Morphology and root canal configuration of maxillary canines: a systematic review and meta-analysis.

BACKGROUND: This study assessed the internal morphology of maxillary canines (MxC) through a systematic review of existing literature. METHODS: Research articles up to June 2024 were retrieved from five electronic databases (MEDLINE via PubMed, Embase, Scopus, LILACS, and Cochrane). Predefined search terms and keywords were used, and potential studies were identified by cross-referencing and bibliographies of the selected articles reviewed. RESULTS: Two hundred studies were identified, 73 duplicates were removed, 127 records were screened, and 113 were removed after consultation of title and abstract. After full-text consultation and hand searching, finally 22 studies were included. Using the method for describing the root canal configuration (RCC) of Briseño Marroquín et al. (2015) and Vertucci (Ve) (1984), the most frequently reported RCC of MxC were 1-1-1/1 (Ve I, 75.4-100%), 2-2-1/1 (Ve II, 0.1-20%), 1-2-1/1 (Ve III, 0.1-11.6%), 2-2-2/2 (Ve IV, 0.1-0.4%), 1-1-2/2 (Ve V, 0.1-2.4%), 2-1-2/2 (Ve VI, 0.5-1.2%), and 1-2-1/2 (Ve VII, 0.1-0.2%). The meta-analysis of six studies (Europe/Asia) showed that a significantly higher number of RCC of 2-2-1/1 (Ve II) (OR [95%CI] = 1.34 [0.53, 3.41]), 1-2-1/1 (Ve III) (OR [95%CI] = 2.07 [1.01, 4.26]), and 1-1-2/2 (Ve V) (OR [95%CI] = 2.93 [1.07, 8.07]), were observed in males, and 2-2-2/2 (Ve IV) (OR [95%CI] = 0.08 [0.00, 4.00]) in females. No sex differences in the RCC of 1-1-1/1 (Ve I) and 1-2-1/2 (Ve VII) were observed. CONCLUSIONS: Cone beam computed tomography is the most frequently used method for research on the RCC of MxC. Despite the high prevalence of type 1-1-1/1 (Ve I) RCC in MxC, clinicians should remain vigilant for more complex and sex-differentiated patterns in up to 25% of cases to prevent endodontic treatment complications or failures.

Design, development and validation of a questionnaire to assess dentists' knowledge and experience in diagnosing, recording, and managing root caries.

OBJECTIVES: The prevalence of root caries is increasing globally, especially in the elderly population, and even though the number of patients with root caries lesions is augmenting, there are still many discrepancies in how dentists manage this condition. The present study aimed to develop and validate a questionnaire to evaluate how dentists diagnose, record and manage root caries lesions, and to verify the validity and reliability of this questionnaire. MATERIALS AND METHODS: An expert panel developed a self-administered questionnaire survey with three domains: (1) dentists' knowledge on diagnosis, recording, and managing root caries; (2) information about their current general clinical routines; (3) their demographics. The original English [E] version was translated into three different languages (French [F], German [G], Italian [I]), and subsequently back-translated into English by independent dentists. For the validation, 82 dentists (20-22 for each of the translated versions) accepted to answer the questionnaire at two different time-points (with 1-week interval). The data was quality checked. Construct validity, internal reliability, and intra-class correlation (ICC) were assessed. RESULTS: Seventy-seven dentists completed the questionnaire twice [E: 17; F: 19; G: 19; I: 22]. The mean ICC (standard deviation) was 0.98(0.03) for E, 0.90(0.12) for F, 0.98 (0.04) for G, and 0.98 (0.01) for I. Overall, the test-retest reliability was excellent (mean ICC (SD): 0.96 (0.08)). Furthermore, the questionnaire demonstrated good internal reliability (inter-observer reliability; Fleiss kappa: overall:0.27(fair); E:0.30 (fair); F: 0.33(fair); G: 0.33(fair); I: 0.89 (almost perfect)). CONCLUSION: The questionnaire was validated and is suitable to be used in the four languages to assess the knowledge of dentists on diagnosing, recording and managing root caries. CLINICAL SIGNIFICANCE: The present questionnaire was validated and seems to be a good tool to evaluate how dentists diagnose, record, and manage root caries lesions both in its original (English) and its translated (French, German, and Italian) versions.

Short-term efficacy of caries resin infiltration during treatment with orthodontic fixed appliances. A randomized controlled trial.

