Systematic review on noninvasive treatment of root caries lesions

The present systematic review critically summarizes results of clinical studies investigating chemical agents to reduce initiation or inactivation of root caries lesions (RCLs). Outcomes were DMFRS/DFRS (decayed, missing, filled root surfaces), surface texture (hard/soft), and/or RCI (root caries index). Three electronic databases were screened for studies from 1947 to 2014. Cross-referencing was used to further identify articles. Article selection and data abstraction were done in duplicate. Languages were restricted to English and German. Mean differences (MD) were calculated for changes in DMFRS/DFRS. Risk ratios (RR) were calculated for changes in surface texture and RCI in a random effects model. Thirty-four articles with 1 or more agents were included; they reported 30 studies with 10,136 patients who were 20 to 101 y old; and they analyzed 28 chemical agents (alone or in combination). Eleven studies investigated dentifrices, 10 rinses, 8 varnishes, 3 solutions, 3 gels, and 2 ozone applications. Meta-analyses revealed that dentifrices containing 5,000 ppm F(-) (RR = 0.49; 95% confidence interval [95% CI] = 0.42, 0.57; high level of evidence) or 1.5% arginine plus 1,450 ppm F(-) (RR = 0.79; 95% CI = 0.64, 0.98; very low level) are more effective in inactivating RCLs than dentifrices containing 1,100 to 1,450 ppm F(-). Self-applied AmF/SnF2-containing dentifrice and rinse decreased the initiation of RCLs when compared with NaF products (standardized MD = 0.15; 95% CI = -0.22, 0.52; low level). Patients rinsing with a mouth rinse containing 225 to 900 ppm F(-) revealed a significantly reduced DMFRS/DFRS (MD = -0.18; 95% CI = -0.35, -0.01; low level) when compared with a placebo rinse. Significantly reduced RCI was found for CHX (MD = -0.67; 95% CI = -1.01, -0.32; very low level) as well as SDF (MD = -0.33; 95% CI = -0.39, -0.28; very low level) when compared with placebo varnish. Regular use of dentifrices containing 5,000 ppm F(-) and quarterly professionally applied CHX or SDF varnishes seem to be efficacious to decrease progression and initiation of root caries, respectively. However, this conclusion is based on only very few well-conducted randomized controlled trials.

Radiopaque Tagging Masks Caries Lesions following Incomplete Excavation in vitro

One-step incomplete excavation seals caries-affected dentin under a restoration and appears to be advantageous in the treatment of deep lesions. However, it is impossible to discriminate radiographically between intentionally left, arrested lesions and overlooked or active lesions. This diagnostic uncertainty decreases the acceptance of minimally invasive excavation and might lead to unnecessary re-treatment of incompletely excavated teeth. Radiopaque tagging of sealed lesions might mask arrested lesions and assist in discrimination from progressing lesions. Therefore, we microradiographically screened 4 substances (SnCl2, AgNO3, CsF, CsCH3COO) for their effect on artificial lesions. Since water-dissolved tin chloride (SnCl2×Aq) was found to stably mask artificial lesions, we then investigated its radiographic effects on progressing lesions. Natural lesions were incompletely excavated and radiopaque tagging performed. Grey-value differences (△GV) between sound and carious dentin were determined and radiographs assessed by 20 dentists. While radiographic effects of SnCl2×Aq were stable for non-progressing lesions, they significantly decreased during a second demineralization ( p < .001, t test). For natural lesions, tagging with SnCl2×Aq significantly reduced △GV ( p < .001, Wilcoxon). Tagged lesions were detected significantly less often than untagged lesions ( p < .001). SnCl2×Aq was suitable to mask caries-affected dentin and discriminate between arrested and progressing lesions in vitro. Radiopaque tagging could resolve diagnostic uncertainties associated with incomplete excavation.

