Application of a standard autoclaving protocol does not harm structural integrity of two-piece zirconia abutments under detachment force testing.

OBJECTIVE: Aim was to assess the influence of a standard autoclaving protocol on the retention of zirconia abutments glued on titanium bases in two-piece implant abutments. MATERIALS AND METHODS: Twenty-four CAD/CAM-generated zirconia abutments were adhesively cemented on prefabricated titanium bases. Before mechanical and thermal aging, the specimens were divided into two groups. Group 1 was subjected to a standard steam autoclaving protocol and Group 2 remained untreated (control). The tensile strength in all specimens was evaluated by a standardized pull-off test limited to a maximum force of 1000 N. RESULTS: Eleven samples in both groups could be subjected to pull-off testing. Ten samples in Group 1 and three samples in Group 2 failed, while all others reached the maximum pull-off force. This difference was statistically significant. The mean retention values for the failed samples were 694.53 ± 369.10 N in Group 1 and 890.78 ± 25.90 N in Group 2. This difference was not statistically significant. CONCLUSIONS: A standard autoclaving protocol does not reduce detachment force of two-piece zirconia abutments. CLINICAL RELEVANCE: Clinical sterilization processes as recommended by regulatory authorities seem to be harmless to the structural integrity of two-piece zirconia implant abutments, at least with regard to the retention of the components.

Development of an analytical prepCheck-supported approach to evaluate tutor-based assessments of dental students' practical skills.

The aim of the present study was to develop an analytical computer-supported assessment concept for the objective evaluation of students' practical skills, and to investigate the assessor-dependent differences by setting tolerance limits applied during the 'glance and grade' evaluation. A sample of 54 conventionally supervised dental undergraduates were given training in the preparation of a macroretentive Class II cavity. The course participants then took a mandatory practical examination. Three (plus one) course instructors performed the visual evaluations of the examination tasks according to predefined assessment criteria, followed by optical impressions (quadrant scan using Omnicam; Cerec; Dentsply Sirona, Wals, Austria) and subsequent assessment of the prepared cavities (tooth 46) using the prepCheck application (Dentsply Sirona). In this course, the maximum permissible deviation was set at ± 10% from the predefined assessment criteria. If no tolerance was applied, the statistical analysis revealed a significant difference between the actually achieved cavity dimensions and the predefined values of a master preparation (P = 0.0001; Student's t-test), thus leading to an overall failure rate of 100%. The application of the initially targeted 10% tolerance led to an insignificant reduction (96.3%), while the stepwise elevation of the permissible deviation up to 35% finally matched with the result of the visual assessment (total failure rate of approximately 20%). Unlike the pronounced subjectivity of the tutors during the assessment of students' practical skills, the utilization of the prepCheck application enables precise evaluations. Further studies are clearly warranted to investigate the possible educational outcome of an advanced interactive computer-supported training with implemented tolerance corridors.

Tridimensional surface roughness analysis after resin infiltration of (deproteinized) natural subsurface carious lesions.

OBJECTIVES: The objectives of this study were to evaluate ex vivo the effects of resin infiltration on the areal surface roughness of natural non-cavitated proximal subsurface lesions with or without previous deproteinization and to determine differences between E2 and D1 lesions or between premolars and molars. MATERIALS AND METHODS: Forty premolars and 40 molars with proximal carious lesions and macroscopically intact surfaces (International Caries Detection and Assessment System (ICDAS) II; code 2) were radiologically assessed and randomly allocated to four groups (with 20 E2 and 20 D1 lesions, respectively). In each group, 10 lesions were deproteinized (NaOCl; 1%) before etching (HCl; 15%) and resin infiltration (Icon). Areal surface roughness (Sa) at the most demineralized lesion part (DIAGNOdent) was evaluated topometrically before and after deproteinization, after etching, and after infiltration using focus variation 3D scanning microscopy. RESULTS: Pretreatment with NaOCl (n = 40) had no significant effects on Sa (p = 0.208), but resulted in significantly differing Sa values between premolars and molars after etching (p = 0.011). Regarding the effects between etching and baseline, significantly differing Sa values (p = 0.0498) were found for premolars and molars (n = 40/40); Sa after resin infiltration (compared to etching) differed significantly between premolars and molars (p = 0.009). No treatment regimen lead to differences among the radiological grades (E2 vs. D1; p > 0.106). CONCLUSIONS: Resin infiltration showed only minor effects on Sa values of etched subsurface lesions (p < 0.170) and did neither equal nor improve baseline surface roughness (p > 0.401) of the different tooth types. CLINICAL RELEVANCE: Deproteinization should be recommended before etching and infiltration, even if surface roughness of infiltrated advanced (pre-)molar lesions will not be improved.