OBJECTIVES: Objective of this trial was to assess the masking results in initial caries lesions (ICL) that were resin infiltrated during fixed orthodontic treatment in comparison to contralateral teeth that were fluoridated only. TRIAL DESIGN: A randomized, controlled, split-mouth trial. METHODS: Adolescent patients (age range: 12-18 years) with fixed orthodontic appliances who had developed ICL [ICDAS 1 or 2 (International Caries Detection and Assessment System)] during orthodontic treatment were consecutively recruited and randomly assigned to either resin infiltration (Icon) with up to 3 etching procedures (Inf) or to a fluoride varnish (Tiefenfluorid) (FV). Both interventions were performed according to the manufacturer's recommendations. Outcome assessors were blinded to the applied intervention. Primary and secondary outcomes included the evaluation of the appearance of the ICL before (T0) and 1 week after (T1) treatment by digital photographs (ΔE), laser fluorescence readings (DD), and ICDAS scores. BLINDING: Due to the treatment nature neither the operators nor the patients could be blinded. However, outcome assessors and the statistician were blinded. RESULTS: Fifteen patients (9 female) with 60 ICL were included (mean age: 14.6 years). At baseline FV and Inf did not differ significantly in ΔE (median ΔE0,T (25th/75th percentiles):10.7(9.1/20.9): ΔE0,I:13.4(10.3/18.5); P = 0.469), DD (P = 0.867) and ICDAS (P = 0.521). One-week after treatment (T1) ΔE values (P < 0.001), DD values (P < 0.001), and ICDAS scores (P = 0.014) for Inf were significantly reduced, whereas ΔE values (P = 0.125) and ICDAS scores (P = 0.073) for FV remained unchanged. LIMITATION: Natural remineralizing in the standard interventional control group cannot be observed yet, since up to 6 months are needed to naturally remineralize ICL. CONCLUSIONS: Based on our short-term data, resin infiltration effectively masked ICL during treatment with fixed orthodontic appliances. Fluoridation was not able to immediately improve the visual appearance of ICL. Further longer-term assessment should focus not only on the aesthetic outcome, but also on the caries inhibitory effect of resin infiltration during treatment with fixed orthodontic appliances. TRIAL REGISTRATION: German Clinical Trials Register (DRKS-ID: DRKS00011797).

Improved Surface Layer Erosion of Pit and Fissure Caries Lesions in Preparation for Resin Infiltration.

The penetration of a low-viscosity resin (infiltrant) into caries lesions depends on the erosion of the relatively impermeable surface layer (SL) that covers the lesion body. The present study aimed to evaluate the effect of different abrasive pretreatments on erosion of the SL and on penetration of an infiltrant into occlusal caries lesions, simultaneously. Sixty extracted human molars showing International Caries Detection and Assessment System (ICDAS-2) lesions were randomly allocated to 5 groups. A small area of each lesion was covered with resin before etching. Twelve lesions each were etched with either 15% HCl-gel (H120) or 37% H3PO4-gel (P120) for 120 s. Furthermore, the standard 15% HCl-gel or either one of two experimental etchants (HCl-gel or H3PO4-gel, each including abrasives) were applied for either 120 s or 30 s using a brush (surface pressure 150 g) (H30B, P120BA, H30BA). After rinsing and drying, all lesions were infiltrated for 180 s (Icon; DMG). From each tooth sections were prepared and visualized using confocal microscopy. SL of unetched areas and the lesion depth were 33 (23/51) µm and 537 (274/876) µm, respectively, both not differing significantly between groups. H120, H30B, and H30BA showed significantly higher SL reduction compared with P120 or P120BA, but only for H30BA SL was eroded almost completely (p < 0.05; Mann-Whitney test). Compared to other groups, occlusal lesions were significantly more infiltrated in H30BA (p < 0.05; Mann-Whitney test). HCl-gel including abrasives that was rubbed onto the enamel surface with a brush seems to be most effective to erode SLs of caries lesion situated in fissures and enable an almost complete subsequent resin infiltration.

Efficacy of nano-hydroxyapatite on caries prevention-a systematic review and meta-analysis.

INTRODUCTION/OBJECTIVES: The review systematically explored in vivo or in situ studies investigating the efficacy of nano-hydroxyapatite (nHA) to reduce initiation of or to remineralize initial caries lesions. DATA: Prospective controlled (non-)randomized clinical trials investigating the efficacy of a nHA compared to any other (placebo) treatment or untreated/standard control. SOURCES: Three electronic databases (Central Cochrane, PubMed-MEDLINE, Ovid EMBASE) were screened. Outcomes were, e.g., ICDAS score, laser fluorescence, enamel remineralization rate, mineral loss, and lesion depth. No language or time restrictions were applied. Risk of bias and level of evidence were graded using the Risk of Bias 2.0 tool and GRADE profiler. STUDY SELECTION/RESULTS: Five in vivo (and 5 in situ) studies with at least 633 teeth (1031 specimens) being assessed in more than 420 (95) patients were included. No meta-analysis could be performed for in vivo studies due to the high heterogeneity of the study designs and the variety of outcomes. In situ studies indicate that under demineralization conditions, NaF was able to hinder demineralization, whereas nHA did not; simultaneously, nHA did not differ from the fluoride-free control. In contrast, under remineralizing conditions, nHA and NaF show the same remineralizing potential. However, the level of evidence was very low. Furthermore, six studies showed a high risk of bias, and six studies were funded/published by the manufacturers of the tested products. CONCLUSION: The low number of clinical studies, the relatively short follow-up periods, the high risks of bias, and the limiting grade of evidence do not allow for conclusive evidence on the efficacy of nHA. CLINICAL RELEVANCE: No conclusive evidence on the efficacy of nHA could be obtained based on the low number of clinical studies, the relatively short follow-up periods, the high risks of bias, the limiting grade of evidence, and study conditions that do not reflect the everyday conditions.

Effects of the association of high fluoride- and calcium-containing caries-preventive agents with regular or high fluoride toothpaste on enamel: an in vitro study.