Cost-effectiveness of One- and Two-step Incomplete and Complete Excavations

The treatment of deep caries lesions carries significant risks for the integrity of the pulp and often initiates a cascade of re-interventions. Incomplete caries removal may reduce these risks and avoid or delay re-treatment. The present study analyzed the cost-effectiveness of one- and two-step incomplete as well as complete excavations. We used Markov models to simulate treatment of a molar tooth with a deep caries lesion in a 15-year-old patient. Retention of the tooth and its vitality as effectiveness measures as well as accruing costs were analyzed over the patient’s lifetime. The model adopted a public-private-payer perspective within German health care. Transition probabilities were calculated based on literature reviews. Monte-Carlo microsimulations were performed with 6-month cycles. One-step incomplete excavation resulted in lower long-term costs and in longer-retained teeth and their vitality (means: 53.5 and 41.0 yrs) compared with two-step incomplete (52.5 and 37.5 yrs) and complete excavations (49.5 and 31.0 yrs), and dominated the other strategies in 70% to 100% of simulations. Regardless of the assumed willingness-to-pay ceiling value, one-step incomplete excavation had the highest probability of being cost-effective. Despite limited evidence levels of input data, we expect one-step incomplete excavation to reduce costs while retaining deeply carious teeth and their vitality for longer.

Attitudes and behaviour regarding deep dentin caries removal: a survey among German dentists

Incomplete removal of deep caries has been shown to reduce the risks of pulp exposure and postoperative pulpal complications. It is therefore of interest whether dentists perform one- or two-step incomplete excavation, and which criteria and methods they use to assess and provide removal of deep caries. This study investigated the attitudes and behaviour of dentists in northern Germany using a new, validated questionnaire. The survey included 2,346 practitioners, 821 (35%) of whom responded. Demographic and sensitivity analysis did not indicate selection bias. 50% of dentists considered only complete excavation, even if pulp exposure was likely. If caries was to be removed incompletely, 77% considered two-step excavation. Hardness was the most important criterion to assess excavation. To treat an exposed pulp, 75% of dentists considered direct capping, 70% refused incomplete excavation fearing caries progression or pulp damage, and 59% reported to prefer more invasive treatment to facilitate restoration longevity. Over 50% recognised an influence of professional regulations on their treatment decisions. There was a moderate correlation between attitudes and behaviour of dentists, with dentists who suspected residual caries to be harmful rejecting incomplete excavation and vice versa. Cluster analysis identified two groups of dentists with opposite attitudes and behaviour, independently from dentist's age or gender. In conclusion, the majority of surveyed dentists was sceptical about leaving caries during excavation and does not practice incomplete caries removal. Therefore, benefits of partial excavation should be highlighted in under- and postgraduate education and regulatory incentives modified to promote minimally invasive techniques.

Micro-hardness and mineral loss of enamel lesions after infiltration with various resins: influence of infiltrant composition and application frequency in vitro

OBJECTIVES

The aim of this in vitro study was to evaluate the influence of infiltrant composition and application frequency on micro-hardness and lesion progression after resin infiltration of artificial enamel lesions.

METHODS

In each of 100 bovine enamel samples, three artificial caries lesions were created (pH=4.95, 50 days). After etching two of the lesions (37% phosphoric acid) specimens were randomly allocated to five infiltrants (four experimental infiltrants with different monomer and solvent compositions and penetration coefficients, and one commercial infiltrant [Icon, DMG]). Lesions were then infiltrated and light-cured, and infiltration repeated afterwards for one of the lesions. Infiltrated samples were cut into halves, with one half being demineralised for further 50 days. Micro-hardness (VHN) and integrated mineral loss (ΔZ) were evaluated at baseline and after second demineralisation. Repeated measures ANOVA and paired t-tests were used to analyse influence of material composition and application frequency on micro-hardness and lesion progression (integrated mineral loss difference ΔΔZ).

RESULTS

Resin infiltration significantly increased micro-hardness and reduced lesion progression compared to untreated artificial lesions (p<0.05, t-test). Neither micro-hardness nor lesion progression were significantly influenced by material composition (p>0.05, ANOVA). In contrast, twice application resulted in significantly increased micro-hardness and demineralisation resistance of infiltrated lesions (p<0.05, ANOVA).

CONCLUSION

Resin infiltration significantly improves micro-hardness and demineralisation resistance of enamel lesions; these effects are significantly enhanced if resins are applied twice. Experimental resins did not outperform the commercial infiltrant.

CLINICAL SIGNIFICANCE

This in vitro study demonstrated that resin infiltration significantly increases both micro-hardness and demineralisation resistance of enamel caries lesions. Twice application of the infiltrant seems to increase these effects. In contrast, the composition of the infiltrant had no significant influence on investigated parameters.

