Which irrigating provides a better bond strength in glass fiber posts: Chlorhexidine or Sodium Hypochlorite? A systematic review with meta-analysis

The aim of this systematic review and meta-analysis was to evaluate the influence of the use of chlorhexidine on endodontic instrumentation on the bond strength of glass fiber posts with resin cements. The guiding question of the study was: “Is the bond strength of glass fiber posts greater when using chlorhexidine as an irrigator in endodontic treatment instead of sodium hypochlorite?”.This study was conducted according to Guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). In vitro studies were included that have compared chlorhexidine and sodium hypochlorite as an endodontic irrigator in the chemical-mechanical preparation.Eight studies were included in the qualitative analysis and seven in the meta-analysis. Both the analysis by subgroups and the total analysis, using a random effect model, showed no statistically significant differences between the groups (p> 0.05), either in the specific analysis for cervical root third (p = 0.30; 95% CI = -2.11, 6.91) or medium (p = 0.05; 95% CI = -0.03, 4.56), or nonspecific regarding the third to the root third (p = 0.48; 95% CI = -4.00, 1.86).There are no statistically significant differences in the bond strength of glass fiber posts and resin cements in teeth endodontically treated under irrigation by both chlorhexidine and sodium hypochlorite

Impact of adhesive and photoactivation method on sealant integrity and polymer network formation

We evaluated the influence of photoactivation method and hydrophobic resin (HR) application on the marginal and internal adaptation, hardness (KHN), and crosslink density (CLD) of a resin-based fissure sealant. Model fissures were created in bovine enamel fragments (n = 10) and sealed using one of the following protocols: no adhesive system + photoactivation of the sealant using continuous light (CL), no adhesive system + photoactivation of the sealant using the soft-start method (SS), HR + CL, or HR + SS. Marginal and internal gaps and KHN were assessed after storage in water for 24 h. The CLD was indirectly assessed by repeating the KHN measurement after 24 h of immersion in 100% ethanol. There was no difference among the samples with regard to marginal or internal adaptation. The KHN and CLD were similar for samples cured using either photoactivation method. Use of a hydrophobic resin prior to placement of fissure sealants and curing the sealant using the soft-start method may not provide any positive influence on integrity or crosslink density

Influence of Antioxidant Agents on the Marginal Seal of Class V Restorations

Svrha: Ovim se istraživanjem željelo ocijeniti in vitro učinak primjene antioksidacijskog sredstva – 10-postotnog natrijeva askorbata na deproteinizirani dentin stijenke kaviteta kompozitnih ispuna te na rubno brtvljenje. Materijali i postupak: Odabrano je 30 humanih ekstrahiranih trećih kutnjaka kod kojih su na bukalnim i lingvalnim plohama bili preparirani kaviteti V. razreda. Šezdeset kaviteta nasumce je bilo podijeljeno u šest skupina po deset uzoraka. U prvoj skupini na dentin je bila 15 sekundi primijenjena samo 37-postotna fosforna kiselina (demineralizacija); u drugoj se skupini nakon demineralizacije od 60 sekundi koristio 10-postotni natrijev hipoklorit (deproteinizacija); od treće do šeste skupine, nakon demineralizacije i deproteinizacije, bilo je upotrijebljeno antioksidacijsko sredstvo – 10-postotni natrijev askorbat i to u trajanju od 15 i 30 sekundi te nakon jedne minute i deset minuta. Zatim je bio primijenjen adhezivni sustav s jetkanjem i ispiranjem (Adper Single Bond 2; 3M/ESPE), a svi su kaviteti restaurirani kompozitom (Filtek Z250; 3M/ESPE). Nakon 24-satnog pohranjivanja u destiliranoj vodi na temperaturi od 37°C, uzorci su bili podvrgnuti termocikliranju (500 ciklusa) i uronjeni 24 sata u 2-postotno metilensko modrilo. Nakon toga su prerezani bukolingvalno te se određivala rubna mikropropusnost na spoju dentina i smole. Rezultati: Statistički značajna razlika zabilježena je između druge i šeste skupine (p=0,002) te treće i šeste (p=0,007). U mikropropusnosti između deproteiniziranih i nedeproteiniziranih skupina nije pronađena statistički velika razlika (p=0,300). Ipak, usporedbom srednjih vrijednosti mikropropusnosti dobivenih u skupinama nakon što je bilo primijenjeno antioksidacijsko sredstvo, zabilježena je znatna razlika između druge skupine i ostalih skupina (p=0,018). Zaključak: Primjena 10-postotnog natrijeva askorbata nakon deproteinizacije dentinskog supstrata omogućila je bolje rubno brtvljenje ispuna V. razreda, iako se navedeno antioksidacijsko sredstvo taložilo na površini dentina.Objective: To evaluate in vitro the effect of the application of the antioxidant agent 10% sodium ascorbate to deproteinized dentin on the marginal seal of composite resin restorations. Methods: Thirty extracted human third molars were selected and had class V cavities prepared on the buccal and lingual surfaces. The 60 cavities were randomly assigned to 6 groups of 10 specimens each. In G1, only 37% phosphoric acid was applied to dentin for 15 s (demineralization); In G2, after demineralization, 10% sodium hypochlorite was applied for 60 s (deproteinization); In G3-G6, after demineralization and deproteinization, the antioxidant agent 10% sodium ascorbate was applied for 15 s, 30 s, 1 min and 10 min, respectively. An etch-and-rinse adhesive system (Adper Single Bond 2; 3M/ESPE) was applied and all cavities were restored with composite resin (Filtek Z250; 3M/ESPE). After storage in distilled water at 37°C for 24 h, the specimens were subjected to a thermal cycling regimen (500 cycles) and immersed in 2% methylene blue for 24 h. The specimens were then sectioned in a buccolingual direction and the occurrence of marginal microleakage at the dentin/resin interface was assessed. Results: There was statistically significant difference between G2 x G6 (p=0.002) and G3 x G6 (p=0.007). No statistically significant difference (p=0.300) was found regarding microleakage between the deproteinized and the non-deproteinized groups. However, comparing the mean microleakage values obtained in the groups that received application of the antioxidant agent, significant difference was found between G2 and the other groups (p=0.018). Conclusion: The application of 10% sodium ascorbate after deproteinization of dentin substrate promoted a better marginal seal of class V restorations, although precipitation of this antioxidant agent occurred on dentin surface