OBJECTIVES: The aim of this in vitro study was to compare the caries-preventive effect of various high fluoride- and calcium-containing caries-preventive agents (> 22.000 ppm F- [ppm]) in adjunct to use of regular (1450 ppm) or high (5000 ppm) fluoride toothpaste on sound as well as demineralized enamel. MATERIALS AND METHODS: Bovine enamel specimens (n = 276; 5 mm × 3.5 mm × 3 mm) having one sound surface [ST] and one artificial caries lesion [DT] were randomly allocated to 12 groups. Interventions before pH-cycling were no intervention ([SC1/SC5]), application of varnishes/solutions containing NaF (22,600 ppm; Duraphat [NaF1/NaF5]); NaF + tricalcium phosphate (22,600 ppm; Clinpro White Varnish [TCP1/TCP5]); NaF + CPP-ACP (22,600 ppm; MI Varnish [CPP1/CPP5]); silver diammine fluoride (35,400 ppm; Cariestop 30%[SDF1/SDF5]); and NaF + calcium fluoride (45,200 ppm; Biophat[CaF1/CaF5]). During pH-cycling (28 days, 6 × 120 min demineralization/day) half of the specimens in each group were brushed (10 s; 2 × /day) with either 1,450 (NaF; named, e.g., TCP1) or 5,000 ppm (NaF; e.g., TCP5) dentifrice slurry. Differences in integrated mineral loss (∆∆Z) and lesion depth (∆LD) were calculated between values after initial demineralization and after pH-cycling using transversal microradiography. RESULTS: After pH-cycling, SC1/SC5 showed significantly increased ∆ZDT/LDDT values, indicating further demineralization (p < 0.05; paired t-test). Decreased ∆ZDT values, indicating non-significant remineralization, could only be observed in CaF1/CaF5 (p > 0.05; paired t-test). Additional use of all varnishes/solutions significantly decreased ∆∆ZDT/∆∆ZST and ∆LDDT/∆LDST compared to SC1/SC5 (p < 0.05;ANCOVA). Between 1450 and 5000 ppm dentifrices, a significant difference in ∆∆ZDT/∆∆ZST and ∆LDDT/∆LDST could only be observed for SC1/SC5 (p < 0.05; ANCOVA). CONCLUSION: Under the conditions chosen, all fluoride varnishes/solutions significantly reduced demineralization. Furthermore, a significant dose-response characteristic for fluoride varnishes could be revealed. However, no additional benefit could be observed, when varnishes were combined with high fluoride instead of regular fluoride dentifrices. CLINICAL RELEVANCE: For children and adolescents with high caries risks varnishes containing more than 22,600 ppm should be further investigated, as they offered higher caries-preventive effects in vitro. Furthermore, there seems to be no difference in the demineralization-inhibitory capacity of fluoride varnishes when used in combination with either standard or highly fluoridated dentifrices.

Increasing dental zirconia micro-retentive aspect through ultra-short pulsed laser microstructuring: study on flexural strength and crystal phase characterization.

OBJECTIVES: Although ultra-short pulsed laser (USPL) microstructuring has previously improved zirconia bond-strength, it is yet unclear how different laser-machined surface microstructures and patterns may influence the material's mechanical properties. Therefore, the aim of this study was to assess the flexural strength of zirconia after different USPL settings creating three different geometrical patterns with structures in micrometer scale. METHODS: One hundred sixty zirconia bars (3Y-TZP, 21 × 4 × 2.1 mm) were prepared and randomly divided into five groups (n = 32): no surface treatment (negative control-NC); sandblasting with Al2O3 (SB); and three laser groups irradiated with USPL (Nd:YVO4/1064 nm/2-34 J/cm2/12 ps): crossed-lines (LC), random-hatching (LR), and parallel-waves (LW). Bars were subjected to a four-point flexural test (1 mm/min) and crystal phase content changes were identified by X-ray diffraction. Surface roughness and topography were analyzed through 3D-laser-profilometry and SEM. Data were analyzed with parametric tests for roughness and Weibull for flexural strength (α = 5%). RESULTS: LR (Mean[95%CI]: 852.0 MPa, [809.2-894.7]) was the only group that did not show a significantly different flexural strength than NC (819.8 MPa, [796.6-842.9]), (p > 0.05). All laser groups exhibited higher Weibull moduli than NC and SB, indicating higher reliability and homogeneity of the strength data. An increase of monoclinic phase peak was only observed for SB. CONCLUSION: In conclusion, USPL created predictable, homogeneous, highly reproducible, and accurate surface microstructures on zirconia ceramic. The laser-settings of random-hatching (12 ps pulses) increased 3Y-TZP average surface roughness similarly to SB, while not causing deleterious crystal phase transformation or loss of flexural strength of the material. Furthermore, it has increased the Weibull modulus and consequently material's reliability. CLINICAL SIGNIFICANCE: Picosecond laser microstructuring (LR conditions) of 3Y-TZP ceramic does not decrease its flexural strength, while increasing materials realiability and creating highly reproducible and accurate microstructures. These features may be of interest both for improving clinical survival of zirconia restorations as well as enhancing longevity of zirconia implants.

Demineralization Inhibitory Effects of Highly Concentrated Fluoride Dentifrice and Fluoride Gels/Solutions on Sound Dentin and Artificial Dentin Caries Lesions in vitro.

