H. Meyer-Lueckel

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.

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.

Failure of incompletely excavated teeth—A systematic review

OBJECTIVESnWhen treating deep caries, one- and two-step incomplete caries removal reduce the risk of pulpal exposure. However, it is currently unclear if incompletely excavated teeth fail due to pulpal or rather non-pulpal complications. The present study systematically analysed how incompletely excavated teeth fail, and if certain tooth- or treatment-related factors may influence risk of failure.nnnDATAnClinical studies investigating clinical or radiologic failure after incomplete excavation of deep caries (depth >1/2 dentine thickness) were evaluated. Weighted annual failure rates (AFRs) were used to analyse frequency and mode of failures. Sub-analyses compared risk of failure in different groups of possible influencing factors.nnnSOURCESnElectronic databases were screened and studies cross-referenced. Language was restricted to English and German. Grey literature was not evaluated.nnnRESULTSn19 studies with a median (Q25/75) follow-up of 24 (12/48) months were included. AFR was 3.8 (1.4/4.4)%. Eleven studies reported pulpal complications being the major reason for failure, and only 2 studies found more non-pulpal than pulpal failures. Sub-analyses found significantly lower risk of failure for teeth after one- compared with two-step excavation (Odds ratio [95% CI]=0.21 [0.08, 0.55]) and teeth with single- compared with multi-surface cavities (0.33 [0.16, 0.67]). Risk of bias differed widely between studies, and evidence levels were graded as very low.nnnCONCLUSIONSnAfter incomplete removal of deep caries, pulpal failure was more common. One- compared with two-step excavation reduces risk of failure, and factors like number of restored surfaces seem to but influence failure, but limited evidence permits drawing definitive conclusions.nnnCLINICAL SIGNIFICANCEnGrowing evidence indicates that one-step incomplete excavation seems suitable to treat deep caries lesions, and might have advantages compared to two-step incomplete or complete caries removal. However, it is too early to recommend certain clinical strategies.

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 dentists 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.

Masking of white spot lesions by resin infiltration in vitro.

OBJECTIVESnThe aim of this in vitro study was to evaluate the ability of one commercial and five experimental infiltrating resins (infiltrants) to camouflage enamel white spot lesions immediately after resin infiltration and after a staining period.nnnMETHODSnIn each of 120 bovine enamel samples, two artificial caries lesions were created (windows A and C; pH=4.95, 50 days), whereas two windows were protected serving as sound controls (B and D). After etching windows C and D (37% phosphoric acid), specimens were randomly allocated to 6 groups. Either one of 5 experimental infiltrants or a commercial infiltrant (Icon, DMG) (refractive indices 1.50-1.55) was applied and light cured. After half of each specimen was polished, samples were remineralized (pH=7.0) and stained with tea and red wine for 50 days. Photographic images after various treatment steps were obtained. Color differences (ΔE) of untreated (A) and treated lesions (C) as well as infiltrated sound enamel (D) were compared with untreated enamel (B).nnnRESULTSnAll infiltrants showed significantly better color match with sound enamel (median ΔE [25th/75th percentile]: 2.2 [1.5/3.1]) than untreated controls (9.3 [8.0/10.9]) (p<0.001, Wilcoxon, post hoc Bonferroni). Moderate correlation between refractive index and ΔE of infiltrated lesions was demonstrated (R(2)=0.43, p>0.05). Staining was significantly reduced for polished infiltrated lesions compared to untreated or infiltrated unpolished lesions (p<0.001).nnnCONCLUSIONSnResin infiltration is suitable to mask artificial white spot lesions. Polished infiltrated lesions are resistant to staining in vitro.nnnCLINICAL SIGNIFICANCEnResin infiltration is a micro-invasive approach to camouflage post-orthodontic white spot lesions.

Costs and effectiveness of treatment alternatives for proximal caries lesions.

