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Materials (Basel, Switzerland) Sep 2023: Testing the influence of various restorative materials (conventional or bulkfill composites) and filling techniques (single- or multi-layered techniques) on the in...
: Testing the influence of various restorative materials (conventional or bulkfill composites) and filling techniques (single- or multi-layered techniques) on the in vitro marginal adaptation of large class II direct composites with supra and sub-gingival margins subjected to thermomechanical loading (TML). : A total of 40 prepared teeth were attributed randomly to five experimental groups. In Group 1, restorations were made of multi-layered high-viscosity conventional composite (Tetric EvoCeram); in Groups 2 and 3, restorations were made of a high viscosity bulkfill composite (Tetric EvoCeram Bulk Fill) applied in one (Group 2) or three layers (Group 3); in Groups 4 and 5, restorations were made of a flowable bulkfill composite (SDR flow) applied in one (Group 4) or two layers (Group 5), covered with a layer of high-viscosity conventional composite (Ceram-X Universal). A single adhesive (OptiBond FL) was used in all groups. All specimens were submitted to a staged TML comprising three phases (2 × 500,000 and 1,000,000 cycles) at 50 N with 3350 thermal cycles (5 to 55 °C) every 500,000 cycles. The tooth-restoration interfaces on proximal surfaces were evaluated quantitatively by scanning electron microscopy, before and after each TML phase, hence at three timepoints (T0, T1, T2 and T3). The following segments were considered for evaluation: proximal, vertical enamel margins (assessed individually on both restoration sides), cervical enamel (restoration side above CEJ) and cervical dentin margin (restoration side below the CEJ). : TML induced a significant reduction in continuous adaptation at both enamel and dentin margins in all groups, with percentages of continuous margins ranging from 75.2 to 91.8% at T0, and decreasing to values ranging from 21.3 to 73.9% at T3. Both composite systems and layering protocols had a significant influence on marginal adaptation of the restorations, with statistical associations depending on the restoration group and the timepoint considered. Defective margins in enamel were all of a cohesive nature with micro-fractures, while in dentin, interfacial gaps were the main defect observed. The present results highlighted significant degradation of marginal adaption after long-term in vitro fatigue test using materials even with high-viscosity conventional resin composites, applied with a proper layering approach in medium-large sub-gingival cavities. While no significant differences were observed at the dentin cervical margins, there was a tendency for better adaptation at the enamel margin when using a higher modulus material with a multi-layered technique.
PubMed: 37763602
DOI: 10.3390/ma16186325 -
Antibiotics (Basel, Switzerland) Sep 2023Endo-periodontal lesions are challenging clinical situations where both the supporting tissues and the root canal of the same tooth are infected. In the present study,...
Endo-periodontal lesions are challenging clinical situations where both the supporting tissues and the root canal of the same tooth are infected. In the present study, chlorhexidine (CHX)-loaded calcium hydroxide (CH) pastes were used as intracanal medications (ICMs). They were prepared and tested on pathogens found in both the root canal and the periodontal pocket. Exposure to 0.5% and 1% CHX-loaded ICMs decreased the growth of and was effective in eradicating or inhibiting an biofilm. CH was injected into the root canal of extracted human teeth immersed in deionized water. CHX-loaded ICMs resulted in the transradicular diffusion of active components outside the tooth through the apex and the lateral dentinal tubules, as shown by the release of CHX (from 3.99 µg/mL to 51.28 µg/mL) and changes in pH (from 6.63 to 8.18) and calcium concentrations (from 2.42 ppm to 14.67 ppm) after 7 days. The 0.5% CHX-loaded ICM was non-toxic and reduced the release of IL-6 by periodontal cells stimulated by lipopolysaccharides. Results indicate that the root canal may serve as a reservoir for periodontal drug delivery and that CHX-based ICMs can be an adjuvant for the control of infections and inflammation in endo-periodontal lesions.
PubMed: 37760713
DOI: 10.3390/antibiotics12091416 -
Cureus Aug 2023This study was performed to determine the temperature rise under human dentin discs of different thicknesses from primary and permanent teeth during the photo-curing...
AIM
This study was performed to determine the temperature rise under human dentin discs of different thicknesses from primary and permanent teeth during the photo-curing process using quartz tungsten halogen (QTH) or light-emitting diode (LED).
MATERIALS AND METHODS
The current experimental study sample consisted of 160 dentin discs of different thicknesses (0.5, 1, 1.5, and 2 mm), of which 80 dentin discs were prepared from sound lower second primary molars, and the remaining 80 dentin discs were prepared from sound lower third permanent molars extracted surgically for various reasons. A "K" type of thermal tentacle was placed in the center of an acrylic resin base, followed by the placement of a dentin disc. Then, the thermal changes were measured during the photo-curing of the composite using a second LED or QTH light curing unit for 20 s. Statistical evaluation was performed using the IBM SPSS Statistics® Version 20.0 software system (SPSS Inc., Chicago, IL, USA).