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

OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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. CLINICAL RELEVANCE: 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.

Equivalence study of the resin-dentine interface of internal tunnel restorations when using an enamel infiltrant resin with ethanol-wet dentine bonding.

This preregistered ex vivo investigation examined the dentinal hybrid layer formation of a resinous infiltrant (Icon), with reference to both thickness (HLT) and homogeneity when combined with modified tunnel preparation (occlusal cavity only) and internal/external caries infiltration. The adhesives Syntac and Scotchbond MP were used as controls (Groups 1 and 3) or in combination with Icon (Groups 2 and 4). A split-tooth design using healthy third molars from 20 donors resulted in 20 prepared dentine cavities per experimental group. The cavity surfaces (n = 80) were etched (37% H3PO4), rinsed, and air-dried. Rewetting with ethanol was followed by application of the respective primers. After labeling with fluorescent dyes, either Syntac Adhesive/Heliobond or Scotchbond MP Adhesive was used alone or supplemented with Icon. HLT, as evaluated by scanning electron microscopy, did not significantly differ (P > 0.05), and confocal laser scanning microscopy revealed homogeneously mixed/polymerized resin-dentine interdiffusion zones in all groups. Icon can be successfully integrated into an ethanol-wet dentine bonding strategy, and will result in compact and homogeneous hybrid layers of comparable thickness considered equivalent to the non-Icon controls, thus allowing for preservation of the tooth's marginal ridge and interdental space in the case of internal/external infiltration of proximal caries.

Prospective case series study on the survival rates of occlusal polymethyl methacrylate veneers as a semipermanent therapy in patients with severe pathologic tooth wear.

OBJECTIVES: To evaluate the survival rate of minimally invasive semipermanent occlusal polymethylmethacrylate (PMMA) onlays/veneers in previous temporomandibular disorder (TMD) patients with severe tooth wear and with a loss of vertical dimension after up to 7 years. METHOD AND MATERIALS: This case series was designed as a follow-up evaluation with consecutive patient recruitment. All patients bearing the indication for this kind of rehabilitation were treated by the same clinician using the same adhesive methodology. The study included 22 patients (3 males/19 females), with a mean [SD] age of 50.7 [11.6] years. Controls followed within the first 4 weeks (and subsequently as required). Failure criteria included damage by fracture, chipping, and retention loss. Survival rates were determined based on the Kaplan-Meier analysis. RESULTS: 328 semipermanent occlusal/incisal veneers were included (142 maxillary/186 mandibular teeth). Almost 80% of the restorations were in place and in function when starting the follow-up treatment after 180 days; failures predominantly occurred within the first 3 to 6 months but proved reparable. Depending on the patients' priorities, scheduled replacements followed successively, and more than 65% did not show repair or any renewal needs for more than 360 days. CONCLUSION: Within the limitations of this study the survival rates of occlusal veneers made of PMMA were sufficiently high to allow for consecutive treatment of the respective teeth by means of permanent restorations while preserving the restored vertical dimension. In patients with severe tooth wear and a TMD history, semipermanent restorative therapy with occlusal PMMA onlays/veneers would seem a noteworthy option.

A Systematic Review and Meta-Analysis on the Efficacy of Locally Delivered Adjunctive Curcumin (Curcuma longa L.) in the Treatment of Periodontitis.

