Minimal intervention dentistry: part 4. Detection and diagnosis of initial caries lesions

Remineralization efficiency of three different agents on artificially produced enamel lesions: A micro-CT study

OBJECTIVE

This study aimed to assess the remineralization efficacy of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), silver diamine fluoride/potassium iodide (SDF/KI), and sodium fluoride with functionalized tricalcium phosphate (NaF/fTCP) on artificial early enamel lesion using laser fluorescence and micro-CT analysis.

METHODOLOGY

On extracted impacted third molars, artificial enamel lesions were prepared. Twenty-eight specimens were randomly assigned to four groups (n = 7 per group): a control group (artificial saliva), CPP-ACP (GC Tooth Mousse), SDF/KI (Riva Star), and NaF/fTCP (Clinpro White varnish). Following the manufacturer's instructions, the remineralization agents were applied to demineralized surfaces. Laser fluorescence and micro-CT were used to evaluate the remineralization efficacy of the agents and analyzes were performed during four stages: before demineralization, after demineralization, 1st day of remineralization and 30th day of remineralization. Shapiro-Wilk test, repeated measures two-way ANOVA, and Spearman correlation tests were used for statistical analysis. A significant level of p < 0.05 was established.

RESULTS

SDF/KI significantly reduced the lesion area and lesion volume on the demineralized enamel surface after 30 days of remineralization. In the T3 period, SDF/KI increased the mineral density statistically significantly compared to the T1 period. The laser fluorescence values for all three remineralizing agents exhibited a linear decrease. A significant correlation between the fluorescence values and the mineral density was found (p = 0.01).

CONCLUSION

All three investigated agents were showed positive remineralization efficacy on artificial enamel lesion. However, SDF/KI, containing silver diamine fluoride and potassium iodide exhibited superior than other agents in promoting remineralization.

CLINICAL SIGNIFICANCE

Although all three remineralization agents showed positive remineralization efficacy on artificial enamel lesions, SDF had higher remineralization performance over the other two agents. SDF has potential to prevent progression of demineralization in treating children with high caries risk in the long-term.

Red Marine Algae Lithothamnion calcareum Supports Dental Enamel Mineralization

The current management of oral conditions such as dental caries and erosion mostly relies on fluoride-based formulations. Herein, we proposed the use of the remaining skeleton of Lithothamnion calcareum (LC) as an alternative to fluorides. LC is a red macroalgae of the Corallinales order, occurring in the northeast coast of Brazil, whose unique feature is the abundant presence of calcium carbonates in its cell walls. Two experimental approaches tested the general hypothesis that LC could mediate enamel de-remineralization dynamics as efficiently as fluorides. Firstly, the effect of LC on enamel de-mineralization was determined in vitro by microhardness and gravimetric measurements to test the hypothesis that LC could either prevent calcium/phosphate release from intact enamel or facilitate calcium/phosphate reprecipitation on an artificially demineralized enamel surface. Subsequently, an in situ/ex vivo co-twin control study measured the effect of LC on the remineralization of chemical-demineralized enamel using microhardness and quantitative light-induced fluorescence. With this second experiment, we wanted to test whether outcomes obtained in experiment 1 would be confirmed by an in situ/ex vivo co-twin control model. Both experiments showed that LC exhibited equivalent or superior ability to modulate enamel de-remineralization when compared to fluoride solution. LC should be explored as an alternative to manage oral conditions involving the enamel demineralization.

