Two-year report of sealant effect on bacteria in dental caries

The revolutionary evolution in carious lesion management

Contemporary paradigms of dental caries management focus on the biological approaches to treating the disease and its principal symptom, the carious lesion. This narrative review traces the evolution of carious lesion management from the operative and invasive approaches of G. V. Black's era to the current period of minimally invasive biological approaches. The paper explains the rationale for adopting biological approaches to dental caries management and lists the five core principles of this management approach. The paper also details the aims, features, and the most recent evidence base for the different biological carious lesion management approaches. Based on current practice guidelines, collated clinical pathways for lesion management are also presented in the paper to aid clinicians in their decision-making. It is hoped that the biological rationale and evidence summarized in this paper will bolster the shift to modern biological carious lesion management approaches among dental practitioners.

The scientific management of deep carious lesions in vital teeth using contemporary materials—A narrative review

Aim

The aim of this article is to review the scientific evidence for deep caries removal in permanent vital teeth and the choice of dentine replacement material and restoration of the teeth to maintain long term tooth vitality and function.

Method

The two position statements namely the European Society of Endodontology and the American Association of Endodontists position statements on vital pulp therapy will be scrutinized and compared with regards to the deep caries removal strategy and assessed for evidence of best practice. The properties of materials used to manage vital pulps and the best way to restore the teeth will be reviewed and guidance on the full management of vital teeth will be suggested.

Conclusions

Promoting new treatment modalities for reversible and irreversible pulpitis allowing for pulp preservation should be considered. Although debatable, cases with deep caries should be managed by complete non-selective caries removal which will allow for pulpal management if needed and a more predictable outcome can be expected when using the new materials and treatment modalities of vital pulp therapy.

Loss of dental tissue after restoration or sealing of occlusal carious lesions: 3-4-year results of randomized clinical trials

Context

Although preservation of the tooth structure is quoted as the main advantage of sealing of carious lesions, there are no long-term studies comparing the maintenance of dental tissue after restoration or after caries sealing.

Aim

To measure the radiographically visible loss of dental tissue after conventional restoration and sealing of carious lesions.

Subjects and Methods

This study was a secondary analysis of two randomized controlled clinical trials, one conducted in Brazil and another in Belgium, which evaluated two different therapies for the treatment of occlusal carious lesions in permanent teeth: sealant (SE) without previous carious tissue removal or restoration (RE) with total removal of carious dentin. The greater depth and width of sealed carious lesions and restorations were compared.

Statistical Analysis

The independent t-test was used to compare therapies at different time points, while the paired t-test was used to compare the same therapy over time.

Results

Carious lesions in the RE and SE groups showed similar measurements at baseline (P > 0.05). Over time, significantly greater loss of tooth structure was observed in the RE group than in the SE group. No increase in lesion depth or width was observed in the SE group, suggesting no progression of sealed lesions.

Conclusion

Sealing of carious lesions resulted in greater preservation of dental tissue.

Minimally Invasive Therapies for the Management of Dental Caries—A Literature Review

In recent years, due to a better understanding of the caries pathology and advances in dental materials, the utilization of non-invasive and minimally invasive techniques that delay/obviate the need for traditional restorations has started gaining momentum. This literature review focuses on some of these approaches, including fluoride varnish, silver diamine fluoride, resin sealants, resin infiltration, chemomechanical caries removal and atraumatic restorative treatment, in the context of their chemistries, indications for use, clinical efficacy, factors determining efficacy and limitations. Additionally, we discuss strategies currently being explored to enhance the antimicrobial properties of these treatment modalities to expand the scope of their application.

Interventions for treating cavitated or dentine carious lesions

BACKGROUND

Traditionally, cavitated carious lesions and those extending into dentine have been treated by 'complete' removal of carious tissue, i.e. non-selective removal and conventional restoration (CR). Alternative strategies for managing cavitated or dentine carious lesions remove less or none of the carious tissue and include selective carious tissue removal (or selective excavation (SE)), stepwise carious tissue removal (SW), sealing carious lesions using sealant materials, sealing using preformed metal crowns (Hall Technique, HT), and non-restorative cavity control (NRCC).

OBJECTIVES

To determine the comparative effectiveness of interventions (CR, SE, SW, sealing of carious lesions using sealant materials or preformed metal crowns (HT), or NRCC) to treat carious lesions conventionally considered to require restorations (cavitated or micro-cavitated lesions, or occlusal lesions that are clinically non-cavitated but clinically/radiographically extend into dentine) in primary or permanent teeth with vital (sensitive) pulps.

SEARCH METHODS

An information specialist searched four bibliographic databases to 21 July 2020 and used additional search methods to identify published, unpublished and ongoing studies.  SELECTION CRITERIA: We included randomised clinical trials comparing different levels of carious tissue removal, as listed above, against each other, placebo, or no treatment. Participants had permanent or primary teeth (or both), and vital pulps (i.e. no irreversible pulpitis/pulp necrosis), and carious lesions conventionally considered to need a restoration (i.e. cavitated lesions, or non- or micro-cavitated lesions radiographically extending into dentine). The primary outcome was failure, a composite measure of pulp exposure, endodontic therapy, tooth extraction, and restorative complications (including resealing of sealed lesions).

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently screened search results, extracted data, and assessed the risk of bias in the studies and the overall certainty of the evidence using GRADE criteria. We measured treatment effects through analysing dichotomous outcomes (presence/absence of complications) and expressing them as odds ratios (OR) with 95% confidence intervals (CI). For failure in the subgroup of deep lesions, we used network meta-analysis to assess and rank the relative effectiveness of different interventions.

MAIN RESULTS

We included 27 studies with 3350 participants and 4195 teeth/lesions, which were conducted in 11 countries and published between 1977 and 2020. Twenty-four studies used a parallel-group design and three were split-mouth. Two studies included adults only, 20 included children/adolescents only and five included both. Ten studies evaluated permanent teeth, 16 evaluated primary teeth and one evaluated both. Three studies treated non-cavitated lesions; 12 treated cavitated, deep lesions, and 12 treated cavitated but not deep lesions or lesions of varying depth.  Seventeen studies compared conventional treatment (CR) with a less invasive treatment: SE (8), SW (4), two HT (2), sealing with sealant materials (4) and NRCC (1). Other comparisons were: SE versus HT (2); SE versus SW (4); SE versus sealing  with sealant materials (2); sealant materials versus no sealing (2).  Follow-up times varied from no follow-up (pulp exposure during treatment) to 120 months, the most common being 12 to 24 months. All studies were at overall high risk of bias. Effect of interventions Sealing using sealants versus other interventions for non-cavitated or cavitated but not deep lesions There was insufficient evidence of a difference between sealing with sealants and CR (OR 5.00, 95% CI 0.51 to 49.27; 1 study, 41 teeth, permanent teeth, cavitated), sealing versus SE (OR 3.11, 95% CI 0.11 to 85.52; 2 studies, 82 primary teeth, cavitated) or sealing versus no treatment (OR 0.05, 95% CI 0.00 to 2.71; 2 studies, 103 permanent teeth, non-cavitated), but we assessed all as very low-certainty evidence. HT, CR, SE, NRCC for cavitated, but not deep lesions in primary teeth The odds of failure may be higher for CR than HT (OR 8.35, 95% CI 3.73 to 18.68; 2 studies, 249 teeth; low-certainty evidence) and lower for HT than NRCC (OR 0.19, 95% CI 0.05 to 0.74; 1 study, 84 teeth, very low-certainty evidence). There was insufficient evidence of a difference between SE versus HT (OR 8.94, 95% CI 0.57 to 139.67; 2 studies, 586 teeth) or CR versus NRCC (OR 1.16, 95% CI 0.50 to 2.71; 1 study, 102 teeth), both very low-certainty evidence. CR, SE, SW for deep lesions The odds of failure were higher for CR than SW in permanent teeth (OR 2.06, 95% CI 1.34 to 3.17; 3 studies, 398 teeth; moderate-certainty evidence), but not primary teeth (OR 2.43, 95% CI 0.65 to 9.12; 1 study, 63 teeth; very low-certainty evidence). The odds of failure may be higher for CR than SE in permanent teeth (OR 11.32, 95% CI 1.97 to 65.02; 2 studies, 179 teeth) and primary teeth (OR 4.43, 95% CI 1.04 to 18.77; 4 studies, 265 teeth), both very low-certainty evidence. Notably, two studies compared CR versus SE in cavitated, but not deep lesions, with insufficient evidence of a difference in outcome (OR 0.62, 95% CI 0.21 to 1.88; 204 teeth; very low-certainty evidence). The odds of failure were higher for SW than SE in permanent teeth (OR 2.25, 95% CI 1.33 to 3.82; 3 studies, 371 teeth; moderate-certainty evidence), but not primary teeth (OR 2.05, 95% CI 0.49 to 8.62; 2 studies, 126 teeth; very low-certainty evidence). For deep lesions, a network meta-analysis showed the probability of failure to be greatest for CR compared with SE, SW and HT.