Influence of Application Time of Antioxidant on the Deproteinized Dentin: a SEM/EDS Study

Svrha: U uvjetima in vitro željelo se procijeniti utječe li i kako primjena 20-postotnog natrijeva askorbata na deproteinizirani dentin, a za to se rabio elektronski mikroskop/rendgenska spektroskopija raspršivanja energije (SEM/EDS). Materijal i metode: Sedam ekstrahiranih humanih trećih kutnjaka odabrano je za istodobnu analizu sastava i dentinske površine uz pomoć SEM/EDS-a. Bilo je odabrano i poduzeto sljedeće: G1 – zdrav dentinski supsrat; G2 – demineralizirani dentinski supstrat demineraliziran 15 sekundi 37-postotnom ortofosfornom kiselinom prema uputi proizvođača; G3 – deproteinizirani dentinski supstrat deproteiniziran 60 sekundi uz neprekidno miješanje u 10-postotnoj vodenoj otopini natrijeva hipoklorida; G4, G5, G6 i G7 – demineralizirani i deproteinizirani dentinski supstrat primjenom 10-postotne vodene otopine natrijeva askorbata tijekom 15, 30, 60 sekundi te jednu minutu prema redoslijedu navedenih grupa. Uzorci su pregledani elektronskim mikroskopom (Quanta 2000 – Fei Company) opremljenim spektrometrom raspršujuće energije i naponom ubrzanja od 10 KV pri povećanju od 2000 X u vakuumu. Rezultati: Analiza SEM/EDS-om pokazala je progresivno odlaganje kristala natrijeva askorbata usporedno s povećanjem antioksidacijskog sredstva, stvarajući koru koja može prouzročiti zatvaranje pojedinih dentinskih tubula. Nije bilo statistički značajne razlike između G2 i G3 (p>0,05). Primjena 10-postotnog natrijva askorbata 60 sekundi smanjila je razinu kisika (P=0,029), magnezija (P=0,019) i natrija (P=0,029). Zaključak: Nakon primjene 10-postotnog natrijeva askorbata, progresivno se talože njegovi kristali i stvaraju koru na dentinskom supstratu koja začepljuje pojedine dentinske kanaliće.Objective: To evaluate in vitro the influence of application time of sodium ascorbate to 10% on the deproteinized by scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS). Methods: Seven extracted human third molars were selected. For analysis of the composition of the dentin surface by SEM/EDS, 7 samples were analyzed simultaneously as follows: G1: Healthy dentin substrate, G2: Demineralized dentin substrate with 37% phosphoric acid for 15 s (demineralization), strictly following the manufacturer’s recommendations, G3: Deproteinized dentin substrate after demineralization, 10% sodium hypochlorite aqueous solution for 60 s under constant agitation (deproteinization), G4, G5, G6 and G7: demineralized, deproteinized dentin substrate after application of 10% sodium ascorbate for 15 s, 30 s, 60 s, 10 min, respectively. The samples were examined by a scanning electron microscope (Quanta 2000 - Fei Company) equipped with an energy dispersive spectrometer with acceleration voltage 10 KV at ×2,000 magnification under vacuum. Results: The SEM/EDS analysis showed progressive deposition of sodium ascorbate crystals as the application time of the antioxidant agent increased, forming crusts which can cause occlusion of some dentinal tubules. There was no statistically significant difference between G2 and G3 (P>0.05). However, the application of 10% sodium ascorbate for 60 s resulted in a decrease in the oxygen (P=0.029), magnesium (P=0.019) and sodium (P=0.029) levels. Conclusion: After application of 10% sodium ascorbate, deposition of sodium ascorbate crystals occurred progressively forming crusts on dentin substrate, which causes occlusion of some dentinal tubules

