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OBJECTIVES: To investigate the cytotoxicity on human dental pulp cells (HDPCs) and Streptococcus mutans (S.mutans) biofilm formation on universal resin composite cements (UCs). METHODS: Three UCs (RelyX Universal, 3 M Oral Care - RXU; Panavia SA Cement Universal, Kuraray Noritake - PSAU; SoloCem, Coltene - SCM) and one 'gold-standard' multi-step cement (Panavia V5, Kuraray Noritake - PV5) were used following two polymerization protocols (light-cured - LC; self-cured - SC). Cytotoxicity (MTT) tests were performed after 1, 3 and 7 days of direct contact. Carboxy-2',7'-dichlorodihydrofluorescein diacetate was used to detect the release of reactive oxygen species (ROS), and interleukin 6 (IL-6) expression was analyzed by IL-6 proquantum high sensitivity immunoassay. S. mutans biofilms were grown on UCs samples in a bioreactor for 24 h, then adherent viable biomass was assessed using MTT assay. For microbiological procedures, half of UCs samples underwent accelerated aging. Data were statistically analyzed (α = 0.05). RESULTS: The highest cytotoxicity was observed for PSAU SC, RXU SC, and PV5 SC at day 1, then for SC RXU after 3 days, and SC PSAU, LC PV5 and SCM after 1-week (p < 0.05). There was no increase in IL-6 expression after 1 day, while it increased depending on the group at 3 and 7 days. The highest ROS expression after 12 h was recorded for PSAU SC, PV5 SC and PV5 LC. Biofilm formation was as follows: RXU > > PSAU = PV5 > SCM, while light-curing systematically decreased biofilm formation (≈-33 %). Aging leveled out differences between UCs and between polymerization protocols. SIGNIFICANCE: The choice of cement brand, rather than category, and polymerization protocol influence cell viability and microbiological behavior. Light-curing is beneficial for reducing the harmful pulpal effect that UCs may possess.
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OBJECTIVES: To evaluate the effect of proanthocyanidin-functionalized hydroxyapatite nanoparticles (nHAp_PA) used as pretreatment at different concentrations on the microtensile bond strength (µTBS) and endogenous enzymatic activity (MMPs) on pH-cycled dentin after 24 h and 6 months of artificial aging. MATERIALS AND METHODS: Fifty human sound dentin blocks were randomly assigned to 5 groups (n = 10): (i) negative control (no treatment); (ii) positive control (pH-cycling); (iii) pH-cycling + 2% nHAp_PA for 60s; (iv) pH-cycling + 6.5% nHAp_PA for 60s; (v) pH-cycling + 15% nHAp_PA for 60s. A self-etch adhesive was used for bonding procedures before resin composite build-ups. Specimens were tested with the µTBS test after 24 h and 6 months of laboratory storage. The proteolytic activity in each group was evaluated with gelatin zymography and in situ zymography. Data were statistically analyzed (p < 0.05). RESULTS: At 24 h, the µTBS of the experimental groups were significantly higher than the controls (p ≤ 0.001), and no differences were observed between different concentrations (p > 0.05). Artificial aging significantly decreased bond strength in all groups (p ≤ 0.008); however, nHAp_PA 2% still yielded higher bonding values than controls (p ≤ 0.007). The groups pretreated with nHAp_PA exhibited lower MMP-9 and MMP-2 activities compared to the positive control group and almost the same enzymatic activity as the negative control group. In situ zymography showed that after 6 months of aging, nHAp_PA 2% and nHAp_PA 6,5% decreased enzymatic activity as well as the negative control. CONCLUSIONS: Dentin pretreatment with nHAp_PA increased the bonding performance of a self-etch adhesive and decreased MMP-2 and MMP-9 activities after 6 months.