AUTHORS' CONCLUSIONS

Compared with CR, there were lower numbers of failures with HT and SE in the primary dentition, and with SE and SW in the permanent dentition. Most studies showed high risk of bias and limited precision of estimates due to small sample size and typically limited numbers of failures, resulting in assessments of low or very low certainty of evidence for most comparisons.

Resilience of the oral microbiome

The human mouth harbors a complex microbiota, the composition of which is potentially influenced by a wide range of factors, including the intake of food and drink, the availability of endogenous nutrients, the host immune system, drug treatments, and systemic diseases. Despite these possible influences, the oral microbiota is remarkably resilient, particularly in comparison with the microbiota of the large intestine. Diet, with the exception of excessive and/or frequent consumption of fermentable carbohydrate or supplementation with nitrate, has minimal impact on the composition of the oral bacterial community. The common oral diseases dental caries and the periodontal diseases is associated with modification of the oral microbiota primarily as a result of the ecological changes induced by excessive acid production and inflammation, respectively. Systemically-administered antimicrobials have only a small effect on the composition of the oral bacterial community, and while locally delivered antimicrobials can have some clinical benefits, the biofilm lifestyle of oral bacteria lends them substantial resistance to the agents used. Saliva plays an important role in oral microbial ecology, by supplying nutrients and providing protection against colonization by nonoral organisms. Dry mouth is one condition that has a major effect on the microbiota, resulting in increased colonization by opportunistic pathogens. Some systemic diseases do affect the oral microbiome, notably diabetes, in which raised levels of glucose in saliva and tissue impact on bacterial nutrition.

Managing dental caries against the backdrop of COVID-19: approaches to reduce aerosol generation

The COVID-19 pandemic resulted in severe limitation and closure of dental practices in many countries. Outside of the acute (peak) phases of the disease, dentistry has begun to be practised again. However, there is emerging evidence that SARS-CoV-2 can be transmitted via airborne routes, carrying implications for dental procedures that produce aerosol. At the time of writing, additional precautions are required when a procedure considered to generate aerosol is undertaken.This paper aims to present evidence-based treatments that remove or reduce the generation of aerosols during the management of carious lesions. It maps aerosol generating procedures (AGPs), where possible, to alternative non-AGPs or low AGPs. This risk reduction approach overcomes the less favourable outcomes associated with temporary solutions or extraction-only approaches. Even if this risk reduction approach for aerosol generation becomes unnecessary in the future, these procedures are not only suitable but desirable for use as part of general dental care post-COVID-19.

A Century of Change towards Prevention and Minimal Intervention in Cariology

Better understanding of dental caries and other oral conditions has guided new strategies to prevent disease and manage its consequences at individual and public health levels. This article discusses advances in prevention and minimal intervention dentistry over the last century by focusing on some milestones within scientific, clinical, and public health arenas, mainly in cariology but also beyond, highlighting current understanding and evidence with future prospects. Dentistry was initially established as a surgical specialty. Dental caries (similar to periodontitis) was considered to be an infectious disease 100 years ago. Its ubiquitous presence and rampant nature-coupled with limited diagnostic tools and therapeutic treatment options-meant that these dental diseases were managed mainly by excising affected tissue. The understanding of the diseases and a change in their prevalence, extent, and severity, with evolutions in operative techniques, technologies, and materials, have enabled a shift from surgical to preventive and minimal intervention dentistry approaches. Future challenges to embrace include continuing the dental profession's move toward a more patient-centered, evidence-based, less invasive management of these diseases, focused on promoting and maintaining oral health in partnership with patients. In parallel, public health needs to continue to, for example, tackle social inequalities in dental health, develop better preventive and management options for existing disease risk groups (e.g., the growing aging population), and the development of reimbursement and health outcome models that facilitate implementation of these evolving strategies. A century ago, almost every treatment involved injections, a drill or scalpel, or a pair of forceps. Today, dentists have more options than ever before available to them. These are supported by evidence, have a minimal intervention focus, and result in better outcomes for patients. The profession's greatest challenge is moving this evidence into practice.

Altered adhesion of dental sealant to tooth enamel microscopically modified by Er:YAG laser irradiation: An in vitro study

Background and Aims

Er:YAG laser has become optional for enamel and dentin preparation for a decade. However, it is unclear if Er:YAG laser is acceptable for enamel conditioning prior to an application of a pit-and-fissure sealant. This in vitro study thus aimed to investigate shear bond strength of a sealant to enamel etched with Er:YAG laser, as well as to demonstrate an alteration of enamel surface after the laser was applied.

Materials and Methods

One hundred and twenty extracted human premolars were divided into 4 groups (N = 30 per group) in which the enamel surfaces were treated with 1) 37% phosphoric acid, 2) Er:YAG laser 80 mJ/pulse, 2 Hz, 3) Er:YAG laser 120 mJ/pulse, 10 Hz, and 4) Er:YAG laser 140 mJ/pulse, 2 Hz. Prior to sealant application. Shear bond strength was determined by using a universal testing machine. Statistical analysis was performed using One-way ANOVA. Modification of enamel surface after laser ablation was also investigated using scanning electron microscope.

Results

Phosphoric acid-etched enamel yielded the highest shear bond strength when bonded with a sealant. Ablation of enamel with Er:YAG laser did not significantly improve sealant bonding since it demonstrated lower shear bond strength, compared to acid-etched enamel. Despite the presence of cracks after Er:YAG laser application, dissolution of enamel substances was limited.

Conclusion

Our study has shown a reduced shear bond strength of dental sealant to an Er:YAG laser-irradiated enamel, compared with phosphoric acid-etched enamel.