This meta-analysis intended to assess evidence on the efficacy of locally delivered curcumin/turmeric as an adjunctive to scaling and root planing (SRP), on clinical attachment level (CAL) and probing pocket depth (PPD), compared to SRP alone or in combination with chlorhexidine (CHX). RCTs were identified from PubMed, Cochrane Library, BASE, LIVIVO, Dentistry Oral Sciences Source, MEDLINE Complete, Scopus, ClinicalTrials.gov, and eLibrary, until August 2022. The risk of bias (RoB) was assessed with the Cochrane Risk of Bias tool 2.0. A random-effects meta-analysis was performed by pooling mean differences with 95% confidence intervals. Out of 827 references yielded by the search, 23 trials meeting the eligibility criteria were included. The meta-analysis revealed that SRP and curcumin/turmeric application were statistically significantly different compared to SRP alone for CAL (-0.33 mm; p = 0.03; 95% CI -0.54 to -0.11; I2 = 62.3%), and for PPD (-0.47 mm; p = 0.024; 95% CI -0.88 to -0.06; I2 = 95.5%); however, this difference was considered clinically meaningless. No significant differences were obtained between patients treated with SRP and CHX, compared to SRP and curcumin/turmeric. The RoB assessment revealed numerous inaccuracies, thus raising concerns about previous overestimates of potential treatment effects.

A blind randomized controlled pilot trial on recombinant human bone morphogenetic protein-2 in combination with a bioresorbable membrane on periodontal regeneration in mandibular molar furcation defects.

OBJECTIVES: In preparation of a definitive randomized clinical trial (RCT), the current parallel-grouped triple-blind pilot RCT assessed the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) with polylactic acid/polyglycolic acid (PLA/PGA) membrane for improvement of periodontal tissue regeneration in Class II furcation type defects. METHOD AND MATERIALS: With the present single-center investigation, 24 patients/24 mandibular molars revealing Class II furcation lesions with involved buccal surfaces were randomly allocated and treated surgically, using either a PLA/PGA membrane alone (control, n = 12) or in combination with rhBMP-2 (n = 12). Assessors, participants, and the statistician were blinded to the treatment groups. Clinical parameters including Plaque Index (PI), Papillary Bleeding Index (PBI), clinical attachment level, vertical probing depth, horizontal probing depth, and gingival recession were assessed at baseline and 6 months postsurgery. RESULTS: Baseline values concerning the investigated parameters were comparable between both groups (P > .05). After 6 months, clinical attachment level gain was similar (P = .76), while greater reductions in vertical probing depth (P = .01) and horizontal probing depth (P = .05), along with less gingival recession (P = .03) were observed in the PLA/PGA + rhBMP-2 group (compared to the controls). An increased number of completely closed furcation type defects was observed in the PLA/PGA + rhBMP-2 group (with no adverse effects). CONCLUSIONS: When treating Class II furcation lesions, the use of rhBMP-2 (combined with PLA/PGA membranes) seems advantageous. The presented set-up seems feasible with regards to recruitment, randomization, acceptance, retention, and adherence to the study protocol. (Quintessence Int 2023;54:112-124; doi: 10.3290/j.qi.b3631815).

The impact of Porphyromonas gingivalis lipids on apoptosis of primary human chondrocytes.

The role of oral bacterial infections including periodontal disease in the pathogenesis of rheumatoid arthritis (RA) has gained increasing interest. Among the major periodontal pathogens, Porphyromonas gingivalis has been mostly associated with RA pathogenesis. The aim of this study was to analyze the effect of P. gingivalis total lipid (TL) fraction and dihydroceramides, as potent virulence factors, on human primary chondrocytes. Primary chondrocyte cultures were incubated with P. gingivalis phosphoglycerol dihydroceramide (PG DHC) lipids, the TL fraction or phosphoethanolamine dihydroceramide. Cell morphology changes were determined by phase contrast light microscopy. Early and late apoptosis cell analysis was performed by Annexin-V, active caspases, and 7-Aminoactinomycin D staining, and examined by flow cytometry, and cell necrosis was evaluated by lactate dehydrogenase release. Procaspase-3 activation was determined by Western blot analysis. Microscopic analysis showed altered cell morphology and cell shrinkage following incubation with P. gingivalis TLs and PG DHC lipids. Flow cytometry demonstrated an increase of Annexin-V positive and active caspases positive chondrocytes after incubation with TL and PG DHC fractions but not after phosphoethanolamine dihydroceramide (control lipid) treatment or in untreated control cells. Furthermore, Western blot analysis showed an early cleavage of procaspase-3 after 1 hr. Significant lactate dehydrogenase release following incubation with P. gingivalis lipids was demonstrated. The present data demonstrate that P. gingivalis lipids promote apoptosis in primary human chondrocytes, and thereby may contribute to the joint damage seen in the pathogenesis of RA.