Subject(s)
Dental Bonding , Durapatite , Materials Testing , Nanoparticles , Proanthocyanidins , Tensile Strength , Proanthocyanidins/chemistry , Proanthocyanidins/pharmacology , Durapatite/chemistry , Nanoparticles/chemistry , Humans , Dental Bonding/methods , Dentin-Bonding Agents/chemistry , Dentin , Surface Properties , In Vitro Techniques , Dental Stress Analysis , Hydrogen-Ion Concentration , Composite Resins/chemistry , Random AllocationABSTRACT
OBJECTIVES: This study aimed to assess the seating accuracy of resin composite CAD/CAM overlay restorations, employing various preparation designs and luting materials (pre-heated composite (HC) or resin cement (RC)). METHODS: A human molar's STL file was utilized to create 100 3D-printed resin tooth replicas, randomly distributed into 5 groups (n = 20) based on finishing line preparation designs: 1) Rounded shoulder above the dental equator - DE (SA); 2) Chamfer above the DE (CA); 3) Butt joint above the DE (BJ); 4) Rounded shoulder below the DE (SB); 5) Chamfer below the DE (CB). Digital impressions were acquired for all replicas, and restorations milled using Tetric CAD (Ivoclar Vivadent). The restorations were luted with HC (Tetric Prime, Ivoclar Vivadent) or RC (RelyX Universal, 3 M). Seating accuracy was evaluated through digital scans during try-in without any luting agent and post-cementation using a 3D analysis software (Geomagic wrap, 3D Systems). Data were statistically analyzed using Two-Way ANOVA (p < 0.05). RESULTS: The type of luting material (RC vs HC), preparation design, and their interactions significantly impacted 3D seating of the restorations (p < 0.001). HC exhibited higer volumetric increase than RC. BJ and CA designs consistently demonstrated superior seating accuracy, irrespective of the luting material used. CONCLUSIONS: The utilization of pre-heated composite resin could negatively influence the seating of overlay restorations, probably due to its higher viscosity when compared to the resin cement. However, when HC is selected as luting agent, preparation designs lacking internal angles are recommended for enhancing the precision of overlays seating.
Subject(s)
Composite Resins , Computer-Aided Design , Dental Restoration, Permanent , Resin Cements , Humans , Composite Resins/chemistry , Resin Cements/chemistry , Dental Restoration, Permanent/methods , Materials Testing , Molar , Dental Materials/chemistry , Surface Properties , Printing, Three-Dimensional , Cementation/methodsABSTRACT
PURPOSE: The aim of the present study was to investigate the influence of three post-and-core systems and two crown materials on stresses in restored premolars using Finite Element Analysis (FEA). MATERIALS AND METHODS: A maxillary second premolar 3D model was created in SolidWorks 2014 (Dassault Systémés). Severe loss of tooth structure was simulated with six restorative options: 1) glass-fiber-reinforced composite post and composite core (GFRC)+CAD/CAM leucite-reinforced glass-ceramic crown (LRC); 2) carbon-fiberreinforced composite post and composite core (CFRC)+LRC; 3) metal cast post-and-core (MPC)+LRC 4) GFRC+CAD/CAM composite resin crown (CC); 5) CFRC+CC; 6) MPC+CC. Three-point occlusal loading (150N) was simulated and von Misses and maximum principal stresses calculated. RESULTS: Although maximum von Mises stresses in the crown and dentin were similar across groups (137.9-139.2MPa crown; 17.2-19.6 dentin), there were important differences in stress distribution in dentin. Only in MPC+CC group the maximum stresses were on the bottom of the post preparation cavity. Stress values within the posts were: CFRC(4.8MPa)>GFRC(6.7MPa)>MPC(10.3MPa). CC-restored models presented higher von Mises stresses within the post-and-core compared to the LRC groups. Maximum principal stresses were lower compared to von Mises stresses, following the same trend, and were distributed similarly in all the groups. CONCLUSIONS: Both GFRC and CFRC showed favourable stresses distribution in the dentin and restorative materials, while MPC increased stresses in core, post and post cement. The more rigid crown material seems to transmit less stresses to the underlying core and crown cement compared to CC.
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OBJECTIVE: To evaluate the effects of an ammonia-based and a water-based silver-containing solutions on bonding performance and matrix-metalloproteinases (MMPs) activity of a universal adhesive to dentin after 1 year of artificial aging. METHODS: Mid-coronal dentin surfaces of 60 sound human molars were exposed and the following groups were formed according to the surface pre-treatment and etching mode of the universal adhesive (Zipbond Universal, SDI) (n = 10): G1) Zipbond in the self-etch mode (ZSE); G2) Riva Star (SDI) applied before ZSE; G3) Riva Star Aqua (SDI) applied before ZSE; G4) Zipbond in the etch-and-rinse mode (ZER); G5) Riva Star applied before ZER; G6) Riva Star Aqua applied before ZER. The specimens were sectioned and subjected to microtensile bond strength (µTBS) test at baseline (T0) and after 12 months (T12) of artificial storage. Scanning electron microscope (SEM) and energy dispersive spectroscopy analysis (EDS) were also conducted. Three additional molars per group were processed for the in situ zymography analysis at T0 and T12. Data were statistically analyzed (p < 0.05). RESULTS: Dentin pre-treatments and aging decreased bonding values, regardless of the etching mode (p < 0.05). No differences in µTBS were observed between the two silver-containing solutions, both at T0 and T12. Riva Star Aqua and etching significantly increased the MMPs activity, independent of the storage period (p < 0.05). SIGNIFICANCE: Dentin surface pre-treatment with silver-containing solutions negatively affects the bonding performances of resin composite restorations placed with a universal adhesive. However, the ammonia-based product Riva Star might show better stability in the long term, due to lower activation of MMPs.