Comparative Clinical Evaluation of Resin-based Pit and Fissure Sealant and Self-adhering Flowable Composite: An In Vivo Study

Aim

The study evaluated the use of self-adhering flowable composite as a fissure sealant and compared it with a resin-based pit and fissure sealant.

Materials and methods

Forty children were selected for the study and all their four permanent first molars were subjected to fluoride free pumice oral prophylaxis. Their occlusal fissures were then prepared with fissurotomy bur using high-speed handpiece under cotton roll isolation and low volume suction. Simple random sampling was done and accordingly a child either received either a resin-based fissure sealant or a self-adhering flowable composite on the prepared fissure. All the restorations were clinically evaluated using Ryge’s direct evaluation criteria for four times i.e., immediately after the treatment, at the end of 3rd, 6th and 12th month. The retention was evaluated using Horowytz criteria.

Results

The retention rate of Dyad flow after one year was significantly higher than that of Helioseal-F (p = 0.015). The marginal integrity of Dyad Flow was significantly better than that of Helioseal-F during every evaluation period (p < 0.05). Both retention and marginal integrity of both sealants were similar in maxillary and mandibular molars at all evaluation periods.

Conclusion

Dyad flow can be used as an alternative to the conventional fissure sealant.

Clinical significance

In pediatric dentistry, where shorter appointment time is warranted, the self-adhering composite has the edge over conventional fissure sealant.

How to cite this article: Wadhwa S, Nayak UA, Kappadi D, Prajapati D, Sharma R, Pawar A. Comparative Clinical Evaluation of Resin-based Pit and Fissure Sealant and Self-adhering Flowable Composite: An In-vivo Study. Int J Clin Pediatr Dent. 2018;11(5):430-434.

In Vitro Microleakage Comparison of Flowable Nanocomposites and Conventional Materials Used in Pit and Fissure Sealant Therapy

Objectives:

Pit and fissure sealants are recognized as an effective preventive approach in pediatric dentistry. Composite resin is the most commonly used sealant material. Adding nanoparticles to composite resin could result in production of flowable composite with higher mechanical properties and better flowability than previous sealants. This study aimed to compare the microleakage of a flowable nanocomposite and materials conventionally used as pit and fissure sealants.

Materials and Methods:

A total of 185 extracted mandibular third molar teeth were selected and randomly divided into 5 groups (n=36): flowable nanocomposite, flowable composite, filled sealants, nano-filled sealants, and unfilled sealants. Five teeth were reserved for examination under a scanning electron microscope (SEM). The samples were thermocycled (5–55°C, 1-minute dwell time) for 1000 cycles and immersed in 0.2% fuchsine solution for 24 hours. Teeth were sectioned buccolingually. Microleakage was assessed qualitatively and quantitatively by means of dye penetration and SEM. Data were analyzed using chi-square, Kruskal-Wallis, and Bonferroni-corrected Mann-Whitney U tests.

Results: Qualitative microleakage assessment showed that flowable composite and nanofilled flowable composite had almost no microleakage (P<0.001). Regarding quantitative scores, the nanofilled flowable composite and unfilled fissure sealant showed the lowest and the highest rate of microleakage, respectively. No statistically significant difference was found between the two flowable composites (P=0.317). Filled resin-based sealant had significantly lower microleakage than unfilled resin-based sealant (P<0.001).

Conclusion:

Use of flowable and nanofilled flowable composites (but not unfilled resin-based fissure sealant) is recommended for sealing of pits and fissures of molars.

Remineralisation - the buzzword for early MI caries management

Minimal intervention (MI) dentistry aims to preserve dental tissues first and restore only when indicated, thus remineralisation of initial (non-cavitated) caries lesions, an integral part of caries management, is an essential treatment strategy in MI. With this understanding, dental practitioners are increasingly embracing the principle of non-operative treatment of initial caries lesions. The purpose of this review was to summarise the most recent literature published in non-operative management of dental caries. Three electronic databases (MEDLINE, EMBASE, Cochrane CENTRAL) were searched, and clinical studies, systematic reviews and meta-analysis were included. This report outlines the strategies and numerous therapeutic materials available to aid in arrestment/remineralisation of initial caries lesions on root and coronal surfaces. However, the level of evidence of effect is variable, as well as the availability in different parts of the world. Options available to practitioners will vary when placing emphasis on the level of evidence supporting them. Strong clinical evidence support the effectiveness of pits/fissure sealants for therapeutic management of active initial caries on occlusal surfaces, and fluoride varnishes for remineralisation of caries lesions on root and coronal smooth surfaces, including proximal surfaces. Other materials formulated to enhance the effectiveness of any chosen remineralisation strategy were discussed. However, it is absolutely necessary that all caries remineralisation treatment be complemented with general behavioural modification in oral health through motivational interviewing directed towards change in oral hygiene to control plaque, dietary attitude modification to reduce the frequency of intake of fermentable sugars, and establishment of risk-based recall visits.

Bacterial reduction in sealed caries lesions is strain- and material-specific

Sealing can arrest caries lesions. We aimed to evaluate if sealing effects and kinetics are bacterial-strain and sealing-material specific. Human dentin discs were mounted in a dual-chamber device. Caries lesions were induced chemically and contaminated with either Lactobacillus rhamnosus (LR) or Streptococcus sobrinus (SS). For (1) kinetics assessment, the initial bacterial load and the sealing period were varied, and lesions sealed using a self-etch adhesive and composite. For (2) comparing materials, six sealing protocols (#1-#6) were evaluated: 1# Self-etch adhesive plus composite placed without a liner, or #2 calcium hydroxide, or #3 mineral trioxide aggregate, or #4 Biodentine liners; #5 antibacterial adhesive plus composite; #6 glass ionomer cement. Pulpal fluid flow was simulated during sealing. The outcome was the number of surviving bacteria (CFU) per g dentin. For LR, bacterial survival increased significantly with increasing initial bacterial load and decreased with longer sealing periods. The relative reduction followed a first-order kinetics. More LR survived under calcium hydroxide or MTA than other materials (p < 0.001). For SS, nearly no bacteria survived sealing regardless of sealing period, initial bacterial load or sealing material. In conclusion, sealing effects and kinetics were strain- and material-specific.

Resin infiltration of deproteinised natural occlusal subsurface lesions improves initial quality of fissure sealing

The aim of this ex vivo study was to evaluate the infiltration capability and rate of microleakage of a low-viscous resin infiltrant combined with a flowable composite resin (RI/CR) when used with deproteinised and etched occlusal subsurface lesions (International Caries Detection and Assessment System code 2). This combined treatment procedure was compared with the exclusive use of flowable composite resin (CR) for fissure sealing. Twenty premolars and 20 molars revealing non-cavitated occlusal carious lesions were randomly divided into two groups and were meticulously cleaned and deproteinised using NaOCl (2%). After etching with HCl (15%), 10 premolar and 10 molar lesions were infiltrated (Icon/DMG; rhodamine B isothiocyanate (RITC)-labelled) followed by fissure sealing (G-ænial Flo/GC; experimental group, RI/CR). In the control group (CR), the carious fissures were only sealed. Specimens were cut perpendicular to the occlusal surface and through the area of the highest demineralisation (DIAGNOdent pen, KaVo). Using confocal laser-scanning microscopy, the specimens were assessed with regard to the percentage of caries infiltration, marginal adaption and internal integrity. Within the CR group, the carious lesions were not infiltrated. Both premolar (57.9%±23.1%) and molar lesions (35.3%±22.1%) of the RI/CR group were uniformly infiltrated to a substantial extent, albeit with significant differences (P=0.034). Moreover, microleakage (n=1) and the occurrence of voids (n=2) were reduced in the RI/CR group compared with the CR group (5 and 17 specimens, respectively). The RI/CR approach increases the initial quality of fissure sealing and is recommended for the clinical control of occlusal caries.