RESULTS
The current study found that the temperature rise in primary teeth (1.17-2.96°C) is significantly lower compared to the rise in permanent teeth (1.55-3.33°C), regardless of the dentin disc thickness or light curing unit used. The temperature rise decreases significantly when the thickness of dentin discs increases, regardless of the type of teeth or light curing unit used (P<0.05). Furthermore, QTH causes less temperature rise (1.17-2.65°C) compared to LED (1.61-3.33°C).
CONCLUSIONS
The temperature rise during polymerization of the resin composite with the second-generation LED appeared to be below 5.5°C. Hence, it appears to be safe for use during the restoration of primary teeth. Primary teeth dentin might be more effective than permanent teeth dentin in protecting the dental pulp.
PubMed: 37746354
DOI: 10.7759/cureus.44029 -
International Journal of Clinical... 2023Vital partial pulpotomy (PP) or cervical pulpotomy (CP) in carious pulp-exposed permanent teeth preserves tooth vitality, promotes pulp healing, decreases treatment...
PURPOSE
Vital partial pulpotomy (PP) or cervical pulpotomy (CP) in carious pulp-exposed permanent teeth preserves tooth vitality, promotes pulp healing, decreases treatment costs, and shortens treatment duration, which is a significant factor in treating noncooperative children. The aim of this retrospective study was to compare clinical and radiographic outcomes of partial and CP in vital carious-exposed permanent teeth.
MATERIALS AND METHODS
All vital permanent teeth with carious pulp exposure, treated by pulpotomy using mineral trioxide aggregate (MTA) during 2017-2019, by two operators in one dental center, were included in the study. Around 118 permanent teeth in 97 children and adolescents (mean age 10.9 years) were evaluated 6-57 months postoperatively.
RESULTS
The total success rates of CP and PP were 82.5 and 80.8%, respectively ( = nonsignificant). The only factor that significantly affected the success rate was the presence of preoperative periapical pathology. Teeth without such pathology showed an 87.3% success rate compared to 74.1 and 58.3% in teeth with preoperative enlarged periodontal ligament (PDL) or with periapical radiolucency, respectively ( = 0.0301). Demographic variables, maturation state of the tooth, type of tooth (incisor, premolar, molar), postoperative variables, such as the presence of radiographic dentinal bridge, partial or full obliteration of the pulp during the follow-up period, and the integrity of the final restoration during the recall examinations did not affect the success rate of the treatment.
CONCLUSION
Partial and CP in vital permanent teeth with carious pulp exposure in children and adolescents might be a reliable alternative to full root canal treatment (RCT).
HOW TO CITE THIS ARTICLE
Yoshpe M, Kaufman AY, Lin S, Clinical and Radiographic Outcomes of Mineral Trioxide Aggregate Pulpotomies in Vital Permanent Teeth with Carious Pulp Exposure: A Pioneering Retrospective Study. Int J Clin Pediatr Dent 2023;16(4):555-559.
PubMed: 37731810
DOI: 10.5005/jp-journals-10005-2483 -
The Journal of Prosthetic Dentistry Nov 2023Layered composite resins may adequately mask discolored substrates. However, whether color changes that occur over time affect masking ability is unclear.
STATEMENT OF PROBLEM
Layered composite resins may adequately mask discolored substrates. However, whether color changes that occur over time affect masking ability is unclear.
PURPOSE
The purpose of this in vitro study was to investigate the effect of layering and water aging on the masking ability of 2 composite resins.
MATERIAL AND METHODS
Disk specimens (1.5 mm-thick and shade A1) from Charisma Diamond (CD) and Filtek Z350XT (Z350) were made according to the composite resin shade combination used in the layering strategies: bilayer for CD (enamel/dentin) and for Z350 (enamel/body and enamel/dentin) and trilayer for Z350 (enamel/body/dentin) (n=5). Color measurements were obtained with a spectrophotometer over an A3.5 ceramic substrate, and the whiteness index for dentistry (WI) was calculated. The specimens were aged in water at 37 °C and evaluated at different times: 24 hours, 1 week, 1 month, 2 months, 6 months, 12 months, 18 months, and 24 months. CIEDE2000 color differences (ΔE) and WI differences (ΔWI) were calculated and interpreted by 50:50% color and whiteness perceptibility and acceptability thresholds. Changes among strategies and aging times were analyzed using the Kruskal-Wallis test (α=.05). Contrasts were made using the Mann-Whitney U test with Bonferroni correction (α=.001).