OBJECTIVES: The aim of this in vitro study was to compare the demineralization inhibitory effect of gels/solutions used in combination with either standard or highly fluoridated dentifrices on sound dentin as well as on artificial dentin caries-like lesions. METHODS: Bovine dentin specimens (n = 240) with two different surfaces each (sound [ST] and artificial caries lesion [DT]) were prepared and randomly allocated to twelve groups. Weekly interventions during pH-cycling (28 days, 6 × 120 min demineralization/day) were: the application of gels/solutions containing amine fluoride/sodium fluoride (12,500 ppm F [ppm]; pH = 4.4; AmF); NaF (12,500 ppm; pH = 6.6; NaF1); NaF (12,500 ppm; pH = 6.3; NaF2); silver diamine fluoride (14,200 ppm; pH = 8.7; SDF); acidulated phosphate fluoride (12,500 ppm; pH = 3.8; APF), and no intervention (standard control; S). Furthermore, half of the specimens in each group were brushed (10 s; twice per day) with dentifrice slurries containing either 1,450 ppm (e.g., AmF1450) or 5,000 ppm (e.g., AmF5000). Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after pH-cycling using transversal microradiography. RESULTS: After pH-cycling Ss showed significantly increased ΔZDT and LDDT values, indicating further demineralization. In contrast, except for one, all groups including fluoride gels/solutions showed significantly decreased ΔZDT values. Additional use of most fluoride gels/solutions significantly enhanced mineral gain, mainly in the surface area; however, acidic gels/solutions seemed to have negative effects on lesion depths. SIGNIFICANCE: Under the present pH-cycling conditions the highly fluoridated dentifrice significantly reduced caries progression and additional application of nearly all of the fluoride gels/solutions resulted in remineralization. However, there was no difference in the remineralizing capacity of fluoride gels/solutions when used in combination with either standard or highly fluoridated dentifrices.

Do bleaching gels affect the stability of the masking and caries-arresting effects of caries infiltration-in vitro.

OBJECTIVES: The aim of this study was to evaluate the influence of different bleaching gels on the masking and caries-arresting effects of infiltrated and non-infiltrated stained artificial enamel caries lesions. MATERIALS AND METHODS: Bovine enamel specimens (n = 240) with each two sound areas (SI and SC) and each two lesions (DI and DC) were infiltrated (DI and SI), stained (1:1 red wine-coffee mixture,70 days), and randomly distributed in six groups to be bleached with the following materials: 6%HP (HP-6), 16%CP (CP-16), 35%HP (HP-35), 40%HP (HP-40), and no bleaching (NBl,NBl-NBr). Subsequently, specimens were pH-cycled (28 days, 6 × 60 min demineralization/day) and all groups except NBl-NBr were brushed with toothpaste slurry (1.100 ppm, 2×/day, 10 s). Differences in colorimetric values (ΔL, ΔE) and integrated mineral loss (ΔΔZ) between baseline, infiltration, staining, bleaching, and pH cycling were calculated using photographic and transversal microradiographic images. RESULTS: At baseline, significant visible color differences between DI and SC were observed (ΔEbaseline = 12.2; p < 0.001; ANCOVA). After infiltration, these differences decreased significantly (ΔEinfiltration = 3.8; p < 0.001). Staining decreased and bleaching increased ΔL values significantly (p ≤ 0.001). No significant difference in ΔΔE was observed between before staining and after bleaching (ΔEbleaching = 4.3; p = 0.308) and between the bleaching agents (p = 1.000; ANCOVA). pH-cycling did not affect colorimetric values (ΔEpH-cycling = 4.0; p = 1.000). For DI, no significant change in ΔZ during in vitro period was observed (p ≥ 0.063; paired t test). CONCLUSIONS: Under the conditions chosen, the tested materials could satisfactorily bleach infiltrated and non-infiltrated stained enamel. Furthermore, bleaching did not affect the caries-arresting effect of the infiltration. CLINICAL RELEVANCE: The present study indicates that bleaching is a viable way to satisfactorily recover the appearance of discolored sound enamel and infiltrated lesions.

Long-term costs of post-restorations: 7-year practice-based results from Germany.

OBJECTIVES: We evaluated the initial and follow-up treatment costs of different post-restorations in a practice-based German healthcare setting. METHODS: A total of 139 incisors, canines, or premolars received post-restorations placed by eight general dental practitioners in Germany, and were followed over a mean ± SD 7.1 ± 4.5 years. Preformed metal (MP, n = 68), glass-fiber (GF, n = 28), or cast post-and-core buildups (MC, n = 23) had been used to retain crowns or bridge anchors. Preformed metal and glass-fiber had also been used to retain directly built up post-retained composite restorations (PC, n = 20). Material and treatment costs for the initial post-restorations as well as restorative, endodontic, or surgical re-treatments were estimated from a public-payer-perspective in Germany. Associations between total and annualized total costs and covariates were assessed using generalized linear modeling. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00012938). RESULTS: MC showed highest initial treatment costs (557.23 Euro), but the least re-treatments (6/23, 26%), while PC showed lowest initial costs (203.52 Euro) but the most re-treatments (11/20, 55%). Costs for MP/GF post-crowns were initially similarly costly (496.47/496.87 Euro), and both also showed similar re-treatments (35%/36%). The overall annual failure rate was 5.2% (MC: 3.5%, MP: 4.6%, GF: 5.3%, PC: 10.3%). Including costs for the resulting re-treatments, mean total costs were 591.66 Euro (MC), 548.31 Euro (MP), 526.37 Euro (GF), and 361.81 Euro (PC). Annualized total costs were 171.36 Euro (MC), 141.75 Euro (MP), 146.12 Euro (GF), and 135.65 Euro (PC). Total and annualized total costs were highest for MC, with PC being the significantly less costly option (p < 0.001). CONCLUSIONS: Within German healthcare, both initial and follow-up costs for post-restorations were considerable. Saving costs initially may, at least partially, be offset by more complications long-term. CLINICAL RELEVANCE: Dentists need to be aware that the placement of posts is not only initially costly but also comes with significant long-term costs for treating occurring complications. This should be communicated with patients and considered during treatment planning.