Sealing Occlusal Dentin Caries in Permanent Molars: 7-Year Results of a Randomized Controlled Trial

The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical and radiographic assessments, all lesions required restorative treatment. After randomization (ratio 2:1), 368 resin sealings and 153 composite-resin restorations were performed by 68 dentists in 9 municipalities. The primary aims were to 1) analyze survival of sealings until replacement by restoration, 2) compare longevity of sealings and restorations until retreatments, and 3) compare effectiveness of sealings and restorations to halt caries progression in sealed lesions and beneath restorations. Furthermore, we aimed to identify factors influencing longevity and the effectiveness of sealings and restorations. Treatments were annually controlled, clinically and radiographically. After 7 y, the drop out rate was 8%, and 54% of the treatments were completed due to age. Of the sealings, 48% were retreated, including 31% replaced by restorations; 12% were still functioning. Of the restorations, 7% were repaired/renewed and 20% were still functioning. No endodontics was performed. Kaplan-Meier and Cox regression survival analyses were performed on 341 sealings and 152 restorations in first and second molar teeth. The 7-y survival was 37% (CI, 29% to 45%) for sealings and 91% (CI, 85% to 96%) for restorations (P < 0.001). The median survival time for sealings not replaced by restorations was 7.3 y (CI, 6.4 y to NA). Survival of sealings was increased in patients with low caries risk and/or excellent oral hygiene, second molars compared with first molars, and lesions not extending the middle one-third of the dentin. Survival of sealings was not influenced by municipality, sex, eruption stage or clinical surface cavitation. The results underline that it is possible to postpone or avoid restorative intervention of occlusal dentin caries lesions in young permanent teeth by non-invasive sealing. Knowledge Transfer Statement: The first restoration can ultimately be fatal for a young permanent tooth. A restoration may not be the final treatment but the start of an ongoing treatment with still more loss of tooth substance. The present study shows the possibility of treating occlusal dentin caries lesions with non-invasive resin sealings instead of conventional resin composite restorations in children and adolescents. Improved oral health can be expected.

Histochemical changes of occlusal surface enamel of permanent teeth, where dental caries is questionable vs sound enamel surfaces

AIM

This in vitro study was to classify questionable for caries occlusal surfaces (QCOS) of permanent teeth according to ICDAS codes 1, 2, and 3 and to compare them in terms of enamel mineral composition with the areas of sound tissue of the same tooth.

METHODS

Partially impacted human molars (60) extracted for therapeutic reasons with QCOS were used in the study, photographed via a polarised light microscope and classified according to the ICDAS II (into codes 1, 2, or 3). The crowns were embedded in clear self-cured acrylic resin and longitudinally sectioned at the levels of the characterised lesions and studied by SEM/EDX, to assess enamel mineral composition of the QCOS. Univariate and multivariate random effect regressions were used for Ca (wt%), P (wt%), and Ca/P (wt%).

RESULTS

The EDX analysis indicated changes in the Ca and P contents that were more prominent in ICDAS-II code 3 lesions compared to codes 1 and 2 lesions. In these lesions, Ca (wt%) and P (wt%) concentrations were significantly decreased (p = 0.01) in comparison with sound areas. Ca and P (wt%) contents were significantly lower (p = 0.02 and p = 0.01 respectively) for code 3 areas in comparison with codes 1 and 2 areas. Significantly higher (p = 0.01) Ca (wt%) and P (wt%) contents were found on sound areas compared to the lesion areas.

CONCLUSIONS

The enamel of occlusal surfaces of permanent teeth with ICDAS 1, 2, and 3 lesions was found to have different Ca/P compositions, necessitating further investigation on whether these altered surfaces might behave differently on etching preparation before fissure sealant placement, compared to sound surfaces.

Occlusal Caries: Biological Approach for Its Diagnosis and Management

The management of occlusal caries still remains a major challenge for researchers as well as for general practitioners. The present paper reviews and discusses the most up-to-date knowledge and evidence of the biological principles guiding diagnosis, risk assessment, and management of the caries process on occlusal surfaces. In addition, it considers the whole spectrum of the caries process on occlusal surfaces, ranging from the molecular ecology of occlusal biofilms to the management of deep occlusal caries lesions. Studies using molecular methods with focus on biofilms in relation to occlusal caries should explore the relationship between the function and the structural composition of these biofilms to understand the role of occlusal biofilms in caries development. State-of-the-art measures to evaluate risk for occlusal caries lesion activity, caries incidence, and progression should include the assessment of the occlusal biofilm and the stage of tooth eruption. Careful clinical examination of non-cavitated lesions, including assessment of the lesion activity status, remains the major tool to determine the immediate treatment need and to follow on the non-operative treatment outcome. Even medium occlusal caries lesions in the permanent dentition may be treated by non-invasive fissure sealing. By extending the criteria for non-invasive treatments, traditional restoration of occlusal surfaces can be postponed or even avoided, and the dental health in children and adolescents can be improved. Selective removal (incomplete) to soft dentin in deep carious lesions has greater success rates than stepwise excavation. Selective (complete) removal to firm dentin has a lower success rate due to increased pulp exposure.

Overtreatment in Caries Management? A Literature Review Perspective and Recommendations for Clinicians

Dentistry, like various branches in the healthcare profession, is susceptible to overtreatment, especially in the management of dental caries, due to the adoption of an aggressive restorative approach. This philosophy provides no actual benefits to the patient in terms of arresting the disease process, which initially led to the carious lesions. Yet practitioners routinely continue to initiate restorative treatment procedures without attempting to understand and alter the biologic factors contributing to the caries process. This paper examines the available scientific literature in this regard and makes recommendations to the clinicians of today based on the available evidence. CPD/Clinical Relevance: The paper provides clinicians an approach to avoiding overtreatment by adhering to established clinical guidelines and accepted operative strategies.

Knowledge, value, opinion and practice about usage of pit and fissure sealant among dental professionals in Chennai, Tamil Nadu, India

AIM

A study was aimed to assess the knowledge, value, opinion, and practice regarding the use of dental sealants among private dental practitioners in Chennai, Tamil Nadu, India.

MATERIALS AND METHODS

A self-administrated questionnaire were distributed to 192 private dental practitioners in Chennai, Tamil Nadu, India by using simple random sampling. A convenience sampling technique was employed. The questionnaire consisted of 28 items, which included information about knowledge, value, opinion, and practice regarding dental sealants. The questionnaire was obtained from the study by San Martin et al. 2013 and Kailash Asawa et al. 2014. Frequency distribution was tabulated. For frequency distribution strongly, strongly agree, and agree were combined as "agree" and strongly disagree and disagree were combined as "disagree." There were no changes in "neutral."

RESULTS

Among the 196 study subjects 56.2% were males and 43.8% were females with their clinical experience of 52.1% for <5 years, 35.4% for 5-10 years, and 13.5% for >15 years. The mean scores for knowledge, value, opinion, and practice were 41.8 ± 3.7, 18.7 ± 2.8, 18.1 ± 1.4, and 12.9 ± 2.3, respectively.

