Dentinal Lesions Research Articles

Clinical cavitation and radiographic lesion depth in proximal surfaces in an Indian population

Objectives. To assess the relationship between clinical cavitation and radiographic caries lesion depth in proximal surfaces of permanent posterior teeth in an Indian population. This study also assessed the clinical feasibility of applying ’western guidelines’ to this population from the developing world. Materials and methods. Relationship between clinical cavitation and radiographic caries lesion depth in proximal surfaces in an Indian population was assessed. Proximal surfaces (n = 126) without restorations were examined on bitewing radiographs in patients with suspected caries and lesion depth was recorded by five observers. The radiographic scoring scale was 0 = sound; 1 = lesion in enamel; 2 = lesion in outer 1/3 of dentine and 3 = lesion in inner 2/3 of dentine. Orthodontic separators were placed interdentally and removed after 3 days, where surfaces were recorded as cavitated (yes/no) by two clinical validators (gold standard). Results. Enamel lesions were cavitated in 25.6–38.3%, outer dentinal lesions were cavitated in 83.3–100% and inner dentinal lesions were cavitated in 96.4–100% depending on observer and validator. On applying ‘western guidelines’ for treatment decision to the radiographic findings of lesion depth, 80–100% of the lesions observed in outer dentine would lead to a false (non-operative) treatment decision. Conclusions. Radiographic shallow carious lesions were often cavitated in this population. The threshold for cavitation in this study population is suggested to be set between enamel and outer dentine in contrast to western guidelines.

Fluoride varnish applications and caries incidence in pre-schoolers.

A two year placebo-controlled, double-blind, randomised control trial in 1-4-year-old children. Children were recruited from low income families in Rio de Janeiro, Brazil, with access to a fluoridated public water supply. Both groups received oral hygiene instruction along with provision of toothbrushes and 1450 ppm F- toothpaste. The control group had a placebo fluoride varnish applied every six months. The intervention group had 22,600 ppm F- varnish applied every six months. Clinical examinations for the presence of caries were conducted at baseline and at each subsequent six monthly visit. The primary outcome was the proportion of children in each group that went on to clinically develop any new carious surfaces using the ICDAS criteria. The number of new carious surfaces was assessed as a secondary outcome, both at the enamel and dentine level. The study also reported on the safety and acceptability of the varnish. Two hundred children participated in the trial, 91% were followed up at two years and adherence to the six-monthly applications was 84% in the intervention and 85% in control groups. The results did not show a significant difference for the development of new lesions between the two groups. In the fluoride varnish group 36% had developed new dentinal lesions compared to 47% in the placebo group, a difference of -10.8% (95% CI -24.9 to 3.3, p = 0.14). In relation to caries increment, at the enamel level, this was a mean of 2.0 teeth in the fluoride varnish group and 2.8 teeth in the placebo group, a difference of -0.8 (95% CI -2.0 to 0.4, p = 0.19). At the dentine level, caries increment was a mean of 1.8 teeth in the fluoride varnish group and 2.5 in the placebo group, a difference of -0.7 (95% CI -1.9 to 0.4, p = 0.23). Two minor complaints related to taste and appearance of the varnish were recorded and no safety events were reported. Whilst no significant difference was found, the authors note that this does not indicate ineffectiveness of fluoride varnish. Re-assessment of the power calculation following study completion demonstrated that a significantly larger sample size would have been indicated, preventing the drawing of any direct conclusions from the results of this study. The use of fluoride varnish amongst this group appears to be safe and overall well tolerated.