Analysis of relative bacterial activity and lactate dehydrogenase gene expression of caries-associated bacteria in a site-specific natural biofilm: an ex vivo study.

OBJECTIVES: Detecting bacterial activity is considered a promising approach to monitor shifts from symbiosis to dysbiosis in oral microbiome. The present study aimed at investigating both the relative bacterial activity and the lactate dehydrogenase (ldh) gene expression of caries-associated bacteria in a site-specific natural biofilm. MATERIAL AND METHODS: Sixty subjects (age, mean ± SE: 30.1 ± 1.4) were allocated to two groups: caries-free subjects (CF) or caries-active subjects (CA). CF presented one sound surface (CFS, n = 30). CA presented two donor sites: a cavitated caries lesion (CAC, n = 30) and a sound reference surface (CAS, n = 30). Real-time quantitative PCR (q-PCR) on species or genus level and total bacteria was performed targeting the 16S gene, the 16S rRNA, the ldh gene, and the ldh mRNA (increasing 16S ribosomal RNA copy numbers can function as an indicator of increased energy metabolism). As the 16S rRNA abundance represents the number of ribosomes, while the 16S gene abundance represents the number of genomes, the quotient of the relative abundances functions as a measure for the relative bacterial activity (%). RESULTS: Both lactobacilli and S. mutans showed the highest relative bacterial activity in CAC ((mean ± SE) 218 ± 60% and 61 ± 16%, respectively) and the lowest values for both sound reference surfaces (69 ± 48%; 8 ± 3%). Significant differences were found between CAC and CAS as well as between CAC and CFS for both lactobacilli and S. mutans (p < 0.05). The ldh gene expression of lactobacilli and S. mutans only showed moderate values in CAC (1.90E+03 ± 2.11E+03; 2.08E+04 ± 4.44E+04 transcripts/µl) and CFS (2.04E+03 ± 2.74E+03; 8.16E+03 ± 6.64E+03 transcripts/µl); consequently no significant differences were detected. CONCLUSION AND CLINICAL RELEVANCE: Caries-associated bacteria (lactobacilli and S. mutans) showed the highest relative bacterial activity in plaque of cavitated lesions, the lowest in sound surfaces, allowing the detection of a significant activity shift in health and disease for caries-active patients. However, no significant differences in ldh gene expression could be determined.

Effect of NaF, AmF, KF gels and NaF toothpaste combined with a saliva substitute on dentin lesions in vitro.

OBJECTIVE: The aim of the present in vitro study was to evaluate the remineralizing effects of NaF, AmF, KF gels and NaF toothpaste in combination with a potentially demineralizing saliva substitute (Glandosane; pH = 5.1) being widely used in Germany. METHODS: In each of 120 dentin specimens, three artificial lesions were created. One lesion was covered for analysis of pre-demineralization (ΔZB). Treatments during pH cycling (3 × 1 h demineralization/day [pH = 5.0] and 3 × 3 h Glandosane/day; 12 h 100%humidity) were as follows: no treatment (NT), application (5 min,2×/day) of 12.500 ppm F- [pH = 6.04] (NaF-gel1), 12.500 ppm F- [pH = 7.34] (NaF-gel2), 12.500 ppm F- [pH = 5.82] (AmF-gel), 1450 ppm F- [pH = 7.35] (KF-gel), and 5000 ppm F- [pH = 8.14]; (NaF-TP) for 7 days (E1). Subsequently, from each specimen, one lesion was covered, while the remaining lesion was cycled for another 7 days (E2). Differences in integrated mineral loss (ΔΔZE1/ΔΔZE2) were calculated between values before and after pH cycling. RESULTS: Mean (95%CI) ΔZB was 3851 (3762;3939) vol% × µm. Except for NaF-gel2 and NaF-TP, specimens of all other groups further demineralized. Only NaF-gel2 induced a significant gain in mineral content (p ≤ 0.004; paired t test). Significant differences in the change of mineral loss were found between NT and all fluoride groups for both ΔΔZE1 and for ΔΔZE2 (p < 0.05, Bonferroni post hoc test). However, only NaF-gel2 and NaF-TP induced remineralization. CONCLUSION: Under the in vitro conditions chosen, all fluoride agents could significantly hamper the adverse effects of a demineralizing saliva substitute. CLINICAL SIGNIFICANCE: In combination with a demineralizing saliva substitute, slight mineral gain was only observed for neutral NaF-gel2 and 5000 ppm F- toothpaste.