Surface substance loss of subsurface bovine enamel lesions after different steps of the resinous infiltration technique: a 3D topography analysis.

Surface substance loss of subsurface enamel lesions before (baseline/demineralization) and after each step of the infiltration technique was evaluated by means of a three-dimensional focus variation. Eighty enamel specimens were prepared and partially varnished (control). Non-varnished areas were demineralized (pH 4.95; 28 days), and etched with phosphoric acid gel (20%; 5 s). Specimens were randomly assigned to eight groups (n = 10), and were infiltrated using four resinous materials. In subgroups 1, polymerization and finishing with abrasive polishing strips followed. In subgroups 2, excess material was removed before polymerization (E1/E2-Excite, Vivadent; F1/F2-Fortify, Bisco; G1/G2-Glaze & Bond, DMG; I1/I2-Icon, DMG). Topometrical evaluation revealed a negligible substance loss of demineralized enamel. After etching, mean (±SD) differences of height decreased uniformly (-6.6 ± 2.0 µm; p = 0.089; ANOVA). For infiltrated lesions, DH of subgroups 1 was comparable to the etched lesions, with a significant increase (compared to etched lesions) in subgroups 2 (1.1 ± 0.1 µm; p < 0.001; t test). Within the limitations of this study, it is concluded that etching of initial subsurface lesions will result in significant surface substance loss; removal of excess material before light-curing should simplify the infiltration procedure, and this will avoid any abrasion resulting from polishing procedures.

Traumatized teeth: clinical practice guideline for the interim management of teeth with various poor prognosis scenarios in growing patients.

OBJECTIVES: Many treatment options accepted for unsalvageable traumatized teeth in adults would seem contraindicated in children and adolescents. Instead, growing patients need interim restorative measures, thus extensively preserving their local bone and soft tissue structures and, ideally, preparing the involved site for later definitive restoration while they transform to skeletal maturity. This narrative topic review addresses the interim management in case of very deep intra-extra-alveolar fractures, extensive infection-related root resorption, tooth ankylosis, and anterior tooth loss in growing patients, and seeks to empower the clinician to select the appropriate treatment approach. DATA SOURCES: The literature up to 2021 was reviewed based on several scoping searches on PubMed and the Cochrane Library using relevant terms. Due to the complexity of the topic (with various poor prognosis scenarios and the differing therapeutic options), a systematic review was deemed inappropriate. CONCLUSION: Suitable interim treatment options include extrusion of teeth showing deep intra-extra-alveolar fractures, and decoronation of ankylosed teeth as well as resin-bonded fixed dental prostheses, natural tooth pontics, and primary tooth autotransplantations after tooth loss. The interim management options described in this article represent compromises chosen in the absence of better alternatives after a careful risk-benefit analysis. However, if adequately performed, the presented treatment options have the potential to achieve the temporary restoration of function and esthetics in growing patients. Close clinical and (if appropriate) radiologic monitoring of these patients is considered mandatory to ensure early detection of possible complications that might jeopardize or could render impossible subsequent therapeutic measures. (Quintessence Int 2022;53:722-731; doi: 10.3290/j.qi.b3236409; Modified from a previously published article (in German) Quintessenz 2022;73(2):162-169).

Systematic Review on Saliva Biomarkers in Patients Diagnosed with Morbus Alzheimer and Morbus Parkinson.

Extracellular plaques composed of the hydrophobic peptide amyloid-ß and intraneuronal accumulation of the hyperphosphorylated protein tau (p-tau) are pathological hallmarks found in the brains of most people affected by Alzheimer's disease (AD). In Parkinson's disease (PD), Lewy bodies, i.e., intraneuronal protein deposits comprising the protein α-synuclein, are a typical disease feature. As these hallmarks located in the brain are hardly traceable, reliable biomarkers from easily accessible body fluids are key for accurate diagnosis. The aim of the present work was to review the available literature regarding potential biomarkers of AD and PD in the saliva. The databases PubMed, Google Scholar, LILACS, LIVIVO, VHL regional portal, Cochrane Library, eLIBRARY, and IOS Press were consulted for the literature search. Screening of titles and abstracts followed the PRISMA guidelines, while data extraction and the assessment of full texts were carried out in accordance with the Newcastle-Ottawa Scale assessment. The review shows significant increases in levels of the amyloid-ß Aß1-42 and elevated p-tau to total tau (t-tau) ratios in salivary samples of AD patients, in comparison with healthy controls. In PD patients, levels of α-synuclein in salivary samples significantly decreased compared to healthy controls, whereas oligomeric α-synuclein and the ratio of oligomeric α-synuclein to total α-synuclein markedly increased. Salivary biomarkers represent a promising diagnostic tool for neurodegenerative diseases. Further high-quality case-control studies are needed to substantiate their accuracy.