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

ObjectivesTo assess and compare the cumulative survival rate of amalgam and atraumatic restorative treatment (ART) restorations in primary molars over 3 years. Methods280 children aged 6–7 years old were enrolled in a cluster randomized controlled clinical trial using a parallel group design covering two treatment groups: conventional restorative treatment with amalgam (CRT) and atraumatic restorative treatment (ART) using a high-viscosity glass-ionomer (HVGIC) Ketac Molar Easymix. Three pedodontists placed 750 restorations (364 amalgam and 386 ART in 126 and 154 children, respectively) which were evaluated at 0.5, 1, 2 and 3 years. The proportional hazard rate regression model with frailty correction, ANOVA and Wald tests, and the Jackknife procedure were applied in analysing the data. ResultsThe cumulative survival rates over 3 years for all, single- and multiple-surface CRT/amalgam restorations (72.6%, 93.4%, 64.7%, respectively) were no different from those of comparable ART/HVGIC restorations (66.8%; 90.1% and 56.4%, respectively) (p=0.10). Single-surface restorations had higher survival rates than multiple-surface restorations for the both treatment procedures (p<0.0001). A higher proportion of restorations failed because of mechanical reasons (94.8%) than of secondary caries (5.2%). No difference in reasons for restoration failures between all types of amalgam and ART/HVGIC restorations were observed (p=0.24). SignificanceThe high-viscosity glass-ionomer used in this study in conjunction with the ART is a viable option for restoring carious dentin lesions in single surfaces in vital primary molars.

English

Periodontal disease and dental caries are infectious diseases resulting from the interactions of oral bacteria residing dental plaque and the host. The indigenous bacteria residing dental plaque are thought to be a relatively stable community of high species diversity, which may vary from site to site throughout the mouth. When this stability is disturbed, due to many host-specific and environmental factors, in addition to oral hygiene and dietary habits which the subjects can regulate, other less benign bacteria may colonize the oral cavity and the bacteria that are normally present in very low number may increase to cause oral diseases. The aim of this review paper is to highlight the oral microbial ecosystems in oral health and disease and to investigate the ecological changes that shift the indigenous bacteria residing dental plaque to be increased in number and cause oral diseases. The paper reviews the different oral ecosystems involving a variety of microbes and the balance between the growth of those microbes and the host health. In addition, the paper discusses the development of periodontal disease and dental caries according to plaque hypotheses. Relatively specific microfloras are associated with various types of periodontal conditions including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia. The genera Streptococcus and Actinomyces are main indicators of periodontal health. The development of caries lesions appears to involve different bacterial succession. Mutans streptococci are implicated more with caries initiation, while lactobacilli appear to be related to progression of enamel and dentine lesions. Key words: Plaque hypotheses, periodontal disease, dental caries, bacterial interactions.

Identification of the microbiota in carious dentin lesions using 16S rRNA gene sequencing.

While mutans streptococci have long been assumed to be the specific pathogen responsible for human dental caries, the concept of a complex dental caries-associated microbiota has received significant attention in recent years. Molecular analyses revealed the complexity of the microbiota with the predominance of Lactobacillus and Prevotella in carious dentine lesions. However, characterization of the dentin caries-associated microbiota has not been extensively explored in different ethnicities and races. In the present study, the bacterial communities in the carious dentin of Japanese subjects were analyzed comprehensively with molecular approaches using the16S rRNA gene. Carious dentin lesion samples were collected from 32 subjects aged 4–76 years, and the 16S rRNA genes, amplified from the extracted DNA with universal primers, were sequenced with a pyrosequencer. The bacterial composition was classified into clusters I, II, and III according to the relative abundance (high, middle, low) of Lactobacillus. The bacterial composition in cluster II was composed of relatively high proportions of Olsenella and Propionibacterium or subdominated by heterogeneous genera. The bacterial communities in cluster III were characterized by the predominance of Atopobium, Prevotella, or Propionibacterium with Streptococcus or Actinomyces. Some samples in clusters II and III, mainly related to Atopobium and Propionibacterium, were novel combinations of microbiota in carious dentin lesions and may be characteristic of the Japanese population. Clone library analysis revealed that Atopobium sp. HOT-416 and P. acidifaciens were specific species associated with dentinal caries among these genera in a Japanese population. We summarized the bacterial composition of dentinal carious lesions in a Japanese population using next-generation sequencing and found typical Japanese types with Atopobium or Propionibacterium predominating.