Evaluation of the effect of a glass ionomer cement containing fluoro-zinc-silicate glass on dentin remineralization using the ultrasonic pulse-echo method

The purpose of this study was to investigate the protective effect of a glass ionomer cement (GIC) consisting of fluoro-zinc-silicate glass on the demineralization of bovine dentin using the ultrasonic pulse-echo method. The findings were compared with those obtained using a conventional GIC. Slabs of dentin from bovine teeth were sliced, shaped into a rectangular form, and immersed in 0.5 M ethylenediaminetetraacetic acid solution at 25ºC for 6 days, followed by storage in distilled water for 3 days. After demineralization, they were immersed in artificial saliva with and without the GIC specimens. The propagation times of the longitudinal ultrasonic waves in the samples were measured. The ultrasonic velocities of the fluoro-zinc-silicate glass-containing GICs were significantly increased 2-3 days after the start of the experiment and showed an upward trend thereafter. These findings indicate that the GICs containing fluoro-zinc-silicate glass might exhibit the potential to promote remineralization in the dentin.

In vivo effectiveness of visual inspection and laser fluorescence in the diagnosis of early pit-and-fissure carious lesions: A cross-sectional study in a group of Romanian children

General practitioners are still facing great challenges in the management of occlusal caries. Therefore, the development of better diagnostic protocols and assessment of caries activity might improve the results of nonoperative treatment. This study aimed to evaluate the effectiveness of visual inspection based on ICDAS-II (International Caries Detection and Assessment System) and DiagnoDent pen in the detection of pit-and-fissure early lesions in young permanent molars. The evaluation of 237 occlusal surfaces and caries risk assessment were performed in 96 children aged 7 to 15 years. The presence of pit-and-fissure noncavitated lesions was recorded using ICDAS-II scoring system and laser fluorescence. Statistical analysis was performed using McNemar test, with a level of significance of P < .05. The caries risk was measured for all participants. In 109 occlusal surfaces both methods identified enamel changes (46%) and in 62 cases both methods excluded the carious lesion (26.2%). The statistical analysis showed a significant moderate agreement between ICDAS-II code and DiagnoDent pen measurements (McNemar chi-squared statistic 9.5, P = .002 and Cohen kappa coefficient = 0.427). The majority of children (69.8%) had moderate caries risk and the most frequent risk factors recorded were sugar intake between meals, lack of regular dental control and poor oral hygiene. We concluded that ICDAS-II is a valuable and reliable diagnostic tool for early pit-and-fissure lesions and could be used alone during dental examination in children. The evaluation of caries risk should become clinical routine, as parameters belonging to high risk were frequently recorded in our study group.

Prevention of acidic attack on tooth enamel surfaces using polishing paste containing ion-releasing filler

The purpose of this study was to investigate the ability of polishing paste containing surface pre-reacted glass-ionomer (S-PRG) filler to prevent acidic attack on tooth enamel surfaces. Resin composites were filled in the standardized cavities and finished with silicon carbide paper. These specimens were divided into three groups: the unpolished "control" group, the "PRG" group polished with S-PRG paste, and the "DDP" group polished with diamond-containing polishing paste. Following polishing, the specimens were immersed in a lactic acid buffer solution for 28 days. Optical coherence tomography (OCT) signals were measured to obtain the signal intensity and width at 1/e² at selected locations on the enamel surface adjacent to the restoration. Although signal intensity significantly increased in all groups, widths at 1/e² did not change significantly in the PRG group. For both the control and DDP groups, signal intensity and width at 1/e² increased and decreased over time, respectively.

White enamel lesions in children: considering caries, chronological and congenital causes and their consequent care

White enamel lesions are a common presentation to the general dentist and aesthetic concerns are the most frequent presenting problem. Aetiology may be multifactorial and management of such lesions is heavily dependent on the cause. In the paediatric patient, differentiating white lesions caused by caries, fluorosis and genetic and developmental disorders is key to offering optimal long-term treatment outcomes. Early intervention allows for carefully planned management of less common disorders. Many of these disorders exist along a spectrum, and white lesions offer a useful clue to prompt intervention and referral to the relevant specialists. This article overviews common white lesions of the teeth and outlines the hierarchy of management options available.

Managing the phase-down of amalgam amongst Nigerian dental professionals and students: A national survey

BACKGROUND

Amalgam is one of the most reliable dental restorative materials. Health and environmental concerns associated with the mercury content of amalgam have necessitated an amalgam phase-down in clinical practice.