Prospective case series on possible effects of local factors on the development of halitosis in new complete denture wearers.

OBJECTIVES: To assess the development of halitosis in participants wearing new removable complete dentures (RCD). METHOD AND MATERIALS: Seventy-five completely edentulous patients receiving RCD were recruited. Halitosis was assessed by means of FitScan Breath Checker on the day of denture insertion (T0), as well as after 1 month (T1), and after 2 months (T2). Risk factors were studied using a validated questionnaire about oral and denture hygiene, and tongue scoring followed for each participant. A modified plaque scoring technique assessed the percentage of newly formed biofilms accumulated on all surfaces of the RCD. RESULTS: At T0, 44% of the participants revealed halitosis. This percentage insignificantly increased at T1 (66.7%) and T2 (65.6%), respectively (P > .109). At T1, halitosis was significantly lower among persons who reported tongue brushing compared to refraining participants (14.3% vs 72.6%; P = .002). At T2, halitosis was significantly higher among patients suffering from moderate to heavy tongue coatings compared to those with no or only light coatings (83.3% vs 50.0%; P = .006), those who did wear their dentures during sleeping (77.5% vs 45.8%; P = .010), and those who did not brush their tongues at all (87.5% vs 29.2%; P < .0001). With a 16-fold increased probability (95% CI 10.0 to 23.31; P < .001), the multivariate analysis revealed that non-brushing the tongue was the only variable significantly linked to halitosis at both follow-ups. CONCLUSION: Non-brushing of tongues as well as sleeping with dentures seems to be the main causes of halitosis in new RCD wearers.

Effect of saliva substitutes in combination with fluorides on remineralization of subsurface dentin lesions.

PURPOSE: Saliva substitutes are prescribed to patients suffering from radiation-induced hyposalivation to alleviate oral complaints; however, some available products have shown to demineralize dentin. The purpose of this in vitro study was to evaluate the effects of two saliva substitutes in combination or not with fluoridation on remineralization of bovine dentin subsurface lesions. MATERIALS AND METHODS: Dentin specimens were demineralized, and stored in either mineral water (control; volvic, danone), Glandosane (cell pharm), or modified Saliva natura (SN, Medac) for 5 weeks (37° C). The following treatments were applied twice daily (n = 12/group): (1) no treatment; (2) immersion in pure Elmex sensitive mouthrinse (250 ppm F-; 10 min; Gaba); (3) brushing with Duraphat toothpaste (5,000 ppm F-; Colgate)/storage solution slurry (5 s; ratio 1:3); (4) combination of treatments 2 and 3. Differences in mineral parameters before and after storage/treatment were microradiographically evaluated. RESULTS: After 5 weeks, Glandosane-induced a significant demineralization of dentin specimens. The mineral loss of specimens stored in Glandosane was significantly higher compared to all other solutions (p < 0.05), and this side effect was inhibited by the fluoride products (p < 0.05; ANOVA, Tukey). Modified Saliva natura enabled considerable remineralization, and this was significantly increased by daily application of both fluoride products (p < 0.05). CONCLUSIONS: Modified Saliva natura has remineralizing properties, while Glandosane is a demineralizing saliva substitute that should only be used with frequently applied fluorides in dentate patients.

Nanoleakage of luting agents for bonding fiber posts after thermomechanical fatigue.