The Caries Assessment Spectrum and Treatment (CAST) instrument: its reproducibility in clinical studies

A new caries assessment instrument, the Caries Assessment Spectrum and Treatment (CAST), was developed. It covers carious lesion progression from no lesion, sealants and restorations to lesions in enamel and dentine, advanced stages in pulpal and tooth-surrounding tissues, and tooth loss owing to dental caries, in nine codes. The objective of this study was to determine the reproducibility of the CAST instrument in primary and permanent dentitions, using three age groups. Two epidemiological surveys were conducted in Brazil, covering three age groups: 2-6-year-old and 6-9-year-old children and 19-30-year-old adults. Four trained and calibrated examiners performed the examinations. Reproducibility was calculated for intra- and inter-examiner at surface and tooth levels and expressed as unweighted kappa-coefficient value (κ) and percentage of agreement (Po) for CAST codes (0-7) and for the categories healthy (0-2) versus diseased (3-7), and non-cavitated (0-3) versus cavitated (4-7) teeth. Using CAST codes (0-7) for the 2-6-year-old age group in primary dentitions, inter-examiner consistency was κ = 0.74 and Po was 98.3%. In the 6-9-year-old age group in primary dentitions, inter-examiner consistency ranged from κ = 0.68 to κ = 0.86 and Po was ≥ 93.7%. In the 19-30-year-old age group inter-examiner consistency was κ = 0.87 and Po was 94.1%. The reproducibility of the CAST instrument for use in the primary dentition of 2-6-year olds and of 6-9-year olds was 'substantial' to 'almost perfect'. The reproducibility for its use in the permanent dentition of 19-30-year olds was 'almost perfect'. The CAST instrument can reliably be applied in epidemiological studies covering these ages.

Self-induced vomiting and dental erosion--a clinical study.

BackgroundIn individuals suffering from eating disorders (ED) characterized by vomiting (e.g. bulimia nervosa), the gastric juice regularly reaches the oral cavity, causing a possible risk of dental erosion. This study aimed to assess the occurrence, distribution and severity of dental erosions in a group of Norwegian patients experiencing self-induced vomiting (SIV).MethodsThe individuals included in the study were all undergoing treatment at clinics for eating disorders and were referred to a university dental clinic for examinations. One calibrated clinician registered erosions using the Visual Erosion Dental Examination (VEDE) system.ResultsOf 72 referred patients, 66 (63 females and three males, mean age 27.7 years) were or had been experiencing SIV (mean duration 10.6 years; range: 3 – 32 years), and were therefore included in the study. Dental erosions were found in 46 individuals (69.7%), 19 had enamel lesions only, while 27 had both enamel and dentine lesions. Ten or more teeth were affected in 26.1% of those with erosions, and 9% had ≥10 teeth with dentine lesions. Of the erosions, 41.6% were found on palatal/lingual surfaces, 36.6% on occlusal surfaces and 21.8% on buccal surfaces. Dentine lesions were most often found on lower first molars, while upper central incisors showed enamel lesions most frequently. The majority of the erosive lesions (48.6%) were found in those with the longest illness period, and 71.7% of the lesions extending into dentine were also found in this group. However, despite suffering from SIV for up to 32 years, 30.3% of the individuals showed no lesions.ConclusionsDental erosion commonly affects individuals with ED experiencing SIV, and is more often found on the palatal/lingual surfaces than on the buccal in these individuals, confirming a common clinical assumption.