Morphology and root canal configuration of maxillary lateral incisors: a systematic review and meta-analysis.

The purpose of this study was to explore maxillary lateral incisors (MxLI) intern morphology by analyzing existing literature. We searched five electronical databases (Cochrane, Embase, LILACS, Scopus, MEDLINE via PubMed) using keywords and predefined search terms. Additional studies were identified by cross-referencing and reviewing bibliographies of relevant articles. From 92 initial studies, 27 duplicates were removed, and 65 records screened. After full-text review and hand searching were 19 studies included. The most reported root canal configurations (RCC) of MxLI were Vertucci (Ve) I (1-1-1/1; 78.1-100%), Ve II (2-2-1/1; 0.2-5%), Ve III (1-2-1/1; 0.1-14.6%), Ve IV (2-2-2/2; 0.5%), and Ve V (1-1-2/2; 0.5-4.9%). A meta-analysis of six studies from Europe and Asia indicated sex-differentiated patterns in RCC prevalence: higher occurrences of Ve II (2-2-1/1; OR [95%CI] = 1.19 [0.51, 2.73]), Ve III (1-2-1/1; (OR [95%CI] = 1.72 [0.61, 4.85]), and Ve V (1-1-2/2; (OR [95%CI] = 2.95 [1.02, 8.55]) configurations were noted in males, whereas females predominantly exhibited Ve I (1-1-1/1; [95%CI] = 0.99 [0.97, 1.02]), and Ve IV (2-2-2/2; (OR [95%CI] = 0.11 [0.01, 2.02]). Examination methods varied, with cone beam computed tomography (CBCT) being most commonly (n = 11), followed by staining & clearing (n = 5), and radiographic analysis (n = 1). The predominant RCC in MxLI is type Vertucci I. CBCT is the most common method for assessing the morphology of root canals. However, up to 20% of cases may present with complex and sex-specific patterns, highlighting the need for clinicians to be aware of these differences to prevent complications during endodontic treatments.

Diagnosing and recording root caries: A survey among Swiss dentists.

OBJECTIVES: Despite the increase in the root caries prevalence, little is still known about how dentists manage this condition. The present study aimed to evaluate the knowledge of dentists on diagnosing and recording root caries lesions (RCL). METHODS: The survey consisted of three domains: (1) dentists' knowledge on diagnosing, recording and managing RCL; (2) information about their current general clinical routines; and (3) their demographics. The four Swiss Universities distributed the survey via e-mail lists for alumni or professionals participating in continuing education. The data was quality checked. Construct validity, internal reliability and intraclass correlation (ICC) were assessed. RESULTS: The survey was answered by 383 dentists from 25(out of 26) cantons [mean(SD) working experience: 22.5(12) years]. The majority replied that they see less than 5 patients with RCL per week, whereas 41 have at least 5 per week, and 40 % (157 dentists) do not distinguish RCL from coronal caries in their patients' medical records. When diagnosing active RCL, tactile sensation was the most predominant criterion (n = 380), whereas color (n = 224) and visual appearance (n = 129) of the lesion were less often selected. The most often chosen risk factors for RCL were poor oral hygiene and presence of biofilm.The responses were significantly influenced by the participants' place of education, their age and working area. CONCLUSION: The present survey highlights the huge diversity in diagnosing, recording and assessing risk factors of RCL. The benefits of an appropriate diagnosis, recording and management of risk factors of RCL should be highlighted in under- and postgraduate dental education. CLINICAL SIGNIFICANCE: A great diversity in diagnosing, recording and assessing risk factors of RCL was observed, which migh strongly impact how dentists manage RCL. The study emphasizes the necessity for intensive efforts to bridge the gap between guideline recommendations and their implementation in private dental practices.

Decision making and management of root caries: A practice-based survey.

OBJECTIVES: With increasing life expectancy and improved preventive measures, teeth are retained longer, leading to a rise in prevalence of root caries lesions (RCL). However, little is known about how dentists manage this condition. The present survey aimed to evaluate the knowledge of Swiss dentists on decision making and management of RCL. METHOD: The survey evaluated dentists' knowledge, clinical routines, and demographics concerning RCL. Dentists were contacted via email and local newsletters, and 383 dentists from 25 (out of 26) cantons responded. Mann-Whitney U test, χ2 test, intraclass correlation coefficients, Spearman correlation and Chi Square were used. RESULTS: The dentists had a mean(SD) working experience of 22.5(12) years. Most dentists correctly classified an inactive (67%) and an active (81%)RCL. Although the inactive lesion did not call for restorative treatments, 61% of the dentist declared they would restore it. From the active lesion,83% would restore it. The invasive treatments leaned toward complete caries excavation with composite resin as preferred restorative material. There were significant correlations between material choice and expected success rates. Among the non-invasive options, oral hygiene instructions and (highly-)fluoridated toothpaste were favored. Most dentists declared having a recall system for such patients, with biannual follow-ups preferred. The dentists' place of education significantly influenced restorative decisions (p < 0.001), while participants' age (≥60years) impacted activity status (p = 0.048) and restorative decisions (p = 0.02). CONCLUSION: Material preferences for non-invasive or invasive management varied greatly and there were minimal differences in the management of inactive or an active RCL. Moreover, diagnosing active lesions appeared easier than diagnosing inactive ones. CLINICAL SIGNIFICANCE: Despite diverse material preferences for (non-)invasive treatments, a strong positive correlation existed between the chosen restorative material and its expected 2-year success rate. Moreover, diagnosing active lesions appeared easier than diagnosing inactive ones. The outcome emphasis the need to align guideline recommendations with their application in private dental practices.