OBJECTIVES

This study investigated the level of awareness and preparedness for the planned amalgam phase-down recommended by the Minamata Convention amongst Nigerian dental students and dentists.

METHODS

This cross-sectional national survey was performed across all geopolitical zones of Nigeria. Data regarding awareness, practice and level of preparedness for amalgam phase-down were obtained using a questionnaire that was distributed amongst clinical dental students and dentists of different cadres, who routinely place dental restorations, in public and private practice. The questionnaires were administered online or were hand delivered. Data were analysed using the chi-square test and Spearman's rank correlation coefficient. A p value ≤ 0.05 was considered statistically significant.

RESULTS

Notably, 845 dental students and dentists participated in the survey. Mean age (±standard deviation) of participants was 30.15 ± 7.67 years, 33.8% were students, and 66.2% were dentists (most dentists [77.1%] were employed at public hospitals). A significant percentage of respondents had poor knowledge of the Minamata Convention (87.7%) and lacked training in the use of alternatives to amalgam (72.0%). Amalgam continues to be commonly used by 39.1% and 31.3% of dental students and dentists, respectively. Only 4.7% of the respondents admitted to following good amalgam phase-down practices. Awareness (P = 0.013) and amalgam phase-down practices (P = 0.011) were significantly higher amongst dentists than amongst dental students.

CONCLUSION

We observed low levels of awareness regarding the Minamata Convention, amalgam phase-down, mercury hygiene practices and training in alternatives to amalgam use amongst Nigerian dental professionals and students.

The effects of 8DSS peptide on remineralization in a rat model of enamel caries evaluated by two nondestructive techniques

Nowadays, dental caries is one of the most common oral health problems, affecting most individuals. It has been found that, by remineralizing enamel at an early stage in the formation of enamel caries, teeth can be effectively protected from dental caries. In this work, a peptide with eight repetitive sequences of aspartate-serine-serine (8DSS) is applied as the bio-mineralizer in an in-vivo rat enamel caries model. Nondestructive quantitative light-induced fluorescence-digital (QLF-D) imaging and micro-computed tomography (micro-CT) are used to evaluate the remineralization of enamel carious lesions by measuring the total fluorescence radiance loss of the molar area (Δ Q_Total), acquired using QLF-D imaging, and the mineral density and residual molar enamel volume, acquired using micro-CT. Correlations are explored between Δ Q_Total and mineral density (strong correlation, r = 0.8000, p < 0.001) and Δ Q_Total and residual molar enamel volume (moderate correlation, r = 0.6375, p < 0.001). Our results demonstrate that 8DSS is a promising in-vivo remineralization agent that exhibits comparable effects to NaF ( p < 0.05), which has been verified using the classical Keyes method. Moreover, the nondestructive QLF-D and micro-CT methods can be combined to quantify the remineralization of enamel carious lesions three-dimensionally in vivo, making them broadly applicable in quantifying hard tissues.

Has the implementation of the Minamata convention had an impact on the practice of operative dentistry in Jordan?

Objective

To assess Jordanian dentists’ current perception and attitudes towards amalgam and composite restorations four years after the Minamata treaty was endorsed and suggest decision making factors that may influence the type of restoration requested by patients.

Methods

The cross-sectional study was conducted through structured questionnaires distributed to dentists in Amman, Jordan from June 2017 to February 2018.

Results

Of the 1686 dentists who were contacted 758 dentists (response rate 45%) responded to the questionnaire either by email or via field visits. Jordanian dentists used more composite restorations than amalgam. Recurrent caries followed by fracture of the restoration were the main reasons for replacement of both fillings by dentists. However, dentists suggested that the main reason patients requested replacement of amalgam was for ‘staining’. In addition, a large proportion of the dentists had experienced patients who had asked either for replacement of amalgam (77%) or refused an amalgam filling (99%) for aesthetic reasons. In the opinion of the dentists, only 20% patients requested replacement of amalgam because of the mercury content.