CONCLUSION

The results suggest that dental practitioners had satisfactory knowledge about pit and fissure sealant and had neutral attitudes about sealants being effective. Dental practitioners adequately used the pit and fissure sealants but they did not follow the standardized procedures and specific guidelines.

Sealing versus partial caries removal in primary molars: a randomized clinical trial

BACKGROUND

The resin-based pit and fissure sealant is considered a successful tool in caries prevention, however there is a growing evidence of its use in controlling already established caries in posterior teeth. The aim of this clinical trial is to verify the efficacy of pit and fissure sealants in arresting dentinal caries lesions compared to partial excavation and restorative treatment in primary molar teeth.

METHODS

Thirty six patients with occlusal cavitated primary molar reaching outer half of dentin were selected. The patients were randomly allocated into two groups: sealant application (experimental group - n = 17) and restoration with composite resin (control group - n = 19). Clinical and radiograph evaluation were performed after 6, 12 and 18 months. The chi-square test was used to verify the distribution of characteristics variables of the sample among the groups. The survival rate of treatments was evaluated using Kaplan-Meier survival and log-rank test. Fisher's Exact and logistic regression tests were calculated in each evaluation period (α = 5%).

RESULTS

The control group showed significantly better clinical survival after 18 months (p = 0.0025). In both groups, no caries progression was registered on the radiographic evaluations.

CONCLUSIONS

Sealing had similar efficacy in the arrestment of caries progression of cavitated occlusal lesions compared to partial excavation of the lesions, even though the frequency of re-treatments was significantly higher in sealed lesions.

TRIAL REGISTRATION

Registro Brasileiro de Ensaios Clínicos (ReBEC): RBR-9kkv53.

Incomplete Caries Removal

Increasing numbers of clinical trials have demonstrated the benefits of incomplete caries removal, in particular in the treatment of deep caries. This study systematically reviewed randomized controlled trials investigating one- or two-step incomplete compared with complete caries removal. Studies treating primary and permanent teeth with primary caries lesions requiring a restoration were analyzed. The following primary and secondary outcomes were investigated: risk of pulpal exposure, post-operative pulpal symptoms, overall failure, and caries progression. Electronic databases were screened for studies from 1967 to 2012. Cross-referencing was used to identify further articles. Odds ratios (OR) as effect estimates were calculated in a random-effects model. From 364 screened articles, 10 studies representing 1,257 patients were included. Meta-analysis showed risk reduction for both pulpal exposure (OR [95% CI] 0.31 [0.19-0.49]) and pulpal symptoms (OR 0.58 [0.31-1.10]) for teeth treated with one- or two-step incomplete excavation. Risk of failure seemed to be similar for both complete and incomplete excavation, but data for this outcome were of limited quality and inconclusive (OR 0.97 [0.64-1.46]). Based on reviewed studies, incomplete caries removal seems advantageous compared with complete excavation, especially in proximity to the pulp. However, evidence levels are currently insufficient for definitive conclusions because of high risk of bias within studies.

Clinical and ultrastructural effects of different liners/restorative materials on deep carious dentin: a randomized clinical trial

We evaluated the effect of calcium hydroxide cement (CHC) and glass ionomer cement (GIC) on carious dentin and bacterial infections after partial caries removal and sealing. Sixty permanent teeth with deep lesions underwent partial caries removal, the application of CHC, GIC or wax, i.e. negative control (NC), and were then sealed for 3-4 months. After the partial caries removal and the sealing period, the dentin was clinically assessed (colour and consistency) and analysed by scanning electron microscopy to assess dentin organization and bacterial infections. The effect of the treatment in each group was assessed by the Wilcoxon and χ2 tests, differences among groups by the Kruskal-Wallis test and the correlations between variables by Spearman correlation. No clinical symptoms or radiographic signals of pulpits or pulp necrosis were observed during the study. Dentin darkening was observed after the sealing period in the CHC and NC groups (p < 0.05). However, there was no difference in the colour after treatment among the 3 groups (p > 0.05). Dentin hardening occurred in all groups after treatment (p < 0.05), also with no differences (p > 0.05). Dentin samples showed better organization after the sealing period than after partial caries removal, with total or partial obliteration of dentinal tubules (CHC p < 0.03, GIC p < 0.05, NC p < 0.01) and a reduction of bacterial infections (CHC p < 0.03, GIC p < 0.05, NC p < 0.03). No differences were observed. Correlations between the different criteria, except for colour and bacterial infection, were detected in all cases. Partial caries removal and sealing resulted in dentin hardening, decreased bacterial numbers and dentin reorganization, irrespective of the dentin protection used.

Laser fluorescence of dentin caries covered with a novel nano-filled sealant

The aim of the present study was to assess the possibility to measure caries-induced laser fluorescence underneath a novel nano-filled fissure sealant. Sixty freshly extracted human teeth with occlusal dentine carious lesions were horizontally divided, exposing the respective lesion. Teeth were randomly assigned to three groups: (I) white fissure sealant with filler particles (Fissurit F, Voco), (II) clear fissure sealant without filler particles (Fissurit, Voco) and (III) novel experimental fissure sealant with nano-filler particles (Voco). Starting with a sealant thickness of 3 mm, laser fluorescence measurements (DIAGNOdent, KaVo) were performed after finishing the sealant surfaces with polishing papers, reducing the material at intervals of 0.5 mm until the sealant was removed completely. Evaluating a thickness of 0.5 mm, both the clear (83 % of the baseline fluorescence after fine grit polishing) and the white sealant (25 %) did not allow to measure baseline fluorescence (p < 0.05) with no fluorescence reduction in the experimental sealant group (p > 0.05). With increasing sealer thickness, fluorescence was influenced even by the experimental material (89 % of the baseline value at 1 mm). However, by using the experimental material, statistically significant higher fluorescence values than those for the other materials under study (p < 0.05) were obtained. Thicker sealant layers and coarse grit polishing caused a decrease of laser fluorescence in all groups (p < 0.05). Employing the experimental nano-filled sealant, laser fluorescence measurements for caries detection can be performed through thicker sealant layers compared to conventional sealant materials. Thus, it might be possible to use this material to assess a caries progression underneath the sealant and administer an appropriate therapy in due time.

Sealing occlusal caries lesions in adults referred for restorative treatment: 2-3 years of follow-up

The aim of this study was to assess the possibility to arrest occlusal caries lesions in adults by sealant as well as to assess the presence of radiographic progression, arrest, and regression of the sealed lesions. Seventy-two occlusal caries lesions in 52 adult patients referred to restorative treatment by senior lecturers at School of Dentistry, Copenhagen, Denmark were included. In case the patient had more than one occlusal caries lesion, randomization between sealing and restoration was made; otherwise, the lesion was sealed. In total, 60 resin sealants and 12 composite restorations were made. Follow-up period was 25-38 months (mean = 33 months). Data were analyzed using non-parametric statistics including kappa statistics. After 2-3 years, the dropout rate was 15%; two patients did not show up for control and nine previously sealed lesions were restored by the patients' general practitioners. All 12 restorations and 39 of the remaining 49 sealants were well functioning, seven (14%) sealants were repaired/replaced due to failure, and three (6%) sealed lesions were restored due to caries progression (p > 0.05). The radiographic assessment showed caries progression beneath five (10%) sealants, caries regression beneath one (2%) sealant, and unchanged depth beneath 43 (88%) sealants and all restorations (p > 0.05). The majority of the referred lesions were successfully arrested by sealants, indicating the possibility for extending the criteria for sealing occlusal caries lesions in adults. However, a longer observation period is needed for final conclusion. Extending the criteria of therapeutic sealing of occlusal caries lesions in adults will lead to increased dental health.