Ex vivo evaluation of caries infiltration after different application times in primary molars

Low viscosity resins (infiltrants) have been shown to penetrate the lesion body of natural caries lesions almost completely in vitro. However, penetration depths (PD) have not been evaluated in vivo. Therefore, the aim of the present study was to evaluate the penetration of an infiltrant into proximal caries lesions in primary molars after different application times using an ex vivo model. 59 proximal lesions from 34 children were randomly allocated to one of the application times and were infiltrated under clinical conditions for 1, 3, or 5 min. After extraction or exfoliation (n = 48), teeth were sectioned perpendicular to their surfaces and lesion depths (LD) as well as lesion areas (LA) were evaluated using polarized light microscopy. PD and penetration areas (PA) were measured on scanning electron microscopic images. Percentage penetration depth (PPD) and percentage penetration area (PPA) were calculated. The mean (±SD) LD and LA were 596 ± 203 µm and 4.03 ± 2.75 × 10(5) µm(2), respectively. PPD ranged from 70 to 80% and PPA from 54 to 60%. Longer application times did not result in significantly deeper or more complete penetration (p > 0.05; ANOVA). In conclusion, proximal caries lesions in primary molars can be infiltrated in vivo to a similar extent as observed previously in vitro. Moreover, 1-min application of the infiltrant led to PD and homogeneity similar to those observed with longer application times up to 5 min.

Relationship of caries and fluorosis in adolescents from high- and low-fluoride areas in Iran

OBJECTIVE

The main aim of the study was to investigate the association between water fluoride concentration and caries as well as fluorosis occurrence in adolescents in Iran. As a secondary aim we studied the relationship between caries and fluorosis occurrence.

BASIC RESEARCH DESIGN

We examined 12-16 year-olds (n = 373) in Orumiyeh [0.3 mgF-/l, low-fluoride (LF)] and Pol Dasht [3.2 mgF-/l, high-fluoride (HF)] for caries-status [D3-Level, Pitts & Fyffe (DMFS)] and fluorosis prevalence [Thylstrup & Fejerskov index (TF)]. Children completed questionnaires about several sociodemographic and oral health related factors of the previous years. To adjust for confounding, we used log risk regression and estimated relative risks (RR) and 95% confidence intervals (CI).

RESULTS

For 12-13 year-olds mean DMFS were 1.9 (sd 2.5) and 1.1 (2.2) in the LF and the HF-areas, respectively. Prevalence of aesthetically relevant fluorosis (TF > 2) was 1% (LF) and 87% (HF). Water fluoride concentration (adjusted for age and SES) was inversely associated with caries-status [RR: 0.7, (CI 0.6-0.8)]. RR for fluorosis was 17 (CI 8-33). In HF-area, caries scores were significantly higher for children with TF > or = 5 on upper central incisors compared with TF < or = 4 (p < 0.05 Mann-Whitney test).

CONCLUSIONS

Caries prevalence in the examined areas in Iran is quite low. Above-optimal water fluoride concentration seems to be effective in reducing caries experience, but increases the occurrence of fluorosis. Severe fluorosis seems to be associated with higher caries occurrence in a high-fluoride area.

Infiltrants inhibit progression of natural caries lesions in vitro

To define the optimized material properties of caries-infiltrating resins (infiltrants), we evaluated the effects of infiltrant composition and penetration coefficient (PC) on the inhibition of the progression of natural approximal caries lesions in vitro. Non-cavitated natural enamel lesions were etched (15% HCl gel) and infiltrated for 5 min with experimental resins varying in PC (cm/sec): PC63, PC185, PC204, and PC391. As a positive control (PosC), lesions were covered with flowable composite resin, whereas untreated lesions served as negative controls (NegC). Specimens were exposed to a demineralizing solution (pH 4.95) for 400 days. Progression of mineral loss was analyzed by transverse wavelength-independent microradiography. Percentage progressions of NegC [median (25th/75th percentile), 24 (10/56)], PC63 [9 (3/39)], and PC185 [12 (9/24)] were significantly higher compared with those of PosC [1 (-8/8)], PC204 [-2 (-4/2)], and PC391 [0 (-5/9)] (p < 0.05). Thus, infiltrants with PC > 200 cm/sec are capable of inhibiting lesion progression.