Photobiomodulation Therapy in the Proliferation and Differentiation of Human Umbilical Cord Mesenchymal Stem Cells: An In Vitro Study

Introduction: Since photobiomodulation therapy (PBMT) favors in vitro mesenchymal stem cell (MSC) preconditioning before MSC transplantation, increasing the proliferation of these cells without molecular injuries by conserving their characteristics, in the present in vitro study we analyzed the effect of PBMT on the proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs).Methods: Irradiation with an InGaAIP Laser (660 nm, 10 mW, 2.5 J/cm2, 0.08 cm2 spot size, and 10 s) was carried out. The cells were divided into four groups: CONTROL [cells grown in Dulbecco’s Modified Eagle Medium (DMEM)], OSTEO (cells grown in an osteogenic medium); PBMT (cells grown in DMEM+PBMT), and OSTEO+PBMT (cells grown in an osteogenic medium-plus PBMT). The cell proliferation curve was obtained over periods of 24, 48 and 72 hours using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Osteogenic differentiation was analyzed by the formation of calcium nodules over periods of 7, 14 and 21 days. Morphometric analysis was performed to quantify the total area of nodular calcification.Results: The highest cell proliferation and cell differentiation occurred in the OSTEO+PBMT group, followed by the PBMT, OSTEO, and CONTROL groups respectively, at the observed times (P < 0.05).Conclusion: PBMT enhanced the osteogenic proliferation and the differentiation of hUCMSCs during the periods tested, without causing damage to the cells and preserving their specific characteristics, a fact that may represent an innovative pretreatment in the application of stem cells

Covid-19: a quarentena, o cidadão em seu contexto social e psíquico e implicações em sua saúde bucal / Covid-19: the quarantine, citizens in their social and psychological context and implications for their oral health

Coronavírus Disease (COVID-19), originada pelo Coronavírus SARS-CoV-2, teve seus primeiros relatos em dezembro de 2019, na cidade de Wuhan, província de Hubei – China. Dessa forma, visando conter a proliferação da doença e evitar superlotação das unidades de emergência, diversos países implantaram medidas restritivas de mobilidade da população. Fatores psicossociais e estilo de vida adotado pelo indivíduo podem influenciar diretamente nos seus hábitos de saúde em todas as etapas da vida. Avaliar a relação entre a qualidade de vida e a saúde bucal da população, antes e durante a quarentena, observando a influência que fatores externos podem causar nos hábitos e costumes da população. Trata-se de um estudo epidemiológico quanti-qualitativo e observacional com a população da região Nordeste do Brasil, com idade igual ou superior a 18 anos. Realizou-se um questionário, através da plataforma Google Forms (GF) e, devido ao distanciamento social imposto pela pandemia, o formulário Google foi disponibilizado por meio da plataforma WhatsApp, e-mail, QR Code e redes sociais dos pesquisadores. O questionário foi composto por 31 perguntas que foram distribuídas de forma que abrangessem sobre higiene bucal e seus sintomas antes da quarentena; cidadão e seu contexto social; estresse e sua influência sobre a saúde bucal; cidadão, seus anseios, e sua postura diante a quarentena e higiene bucal do cidadão e seus sintomas durante a quarentena. Evidências científicas que relacionam a saúde bucal e a COVID-19 são cada vez mais frequentes. Depressão, estresse, ansiedade, hábitos saudáveis e atendimentos odontológicos também foram afetados pela pandemia.