A Comparative Study of Different Radiographic Methods for Detecting Occlusal Caries Lesions

Objectives: The aim of this in vitro study was to compare the diagnostic accuracy of different radiographic imaging modalities in detecting occlusal caries lesions. Materials and Methods: Under standardized conditions, 125 extracted human permanent molar teeth with sound or occlusal caries lesions were radiographed using a conventional film system (F-speed), a direct digital imaging system (complementary metal oxide semiconductor sensor), an indirect digital imaging system (photostimulable phosphor plate) and a cone beam computed tomography system (CBCT). Two observers scored the resultant images for the presence or absence of caries. Then, the teeth were histologically prepared and a definite diagnosis was determined by stereomicroscopic assessment. The area under the receiver operating characteristic curve (A_z), sensitivity, specificity and accuracy of each imaging modality were calculated, as well as the intra- and interexaminer reproducibility. Results: For both thresholds, interexaminer agreement were higher for CBCT. For intraexaminer agreement, observers had different scores for both thresholds, but the scores were generally higher for CBCT. Similar A_z values were achieved with all imaging methods at a diagnostic D1 threshold. The A_z values of the CBCT system were found to be statistically higher than those of the other imaging modalities at a diagnostic D3 threshold (p > 0.05); no significant differences were found among the other imaging modalities. All radiographic methods showed similar sensitivities, specificities and accuracy in detecting D1 threshold. The CBCT system showed higher sensitivity and accuracy in detecting dentine lesions. Conclusions: Within the limitations of this study, CBCT exhibited better performance in detecting deep occlusal caries lesions than the other radiographic systems.

COMPARATIVE EVALUATION OF THE EFFECTIVENESS OF FIVE METHODS FOR EARLY DIAGNOSIS OF OCCLUSAL CARIES LESIONS – in vitro study.

SUMMARY: Purpose: The aimof the presented in vitro study was to evaluate the effectiveness of the device DIAGNOcam and the laser fluorescence device DIAGNOdent for early diagnosis of occlusal caries and to compare it with three traditional methods – visual and tactile, dye and radiographic examination. Material and methods: The sample consisted of 60 extracted human teeth. Three clinicians diagnosed independently the presence or absence of early occlusal surface caries with the visible tactile method, DIAGNOcam and DIAGNOdent. Then X-rays were taken and the dentists viewed them separately, without magnification. Fuchsine was applied for 30 sec. and then washed under running water for 20 min. Places where dye was present were registered. Statistical analysis was performed with SPSS package of Windows. Results: The results showed high level of correspondence between the authors for all the diagnostic methods. Concerning different methods applied for caries diagnosis there was a correlation between the methods, but it was diverging for the different methods. No correlation between radiographic exam and data obtained with DIAGNOdent and dye staining was observed. Conclusions: Based on the obtained results we may conclude that the least sensitive method for fissure caries diagnosis was the dye staining, followed by the radiographic exam. The results, obtained by DIAGNOdent and DIAGNOcam were very close, but DIAGNOcams’ data was better correlating with the clinical results. DIAGNOcam procedure can be judged as equivalent in the detection of occlusal dentine lesions when compared to clinical results.

COMPARATIVE EVALUATION OF THE EFFECTIVENESS OF THREE METHODS FOR PROXIMAL CARIES DIAGNOSIS – A CLINICAL STUDY

SUMMARY Aim: The aim of the presented study is to compare the effectiveness of the diagnosis with a dental microscope, laser fluorescence (DIAGNOcam) and X-ray examination in proximal caries diagnosis. Material and methods: Thirty-eight adult patients were examined. They were first examined with a dental mirror and a probe, under magnification 6.4 times. After that a diagnosis with DIAGNOcam was performed. Bitewing Xray images were administered. The data from the three diagnostic methods was compared using SPSS 16 package of Windows. The lesions that were diagnosed as involving dentin were then excavated which served as a confirmation of the diagnosis. Results: The results of the study showed that dentinal lesions were detected with a high degree of correlation with all three diagnostic methods. The visual examination seriously underestimated lesions involving only enamel. In these cases there was a good correlation between laser fluorescence and X-ray data. Conclusions: Based on the conducted study we could conclude that the diagnosis of proximal caries with DIAGNOcam is equivalent to X-ray, both being more accurate in cases with early lesions, compared to visual diagnosis.