Resin infiltration of caries lesions: an efficacy randomized trial

Resin infiltration is an innovative approach to arrest progression of caries lesions. The aim of this randomized split-mouth placebo-controlled clinical trial was to assess whether resin infiltration of proximal lesions is more effective than non-operative measures alone with respect to the inhibition of caries progression. In 22 young adults, 29 pairs of interproximal lesions with radiological extension into the inner half of enamel or the outer third of dentin were randomly allocated to two treatment groups. In the test group, lesions were infiltrated (Icon, pre-product; DMG). A placebo treatment was performed in the control group. All participants received instructions for diet, flossing, and fluoridation. The primary outcome after 18 months was radiographic lesion progression (assessed by digital subtraction radiography). No unwanted effects could be observed. In the effect group, 2/27 lesions (7%) and in the control group 10/27 lesions (37%) showed progression (p = 0.021; McNemar). Infiltration of interproximal caries lesions is efficacious in reducing lesion progression.

Inhibition of caries progression by resin infiltration in situ

The infiltration of caries lesions with low-viscosity light-curing resins (infiltrants) has been shown to inhibit further demineralization in vitro. The aim of the present study was to assess the efficacy of resin infiltration in preventing lesion progression in situ. In each of 104 bovine enamel specimens, 2 artificial enamel caries lesions were created. The specimens were randomly allocated to 2 groups: in the test group, 1 of the lesions was etched for 5 s (37% H(3)PO(4)) and subsequently infiltrated twice with a preproduct infiltrant, each time for 60 s. As a positive control, 1 lesion was superficially sealed with a fissure sealant. The second lesion in each specimen served as an untreated control. The specimens were inserted into intraoral appliances and worn by 11 volunteers in the mandibular buccal sulcus for 100 days. Plaque accumulation was promoted by a mesh, and the appliances were stored in 10% sucrose solution (2 x 30 min/day). The specimens were analyzed using transversal microradiography and wavelength-independent microradiography. The specimens of 2 participants were excluded from analysis. The baseline integrated mineral losses (transversal microradiography values; mean +/- SD: 2474 +/- 549 vol% x mum) and lesion depths (98 +/- 20 mum) did not differ significantly between the various groups (p > 0.05; paired t test). After the in situ phase, the infiltrated and positive control lesions showed significantly less progression compared to the untreated controls (p < 0.05). It can be concluded that resin infiltration is efficacious in preventing further demineralization of artificial enamel caries lesions under cariogenic conditions in situ.

Sealants in dentistry: outcomes of the ORCA Saturday Afternoon Symposium 2007

Sealants are a successful tool in caries prevention, but their role in preventive strategies after the caries decline has to be discussed. A survey of paediatric departments across Europe revealed that indications for pit and fissure sealants vary considerably, both nationally and internationally. Evidence for effectiveness of sealants in controlling caries in posterior teeth implies that sealants should be an integrated part of management of pit and fissure caries. Still, the indication for occlusal sealants seems to be shifting from primary prevention to a therapeutic decision for caries management of lesions in enamel and the outer part of the dentine. Sealants are also an interesting concept for caries management in approximal surfaces. Clinical trials suggest that novel techniques of sealing or infiltrating approximal lesions show promise. However, approximal sealing techniques are as complex to apply and time-consuming as approximal fillings. The article proposes guidelines for teaching on the use of sealants.

Improved Resin Infiltration of Natural Caries Lesions

In artificial lesions, improved penetration and the caries-inhibiting properties of infiltrating resins could be observed with increasing penetration coefficients (PCs). The aim of the present study was to compare the penetration abilities of an experimental ‘infiltrant’ into natural lesions with those of an adhesive in vitro. Extracted human molars and premolars showing proximal white spots were cut across the lesions perpendicular to the surface. Corresponding lesion halves were etched for 120 sec with 15% hydrochloric acid gel and were subsequently treated with either an adhesive (PC: 31 cm/sec) or an infiltrant (PC: 273 cm/sec). Specimens were observed by confocal microscopy and transverse microradiography. Penetration depths of the adhesive were significantly lower compared with those of the infiltrant (p < 0.001; Wilcoxon). It can be concluded that resins with higher PCs (infiltrants) show superior ability to penetrate natural lesions compared with resins with lower PCs.