Subject(s)
Ammonia , Dental Bonding , Dentin-Bonding Agents , Materials Testing , Microscopy, Electron, Scanning , Silver , Surface Properties , Tensile Strength , Water , Humans , Water/chemistry , Dentin-Bonding Agents/chemistry , Silver/chemistry , Ammonia/chemistry , Dentin/chemistry , In Vitro Techniques , Matrix Metalloproteinases/metabolism , Matrix Metalloproteinases/chemistry , Resin Cements/chemistry , Molar , Acid Etching, Dental , Spectrometry, X-Ray Emission , Dental Stress AnalysisABSTRACT
PURPOSE: To evaluate the effect of different lithium-disilicate (LiSi) glass-ceramic surface decontamination procedures on the shear bond strength (SBS) to resin cement. MATERIALS AND METHODS: Seventy CAD/CAM LiSi ceramic specimens (IPS e.max CAD, Ivoclar) were cut and sintered. Fifty specimens were treated with 5% hydrofluoric acid (HF) for 20 s, while 20 were left untreated. All 70 specimens were then contaminated with human saliva and try-in silicone paste. The following surface cleaning methods were investigated (n = 10): C: water rinsing (control); PA: 37% H3PO4 etching for 20 s; E: 70% ethanol applied for 20 s; CP: cleaning paste (Ivoclean, Ivoclar) brushed for 20 s; HFSEP: self-etching ceramic primer (Monobond Etch&Prime, Ivoclar) rubbed for 20 s; HF: 5% HF applied for 20 s or no HF etching prior to contamination; SEP: self-etching ceramic primer rubbed for 20 s and no HF etching prior to contamination. Composite cylinders were created and luted with an adhesive resin cement to the decontaminated surfaces. After storage for 24 h at 37°C, the SBS test was conducted. Two fractured specimens per group were observed under SEM to perform fractographic analysis. The data were statistically analyzed with p set at <0.05. RESULTS: The type of surface cleaning approach influenced bond strength (p < 0.001). HFSEP, SEP, and HF attained higher SBS (p < 0.001) compared to other groups. None of the approaches were able to completely remove contaminants from the ceramic surfaces. SEM images showed residual traces of contaminants on CP-treated surfaces. CONCLUSIONS: The self-etching ceramic primer enhanced bond strength to contaminated LiSi ceramic surfaces, irrespective of previous treatment with hydrofluoric acid.
Subject(s)
Dental Bonding , Resin Cements , Humans , Lithium , Hydrofluoric Acid , Surface Properties , Materials Testing , Dental Porcelain , Ceramics , 2-Propanol , SilanesABSTRACT
OBJECTIVE: A comprehensive classification of structurally compromised teeth (SCT) was introduced. CLINICAL CONSIDERATIONS: Dental injuries or operative mismanagement undermine the structural integrity of the tooth abutment, reducing its biomechanical strength and rendering restorative procedures challenging. To standardize the overall pre-operative evaluations and determine the biological and mechanical features, a classification of the coronal and cervical tooth defects, as well as an attentive analysis of the most apical location of the residual cervical tooth structure along the whole perimeter and the most coronal location of the bucco/lingual residual structure was presented. Considering the residual cervical structure, five possible clinical scenarios were individuated with respect to the gingival margin, gingival sulcus, supracrestal tissue attachment and bone crest (BC). The latter prevents the isolation procedures rendering the adhesive restorations unfeasible. Instead, the location of the most apical portion of residual cervical structure within subgingival/intrasulcular depth (>1.5 mm above BC) can be considered restorable. CONCLUSIONS: This classification is threefold: to enclose all the possible clinically encountered tooth defects, to identify the apical problems of SCT to appropriately manage the perio-restorative interfaces, and to evaluate the tooth resistance capacity of SCT, as to plan and perform the most adequate biomechanical restorative approach. CLINICAL SIGNIFICANCE: The present classification is proposed to provide a complete perspective of structurally compromised teeth to standardize the biologic and biomechanical evaluations during planning of restorative procedures.