Effects of Hydroxyapatite-Containing Toothpastes on Some Caries-Related Variables: A Randomised Clinical Trial.

OBJECTIVES: This randomised clinical trial was designed and carried out with the aim to evaluate the capacity of fluoride-substituted hydroxyapatite (HAF) toothpaste to modulate oral microflora composition and biofilm acidogenicity in schoolchildren. METHODS: In all, 610 children (4 to 5 and 6 to 7 years) were enrolled. Four toothpastes were randomly administered during 24 months: 2 contained fluoride-substituted hydroxyapatite (HAF1000 and HAF1450; 1000 and 1450 ppmF) and magnesium-, strontium-, and carbonate-substituted hydroxyapatite in a chitosan matrix, and 2 were monofluorophosphate fluoridated toothpastes (F1000 and F1450; 1000 and 1450 ppmF). Caries lesions were assessed by International Caries Detection and Assessment System scores, supragingival plaque was sampled from the approximal sites between primary molars using sterile Gracey curettes for microbiological analysis, and plaque pH curves after sucrose challenge were assessed at baseline and reevaluated after 1 year and after 2 years. The minimum and maximum pH decrease was calculated for caries-free patients and participants with a caries lesion(s) at baseline and at the end of the experimental period (24 months). Differences amongst measurements were analysed with 1-way analysis of variance. RESULTS: During the trial, the minimum pH value increased statistically significantly in all groups; in HAF1000 and HAF1450, the increase was greatest. At the end of trial, in the 2 HAF groups all primary cariogenic bacteria were statistically significantly lower with respect to F groups (P = .03 for Streptococcus mutans and sobrinus, for Lactobacillus casei, and for Lactobacillus fermentum). CONCLUSIONS: The trial provides robust but still inconclusive evidence on the efficacy of HAF toothpastes compared to traditional fluoridated toothpastes to reduce caries risk factors and to prevent caries lesions.

Longevity of posterior direct versus indirect composite restorations: A systematic review and meta-analysis.

OBJECTIVES: The goal of this systemic review and meta-analysis was to compare the longevity of direct and indirect composite restorations in posterior teeth. DATA: Randomized controlled trials (RCT) investigating direct and indirect composite restorations in permanent posterior teeth. SOURCES: Three electronic databases (PubMed, CENTRAL (Cochrane) and Embase) were screened. No language or time restrictions were applied. Study selection, data extraction and quality assessment were done in duplicate. Risk of bias and level of evidence was graded using Risk of Bias 2.0 tool and Grade Profiler 3.6. RESULTS: A total of 3056 articles were found by electronic databases. Finally, five RCTs were selected. Overall, 627 restorations of which 323 were direct and 304 indirect composite restorations have been placed in 279 patients (age: 28-81 years). The highest annual failure rates (AFR) were found for indirect restorations ranging from 0 % to 15.5 %. Lower AFR were found for direct restorations ranging from 0 % to 5.4 %. The most frequent failures were found to be chipping and fracture of the restoration followed by caries. Meta-analysis revealed that the failure rate for direct restorations was significantly lower than for indirect restorations (Risk Ratio (RR) [95 %CI] = 0.61 [0.47; 0.79]; very low level of evidence). Furthermore, all studies showed a high risk of bias. CONCLUSION: Direct and indirect composite restorations can be recommended for large class II cavities including cusp coverage in posterior teeth for single tooth restoration. Meta-analysis revealed significantly lower relative risk to fail for direct composite restorations than for indirect restorations but results are with high risk of basis.

Masking-efficacy and caries arrestment after resin infiltration or fluoridation of initial caries lesions in adolescents during orthodontic treatment-A randomised controlled trial.