RESULTS
ΔE decreased from 24 hours to 2 months of aging. From 2 months onwards, ΔE increased for all layering strategies and times, without significant changes in lightness for CD (P>.004). Overall, for the CD restorative system, an increase in ΔWI was observed after 1 month of aging (P<.001), while for the Z350 restorative system, ΔWI decreased after aging (P<.001), except for the Z350 bilayer strategy (enamel + dentin) at 1 week and 2 months (P>.004). For all layering strategies and aging times, color differences were higher than the 50:50% perceptibility threshold for ΔE and, after 6 months, higher than the 50:50% acceptability threshold for ΔE and the 50:50% whiteness acceptability threshold.
CONCLUSIONS
The ability of the tested composite resins to mask a discolored substrate was affected by the layering approach applied and by prolonged water aging.
Topics: Color; Composite Resins; Ceramics; Spectrophotometry; Materials Testing
PubMed: 37730467
DOI: 10.1016/j.prosdent.2023.08.031 -
Journal of Applied Oral Science :... 2023This study aimed to analyze the effect of irradiation on the push-out bond strength of mineral trioxide aggregate (MTA) and Biodentine to radicular dentin.
OBJECTIVE
This study aimed to analyze the effect of irradiation on the push-out bond strength of mineral trioxide aggregate (MTA) and Biodentine to radicular dentin.
METHODOLOGY
A total of 60 extracted mature human teeth with single root canals were categorized into two groups (irradiated and non-irradiated) (n=30). Each group was further divided into two sub-groups based on cements used (Biodentine and MTA). Then, a cumulative radiation dose of 60 Gy was divided into 30 fractions (two Gy for every fraction) and administered for five successive days per week over six weeks. Obturation was then performed using MTA and Biodentine. Afterwards, 1.5 mm thick horizontal sections were procured from the middle one-third of all the specimens and then subjected to push-out bond test. Results were analyzed using one-way analysis of variance with post-hoc Tukey's test.
RESULTS
The bond strength of Biodentine and MTA to irradiated teeth was lower than non-irradiated teeth. Highest push-out bond strength was observed in non-irradiated specimens filled with Biodentine (p=0), followed by irradiated specimens filled with Biodentine (p=0); non-irradiated specimens filled with MTA (p=0); and irradiated specimens filled with MTA (p=0.9).
CONCLUSION
The push-out bond strength of Biodentine and MTA to root canal dentin decreased significantly post irradiation.
Topics: Humans; Dental Cementum; Tooth Root; Silicates; Dentin
PubMed: 37729257
DOI: 10.1590/1678-7757-2023-0118 -
Journal of Bone Metabolism Aug 2023Iris Koreana NAKAI (IKN) is a flowering perennial plant that belongs to the Iridaceae family. In this study, we aimed to demonstrate the effects of IKN on osteoclast...
BACKGROUND
Iris Koreana NAKAI (IKN) is a flowering perennial plant that belongs to the Iridaceae family. In this study, we aimed to demonstrate the effects of IKN on osteoclast differentiation in vitro and in vivo. We also sought to verify the molecular mechanisms underlying its anti-osteoclastogenic effects.
METHODS
Osteoclasts were formed by culturing mouse bone marrow macrophage (BMM) cells with macrophage colony-stimulating factor and receptor activator of nuclear factor-κB ligand (RANKL). Bone resorption assays were performed on dentin slices. mRNA expression levels were analyzed by quantitative polymerase chain reaction. Western blotting was performed to detect protein expression or activation. Lipopolysaccharide (LPS)-induced osteoclast formation was performed using a mouse calvarial model.
RESULTS
In BMM cultures, an ethanol extract of the root part of IKN suppressed RANKL-induced osteoclast formation and bone resorptive activity. In contrast, an ethanol extract of the aerial parts of IKN had a minor effect on RANKL-induced osteoclast formation. Mechanistically, the root part of IKN suppressed RANKL-induced p38 mitogen-activated protein kinase (MAPK) activation, effectively abrogating the induction of c-Fos and nuclear factor of activated T cells 1 (NFATc1) expression. IKN administration decreased LPS-induced osteoclast formation in a calvarial osteolysis model in vivo.
CONCLUSIONS
Our study suggested that the ethanol extract of the root part of IKN suppressed osteoclast differentiation and function partly by downregulating the p38 MAPK/c-Fos/NFATc1 signaling pathways. Thus, the root part.
PubMed: 37718903
DOI: 10.11005/jbm.2023.30.3.253 -
Swiss Dental Journal Feb 2024GSK-3 inhibitors, such as Tideglusib (TG) and CHIR-99021 (CHIR), show promise in stimulating reparative dentin formation. The aim of this study was to assess the...