Subject(s)
Gingiva , Tooth CrownABSTRACT
OBJECTIVE: To introduce the "Peripheral Build-Up technique - PBUt" as a foundation restoration strategy for structurally compromised teeth (SCT). CLINICAL CONSIDERATIONS: Several strategies have been proposed over time (cervical marginal relocation, doughnut, and preformed ring techniques) to enable the management of restorative procedures in challenging situations such as the presence of deep subgingival defects. The PBUt is a versatile, completely additive direct technique that share some strategical concepts with these techniques to approach critical clinical situations while supplying a wider field of application thanks to distinct operative expedients. The clamp insertion modality, the extension of the proximal wall and the matrix customization/stabilization strategies adopted in PBUt endorse the possibility to manage the most apical and peripheral border of the residual tooth structure when located up to >1.5 mm above the bone crest. The periodontal response has to be then monitored over time. Moreover, thanks to the peripheral and apically-extended addictive approach, it allows a massive preservation of residual sound tooth structure and improves the resistance and retentive physical/geometrical features of the abutment tooth. The PBUt operative workflow is herein explained. CLINICAL SIGNIFICANCE: The Peripheral-Build-Up technique (PBUt) advocates some innovative clinical restorative steps for the management of SCT with coronal and deep subgingival defects.
Subject(s)
Composite Resins , Dental Restoration, Permanent , Composite Resins/chemistry , Dental Restoration, Permanent/methods , MolarABSTRACT
OBJECTIVES: To answer the PICO(S) question: Is there a difference in clinical longevity between direct and indirect resin composite restorations placed on permanent posterior teeth? DATA: Randomized controlled clinical trials (RCTs) investigating direct and indirect resin composite restorations in posterior permanent teeth were considered. SOURCES: Several electronic databases were searched, with no language or date restrictions. The revised Cochrane Collaboration's tool for assessing risk of bias (RoB-2) was used to analyze the studies; meta-analyses were run and the certainty of evidence was assessed by the GRADE tool. A subgroup meta-analysis was performed for resin composite restorations placed on posterior worn dentition. STUDY SELECTION: Twenty-three articles were included in qualitative synthesis, while 8 studies were used for meta-analyses. According to the RoB-2 tool, 5 studies were ranked as "low risk", 7 had "some concerns", while 11 papers were rated as "high risk" of bias. There were no statistically significant differences in short-term (p = 0.27; RR=1.54, 95% CI [0.72, 3.33]), medium-term (p = 0.27; RR=1.87, 95% CI [0.61, 5.72]) and long-term longevity (p = 0.86; RR=0.95, 95% CI [0.57, 1.59]). The choice of restorative technique had no influence on short-term survival of resin composite restorations placed on worn dentition (p = 0.13; RR=0.46, 95% CI [0.17, 1.25]). The certainty of evidence was rated as "very low". CONCLUSIONS: Direct and indirect resin composite restorations may show similar clinical longevity in posterior region, regardless of the observation period or substrate (wear-affected and non-affected dentition). The very low quality of evidence suggests that more long-term RCTs are needed to confirm our results.
Subject(s)
Composite Resins , Dental Restoration, Permanent , Dental Restoration, Permanent/methods , Composite Resins/therapeutic use , MolarABSTRACT
PURPOSE: To evaluate the accuracy, working time, and patient satisfaction of digital impressions (DI) vs conventional impressions (CI) taken for removable prostheses on edentulous arches. MATERIALS AND METHODS: A systematic search of the literature was conducted in electronic databases. The English language was filtered with no limitation on publication date. The search was performed up to June 2022. Only in vivo studies comparing DI and CI techniques for the fabrication of complete removable prostheses were included. The primary outcome was accuracy (in terms of trueness and precision), working time (scanning time), and patient satisfaction of DI procedures. RESULTS: After title and abstract screening, six articles were considered eligible for inclusion. All articles investigated the trueness of DI, while no study evaluated the accuracy in terms of precision. The discrepancies between DI and CI were primarily in the peripheral areas. Only one article focused on the working time for scanning procedures. Patient satisfaction was surveyed in just one study. Lack of standardization of the CI procedures and sample size collection were observed in all studies. CONCLUSIONS: The scientific evidence so far collected on IOS for complete edentulous arches is not exhaustive, in particular when dealing with scanning time and patient satisfaction. Regarding accuracy, digital scanning in edentulous patients seems to be a predictable procedure within the limits of the attached mucosa.