Dental caries in primary and permanent molars in 7-8-year-old schoolchildren evaluated with Caries Assessment Spectrum and Treatment (CAST) index.

BackgroundNo reports on a caries pattern covering the full spectrum of the disease could be found in the literature. The aim of this study was to evaluate caries in primary and first permanent molars of 7-8-year-old Polish children by the Caries Assessment Spectrum and Treatment (CAST) index and to find whether there was any correlation between the caries stages in such teeth.MethodsThe study covered 284 7-8-year-old children from randomly selected schools in the Bialystok District, Poland. The prevalence of CAST categories was evaluated with regard to the first and second primary, and first permanent, molars. The Spearman’s rank correlation coefficient was used to explore the correlation of the distribution of CAST codes among the evaluated teeth. The level of statistical significance was established at p < 0.05. The intra-examiner reliability was determined by the unweighted kappa coefficient.ResultsWith regard to the permanent molars, caries was observed in 14.8% to 17.3% of the molar and most lesions were scored at the non-cavitation level. Caries in primary molars was most often recorded at the stage of cavitated dentine lesion. Teeth with pulpal involvement, sepsis and extracted due to caries were found to be more prevalent in first, and then in second primary molars. A strong correlation was found between the status of teeth from the right and left sides of the oral cavity. The correlation of the status of first and second primary teeth was stronger for the left than for the right side of the mouth, r was 0.627 and 0.472 in maxilla and 0.513 and 0.483 in mandible (p < 0.001), respectively. For the neighbouring primary and permanent molars the correlation was assessed to be weak. With regard to the teeth situated in opposite jaws the study revealed that the correlations were moderate - r between 0.33 and 0.49. The intra-examiner reliability was established at 0.96 for the primary dentition and at 0.878 for permanent molars.ConclusionThe strongest correlation found in the evaluated population concerned the distribution of caries in primary molars on the left side of the mouth. The study proved the usefulness of the CAST index in epidemiological surveys.

Randomized controlled clinical trial on the efficacy of dentin desensitizing agents

Objective. To investigate the effects of four dentin desensitizers on pain reduction in hypersensitive cervical dentin lesions. Materials and methods. The trial was designed as a randomized, controlled, four-arm, single-masked study. Fifty subjects with at least one hypersensitive lesion in each of the four quadrants were allocated. The requested pre-operative pain, determined as a response to 2-s air-blast (AB) and probe scratching (PS), was ≥5 on a VAS scale, 0 = no through to 10 = worst pain. Randomly each subject received each of the four treatments: MS Coat One F (MSC, Sun Medical, Japan), Nanoseal (NAN, Nishin, Japan), Teethmate Desensitizer (TMD, Kuraray Noritake, Japan) and Gluma Desensitizer PowerGel (GLU, HeraeusKulzer, Germany). The investigator assessed blindly the pain response using the two stimuli and recorded the patients’ VAS scores before and immediately after application, after 1 week and after 1, 3 and 6 months. Statistical data treatment. ANOVA and post-hoc testing (p ≤ 0.05). Results. Forty-nine subjects completed the trial. Pre-operative dentin hypersensitivity (DH) for the groups was not significantly different. All desensitizers reduced DH significantly throughout the 6-months observation. ANOVA revealed significant differences among VAS scores, obtained with the desensitizing agents (p < 0.001). Ranking by post-hoc testing was: MSC > NAN > TMD > GLU (p < 0.05). Upon PS NAN and TMD showed slight but significant regain of sensitivity after 6 months. For GLU PS scores immediately after application and after 6 months were not significantly different, whereas recalls after 1 week, 1 month and 3 months revealed significantly lower scores. Conclusion. The calcium phosphate-based TMD and GLU proved highly effective in reducing sensitivity.