Conclusion

The findings of this survey suggest that a ‘phase-down’ of dental amalgam is being implemented in Jordan's dental clinics but it is not associated with commitment to the Minamata Convention, rather to current dental practice trends and patients’ aesthetic demands.

Knowledge, attitude and skills of dental practitioners of Puducherry on minimally invasive dentistry concepts: A questionnaire survey

BACKGROUND

Minimally invasive dentistry (MID) encompasses early caries diagnosis through caries risk assessment (CRA), early detection of incipient carious lesion including primary and secondary prevention based on scientific evidence that remineralization of demineralized enamel and dentin is possible if detected early. Although the dental curriculum focuses on the advantages of MID in tooth preservation, this science is not usually translated into practice.

AIM

This study aimed to evaluate the knowledge, attitude, and skills of dental practitioners of Puducherry regarding the concepts of MID.

SUBJECTS AND METHODS

Data were collected through an online survey questionnaire based on awareness and practice of MID. Statistical evaluation was done on SPSS by Chi-square test.

RESULTS

A total of 126 dentists responded of which only 55% were trained in MID during their undergraduate and internship period, mainly through lectures (49.6%). Nearly 81% agreed that CRA should be conducted for all patients. Almost 42.7% had heard about International Caries Detection and Assessment System, but only 25.9% used a blunt explorer for caries detection. About 13.7% use magnification (loupes/microscope), but majority (84.7%) use radiographs. More than 70% were unaware of newer methods of caries detection. Statistically significant differences were found (P < 0.05) regarding qualification and experience about the effectiveness of Atraumatic Restorative Treatment and sandwich technique for treatment of caries in permanent teeth and high caries-risk children.

CONCLUSION

Although there is knowledge about advantages of MID among dentists of Puducherry, it does not benefit patients, as many practitioners still follow the traditional principles of total caries removal.

Phase down of amalgam. Awareness of Minamata convention among Jordanian dentists

OBJECTIVES

To assess the knowledge of Jordanian dentists toward phase down of dental amalgam as recommended by the Minamata Convention, and their training and competency in placing posterior composites.  Methods: This study was conducted through structured questionnaire interviews with randomly selected cohort of dentists in Jordan between March 2015 and June 2015. Out of 230 dentists who were invited, 196 (85.2%) agreed to participate. Dentists were asked if they know about the Minamata Convention. They were also asked about their training in placement of posterior composite.  Results: Out of the 196 interviewed, only 13.8% know about Minamata Convention and 17% had an undergraduate training in favor of placing composites in posterior teeth. Approximately 50% of those dentists were not trained in using rubber dam when placing posterior composites, while only 38.3% had training in sectional matrix placement. Undergraduate training did not influence (p=0.00) the dentists' decision to remove old amalgam based on patient's demands. Only 28.1% were of the opinion of discontinuing the use of amalgam due to its alleged health and environmental hazards. There was no general agreement on the type of composite, liner, and bonding strategy when placing posterior composites. Conclusion: Dentists are not well informed on the Minamata Convention and the phase down of amalgam. Training in posterior composite placement should be given more room in undergraduate curriculum and continuous dental education.

Laser fluorescence of caries detection in permanent teeth in vitro: a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

The detection of dental caries in the early stages, particularly on the occlusal surfaces, has become a mainstay of contemporary clinical practice. The objective of the study was to verify the accuracy of laser fluorescence for caries detection.

METHODS

A comprehensive search of the MEDLINE (PubMed), EMBase, Cochrane Central Register of Controlled Trials, IBECS, BIOSIS, Web of Science, SCOPUS, Congress Abstracts, and Grey literature databases was undertaken from 1980 through January 2016. We included cross-sectional studies that evaluated laser fluorescence in caries diagnoses in vitro and compared them with histological analyses.