Subject(s)
Mouth, Edentulous , Humans , Patient Satisfaction , Research DesignABSTRACT
OBJECTIVES: To evaluate the influence of two glutaraldehyde-based desensitizers (L: GLUMA Desensitizer, Heraeus Kulzer and G: GLUMA Desensitizer PowerGel) prior to the adhesive procedures on microtensile bond strength (µTBS) to dentin and endogenous enzymatic activity. METHODS: Noncarious human third molars (N = 48) were cut to expose middle coronal dentin. Six experimental groups were formed according to the dentin pre-treatment (L or G) and the universal adhesives (IBU - iBond universal, Kulzer or AU - Adhese Universal, Ivoclar Vivadent) used in the self-etch mode (n = 8): 1) L/IBU; 2) G/IBU; 3) IBU; 4) L/AU; 5) G/AU; 6) AU. Specimens were cut into sticks and stressed until failure after 24 h (T0) or 1 yr of aging (T12). Additional 4 teeth were used for in situ zymography evaluation and data were statistically analyzed (α = 0.05). RESULTS: Dentin pre-treatment, adhesive and aging statistically influenced bond strength and enzymatic activity (P<0.001). AU demonstrated higher bond strength values than IBU (P<0.001). The L resulted in higher bond strength compared to the G and control groups (P<0.001). aging statistically influenced bonding performance, especially when no dentin pre-treatment was performed (P<0.001). In situ zymography revealed that at baseline the control groups exhibited lower interfacial fluorescence compared to the experimental groups, irrespective of the adhesive used (P<0,001). However, after 1 yr of artificial storage, no differences were found among the groups (P>0.05). CONCLUSIONS: Glutharldeadeyde-based products increased bond strength and determined a stabilization of the adhesive interface over time apparently not related to the MMPs inhibition. CLINICAL SIGNIFICANCE: The results of this in vitro study suggest that the application of glutaraldehyde-based desensitizers prior to the adhesive procedures when associated with universal adhesives could result in increased bond strength and stabilization of the adhesive interface over time.
Subject(s)
Dental Bonding , Dental Cements , Humans , Dental Cements/pharmacology , Glutaral/pharmacology , Dentin-Bonding Agents/chemistry , Resin Cements/chemistry , Materials Testing , Tensile Strength , AdhesivesABSTRACT
BACKGROUND: To investigate the effect of 0.3 M 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (EDC) aqueous solution pretreatment on push-out bond strength (PBS) and matrix-metalloproteinases (MMPs) activity within radicular dentin when different post cementation strategies were employed. METHODS: One hundred and twenty monoradicular human teeth were endodontically treated and randomly divided into six groups, depending on the cementation strategy and root dentin pretreatment (n = 20): EAR: cementation with an etch-and-rinse adhesive (LuxaBond Total Etch, DMG) and resin cement (LuxaCore Z Dual, DMG); EAR/EDC: 1 min EDC pretreatment after etching + EAR; SE: cementation with a self-etch primer (Multilink Primer, Ivoclar Vivadent) and corresponding cement (Multilink Automix, Ivoclar Vivadent); SE/EDC: self-etch primer + EDC pretreatment + SE; SA: cementation with a universal self-adhesive cement (RelyX Universal, 3 M); SA/EDC: EDC pretreatment + SA. Slices were submitted to PBS test and interfacial nanoleakage evaluation 24 h after cementation or after thermocycling (40.000 cycles, 5-55 °C). To investigate the effect of EDC on MMPs activity, 4 additional first maxillary premolars per group were processed for in situ zymography analysis. Multivariate ANOVA and post hoc Tukey tests were used to analyze PBS values. The data from in situ zymography were analyzed with Kruskal-Wallis test and Dunn's pairwise multiple comparison procedures (α = 0.05). RESULTS: The variables "EDC pretreatment", "root region" and "thermocycling" significantly influenced PBS (p < 0.05), while the variable "cementation strategy" had no influence (p > 0.05). Thermocycling significantly reduced PBS in SE and SA groups (p < 0.05). EDC was effective in preserving PBS after artificial aging. EDC pretreatment significantly reduced enzymatic activity at baseline in EAR and SE groups, and in SA group after thermocycling (p < 0.05). CONCLUSIONS: The use of EDC prevents the reduction of bond-strength values after artificial aging and silences endogenous enzymatic activity within radicular dentin when different cementation strategies were employed.
