRD42024561179). The review followed PRISMA guidelines, utilizing a PICO framework. Studies were identified through searches in six databases (PubMed, Scopus, Cochrane, Embase, Scielo, Web of Science) up to May 2024.

STUDY SELECTION

Two independent reviewers applied inclusion criteria, selecting randomized clinical trials evaluating bioactive resin composites in restorative dentistry. Data were extracted into pre-designed forms, and article quality was assessed using the CONSORT, RoB 2, and GRADE tools. Meta-analyses focused on secondary caries incidence and restoration longevity using USPHS and FDI criteria.

RESULTS

Of 1,565 articles identified, 10 met the inclusion criteria. These studies, conducted in five countries, included 411 participants with follow-up periods ranging from 1 to 8 years. Materials evaluated included ACTIVA™ BioACTIVE, Giomer, and Cention N. Meta-analysis found no statistically significant differences between bioactive and conventional resin composites in preventing secondary caries or reducing retention loss (p > 0.05), the two primary outcomes considered in this review for assessing restoration longevity. Subgroup analysis showed no differences between follow-up periods.

CONCLUSIONS

Bioactive materials demonstrated similar clinical performance to conventional composites in preventing secondary caries and retaining restorations, offering no additional benefit in enhancing the longevity of direct posterior restorations.

CLINICAL SIGNIFICANCE

This review provides evidence that bioactive resin materials offer no significant clinical advantage over traditional composites, guiding (or informing) clinicians in (or about) material selection for restorative treatments.

Updates on the clinical application of glass ionomer cement in restorative and preventive dentistry

The World Health Organization (WHO) has added glass ionomer cement (GIC) to the WHO Model List of Essential Medicines since 2021, which represents the most efficacious, safe and cost-effective medicines for priority conditions. With the potential increase in the use of GIC, this review aims to provide an overview of the clinical application of GIC with updated evidence in restorative and preventive dentistry. GIC is a versatile dental material that has a wide range of clinical applications, particularly in restorative and preventive dentistry. It has unique properties, such as direct adhesion to tooth structures, minimal shrinkage or expansion, a similar coefficient of thermal expansion to natural tooth structure, biocompatibility, and long-lasting fluoride release. According to the chemical composition, GIC can be classified as conventional glass ionomer cement (CGIC) and resin-modified glass ionomer cement (RMGIC). It has been used as restorative materials, luting cement for indirect restorations, liner and base of restorations, and dental sealants. While its use as a base material and liner is debatable, the clinical application of GIC as restorative cement, luting cement, and dental sealant is supported by current research.

Evaluating Glass Ionomer Cement Longevity in the Primary and Permanent Teeth-An Umbrella Review

The aim of this umbrella review was to evaluate the longevity of glass ionomer cement (GIC) as a restorative material for primary and permanent teeth. Research in the literature was conducted in three databases (MedLine/PubMed, Web of Science, and Scopus). The inclusion criteria were: (1) to be a systematic review of clinical trials that (2) evaluated the clinical longevity of GICs as a restorative material in primary and/or permanent teeth; the exclusion criteria were: (1) not being a systematic review of clinical trials; (2) not evaluating longevity/clinical performance of GICs as a restorative material; and (3) studies of dental restorative materials in teeth with enamel alterations, root caries, and non-carious cervical lesions. Twenty-four eligible articles were identified, and 13 were included. The follow-up periods ranged from 6 months to 6 years. Different types of GICs were evaluated in the included studies: resin-modified glass ionomer cement (RMGIC), compomers, and low- and high-viscosity glass ionomer cement. Some studies compared amalgam and composite resins to GICs regarding longevity/clinical performance. Analyzing the AMSTAR-2 results, none of the articles had positive criteria in all the evaluated requisites, and none of the articles had an a priori design. The criteria considered for the analysis of the risk of bias of the included studies were evaluated through the ROBIS tool, and the results of this analysis showed that seven studies had a low risk of bias; three studies had positive results in all criteria except for one criterion of unclear risk; and two studies showed a high risk of bias. GRADE tool was used to determine the quality of evidence; for the degree of recommendations, all studies were classified as Class II, meaning there was still conflicting evidence on the clinical performance/longevity of GICs and their recommendations compared to other materials. The level of evidence was classified as Level B, meaning that the data were obtained from less robust meta-analyses and single randomized clinical trials. To the best of our knowledge, this is the first umbrella review approaching GIC in permanent teeth. GICs are a good choice in both dentitions, but primary dentition presents more evidence, especially regarding the atraumatic restorative treatment (ART) technique. Within the limitation of this study, it is still questionable if GIC is a good restorative material in the medium/long term for permanent and primary dentition. Many of the included studies presented a high risk of bias and low quality. The techniques, type of GIC, type of cavity, and operator experience highly influence clinical performance. Thus, clinical decision-making should be based on the dental practitioner's ability, each case analysis, and the patient's wishes. More evidence is needed to determine which is the best material for definitive restorations in permanent and primary dentition.

Porosity and pore size distribution in high-viscosity and conventional glass ionomer cements: a micro-computed tomography study

Objectives

This study aimed to compare and evaluate the porosity and pore size distribution of high-viscosity glass ionomer cements (HVGICs) and conventional glass ionomer cements (GICs) using micro-computed tomography (micro-CT).