OBJECTIVES: The aim of this randomised, controlled, split-mouth trial was to assess the masking results in initial caries lesions (ICL) that were either resin infiltrated or fluoridated during treatment with fixed orthodontic appliances. METHODS: Adolescent patients (age range:12-18years) with fixed orthodontic appliances who had developed ICL [ICDAS 1 or 2 (International Caries Detection and Assessment System)] during orthodontic treatment were consecutively recruited and randomly assigned to either resin infiltration with up to 3 etching procedures (Group:Inf) or to 3-monthly application of a fluoride varnish (Group:FV). Both interventions were performed according to the manufacturer's recommendations. Primary and secondary outcomes (ΔE, ICDAS, DIAGNOdent) included the evaluation of the appearance of the ICL before (T0), 1 week after (T1) treatment and at the last appointment before debonding (T2). RESULTS: Fifteen patients (8females, 7males) with 57ICL were included. Mean (SD) observation time at the last appointment before debonding was 0.5 (0.3) years. At T0 FV and Inf did not differ significantly in ΔE (median ΔE0,FV(25th/75th percentiles):11.6 (8.7/20.3): ΔE0,Inf:15.1 (11.4/19.5); pT0 = 0.135), ICDAS (pT0 = 0.920) and DD (pT0 = 0.367). At T1 and T2 ΔE values (pT1<0.001, pT2<0.001), ICDAS scores (pT1<0.001, pT2<0.001) and DIAGNOdent values (pT1 = <0.001, pT2 = <0.001) for Inf were significantly reduced whereas ΔE values (pT1 = 0.382, pT2 = 0.072) and ICDAS scores (pT1 = 0.268, pT2<0.001) for FV remained unchanged. CONCLUSIONS: Resin infiltration effectively masked ICL during treatment with fixed orthodontic appliances both immediately after application and at the last appointment before debonding. Furthermore, the visual appearance of fluoridated lesions was not as satisfactory as that of the infiltrated ones at both T1 and T2. CLINICAL SIGNIFICANCE: Resin infiltration effectively masked ICL during treatment with fixed orthodontic appliances both immediately after application and at the last appointment before debonding. Furthermore, the visual appearance of fluoridated lesions was not as satisfactory as that of the infiltrated ones immediately after first application as well as half a year after application. TRIAL REGISTRATION: German Clinical Trials Register (DRKS-ID: DRKS00011797).

Aesthetic caries infiltration - Long-term masking efficacy after 6 years.

OBJECTIVES: This study aimed to evaluate the masking efficacy of caries infiltration technique of initial caries lesions (ICL) six years after debonding and single treatment. METHODS: In 10 adolescents, 74 ICL (ICDAS 2) in 74 teeth were treated by resin infiltration (Icon, DMG) at a mean (SD) of 1.2 (1.2) months after bracket removal. The etching procedure was performed up to 3 times. Standardized digital images were taken before treatment (T0), seven days (T7) and 6 years (T2190) after treatment. Outcomes included the evaluation of the color differences between carious and healthy enamel at T0, T7 and T2190 by quantitative colorimetric analysis (ΔE), ICDAS scores, quantitative light-induced fluorescence (QLF; ΔF,ΔQ,WS Area) and qualitative visual evaluation (5-point Likert-scale [deteriorated (1), unchanged (2), improved, but not satisfying (3), improved and no further treatment required (4), completely masked (5)). RESULTS: The median color difference ΔΕ0 (25th/75th percentiles) at T0 was 10.3 (8.56/13.0). At T7 a significant decrease was observed (ΔΕ7=3.7 (2.0/5.8); p<0.001; Friedmann-test; ICDAS p<0.001; Chi-square test). No significant changes based on ΔΕ (p=0.972; Friedmann-test) and ICDAS grading (p=0.511, chi-square test) were observed between T7 and T2190 (ΔΕ2190=2.9 (1.8/4.2)). Furthermore, at T2190 four experienced dentists classified 50% and 37% of the lesions as "improved and no further treatment required" and "completely masked", respectively (Fleiss kappa: T2190: 0.782 (substantial agreement)). CONCLUSION: Aesthetic caries infiltration can effectively mask post-orthodontic initial caries lesions for at least 6 years. These results for most of the teeth could not only be observed by quantitative but also by qualitative analysis. CLINICAL SIGNIFICANCE: Resin infiltration efficaciously masks post-orthodontic initial carious lesions. The optical improvement can be observed directly after treatment and remains stable for at least six years.

Posterior ceramic versus metal restorations: A systematic review and meta-analysis.

OBJECTIVES: The goal of this systemic review and meta-analysis was to evaluate the longevity of indirect adhesively-luted ceramic compared to conventionally cemented metal single tooth restorations. DATA: Randomized controlled trials (RCT) investigating indirect adhesively-luted ceramic restorations compared to metal or metal-based cemented restorations in permanent posterior teeth. SOURCES: Three electronic databases (PubMed, CENTRAL (Cochrane) and Embase) were screened. No language or time restrictions were applied. Study selection, data extraction and quality assessment were done in duplicate. Risk of Bias and level of evidence was graded using Risk of Bias 2.0 tool and Grade Profiler 3.6. RESULTS: A total of 3056 articles were found by electronic databases. Finally, four RCTs were selected. Overall, 443 restorations of which 212 were adhesively-luted ceramic restorations and 231 conventionally cemented metal restorations have been placed in 314 patients (age: 22-72 years). The highest annual failure rates were found for ceramic restorations ranging from 2.1% to 5.6%. Lower annual failure rates were found for metal (gold) restorations ranging from 0% to 2.1%. Meta-analysis could be performed for adhesively-luted ceramic vs. conventionally cemented metal restorations. Conventionally cemented metal restoration showed a significantly lower failure rate than adhesively-luted ceramic ones (visual-tactile assessment: Risk Ratio (RR)[95%CI]=0.31[0.16,0.57], low level of evidence). Furthermore, all studies showed a high risk of bias. CONCLUSION: Conventionally cemented metal restorations revealed significantly lower failure rates compared to adhesively-luted ceramic ones, although the selected sample was small and with medium follow-up periods with high risks of bias.