Reduced odds of pulpal exposure when using incomplete caries removal in the treatment of dentinal cavitated lesions: A critical summary of Schwendicke F, Dörfer CE, Paris S. Incomplete caries removal: a systematic review and meta-analysis (published correction appears in J Dent Res 2013;92[8]:759). J Dent Res 2013;92(4):306-314.

Systematic review conclusion.In dentinal cavitated lesions, incomplete caries removal compared with complete excavation may reduce the risk of experiencing pulpal exposures and postoperative symptoms.Critical summary assessment.There is moderate-quality evidence of reduced odds of experiencing pulpal exposure when a two- or one-/two-step combined incomplete caries removal is performed compared with complete caries removal for restoration of dentinal cavitated lesions, although risk of bias among the included studies was high.Evidence quality rating.Limited. In dentinal cavitated lesions, incomplete caries removal compared with complete excavation may reduce the risk of experiencing pulpal exposures and postoperative symptoms.

Saliva substitutes in combination with high-fluoride gel on dentin remineralization.

This study aimed to determine whether the application of a high-fluoride gel could increase the remineralization of subsurface dentin lesions stored in saliva substitutes. Demineralized bovine dentin specimens were stored in mineral water (W), Glandosane (G), or modified Saliva natura (SN). Different treatments were applied twice daily: no treatment, Elmex sensitive mouth rinse (E), ProSchmelz gel (P), Duraphat toothpaste (D), ED, PD, and EPD. Differences in mineral loss were evaluated by transversal microradiography after 2 and 5 weeks. The treatments with E, D, and ED inhibited the mineral loss induced by G and enabled some mineral gain. ProSchmelz was not able to inhibit the demineralizing effect of G. This high-fluoride gel induced an erosive mineral loss in combination with G. The use of ProSchmelz in combination or not with other fluoride products did not increase remineralization of specimens stored in SN or W (p > 0.05). ProSchmelz resulted in an erosion of the specimens stored in W and revealed a lower mineralized surface layer of specimens stored in SN. Topical application of high-fluoride gel reduced the mineral loss induced by G but resulted in an erosion of specimens' surface. In addition, ProSchmelz did not demonstrate beneficial effects in combination with SN on subsurface dentin lesion remineralization. Within the limitations of an in vitro study, it was concluded that the application of a high-fluoride gel did not promote additional effects on remineralization of subsurface dentin lesions in combination with saliva substitutes when compared to products with lower fluoride concentration.

Bacterial Profile of Dentine Caries and the Impact of pH on Bacterial Population Diversity

Dental caries is caused by the release of organic acids from fermentative bacteria, which results in the dissolution of hydroxyapatite matrices of enamel and dentine. While low environmental pH is proposed to cause a shift in the consortium of oral bacteria, favouring the development of caries, the impact of this variable has been overlooked in microbial population studies. This study aimed to detail the zonal composition of the microbiota associated with carious dentine lesions with reference to pH. We used 454 sequencing of the 16S rRNA gene (V3–V4 region) to compare microbial communities in layers ranging in pH from 4.5–7.8 from 25 teeth with advanced dentine caries. Pyrosequencing of the amplicons yielded 449,762 sequences. Nine phyla, 97 genera and 409 species were identified from the quality-filtered, de-noised and chimera-free sequences. Among the microbiota associated with dentinal caries, the most abundant taxa included Lactobacillus sp., Prevotella sp., Atopobium sp., Olsenella sp. and Actinomyces sp. We found a disparity between microbial communities localised at acidic versus neutral pH strata. Acidic conditions were associated with low diversity microbial populations, with Lactobacillus species including L. fermentum, L. rhamnosus and L. crispatus, being prominent. In comparison, the distinctive species of a more diverse flora associated with neutral pH regions of carious lesions included Alloprevotella tanerrae, Leptothrix sp., Sphingomonas sp. and Streptococcus anginosus. While certain bacteria were affected by the pH gradient, we also found that ∼60% of the taxa associated with caries were present across the investigated pH range, representing a substantial core. We demonstrated that some bacterial species implicated in caries progression show selective clustering with respect to pH gradient, providing a basis for specific therapeutic strategies.