GSK-3 inhibitors, such as Tideglusib (TG) and CHIR-99021 (CHIR), show promise in stimulating reparative dentin formation. The aim of this study was to assess the discoloration potential of TG and CHIR in an established in vitro model. Enamel-dentin specimens made from bovine incisors were randomly allocated to five groups (n=15 each): group bovine blood (BB), group dimethyl sulfoxide (DMSO), group TG, group CHIR, and group mineral trioxide aggregate (MTA). Each specimen had a central cavity in which the respective material was applied and sealed with resin-based luting material. Color determination was conducted using a dental spectrophotometer at t0 (before filling), t1 (immediately after filling), t2 (after one week), t3 (after one month), t4 (after three months), t5 (after six months), and t6 (after one year). Statistical analysis involved descriptive statistics, Kruskal-Wallis tests, and analysis of variance (α=0.05). Group BB and group CHIR exhibited the most significant decrease in lightness (ΔL*) after one year (ΔL*-4.7 and ΔL* -5.7, respectively), whereas groups DMSO, TG, and MTA showed minimal changes (DMSO ΔL*: -0.3; TG ΔL*: 1.4; MTA ΔL*: -0.5). Group BB and CHIR exhibited the highest ΔE values (6.4Å}0.6 and 6.5Å}0.8, respectively). Unlike CHIR, TG did not result in discoloration exceeding the threshold of visual perception, defined by a ΔE value of 5.5, during the one-year observation period. This laboratory study therefore suggests that TG could be utilized for indirect or direct pulp capping without major discoloration concerns. However, additional research is required to corroborate these findings.
Topics: Animals; Cattle; Drug Combinations; Aluminum Compounds; Silicates; Calcium Compounds; Oxides; Glycogen Synthase Kinase 3; Tooth Discoloration; Spectrophotometry; Dentin; In Vitro Techniques; Dental Enamel; Dimethyl Sulfoxide
PubMed: 37702307
DOI: 10.61872/sdj-2024-01-01 -
Journal of Dental Research, Dental... 2023This study aimed to investigate and compare the penetration and durability of two dentin desensitizers, sodium fluoride varnish and casein phosphopeptide-amorphous...
BACKGROUND
This study aimed to investigate and compare the penetration and durability of two dentin desensitizers, sodium fluoride varnish and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste, using electron microscopy.
METHODS
The study was performed on 60 dentin specimens prepared from extracted human premolars. After applying 17% EDTA to remove the smear layer, the specimens were divided into two groups. MI Paste and Bi-fluoride varnish were applied to the specimens. Microscopic images of 20 samples were obtained immediately. Twenty other samples were accessed after 15 days, and the other 20 were accessed after 30 days of toothbrushing and thermal cycling. Both surface and longitudinal cross-sectional images (after sample fracture) were studied. Data were analyzed with two-way ANOVA and Mann-Whitney U test at a significance level of <0.05.
RESULTS
The mean depth of material penetration was significantly time-dependent and fluctuated in both groups. There was a significant difference between the mean level of plugs between 0, 15, and 30 days (<0.001). Penetration increased with time for the MI Paste group, while in the Bi-fluoride group, the increase was significant at 15 and 30 days than immediately after application. The mean thickness of the plugs was significantly different at the three time periods, and MI Paste showed a sudden decrease in plug thickness after 15 days.
CONCLUSION
Immediately after application, Bi-fluoride occluded dentinal tubules more effectively, and its durability after abrasion and thermal fatigue were higher than MI Paste.
PubMed: 37649823
DOI: 10.34172/joddd.2023.28050 -
Materials (Basel, Switzerland) Aug 2023As dental 5 mol% yttria-stabilized (5Y-) zirconia demand high esthetics, it is necessary to clarify how the optical properties are affected by high-speed sintering,...
As dental 5 mol% yttria-stabilized (5Y-) zirconia demand high esthetics, it is necessary to clarify how the optical properties are affected by high-speed sintering, which is not yet fully understood. Our study aimed to investigate the effect of high-speed sintering on the translucency and opalescence parameters (TP and OP, respectively), as well as their related microstructure and phase distribution, using two types of multilayered 5Y-zirconia. Multilayered 5Y-zirconia (Cercon xt ML, Lava Esthetic) were cut layer-by-layer, followed by conventional and high-speed sintering. The TP and OP values were subsequently obtained using a spectrophotometer, and field emission scanning electron microscopy images were used to analyze the average grain size. The phase fractions were analyzed using X-ray diffraction. Regardless of the zirconia type, the TP was slightly lowered by high-speed sintering in all the layers except the dentin layer (DL) for Lava Esthetic ( < 0.05). The OP decreased by high-speed sintering in the DL for Cercon xt ML and in all the layers for Lava Esthetic ( < 0.05). The decrease in translucency after high-speed sintering was attributed to a decrease in the yttria-rich '-phase with low tetragonality, along with an increase in the yttria-lean -phase with high tetragonality.
PubMed: 37629861
DOI: 10.3390/ma16165570