Subject(s)
Dental Bonding , Humans , Carbodiimides/chemistry , Dentin , Resin Cements/therapeutic use , Resin Cements/chemistry , Matrix Metalloproteinases , Materials TestingABSTRACT
PURPOSE: The aim of this study is to evaluate the accuracy of removable partial denture (RPD) frameworks produced using different digital protocols. MATERIALS AND METHODS: 80 frameworks for RPDs were produced using CAD-CAM technology and divided into four groups of twenty (n = 20): Group 1, Titanium frameworks manufactured by digital metal laser sintering (DMLS); Group 2, Co-Cr frameworks manufactured by DMLS; Group 3, Polyamide PA12 castable resin manufactured by multi-jet fusion (MJF); and Group 4, Metal (Co-Cr) casting by using lost-wax technique. After the digital acquisition, eight specific areas were selected in order to measure the Δ-error value at the intaglio surface of RPD. The minimum value required for point sampling density (0.4 mm) was derived from the sensitivity analysis. The obtained Δ-error mean value was used for comparisons: 1. between different manufacturing processes; 2. between different manufacturing techniques in the same area of interest (AOI); and 3. between different AOI of the same group. RESULTS: The Δ-error mean value of each group ranged between -0.002 (Ti) and 0.041 (Co-Cr) mm. The Pearson's Chi-squared test revealed significant differences considering all groups paired two by two, except for group 3 and 4. The multiple comparison test documented a significant difference for each AOI among group 1, 3, and 4. The multiple comparison test showed significant differences among almost all different AOIs of each group. CONCLUSION: All Δ-mean error values of all digital protocols for manufacturing RPD frameworks optimally fit within the clinical tolerance limit of trueness and precision.
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PURPOSE: Digital technology has enabled improvements in the fitting accuracy of denture bases via milling techniques. The aim of this study was to evaluate the trueness and precision of digital and analog techniques for manufacturing complete dentures (CDs). MATERIALS AND METHODS: Sixty identical CDs were manufactured using different production protocols. Digital and analog technologies were compared using the reference geometric approach, and the Δ-error values of eight areas of interest (AOI) were calculated. For each AOI, a precise number of measurement points was selected according to sensitivity analyses to compare the Δ-error of trueness and precision between the original model and manufactured prosthesis. Three types of statistical analysis were performed: to calculate the intergroup cumulative difference among the three protocols, the intergroup among the AOIs, and the intragroup difference among AOIs. RESULTS: There was a statistically significant difference between the dentures made using the oversize process and injection molding process (P < .001), but no significant difference between the other two manufacturing methods (P = .1227). There was also a statistically significant difference between the dentures made using the monolithic process and the other two processes for all AOIs (P = .0061), but there was no significant difference between the other two processes (P = 1). Within each group, significant differences among the AOIs were observed. CONCLUSION: The monolithic process yielded better results, in terms of accuracy (trueness and precision), than the other groups, although all three processes led to dentures with Δ-error values well within the clinical tolerance limit.
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OBJECTIVES: Currently, a classification of resin cements that includes relatively recently formulated ("universal") cements is lacking. Furthermore, the terminology used to define different resin cements in the scientific reports is inconsistent. Accordingly, this work aims to: (i) propose a novel classification of resin composite cements; (ii) disambiguate the term "universal cements" and (iii) present an overview of the properties of these cements. METHODS: An analysis of peer-reviewed literature (PubMed search), as well as market research on definitive resin composite cements were performed. RESULTS: A tendency toward simplified and versatile luting materials was observed both in the scientific literature and on the dental market with the advent of self-adhesive/one-step resin cements. However, additional priming procedures were necessary to improve their bonding performance in certain clinical situations. Hence, several cements that can be applied both in adhesive and self-adhesive mode were introduced. These cements are associated with a universal adhesive resin, that can be used as a tooth and/or restorative material primer, without the need for other priming systems, regardless of the substrate. These systems should be considered truly universal. Therefore, we hereby suggested a new classification of resin-based cements: (1) adhesive/multi-step; (2) self-adhesive/one-step; (3) universal cements (one- or multi-step). Despite promising in vitro results, clinical trials and long-track laboratory studies are necessary to confirm the reliability of the universal cements. CONCLUSIONS: This review presented the current advances in the field of resin-based cements, which are reflected in the proposed classification. The term "universal cement" was disambiguated, which will help standardize the terminology used in published research. CLINICAL SIGNIFICANCE: The classification of resin-based cements and a better understanding of the proper terminology will help standardize the terminology in published research, as well as improve the understanding of the clinical practitioners of the different indications and possible modalities of use of the available cements.