Objectives Invasive therapy of proximal caries lesions initiates a cascade of re-treatment cycles with increasing loss of dental hard tissue. Non- and micro-invasive treatment aim at delaying this cascade and may thus reduce both the health and economic burden of such lesions. This study compared the costs and effectiveness of alternative treatments of proximal caries lesions. Methods A Markov-process model was used to simulate the events following the treatment of a proximal posterior lesion (E2/D1) in a 20-year-old patient in Germany. We compared three interventions (non-invasive; micro-invasive using resin infiltration; invasive using composite restoration). We calculated the risk of complications of initial and possible follow-up treatments and modelled time-dependent non-linear transition probabilities. Costs were calculated based on item-fee catalogues in Germany. Monte-Carlo-microsimulations were performed to compare cost-effectiveness of non- versus micro-invasive treatment and to analyse lifetime costs of all three treatments. Results Micro-invasive treatment was both more costly and more effective than non-invasive therapy, with ceiling-value-thresholds for willingness-to-pay between 16.73 € for E2 and 1.57 € for D1 lesions. Invasive treatment was the most costly strategy. Calculated costs and effectiveness were sensitive to lesion stage, patient’s age, discounting rate and assumed initial treatment costs. Conclusions Non- and micro-invasive treatments have lower long-term costs than invasive therapy of proximal lesions. Micro-invasive therapy had the highest cost-effectiveness for treating D1 lesions in young patients. Decision makers with a willingness-to-pay over 16.73 € and 1.57 € for E2 and D1 lesions, respectively, will find micro-invasive treatment more cost-effective than non-invasive therapy.

Cariogenic Effects of Probiotic Lactobacillus rhamnosus GG in a Dental Biofilm Model

Probiotic bacteria have been suggested to inhibit Streptococcus mutans (SM) and thus prevent dental caries. However, supporting evidence is weak and probiotic species might be cariogenic themselves. Thus, we compared and combined the probiotic Lactobacillus rhamnosus GG (LGG) with SM and analysed the resulting mineral loss (ΔZ) in dental tissues. We simulated three biofilm compositions (SM, LGG, SM × LGG), two lesion sites (smooth enamel, dentin cavity) and two nutrition supply frequencies (twice/day, 6 times/day) in a multi-station, continuous-culture biofilm model. A total of 240 bovine enamel and dentin samples were cut, polished and embedded. All experimental procedures were performed in independent duplicates, with 10 samples being allocated to each group for each experiment (final sample size n = 20/group). Biofilms were cultured on the specimens and supplied with 2% sucrose medium and artificial saliva in consecutive pulses. After 10 days, ΔZ and bacterial numbers were assessed. SM × LGG biofilms caused significantly increased ΔZ compared with SM or LGG biofilms (p < 0.01, Mann-Whitney test), and ΔZ was significantly increased in dentin cavities compared with smooth enamel lesions (p < 0.01). Bacterial numbers did not significantly differ between biofilms of different species (p > 0.05, ANOVA). Frequent nutrition supply significantly increased bacterial numbers (p < 0.01). Biofilms in dentin cavities compared to smooth enamel harboured significantly more bacteria (p < 0.05). LGG induced mineral loss especially in dentin cavities and under highly cariogenic conditions. LGG did not have inhibitory effects on SM, but rather contributed to the caries process in vitro.

Detecting and Treating Occlusal Caries Lesions A Cost-Effectiveness Analysis

The health gains and costs resulting from using different caries detection strategies might not only depend on the accuracy of the used method but also the treatment emanating from its use in different populations. We compared combinations of visual-tactile, radiographic, or laser-fluorescence–based detection methods with 1 of 3 treatments (non-, micro-, and invasive treatment) initiated at different cutoffs (treating all or only dentinal lesions) in populations with low or high caries prevalence. A Markov model was constructed to follow an occlusal surface in a permanent molar in an initially 12-y-old male German patient over his lifetime. Prevalence data and transition probabilities were extracted from the literature, while validity parameters of different methods were synthesized or obtained from systematic reviews. Microsimulations were performed to analyze the model, assuming a German health care setting and a mixed public-private payer perspective. Radiographic and fluorescence-based methods led to more overtreatments, especially in populations with low prevalence. For the latter, combining visual-tactile or radiographic detection with microinvasive treatment retained teeth longest (mean 66 y) at lowest costs (329 and 332 Euro, respectively), while combining radiographic or fluorescence-based detections with invasive treatment was the least cost-effective (<60 y, >700 Euro). In populations with high prevalence, combining radiographic detection with microinvasive treatment was most cost-effective (63 y, 528 Euro), while sensitive detection methods combined with invasive treatments were again the least cost-effective (<59 y, >690 Euro). The suitability of detection methods differed significantly between populations, and the cost-effectiveness was greatly influenced by the treatment initiated after lesion detection. The accuracy of a detection method relative to a “gold standard” did not automatically convey into better health or reduced costs. Detection methods should be evaluated not only against their criterion validity but also the long-term effects resulting from their use in different populations.