PURPOSE: To investigate the depth of nanoleakage of four luting agents for bonding fiber posts after thermomechanical fatigue. MATERIALS AND METHODS: Twenty-four extracted human anterior teeth were endodontically treated, sectioned at the cementoenamel junction, and restored with fiber posts using four commercially available resin cements with the corresponding core buildup materials (n = 6): Panavia F 2.0/Clearfil DC Core Automix (Kuraray), Variolink II/Multicore Flow (Ivoclar Vivadent), RelyX Unicem/Filtek Z250 (3M ESPE), and Multilink Sprint/Multicore Flow (Ivoclar Vivadent). The specimens received all-ceramic crowns and were subjected to thermomechanical fatigue (1.2 million cycles). After cutting off the crowns, the roots were isolated with nail polish except for a 1-mm rim around the root canal, and immersed in 50 wt% ammoniacal silver nitrate solution for 24 h. The specimens were sectioned perpendicular to the long axis of the tooth into four slices, fixed, dehydrated, and processed for FE-SEM. Leakage was analyzed using backscattered FE-SEM and EDS. RESULTS: The depth of nanoleakage was significantly affected by the factor resin cement (p < 0.015; Kruskall-Wallis). Multilink Sprint resulted in significantly deeper penetration of silver particles than the other materials (p < 0.05; Mann Whitney U-Test). CONCLUSION: Hybridization of the root canal dentin created by self-etching or etch-and-rinse adhesive systems demonstrated distinctive nanoleakage up to 0.8 mm, whereas the self-adhesive resin cement RelyX Unicem was able to prevent distinctive leakage at this penetration depth. However, none of the investigated luting systems would be able to hermetically seal the root canal if leakage occurred around the margins of the coronal restoration.

The influence of daily application of fluoride products on subsurface bovine enamel lesions stored in saliva substitutes.

PURPOSE: To evaluate in the laboratory the effects of daily fluoride applications on remineralization of subsurface bovine enamel lesions stored in different saliva substitutes. METHODS: Enamel specimens were prepared (n = 144) and demineralized (subsurface lesions; 37 degrees C; pH 4.95; 10 days). Before and after demineralization, specimen surfaces were partly covered with nail varnish (control of sound/demineralized enamel). The specimens were either stored (5 weeks; 37 degrees C) in mineral water (W, control, S(OCP) 0.7, pH 7.0), Glandosane (G, S(OCP) 0.3, pH 5.2), or modified Saliva Natura (SN, S(OCP) 2.0, pH 5.98), and were submitted to the following treatments twice daily: (0) no treatment; (ES) immersion in pure Elmex Sensitive mouthrinse (10 minutes); (D) brushing with Duraphat toothpaste/storage solution slurry (5 seconds + contact time 115 seconds; ratio 1:3); (ES+D) combination of ES and D treatments. Mineral parameters before and after storage/treatment were evaluated from microradiographs. RESULTS: Specimens stored in G showed significantly higher demineralization compared to the other solutions (P < 0.05, ANOVA, Tukey's post hoc test); the combined treatment with fluoride products significantly reduced the demineralizing effect of G. After 2 and 5 weeks, specimens stored in SN revealed a higher remineralization compared to the control solution (P < 0.05). Daily application of fluoride products did not promote an additional effect on remineralization of specimens stored in SN (P > 0.05).

Design of a randomized controlled double-blind crossover clinical trial to assess the effects of saliva substitutes on bovine enamel and dentin in situ.

BACKGROUND: Hyposalivation is caused by various syndromes, diabetes, drugs, inflammation, infection, or radiotherapy of the salivary glands. Patients with hyposalivation often show an increased caries incidence. Moreover, hyposalivation is frequently accompanied by oral discomfort and impaired oral functions, and saliva substitutes are widely used to alleviate oral symptoms. However, preference of saliva substitutes due to taste, handling, and relief of oral symptoms has been discussed controversially. Some of the marketed products have shown demineralizing effects on dental hard tissues in vitro. This demineralizing potential is attributed to the undersaturation with respect to calcium phosphates. Therefore, it is important to modify the mineralizing potential of saliva substitutes to prevent carious lesions. Thus, the aim of the present study was to evaluate the effects of a possible remineralizing saliva substitute (SN; modified Saliva natura) compared to a demineralizing one (G; Glandosane) on mineral parameters of sound bovine dentin and enamel as well as on artificially demineralized enamel specimens in situ. Moreover, oral well-being after use of each saliva substitute was recorded. METHODS/DESIGN: Using a randomized, double-blind, crossover, phase II/III in situ trial, volunteers with hyposalivation utilize removable dentures containing bovine specimens during the experimental period. The volunteers are divided into two groups, and are required to apply both saliva substitutes for seven weeks each. After both test periods, differences in mineral loss and lesion depth between values before and after exposure are evaluated based on microradiographs. The oral well-being of the volunteers before and after therapy is determined using questionnaires. With respect to the microradiographic analysis, equal mineral losses and lesion depths of enamel and dentin specimens during treatment with SN and G, and no differences in patients' experienced oral comfort after SN compared to G usage are expected (H0). DISCUSSION: Up to now, 14 patients have been included in the study, and no reasons for early termination of the trial have been identified. The design seems suitable for determining the effects of saliva substitutes on dental hard tissues in situ, and should provide detailed information on the oral well-being after use of different saliva substitutes in patients with hyposalivation. TRIAL REGISTRATION: ClinicalTrials.gov ID. NCT01165970.