Subject(s)
Dental Bonding , Resin Cements , Resin Cements/chemistry , Reproducibility of Results , Dental Bonding/methods , Materials Testing , Composite Resins/chemistry , Dental Cements/chemistry , Surface PropertiesABSTRACT
OBJECTIVE: We aimed to introduce the concept of "Selective adhesive luting-SAL" which is explained through clinical steps and supported by preliminary laboratory evidence. CLINICAL CONSIDERATIONS: Cementation with rubber dam is difficult to perform in case of short abutment teeth and/or subgingival crown margins. By means of universal resin cements/universal adhesive systems, which can be employed in self-adhesive as well as adhesive luting procedures, this paper presents a novel technique allowing clinicians to perform reliable cementation where rubber dam isolation is difficult. The SAL technique entails the application of a universal adhesive system only on easily accessible abutment surfaces, enabling simultaneous adhesive and self-adhesive luting in different portions of the abutment. The SAL clinical workflow is explained through prosthodontic rehabilitation of maxillary right central incisor affected by microdontia and restored with a lithium-disilicate crown. Furthermore, our laboratory microshear bond strength study supports the rationale behind SAL application demonstrating higher bond strength even when the adhesive resin is placed only on one portion of the cementation substrate. CLINICAL SIGNIFICANCE: This article advocates the application of SAL technique in clinical situations where effective adhesive luting is uncertain, since it can improve the adhesion between the tooth and universal resin cements.
Subject(s)
Dental Bonding , Resin Cements , Resin Cements/chemistry , Dental Cements/chemistry , Cementation/methods , Crowns , Materials Testing , Surface PropertiesABSTRACT
BACKGROUND: To evaluate the effect of different experimental staining procedures on color stability and translucency of a nano-hybrid resin-based composite (RBC). METHODS: Forty-eight cylindrical-shaped specimens (10 × 2 mm) were prepared with a nano-hybrid RBC (Clearfil Majesty ES-2) and randomly divided in four groups according to the experimental staining procedure: G1) static immersion in a staining solution (coffee) (44 ± 1 °C); G2) staining cycling between coffee (44 ± 1°C) and distilled water (37 ± 1°C) with an experimental staining machine based on Arduino, an Open Source hardware development platform; G3) staining cycles as in G2 + brushing with a low abrasive toothpaste (Relative Dentin Abrasion RDA = 30) (Elmex Sensitive Professional); G4) staining cycles as in G3, with brushing performed with a very strong abrasive toothpaste (RDA = 90) (Lacult Active). Color parameters were recorded at the baseline (T0) after staining procedures (T1) and repolishing (T2) using a spectrophotometer. Color change (∆E00) and translucency (TP, CR) were evaluated. Data were statistically analyzed (p < 0.05). RESULTS: For ∆E00 after staining, Group 1 showed the highest color change and Group 3 the lowest. All groups were significantly different (p < 0.001) except for Group 2 vs. Group 4; after repolishing, Group 1 was significantly higher than Group 3 (p < 0.001), Group 2 (p < 0.001), and Group 4 (p = 0.003); Group 2 was higher than Group 3 (p < 0.001). For TP variable, after staining procedures, Group 2 was significantly higher than all other groups (p < 0.001), and Group 1 was significantly higher than Group 3 (p < 0.001) and Group 4 (p = 0.007). After repolishing, Group 4 was significantly lower than Group 3 (p = 0.008) and Group 2 (p = 0.027). Repolishing procedure significantly reduced color parameters. CONCLUSIONS: The investigated staining procedure induced significant differences in color stability and translucency. The use of a very strong abrasive toothpaste (RDA = 90) induced higher color change than a low abrasive one (RDA = 30). Repolishing procedures are able to partially reduce color change induced by artificial staining procedures.