Materials and Methods

Forty cylindrical specimens (n = 10) were produced in standardized molds using HVGICs and conventional GICs (Ketac Molar Easymix, Vitro Molar, MaxxionR, and Riva Self-Cure). The specimens were prepared according to ISO 9917-1 standards, scanned in a high-energy micro-CT device, and reconstructed using specific parameters. After reconstruction, segmentation procedures, and image analysis, total porosity and pore size distribution were obtained for specimens in each group. After checking the normality of the data distribution, the Kruskal-Wallis test followed by the Student-Newman-Keuls test was used to detect differences in porosity among the experimental groups with a 5% significance level.

Results

Ketac Molar Easymix showed statistically significantly lower total porosity (0.15%) than MaxxionR (0.62%), Riva (0.42%), and Vitro Molar (0.57%). The pore size in all experimental cements was within the small-size range (< 0.01 mm³), but Vitro Molar showed statistically significantly more pores/defects with a larger size (> 0.01 mm³).

Conclusions

Major differences in porosity and pore size were identified among the evaluated GICs. Among these, the Ketac Molar Easymix HVGIC showed the lowest porosity and void size.

Physical Properties of Glass Ionomer Cement Containing Pre-Reacted Spherical Glass Fillers

The aim of this study was to assess the effect of different commercial liquid phases (Ketac, Riva, and Fuji IX) and the use of spherical pre-reacted glass (SPG) fillers on cement maturation, fluoride release, compressive (CS) and biaxial flexural strength (BFS) of experimental glass ionomer cements (GICs). The experimental GICs (Ketac_M, Riva_M, FujiIX_M) were prepared by mixing SPG fillers with commercial liquid phases using the powder to liquid mass ratio of 2.5:1. FTIR-ATR was used to assess the maturation of GICs. Diffusion coefficient of fluoride (DF) and cumulative fluoride release (CF) in deionized water was determined using the fluoride ion specific electrode (n=3). CS and BFS at 24 h were also tested (n=6). Commercial GICs were used as comparisons. Riva and Riva_M exhibited rapid polyacrylate salt formation. The highest DF and CF were observed with Riva_M (1.65x10-9 cm2/s) and Riva (77 ppm) respectively. Using SPG fillers enhanced DF of GICs on average from ~2.5x10-9 cm2/s to ~3.0x10-9 cm2/s but reduced CF of the materials on average from ~51 ppm to ~42 ppm. The CS and BFS of Ketac_M (144 and 22 MPa) and Fuji IX_M (123 and 30 MPa) were comparable to commercial materials. Using SPG with Riva significantly reduced CS and BFS from 123 MPa to 55 MPa and 42 MPa to 28 MPa respectively. The use of SPG fillers enhanced DF but reduced CF of GICs. Using SPG with Ketac or Fuji IX liquids provided comparable strength to the commercial materials.

Biomimetic Aspects of Restorative Dentistry Biomaterials

Biomimetic has emerged as a multi-disciplinary science in several biomedical subjects in recent decades, including biomaterials and dentistry. In restorative dentistry, biomimetic approaches have been applied for a range of applications, such as restoring tooth defects using bioinspired peptides to achieve remineralization, bioactive and biomimetic biomaterials, and tissue engineering for regeneration. Advancements in the modern adhesive restorative materials, understanding of biomaterial-tissue interaction at the nano and microscale further enhanced the restorative materials' properties (such as color, morphology, and strength) to mimic natural teeth. In addition, the tissue-engineering approaches resulted in regeneration of lost or damaged dental tissues mimicking their natural counterpart. The aim of the present article is to review various biomimetic approaches used to replace lost or damaged dental tissues using restorative biomaterials and tissue-engineering techniques. In addition, tooth structure, and various biomimetic properties of dental restorative materials and tissue-engineering scaffold materials, are discussed.

Electronic primary dental care records in research: A case study of validation and quality assurance strategies

BACKGROUND

In dentistry, the use of electronic patient records for research is underexplored. The aim of this paper is to describe a case study process of obtaining research data (sociodemographic, clinical and workforce) from electronic primary care dental records, and outlining data cleaning and validation strategies. This study was undertaken at the University of Portsmouth Dental Academy (UPDA), which is a centre of education, training and provision of state funded services (National Health Services). UPDA's electronic patient management system is R4/Clinical +. This is a widely used system in general dental practices in the UK.

METHOD

A two-phase process, involving first Pilot and second Main data extraction were undertaken. Using System Query Language (SQL), data extracts containing variables related to patients' demography, socio-economic status and dental care received were generated. A data cleaning and validation exercise followed, using a combination of techniques including Maletic and Marcus's (2000) general framework for data cleaning and Rahm and Haido's (2010) principles of data cleaning.

RESULTS

The findings of the case study support the use of a two-phase data extraction process. The data validation processes highlighted the need for both manual and analytical strategies when cleaning these data. Finally, the process demonstrated that electronic dental records can be validated and used for epidemiological and heath service research. The potential to generalise findings is great due to the large number of records. There are, however, limitations to the data which need to be considered, relating to quality (data input), database structure and interpretation of data codes.

CONCLUSION

Electronic dental records are useful in health service research, epidemiological studies and skill mix research. Researchers should work closely with clinicians, managers and software developers to ensure that the data generated are accurate, valid and generalisable. Following data extraction the researchers need to adapt stringent validation and data cleaning strategies to guarantee that the extracted electronic data are accurate.

The role of the randomised controlled trial in restorative dentistry and the correct purpose of observational data

It has been argued that the randomised controlled trial design is unsuitable for restorative dentistry and that cohort studies or the analysis of large observational datasets without randomisation is more suitable. This opinion article examines why randomisation in clinical trials is needed and why big observational data is not enough for clinical inference.