Comparison of sealant and infiltrant penetration into pit and fissure caries lesions in vitro

OBJECTIVESnThe aim of this in vitro study was to evaluate the penetration of an infiltrant and a sealant, when applied as recommended, into fissure caries lesions.nnnMETHODSnThe fissure systems of extracted human teeth were classified according to the international caries detection and assessment system (ICDAS, codes: 0, 1, 2). Within each ICDAS-code ten teeth were either etched with 37% H3PO4-gel for 60s and subsequently sealed (Fissure Sealing; Helioseal; Ivoclar Vivadent) or etched with 15% HCl-gel for 120s and subsequently infiltrated (Resin Infiltration; Icon; DMG). Additionally, ten teeth with ICDAS-code 2 were etched with 37% H3PO4-gel for 120s and infiltrated (Soft-Etch-Infiltration). Specimens were cut perpendicular to their surfaces, polished, and confocal microscopic images were obtained. Lesion depths (LDmax) and penetration depths (PDmax) were measured and percentage penetration was calculated as PPmax=PDmax/LDmax×100.nnnRESULTSnBaseline LDmax [median (interquartile range)] for ICDAS-code 2 lesions was 1192 (805-1512)μm. In ICDAS-code 2 lesions PPmax was significantly higher for specimens treated with Resin Infiltration [41 (30-78)%] compared to Soft-Etch-Infiltration [11 (0-21)%] or Fissure Sealing [5 (0-9)%] (p<0.05; Mann-Whitney test). PPmax did not differ significantly between groups in ICDAS-code 0 and 1 lesions (p>0.05).nnnCONCLUSIONnThe fissure sealant when applied after etching with H3PO4-gel only penetrates superficially into non-cavitated fissure caries lesions. Penetration of an infiltrant is superior in particular after etching with HCl-gel.nnnCLINICAL SIGNIFICANCEnCompared with sealing, infiltration of fissure caries lesions leads to more deeply infiltrated lesions, which might in turn result in superior abilities to hamper caries progression.

Remineralizing Efficacy of a CPP-ACP Cream on Enamel Caries Lesions in situ

The aim of this double-blind, randomized, cross-over in situ study was to compare the remineralizing effects induced by the application of casein phosphopeptide-stabilized amorphous calcium phosphate complexes (CPP-ACP)-containing cream (without fluoride) after the use of fluoride toothpaste with the prolonged use of fluoride toothpaste on enamel caries lesions in situ. During each of three experimental legs of 4 weeks, 13 participants wore intra-oral mandibular appliances with 8 pre-demineralized bovine enamel specimens in the vestibular flanges mimicking either ‘easily cleanable or ‘proximal surfaces (n = 312). The three randomly allocated treatments were as follows: (1) application of CPP-ACP-containing cream (GC Tooth Mouse, non-fluoride) after the use of fluoride toothpaste (1,400 ppm NaF; TM), (2) prolonged application of fluoride toothpaste (1,400 ppm NaF; positive control, PC) and (3) prolonged application of fluoride-free toothpaste (negative control, NC). Additionally, one of each of the two flanges was brushed twice daily with the respective toothpaste. The differences in integrated mineral loss as assessed by transversal microradiography were calculated between values before and after the in situ period. Changes in mineral loss were analysed for those pairs of subgroups differing in only one of the three factors (intervention, brushing and position). The PC treatment induced a significantly higher mineral gain compared with the TM and NC treatments. No significant differences between TM and NC for both positions were observed. In conclusion, the additional use of a CPP-ACP-containing cream seems to be less efficacious in remineralizing caries lesions than the prolonged application of fluoride toothpaste.