In vitro wear of (resin-coated) high-viscosity glass ionomer cements and glass hybrid restorative systems.

OBJECTIVES: The aim of the present study was to investigate the volumetric abrasive wear of a high-viscosity glass ionomer cement (hvGIC; Equia Fil) and a glass hybrid restorative system (ghRS; Equia Forte), each being recommended as amalgam alternatives. Both materials were applied with or without their respective resinous coating, and were compared with a conventional GIC (Ketac Fil) and a hybrid composite resin (CR; G-ænial Posterior). METHODS: 78 standardized occlusal Class I cavities were restored with the various materials (n = 13 per group). Before and after chewing simulation (30,000 cycles at 40 N), each sample underwent optical scanning procedures (Omnicam). A comparison of the total wear using a fluorescence-aided identification technique (OraCheck) followed, and differences (α = 5%) between groups were compared by means of MANOVA. RESULTS: Regarding the wear rates of hvGIC and ghRS, no differences could be observed (p > .050), and this was not affected by the resinous coating. All hvGIC and ghRS restorations showed significantly higher abrasive wear than CR (p < .001), while the conventional GIC displayed a significant underperformance compared with any other material (p < .001). CONCLUSIONS: Resinous coating of hvGIC or ghRS does not appear to exert an effective long-term protection against advanced abrasive wear. Compared to the conventional GIC showing a considerable substance loss, both hvGIC and ghRS materials revealed an improved abrasion resistance, but clearly failed to meet the excellent values of the CR. CLINICAL SIGNIFICANCE: Occlusal loading should be carefully considered when using hvGIC or ghRS as amalgam (or composite resin) alternatives for the restoration of posterior teeth.

Erratum: Denture-related stomatitis in new complete denture wearers and its association with Candida species colonization: a prospective case-series Denture-related stomatitis in new complete denture wearers and its association with Candida species colonization: a prospective case-series.

The following amendments are made to the published article: Quintessence Int 2020;51(7):554-565; First published 5 June 2020; doi: 10.3290/j.qi.a44630.

Denture-related stomatitis in new complete denture wearers and its association with Candida species colonization: a prospective case-series.

OBJECTIVES: To assess the relationship between the development of denture-related stomatitis (DRS) and the identification of commonly isolated yeast species, and to evaluate various predisposing factors in Saudi participants wearing new removable dental prostheses. METHOD AND MATERIALS: A total of 75 edentulous male participants were recruited, and 64 patients finished the present case-series. All participants received new conventional complete dentures. Colonization of Candida species was assessed, and species were identified by means of the VITEK 2 (bioMérieux) laboratory components. RESULTS: The most prevalent type of Candida at baseline was C albicans, followed by non-C albicans species (C glabrata). Counts of Candida species significantly increased from the day of insertion to the first month (P < . 05), but there were no significant changes between the first and second month (P > . 05). On the day of insertion, C tropicalis, C dubliniensis, and C krusei were extracted from few subjects only, with no significant changes over the first and second month (P > .05). Patients revealing habits of sleeping with their dentures were found to frequently suffer from DRS; development of the latter was rapid, and mixed Candida biofilms (with high CFU/mL counts), along with inadequate oral and denture hygiene, turned out to be contributing factors (P < .05). CONCLUSION: DRS can develop faster than previously reported, even with new dentures; continued denture wearing and poor cleaning of dentures revealed a considerable impact on DRS onset. In the present cohort, C albicans was the most identified kind of yeast, and was followed by C glabrata infection in cases with DRS.