The use of dental sealants in adults: a long-neglected preventive measure

The consensus among the general public appears to be that dental sealants are intended to be used primarily with children whose teeth are in the early developmental stage, yet little attention is given to the preventive long-term aspects when applying them to adult permanent dentition. This article explores the rationale and substantiates the use of dental sealants among the adult population in reducing occlusal pit-and-fissure caries while accentuating a beneficial oral health lifestyle.

Clinical threshold for carious tissue removal

There would appear to be little logic in the current practice of caries removal. Biologically, it would appear to be potentially damaging even to attempt to remove all infected dentin in a symptomless, vital tooth. It is neither possible nor necessary to achieve this. The evidence would seem to show that, provided a restoration is placed that seals the cavity, infected dentin may be left. It does not prejudice pulpal health, and the caries lesion does not progress.

Antibacterial Properties of Fluoride Releasing Glass lonomer Cements (GICs) and Pit and Fissure Sealants on Streptococcus Mutans

TITLE

Antibacterial properties of fluoride releasing glass Ionomer cements (GICs) and pit and fissure sealants on Streptococcus mutans.

BACKGROUND

Occlusal pit and fissures are the most susceptible sites for dental caries. The clinical effectiveness of GICs and fissure sealants in preventing caries is well-documented, but there is some concern about bacteria left beneath sealants.

OBJECTIVE

(1) Study the antibacterial activity of GICs and pit and fissure sealants. (2) Compare between these materials.

METHODOLOGY

GICs (Fuji IX GP and Ketac molar) and pit and fissure sealants (Teethmate-F1 and Helioseal-F ). The strains was grown in the Brain Heart Infusion broth and was incubated anaerobically for 18 hours at 37°C and subcultured in MSB agar.Four wells measuring 5 mm diameter was prepared on each agar plate and the prepared materials was placed and further incubated anaerobically for 48 hours at 37°C. The zone of inhibition was measured.

RESULTS

All the materials tested showed antibacterial properties to varying levels except; among pit and fissure sealants it is Teethmate-F which showed more antibacterial property.

CONCLUSION

Teethmate-F1 sealant showed more antibacterial property compared to Fuji IX and Ketac molar. Helioseal-F did not show any antibacterial property.

Pit and fissure sealants in dental public health - application criteria and general policy in Finland

Background

Pit and fissure sealants (sealants) are widely used as a non-operative preventive method in public dental health in Finland. Most children under 19 years of age attend the community-organized dental health services free of charge. The aims of this study were to find out to what extent sealants were applied, what the attitudes of dental professionals towards sealant application were, and whether any existing sealant policies could be detected among the health centres or among the respondents in general. The study evaluated changes that had taken place in the policies used during a ten year period (1991–2001).

Methods

A questionnaire was mailed to each chief dental officer (CDO) of the 265 public dental health centres in Finland, and to a group of general dentists (GDP) applying sealants in these health centres, giving a total of 434 questionnaires with 22 questions. The response rate was 80% (N = 342).

Results

A majority of the respondents reported to application of sealants on a systematic basis for children with increased caries risk. The criteria for applying sealants and the actual strategies seemed to vary locally between the dentists within the health centres and between the health centres nationwide. The majority of respondents believed sealants had short- and long-term effects. The overall use of sealants decreased towards the end of the ten year period. The health centres (N = 28) choosing criteria to seal over detected or suspected enamel caries lesion had a DMFT value of 1.0 (SD ± 0.49) at age 12 (year 2000) compared to a value of 1.2 (SD ± 0.47) for those health centres (N = 177) applying sealants by alternative criteria (t-test, p < 0.05).

Conclusion

There seems to be a need for defined guidelines for sealant application criteria and policy both locally and nationwide. Occlusal caries management may be improved by shifting the sealant policy from the traditional approach of prevention to interception, i.e. applying the sealants over detected or suspected enamel caries lesions instead of sealing sound teeth.

The management of incipient or suspicious occlusal caries: a decision-tree analysis

OBJECTIVE

To perform a comprehensive decision-tree analysis for the management of the suspicious/incipient occlusal lesion on a molar tooth.

METHODS

A quantitative decision tree was constructed to assess the expected utility value of three global strategies to dentally manage the incipient or suspicious occlusal carious lesion.

RESULT

A preventive strategy offered an optimal expected utility value (0.98 utile) compared with the other two strategies of visual inspection (0.84 utile) or referring to one of four diagnostic tests (0.74-0.82 utile).

CONCLUSION

Although the general conclusion of this analysis agrees with current recommendations, this analysis offers a more complete mathematical model that provides a unified value for each strategy (i.e. expected utility value) thus allowing for complex quantitative comparison between strategies. This paper provides a specific example of how decision-tree analysis can be a powerful tool in guiding dental practice.

Treatment of deep carious lesions by complete excavation or partial removal: a critical review

BACKGROUND

The classical approach to treatment of deep carious lesions approaching the pulp mandates removing all infected and affected dentin. Several studies call this approach into question.

TYPES OF STUDIES REVIEWED

A search of five electronic databases using selected key words to identify studies relating to partial versus complete removal of carious lesions yielded 1,059 reports, of which the authors judged 23 to be relevant. Three articles reported the results of randomized controlled trials.

RESULTS

The results of three randomized controlled trials, one of which followed up patients for 10 years, provide strong evidence for the advisability of leaving behind infected dentin, the removal of which would put the pulp at risk of exposure. Several additional studies have demonstrated that cariogenic bacteria, once isolated from their source of nutrition by a restoration of sufficient integrity, either die or remain dormant and thus pose no risk to the health of the dentition.

CLINICAL IMPLICATIONS

There is substantial evidence that removing all vestiges of infected dentin from lesions approaching the pulp is not required for caries management.

Comparing the caries-preventive effect of two fissure sealing modalities in public health care: a single application of glass ionomer and a routine resin-based sealant programme. A randomized split-mouth clinical trial

AIM

The aim of this study was to compare the caries-preventive effect of two types of sealant modalities and to evaluate whether the caries-preventive effect is related to sealant retention. A hypothesis was tested in which a glass ionomer sealant, once applied to the occlusal surface, was able to protect the fissure from caries even if the sealant appeared lost at visual inspection.

DESIGN

A 3-year randomized split-mouth trial evaluating two sealant modalities was performed at a public health centre in Finland. A chemically curing glass ionomer cement (GIC) and light-curing resin-based (RB) sealant material were applied randomly to the permanent second molars. Sealant application as a routine treatment procedure was carried out to 599 children in the age group of 12-16 years. Caries rate of the sealed teeth and sealant retention with both materials were analysed by a modified McNemar's test. The effectiveness, rate difference, and relative risk with both sealant materials were measured.

