Effectiveness of Clinpro XT in Reducing Dentin Permeability and its Resistance to Acid Challenges.

PURPOSE: To evaluate the efficacy of Clinpro XT in reducing dentin permeability and the stability of this effect after different acid challenges. MATERIALS AND METHODS: Sixty-five roots of extracted human third molars were used. From each tooth, one dentin specimen was prepared and connected to a fluid filtration system to measure the dentin permeability after each of the following steps: sample preparation; treatment with 37% phosphoric acid; application of Clinpro XT; three acid challenges. Specimens were randomly assigned to 5 groups (n = 13) according to the acidic solution applied: Coca-Cola, natural lemon juice, wine vinegar, white wine and Red Bull energy drink. An additional 10 third molars were used to evaluate the degree of occlusion of the dentinal tubules and the surface roughness. RESULTS: Clinpro XT statistically significantly reduced dentin permeability after just a single application. No statistically significant increase in dentin permeability could be detected after three consecutive challenges. The application of Clinpro XT promotes the occlusion of dentinal tubules and reduces the surface roughness. CONCLUSION: The Clinpro XT is effective in reducing dentin permeability. This effect persists even after acid challenges.

Topical application of bFGF on acid-conditioned and non-conditioned dentin: effect on cell proliferation and gene expression in cells relevant for periodontal regeneration.

MATERIAL AND METHODS: Periodontal regeneration is still a challenge in terms of predictability and magnitude of effect. In this study we assess the biological effects of combining chemical root conditioning and biological mediators on three relevant cell types for periodontal regeneration. Bovine dentin slices were conditioned with 25% citric acid followed by topical application of basic fibroblast growth factor (bFGF, 10 and 50 ng). We used ELISA to assess the dynamics of bFGF release from the dentin surface and RT-qPCR to study the expression of Runx2, Col1a1, Bglap and fibronectin by periodontal ligament (PDL) fibroblasts, cementoblasts and bone marrow stromal cells (BMSC) grown onto these dentin slices. We also assessed the effects of topical application of bFGF on cell proliferation by quantification of genomic DNA. RESULTS: Acid conditioning significantly increased the release of bFGF from dentin slices. Overall, bFGF application significantly (p<0.05) increased cell proliferation, except for BMSC grown on non-conditioned dentin slices. Dentin substrate discretely increased expression of Col1a1 in all cell types. Expression of Runx2, Col1a1 and Fn was either unaffected or inhibited by bFGF application in all cell types. We could not detect expression of the target genes on BMSC grown onto conditioned dentin. CONCLUSION: Acid conditioning of dentin improves the release of topically-applied bFGF. Topical application of bFGF had a stimulatory effect on proliferation of PDL fibroblasts, cementoblasts and BMSC, but did not affect expression of Runx2, Col1a1, Bglap and fibronectin by these cells.

Topical application of bFGF on acid-conditioned and non-conditioned dentin: effect on cell proliferation and gene expression in cells relevant for periodontal regeneration

Abstract Periodontal regeneration is still a challenge in terms of predictability and magnitude of effect. In this study we assess the biological effects of combining chemical root conditioning and biological mediators on three relevant cell types for periodontal regeneration. Material and Methods: Bovine dentin slices were conditioned with 25% citric acid followed by topical application of basic fibroblast growth factor (bFGF, 10 and 50 ng). We used ELISA to assess the dynamics of bFGF release from the dentin surface and RT-qPCR to study the expression of Runx2, Col1a1, Bglap and fibronectin by periodontal ligament (PDL) fibroblasts, cementoblasts and bone marrow stromal cells (BMSC) grown onto these dentin slices. We also assessed the effects of topical application of bFGF on cell proliferation by quantification of genomic DNA. Results: Acid conditioning significantly increased the release of bFGF from dentin slices. Overall, bFGF application significantly (p<0.05) increased cell proliferation, except for BMSC grown on non-conditioned dentin slices. Dentin substrate discretely increased expression of Col1a1 in all cell types. Expression of Runx2, Col1a1 and Fn was either unaffected or inhibited by bFGF application in all cell types. We could not detect expression of the target genes on BMSC grown onto conditioned dentin. Conclusion: Acid conditioning of dentin improves the release of topically-applied bFGF. Topical application of bFGF had a stimulatory effect on proliferation of PDL fibroblasts, cementoblasts and BMSC, but did not affect expression of Runx2, Col1a1, Bglap and fibronectin by these cells.