Acceptability of different caries management methods for primary molars in a RCT

More conservative techniques for managing dental caries including 'partial' and 'no caries removal' have been increasingly of interest. To compare children's behaviour and pain perception, also technique acceptability (parents and dentists), when approximal dentinal lesions (ICDAS 3-5) in primary molars (3-8-year-olds) were managed with three treatment strategies; conventional restorations (CR), hall technique (HT), and non-restorative caries treatment (NRCT). Secondary care-based, three-arm parallel-group, randomised controlled trial, with 169 participants treated by 12 dentists. child's pain perception (Visual Analogue Scale of Faces); behaviour (Frankl scale); and parents' and dentists' treatment opinions (5-point Likert scales). Children showed more negative behaviour in the CR group (37%) compared to NRCT (21%) and HT (13%) (P=0.047, CI=0.41 to 0.52). Pain intensity was rated 'very low' or 'low' in 88% NRCT, 81% HT, and 72% CR (P=0.11, CI=0.10 to 0.12). NRCT and HT were 'very easy' or 'easy' to perform for >77% of dentists, compared to 50% in CR group (P<0.000). There were no statistically significant differences in parents' rating of their child's level of comfort (P=0.46, CI=0.45 to 0.48). Dentists reported more negative behaviour in CR group. For all techniques, children's pain perception and dentist/parent acceptability were similar.

The effect of fluoride toothpaste on root dentine demineralization progression: a pilot study

The anticaries effect of fluoride (F) toothpaste containing 1100 µg F/g in reducing enamel demineralization is well established, but its effect on dentine has not been extensively studied. Furthermore, it has been shown that toothpaste containing a high F concentration is necessary to remineralize root dentine lesions, suggesting that a 1100 µg F/g concentration might not be high enough to reduce root dentine demineralization, particularly when dentine is subjected to a high cariogenic challenge. Thus, the aim of this pilot study was to evaluate in situ the effect of F toothpaste, at a concentration of 1100 µg F/g, on dentine demineralization. In a crossover and double-blind study, conducted in two phases of 14 days, six volunteers wore a palatal appliance containing four slabs of bovine root dentine whose surface hardness (SH) was previously determined and to which a 10% sucrose solution was applied extra-orally 8×/day. Volunteers used a non-F toothpaste (negative control) or F toothpaste (1100 µg F/g, NaF/SiO2) three times a day. On the 10th and 14th days of each phase, two slabs were collected and SH was determined again. Dentine demineralization was assessed as percentage of SH loss (%SHL). The effect of toothpaste was significant, showing lower %SHL for the F toothpaste group (42.0 ± 9.7) compared to the non-F group (62.0 ± 6.4; p < 0.0001), but the effect of time was not significant (p > 0.05). This pilot study suggests that F toothpaste at 1100 µg F/g is able to decrease dentine caries even under a high cariogenic challenge of biofilm accumulation and sugar exposure.

Radiographic display of carious lesions and cavitation in approximal surfaces: Advantages and drawbacks of conventional and advanced modalities