RESULTS

The difference in caries rate between the two modalities was highly significant. When compared to the GIC sealant method, the effectiveness of RB sealant method was 74.1% and the rate difference 3.2% (95% CI 1.44%, 4.98%). The relative risk for RB-sealed surfaces vs. GIC-sealed surfaces of having detectable dentin caries was 0.26 (95% CI 0.12, 0.57). The retention rate of sealants was higher with RB than GIC (P < 0.001). The effectiveness of the retention rate for RB sealants was 94.8% and the rate difference 87.2% (95% CI 83.86%, 90.50%). The relative risk during the 3-year study period of having a defective or lost RB sealant was 0.052 (95% CI 0.036, 0.075) when compared to having a defective or lost GIC sealant.

CONCLUSION

It is concluded that in preventing dentin caries a RB sealant programme including resealing when necessary was more effective than a single application of GIC. The original hypothesis was thus falsified.

Effects of composite fissure sealants on IR laser fluorescence measurements

The influence of composite fissure sealants on caries detection with IR laser fluorescence measurements should be assessed. Thirty-five extracted human teeth with 105 initial carious lesions were included. Six groups containing 15 lesions each were sealed with either a clear or a white version of three sealants. Group 7 was sealed with an experimental nanofilled material. Occlusal surfaces were irradiated by a diode laser (<1 mW, 655 nm). Fluorescence was measured before and after acid etching, directly and 1 week after application of the sealants. Values significantly increased after etching (p < 0.05). Compared to initial measurements, values decreased after sealing with the white materials (p < 0.05). There was no difference between values before and after sealing with the clear and the experimental materials (p > 0.05). All values were reproducible. The study indicates that it might be possible to monitor caries activity under clear or nanofilled fissure sealants by means of laser fluorescence.

The evidence supporting alternative management strategies for early occlusal caries and suspected occlusal dentinal caries

OBJECTIVE

To assess the strength of the evidence describing the effectiveness of alternative strategies to the detection and management of early occlusal caries and suspected occlusal dentinal caries.

METHODS

Nine detection and intervention decision points were identified as being central to the management of early occlusal caries and suspected occlusal dentinal caries, or suspicious areas. For each decision point, the evidence for effectiveness was assessed, using existing systematic reviews when available, and nonsystematic review methods when necessary.

RESULTS

For the 2 detection decisions (early occlusal caries and suspicious areas) the strength of the evidence was weak. Accuracy in detecting early occlusal caries was extremely variable within and across detection methods. Approximately 50% of suspicious areas identified had dentinal caries. The strength of the evidence for effectiveness of nonsurgical approaches for the management of early occlusal caries was weak for all 3 management strategies examined (doing nothing, sealants, remineralization). This evidence suggested that sealants were highly effective, with remineralization reflecting moderate effectiveness. For the management of suspicious areas, the strength of the evidence was still weaker and reflected the same relative effectiveness. For the surgical management strategy for suspicious areas, operative treatment, the evidence was strong and reflected high effectiveness for preventive resin restorations, but no evidence was available for minimally invasive techniques.

CONCLUSION

Identification methods for early occlusal caries are not accurate. The strength of the evidence for effectiveness of nonsurgical management strategies for early occlusal caries is at best, weak. The available evidence suggests that sealing both enamel caries and suspected occlusal dentinal caries is the most effective management approach if subsequent maintenance of the sealed surfaces can be assured.

Performance of a Conventional Sealant and a Flowable Composite on Minimally Invasive Prepared Fissures

Preparation prior to fissure sealing did not enhance the performance of the sealant. However, if caries is suspected and an enameloplasty has to be performed, opening the fissure with a diamond bur and sealing it with a conventional sealer is recommended.

Complete or ultraconservative removal of decayed tissue in unfilled teeth

BACKGROUND

The treatment of deep dental decay has traditionally involved removal of all the soft demineralised dentine before a filling is placed. However this has been challenged in three groups of studies which involve sealing soft caries into the tooth. The three main groups either remove no caries and seal the decay into the tooth, remove minimal (ultraconservative) caries at the entrance to a cavity and seal the remaining caries in, or remove caries in stages over two visits some months apart to allow the pulp time to lay down reparative dentine (the stepwise excavation technique).

OBJECTIVES

To test the null hypothesis of no difference in the incidence of damage or disease of the nerve of the tooth (pulp), progression of decay and longevity of restorations irrespective of whether the removal of decay had been minimal (ultraconservative) or complete.

SEARCH STRATEGY

The Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PubMed and EMBASE databases were searched. The reference lists in relevant papers were checked.

SELECTION CRITERIA

Randomised controlled trials and controlled clinical trials comparing minimal (ultraconservative) caries removal with complete caries removal in unrestored permanent and deciduous teeth.

DATA COLLECTION AND ANALYSIS

Outcome measures recorded were exposure of the nerve of the tooth (pulp) during caries removal, patient experience of symptoms of pulpal inflammation or necrosis, progression of caries under the filling, time until the filling was lost or replaced. Due to the heterogeneity of the included studies the overall estimate of effect was calculated using a random-effects model.

MAIN RESULTS

Four studies met the inclusion criteria; two stepwise excavation studies and two ultraconservative caries removal studies. Partial caries removal in symptomless, primary or permanent teeth reduces the risk of pulp exposure. We found no detriment to the patient in terms of pulpal symptoms in this procedure and no reported premature loss or deterioration of the restoration.

AUTHORS' CONCLUSIONS

The results of this systematic review reject the null hypothesis of no difference in the incidence of damage or disease of the nerve of the tooth (pulp) irrespective of whether the removal of decay had been minimal (ultraconservative) or complete and accepts the null hypothesis of no difference in the progression of decay and longevity of restorations. However, the number of included studies is small and differ considerably. Partial caries removal is therefore preferable to complete caries removal in the deep lesion, in order to reduce the risk of carious exposure. However, there is insufficient evidence to know whether it is necessary to re-enter and excavate further but studies that have not re-entered do not report adverse consequences.

Treatment decisions and conservation of tooth structure

New technology is becoming available to help establish an early diagnosis of incipient and hidden pit and fissure caries, and microdentistry techniques are being developed to follow the principles of minimal intervention. Following the accurate diagnosis of suspected lesions, early intervention can be in the form of chemotherapeutics to promote remineralization or conservative intervention to minimize tooth structure loss. Patient risk factors should have a role in developing and individualized treatment program. The life cycle of a restored molar is used in this article to illustrate the long-term value of early diagnosis, preventive therapy, and conservative intervention to preserve tooth structure and to extend the retention of healthy teeth.

Phenotypic and genotypic selection of microbiota surviving under dental restorations

The effects of sealing infected carious dentine below dental restorations on the phenotypic and genotypic diversity of the surviving microbiota was investigated. It was hypothesized that the microbiota would be subject to nutrient limitation or nutrient simplification, as it would no longer have access to dietary components or salivary secretion for growth. The available nutrients would be limited primarily to serum proteins passing from the pulp through the patent dentinal tubules to the infected dentine. Ten lesions were treated, and infected dentine was sealed below dental restorations for approximately 5 months. Duplicate standardized samples of infected dentine were taken at baseline and after the removal of the restorations. The baseline microbiota were composed primarily of Lactobacillus spp., Streptococcus mutans, Streptococcus parasanguinis, Actinomyces israelii, and Actinomyces gerencseriae. None of these taxa were isolated among the microbiota of the dentine samples taken after 5 months, which consisted of only Actinomyces naeslundii, Streptococcus oralis, Streptococcus intermedius, and Streptococcus mitis. The microbiota of the final sample exhibited a significantly (P < 0.001) increased ability to produce glycosidic enzymes (sialidase, beta-N-acetylglucosaminidase, and beta-galactosidase), which liberate sugars from glycoproteins. The genotypic diversity of S. oralis and A. naeslundii was significantly (P = 0.002 and P = 0.001, respectively) reduced in the final samples. There was significantly (P < 0.001) greater genotypic diversity within these taxa between the pairs of dentine samples taken at baseline than was found in the 5-month samples, indicating that the dentine was more homogenous than it was at baseline. We propose that during the interval between placement of the restorations and their removal, the available nutrient, primarily serum proteins, or the relative simplicity and homogeneity of the nutrient supply significantly affected the surviving microbiota. The surviving microbiota was less complex, based on compositional, phenotypic, and genotypic analyses, than that isolated from carious lesions which were also exposed to salivary secretions and pH perturbations.