RESULTS

A total of 39 articles were included in the meta-analysis, which included 2082 caries sites. The pooled sensitivity was 0.71 (0.69, 0.73), and the specificity was 0.81 (0.73, 0.82). The diagnostic odds ratio was 14.93 (11.2, 19.9). A summary receiver operating characteristic curve was constructed. The area under the curve was 0.865.

CONCLUSION

This meta-analysis showed that laser fluorescence in vitro had the ability to diagnose occlusal caries lesions in permanent teeth and enamel and dentin caries.

Potential of an amelogenin based peptide in promoting reminerlization of initial enamel caries

OBJECTIVE

In this study we give a preliminary study of a rationally designed small peptide, which is based on the enamel matrix protein amelogenin, to investigate its effect on remineralization of initial enamel caries lesions.

DESIGN

A novel peptide was designed and synthesized to investigate its effects on the remineralization of initial enamel carious lesions during pH cycling that simulates intra-oral conditions. Initial lesions were created in bovine enamel blocks, which were then pH-cycled for 12 days in the presence of 25μM peptide, 1g/L NaF (positive control), 50mM HEPES buffer(negative control). Before and after pH cycling, enamel blocks were analyzed by surface microhardness testing, polarized light microscopy and transverse microradiography.

RESULTS

Percentage of surface microhardness recovery (SMHR%) after pH cycling was significantly higher in peptide group than HEPES group. Lower lesion depth and less mineral mineral loss were found in peptide or NaF treatment groups after the cycling, and were significantly different to HEPES group. No significant differences were observed between the blocks treated with peptide and those treated with NaF.

CONCLUSSION

This study provides in vitro evidence that this amelogenin based peptide promotes enamel caries remineralization, offering a promising remineralizing biomaterial in initial enamel carious treatment.

Comparing potential early caries assessment methods for teledentistry

BACKGROUND

Optical caries detection has the potential to be incorporated in telehealth medicine for preventive dental screening. The objective of this study was to evaluate and compare visible and near infrared detection methods for identifying early non-cavitated ex vivo occlusal demineralization.

METHODS

Six blinded examiners were used to compare the accuracy of the following three examinations in detecting occlusal demineralization: Midwest Caries ID (MID), visual photographic examination (CAM) and Cross Polarization Optical Coherence Tomography (CP-OCT). For each diagnostic method, two examiners assessed the extracted tooth samples 1-2 weeks apart. Teeth were then sectioned and lesion depth was confirmed (n = 42) by a blinded histological examination using a glycol based caries indicator dye. The sensitivity (Sen), specificity (Sp), Intraclass Correlation Coefficient (ICC), and Area under the Receiver Operator Curve (AUC) were calculated.

RESULTS

For detecting any demineralization versus sound pit and fissure enamel, the mean Sen/Sp found was 46.9/85.0 for MID, 80.5/52.5 for CAM, and 83.4/45.0 for CP-OCT. For detecting non-cavitated demineralization that progressed into the dentin, the mean Sen/Sp found was 17.3/88.0 for MID, 48.0/57.8 for CAM, and 44.2/72.7 for CP-OCT. AUC values were statistically significant (P < 0.05) in three out of four examiner assessments when MID and CP-OCT were used to detect any demineralization. AUC values were significant for a single CAM examination. When assessing deeper non-cavitated lesions, none of the assessment methods were able to yield AUC values that were significantly different than a random 'coin flip' test. When examining reliability, MID demonstrated the highest ICC score (0.83) and CP-OCT had the lowest (0.49).

CONCLUSION

Although MID and CP-OCT were useful in detecting the presence of demineralization, examiners were not able to utilize these devices to adequately assess the depth of the demineralization. This study found that MID and CP-OCT did not have markedly superior diagnostic values from simple CAM assessment for use in teledentistry.