Background. Treatment strategies have changed with efforts on arresting carious lesions suspected to have an intact surface sparing operative treatment for cavitated lesions. Radiography is still the most recommended adjunct method in the diagnosis of clinically inaccessible approximal surfaces. Bitewing radiography. The major drawback of bitewing radiography for caries diagnosis is that the clinical state of the surface cannot be determined; i.e. if cavitation has developed or the demineralized surface is still intact. Based on studies of the relationship between radiographic lesion depth and clinical cavitation in approximal surfaces, a threshold for operative treatment decision has been suggested when a lesion is observed radiographically more than one-third into dentine. However, the results from previous studies are contradictory and the majority of studies are ∼25 years old. In addition, there are few longitudinal observational studies on the behaviour of dentinal carious lesions, particularly in adults. Cone beam computed tomography.Cone beam CT is an advanced 3-dimensional radiographic modality, which seems much more accurate than intra-oral modalities for displaying cavitation in approximal surfaces. Nonetheless, there are several drawbacks with CBCT, such as radiation dose, costs and imaging artefacts. Therefore, CBCT cannot be advocated at current as a primary radiographic examination with the aim of diagnosing cavitated carious lesions. Conclusions. Bitewing radiography is, thus, still state-of-the-art as an adjunct in diagnosing carious lesions in clinically inaccessible approximal surfaces. The risk for cavitation is related to lesion depth, but new studies are needed in both child and adult populations to validate current thresholds for the operative treatment decision based on the radiographic lesion depth.

Pyrosequencing Analysis of Oral Microbiota Shifting in Various Caries States in Childhood

Dental caries is one of the most prevalent childhood diseases worldwide, but little is known about the dynamic characteristics of oral microbiota in the development of dental caries. To investigate the shifting bacterial profiles in different caries states, 60 children (3-7-year-old) were enrolled in this study, including 30 caries-free subjects and 30 caries-active subjects. Supragingival plaques were collected from caries-active subjects on intact enamel, white spot lesions and carious dentin lesions. Plaques from caries-free subjects were used as a control. All samples were analyzed by 454 pyrosequencing based on 16S rRNA gene V1-V3 hypervariable regions. A total of 572,773 pyrosequencing reads passed the quality control and 25,444 unique phylotypes were identified, which represented 18 phyla and 145 genera. Reduced bacterial diversity in the cavitated dentin was observed as compared with the other groups. Thirteen genera (including Capnocytophaga, Fusobacterium, Porphyromonas, Abiotrophia, Comamonas, Tannerella, Eikenella, Paludibacter, Treponema, Actinobaculum, Stenotrophomonas, Aestuariimicrobium, and Peptococcus) were found to be associated with dental health, and the bacterial profiles differed considerably depending on caries status. Eight genera (including Cryptobacterium, Lactobacillus, Megasphaera, Olsenella, Scardovia, Shuttleworthia, Cryptobacterium, and Streptococcus) were increased significantly in cavitated dentin lesions, and Actinomyces and Corynebacterium were present at significant high levels in white spot lesions (P < 0.05), while Flavobacterium, Neisseria, Bergeyella, and Derxia were enriched in the intact surfaces of caries individuals (P < 0.05). Our results showed that oral bacteria were specific at different stages of caries progression, which contributes to informing the prevention and treatment of childhood dental caries.

Dental erosion: a widespread condition nowadays? A cross-sectional study among a group of adolescents in Norway

Objective. This study aimed to investigate the prevalence, distribution and severity of erosive wear in a group of 16–18-year-olds in the western part of Norway. A second aim was to describe possible associations between caries experience, socioeconomic background and origin of birth. Materials and methods. Adolescents (n = 795) attending recall examinations at Public Dental Service (PDS) clinics were also examined for dental erosive wear on index surfaces, using the Visual Erosion Dental Examination scoring system (VEDE). Results. In total, 795 individuals were examined. Dental erosive wear was diagnosed in 59% of the population (44% erosive wear in enamel only, 14% combination of enamel and dentine lesions, 1% erosive wear in dentine only). The palatal surfaces of upper central incisors and occlusal surfaces of first lower molars were affected the most (33% and 48% of all surfaces, respectively). Cuppings on molars were registered in 66% of the individuals with erosive wear. Erosive wear was significantly more prevalent among men (63%) than women (55%) (p = 0.018). Conclusions. There were no significant associations between dental erosive wear and caries experience, socioeconomic background or origin of birth.