Partial caries removal and cariostatic materials in carious primary molar teeth: a randomised controlled clinical trial

OBJECTIVE

To determine the durability and effectiveness of a black copper cement (BCC) and a conventional glass ionomer cement (GIC) when used to restore primary molars following partial caries removal (PCR) and to compare these results with conventional cavity preparation and restoration.

DESIGN

Split-mouth randomised controlled clinical trial.

SETTING

Department of Paediatric Dentistry, Dundee Dental Hospital, Dundee, 1998-1999.

SUBJECTS

Patients with previously unrestored, matched carious cavities in non-pulpally involved primary molars.

INTERVENTIONS

Three treatment groups: (1) Partial caries removal followed by lining with BCC and restoration with GIC (PCR:BCC); (2) Partial caries removal and restoration with GIC alone (PCR:GIC), and (3) Complete caries removal and conventional restoration (CR). Restoration durability and effectiveness was assessed both clinically and radiographically over 24 months.Main outcome measures Median survival time (MST) of restorations.

RESULTS

Forty-four patients (F: 31; M: 13), mean age 6.8 years (range: 3.7-9.5), had 120 restorations placed (PCR:GIC: 43; CR: 41; PCR:BCC: 36). Eighty-six molars (29 patients) (PCR:GIC: 30; CR: 29; PCR:BCC: 27) were reviewed at 24 months. The median survival times (MST) with 25% and 75% quartiles in parenthesis were as follows: PCR:BCC, MST = 24 months (6, 24); PCR:GIC, MST = 24 months (24, 24) and CR, MST = 24 months (24, 24). The MST for PCR:BCC restorations was significantly less than for PCR:GIC and CR restorations (W = 1163.5, P = 0.028 and W = 1081.0, P = 0.004 respectively).

CONCLUSION

There were no differences in the proportions of restorations lost between restoration types, although PCR:BCC restorations did have significantly more abscess/sinus formation over the 24-month study period.

Randomized, controlled trial comparing the retention of a flowable restorative system with a conventional resin sealant: one-year follow up

This clinical trial evaluated the retention rate of a flowable restorative system (Bond 1 + Flow-It!) used as a pit-and-fissure sealant compared with a conventional filled resin sealant (Fluroshield) over a 1-year period.

METHOD

Using a half-mouth design, 160 sealants (80 in primary and 80 in permanent teeth) were placed on sound first/second primary molars and first permanent molars of 40 children aged between 4 and 7 years. For both primary and permanent dentitions, half the teeth (n = 40) were sealed with Fluroshield and half (n = 40) with Bond 1 + Flow-It! Teeth were evaluated at baseline, 6- and 12-month intervals.

RESULTS

For both materials, there was no total loss of sealants placed on either the primary or permanent molars over 1 year. From Fluroshield sealants placed on primary teeth, 33 were completely intact after 6 months and 31 after 1 year. From those placed on permanent molars, no loss of material was observed after 6 months, while partial loss was noticed on 5% of teeth at 1-year recall. For Flow-It! resin applied on primary molars, partial loss of material was observed in only 1 sealant after 6 months and in 2 sealants after 1 year. On permanent teeth, 100% retention rate was observed over a 1-year follow up. There was a statistically significant difference (P < 0.01) between the sealing materials on primary but not permanent teeth, and, overall, Flow-It! sealants presented a higher retention rate at both 6-month and 1-year evaluations. Significant differences (P < 0.01) between baseline and the other evaluation periods were also observed.

CONCLUSION

It may be concluded that the flowable restorative system yielded optimal retention on both primary and permanent molars. Its retention rate was significantly higher than that of the conventional pit-and-fissure sealant on primary teeth.

Resistance of an enamel-bonding agent to saliva and acid exposure in vitro assessed by liquid scintillation

OBJECTIVES

To determine the leakage and resistance of a bonding agent and a light-curing fine hybrid composite when exposed to saliva or lactic acid (pH 4) in vitro.

METHODS

Twenty discs in each of four groups of selected irradiated bovine lower central incisors were treated with one of three sealing options: an enamel bond (Heliobond, Vivadent, Schaan, Liechenstein) in a single-step application; Heliobond in a two-step application; and Tetric Flow (Vivadent) as the negative control. One group served as the positive control and remained unsealed. Loss of apatite was determined using the radiochemical method of liquid scintillation. The Cherenkov radiation was assessed in order to evaluate the acid resistance and leakage of smooth surface enamel bonding after exposure to saliva and lactic acid. In addition, replicas were made for SEM analysis of micromorphologic surface changes.

RESULTS

A mean loss of 416.5 g (s.d. 57.0) apatite was observed over the unsealed sites following 14 days of exposure to lactic acid. The application of Heliobond in a one- and two-step application still revealed a remarkable degree of leakage, and substance losses of 196.5 g (s.d. 38.9) and 161.8 g (s.d. 39.7), but a protective potential was evident. In saliva, untreated, as well as sealed teeth, showed a modest leakage that was less than 20 g. When Tetric Flow was used (negative control) leakage was reduced to a minimum of 2.4 g (s.d. 1.0) in saliva and 12.8 g (s.d. 19.6) in lactic acid. These results were confirmed by SEM analysis.

SIGNIFICANCE

The method of liquid scintillation was revealed to be of considerable value in evaluating leakage and acid resistance of potential smooth enamel sealing options. Sealing with an unfilled resin still demonstrated remarkable levels of acid dissolution, although a protection tendency could be observed. This leads to the conclusion that there is a need for further investigation to establish more acid-resistant enamel sealing agents.

Conservative cavity preparations

When a caries lesion is detected, non-surgical means of treatment (fluorides, antimicrobials, and patient education) should be used unless it is a frank caries lesion. In that case, the lesion should be treated restoratively, but the patient should also be educated and treated to reduce caries risk. When the frank caries lesion is relatively small, the restorative treatment should simply involve removal of carious dentin and overlying unsupported enamel and placement of the restorative material. Of course, for weakened areas of the tooth, more extensive restorations may be indicated.

Management of the deep carious lesion and the vital pulp dentine complex

This article describes the relationship between the carious process and pulp-dentine complex reactions. Where the balance between the two is in favour of the carious process and where conventional cavity preparation leads to a direct pulp exposure, the direct pulp cap technique is described. The success of the technique is addressed and more importantly an alternative technique for caries removal, namely stepwise excavation, is described which may lead to a reduced risk of carious exposure and the need for the direct pulp cap technique.