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BACKGROUND: This systematic review aims to evaluate the color stability of resin composite CAD/CAM blocks (CCB) when submitted to staining solutions. METHODS: A systematic search was performed on different databases (Embase, Medline, Scopus, Web of Science). Search terms were: 'polymer infiltrated', 'polymer-based', 'resin nanoceramic', 'resin ceramic', 'hybrid composite', 'hybrid ceramic', 'composite ceramic', 'resin infiltrated', 'CAD-CAM', 'CAD/CAM', 'color stability', 'staining', 'staining susceptibility', 'color change', 'color difference'. INCLUSION CRITERIA: in vitro articles published in the English language until 18 September 2022 without initial time restriction evaluating the color stability of CCB when submitted to staining solutions. EXCLUSION CRITERIA: studies investigating color change induced by smoke or whitening treatments; studies not including a clinical evaluation of the results using the thresholds for color perceptibility and acceptability. Risk of bias assessment using the QUIN tool. FINDINGS: Out of the 378 initially retrieved articles, 19 were included in this review. They investigated 17 different CCBs and different artificial staining by liquid protocols, including coffee, red wine, tea, and cola. CCBs exceeded clinical acceptability thresholds for color shift in 18 out of 19 studies, with a significantly higher color stability than conventional hybrid resin-based composites (RBCs), and a significantly lower color stability than ceramic materials. The identified differences in CCBs in color stability can be attributed to the material's composition, but also to the heterogeneity of staining procedures. Interpretation and clinical implication: Clinicians should be aware that, although to a lower degree when compared to RBCs used in direct or indirect procedures, CCBs undergo color changes to a higher degree in comparison to ceramic materials.
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OBJECTIVE: The cement bonding strategy and the polymerization mode can influence the prognosis of indirect restorations. The microtensile bond strength (µTBS) and dentin endogenous enzymatic activity of a dual-cure resin cement (PV5) used in combination with two dentin surface conditioners (accelerator-enhancer primer, TP or universal adhesive, UA) were evaluated. MATERIALS AND METHODS: PV5 was used to lute composite overlays after dentin treatment with TP or UA. The resin cement was self-cured, SC (1 h at 37 °C) or dual-cured, DC (20 s light-cure followed by 15 min self-cure at 37°C). The µTBS test, fractographic analysis, and the in situ zymography evaluations were performed after 24 h (T0 ) or 1 yr (T12 ) of artificial storage. Data were statistically analyzed (α = 0.05). RESULTS: TP/DC obtained the highest adhesive strengths (45 ± 9 and 36.6 ± 8), while UA/SC (17 ± 8 and 11 ± 4) the lowest, both at T0 and T12 , respectively. DC resulted in superior bonding values than the SC, independent of the dentin surface treatment (p < 0.05). The type of adhesive, curing mode and aging influenced the gelatinolytic activity (p < 0.05). CONCLUSIONS: The dual-cure resin cement used in combination with its accelerator-enhancer primer showed superior bonding performances with respect to universal adhesive. Dual-curing the resin cement was determinant to enhance bonding capability over time, independent of the adhesive strategy. CLINICAL RELEVANCE: Clinicians must be aware to faithfully follow manufacturer's recommendation regarding the adhesive strategy suggested with the resin cement used.
Subject(s)
Dental Bonding , Resin Cements , Dental Cements , Glass Ionomer Cements , Dentin , Materials Testing , Tensile Strength , Dentin-Bonding Agents , Surface PropertiesABSTRACT
Resin infiltration is a conservative treatment of initial enamel carious lesions. Only one infiltrant material is available on the market (Icon, DMG), and research is now investigating new chemical compositions so as to further exploit the benefits of the resin infiltration technique. A literature search of the articles testing the effects of different formulations on mechanical properties, resin penetration ability, remineralizing, and antibacterial activities was conducted. Of 238 articles, 29 resulted in being eligible for the literature review. The formulations investigated were all different and consisted in the inclusion of hydrophobic monomers (i.e., BisEMA, UDMA), solvents (ethanol, HEMA), alternative etchants (PAM) or molecules with antibacterial or bioactivity features (i.e., AgNP, YbF3, MTZ, chitosan, DMAMM, HAp, MC-IL, NACP, PUA, CHX) and microfilled resins. Information on the long-term performances of the tested experimental materials were scarce. The combination of TEGDMA with hydrophobic monomers and the inclusion of a solvent alternative to ethanol reinforced mechanical properties of the materials. Hybrid-glass materials demonstrated an enhanced remineralization capacity. Techniques such as tunnelization increased the penetration depth and preserved the recourse to less-conservative treatments. Combining the min-invasive infiltrant approach with remineralizing and bacteriostatic properties would be beneficial for therapeutic and economical aspects, according to the principles of minimally invasive dentistry.