Avaliação in vitro de novos produtos na diminuição da permeabilidade dentinária antes e após desafios ácidos / In vitro evaluation of new products in regarding dentin permeability reduction before and after acid challenge model

Objetivo: avaliar in vitro a efetividade de aplicações sucessivas de diferentes produtos utilizados para o tratamento da hipersensibilidade dentinária cervical na redução da permeabilidade dentinária, assim como avaliar a resistência destes produtos a desafios ácidos. Material e métodos: foram utilizados 72 terceiros molares humanos íntegros para a preparação de 72 amostras, que foram ligadas a um sistema de pressão hidráulica para mensurar a permeabilidade dentinária após os seguintes passos: 1) preparação da amostra; 2) tratamento com ácido fosfórico a 37% durante 30 segundos; 3) cinco aplicações dos produtos testados; 4) primeiro desafio ácido; 5) segundo desafio ácido; e 6) terceiro desafio ácido. As amostras foram divididas aleatoriamente em seis grupos (n=12), de acordo com os tratamentos propostos: Desensibilize Nano P, Clinpro XT, dentifrício Colgate Sensitive Pró-Alívio, dentifrício Duraphat, dentifrício Sensodyne Repair e após restauração com resina composta (grupo-controle). Conclusão: que todos os produtos testados foram capazes de promover a redução da permeabilidade dentinária significativamente, sendo que os grupos Clinpro XT, Desensibilize Nano P e controle mantiveram esses níveis reduzidos estatisticamente até o terceiro desafio ácido, enquanto que os dentifrícios Duraphat, Sensodyne Repair e Colgate Sensitive Pró-Alívio mantiveram essas reduções estatisticamente significativas até o segundo desafio ácido.

Objective: to evaluate in vitro the effectiveness of successive applications of different products used for the treatment of cervical dentinal hypersensitivity, reducing dentin permeability, as well as to evaluate the resistance of these products, acids challenges. Material and methods: 72 intact human third molars were used for the preparation of 72 samples were bound to a hydraulic pressure system to measure the dentin after the following steps: 1) sample preparation; 2) treatment with 37% phosphoric acid for 30 seconds; 3) 5 applications of the products tested; 4) first challenge acid; 5) second challenge acid; 6) third challenge acid. The samples were randomly divided into 6 groups (n=12) according to the proposed treatments: Desensibilize Nano P, Clinpro XT, toothpaste Colgate Sensitive Pro-Relief, Duraphat toothpaste, toothpaste Sensodyne Repair and after restoration with composite resin (control group). Conclusion: all products tested were able to significantly promote the reduction of dentin, and the Clinpro XT groups Desensibilize Nano P and control these reduced levels remained statistically to the third challenge acid, while toothpaste Duraphat, Sensodyne Repair and Colgate Sensitive Pro-Relief kept these statistically significant reductions to the second challenge acid.

Avaliação do Biosilicato e do flúor gel acidulado na permeabilidade da dentina radicular: estudo in vitro / Evaluation of Biosilicate and acidulated fluoride gel on the permeability of root dentin: in vitro study

Objetivo: avaliar in vitro a efetividade do biosilicato adicionado ao flúor gel acidulado e do próprio flúor gel acidulado, na redução da permeabilidade dentinária antes e após desafios ácidos. Material e métodos: 240 espécimes de dentina radicular foram aleatoriamente divididos em dois grupos, que diferiram quanto ao tratamento da superfície (Biosilicato + flúor gel ou flúor gel), e dez subgrupos, que diferiram nos desafios ácidos (sucos naturais de limão, laranja, abacaxi, uva e acerola, Gatorade (limão), Coca-Cola, suco industrializado de laranja, vinagre e vinho branco). Os espécimes foram conectados a um aparelho de pressão hidráulica para medir a permeabilidade dentinária após as seguintes etapas: I) condicionamento com ácido fosfórico a 37% por 30 segundos; II) tratamento com biosilicato ou flúor gel; III) desafios ácidos da dieta, sendo essa última fase repetida duas vezes, somando desafios ácidos. Resultados: após análise estatística com os testes de Mann-Whitney, Kruskall-Wallis e Wilcoxon, ambos os produtos diminuíram estatisticamente a permeabilidade dentinária (p < 0,001), porém, o Biosilicato adicionado ao flúor gel promoveu uma permeabilidade residual menor do que o flúor gel (p < 0,001). Porém, quase todas as substâncias ácidas promoveram aumento gradativo da permeabilidade (p < 0,05), com exceção entre o segundo e terceiro desafio ácido com vinho branco nos espécimes tratados com Biosilicato. Conclusão: ambos foram efetivos em diminuir a permeabilidade, no entanto, os desafios ácidos resultaram no aumento gradativo da permeabilidade.

Objective: to evaluate in vitro the effectiveness of the biosilicate added to acidified gel fluoride and the acidifi ed fluorine gel itself, in the reduction of dentin permeability before and after acidic challenges. Material and methods: 240 specimens of root dentin were randomly divided into two groups, differing in surface treatment (Biosilicate + fl uorine gel or fl uorine gel), and ten subgroups, differing in acidic challenges (natural juices of lemon, orange, pineapple, Grape, and acerola, Gatorade (lemon), Coca-Cola, industrialized orange juice, vinegar and white wine). The specimens were connected to a hydraulic pressure apparatus to measure the dentin permeability after the following steps: I) conditioning with 37% phosphoric acid for 30 seconds, II) treatment with biosilicate or fluoride gel, III) acidic challenges of the diet, this last phase being repeated twice, adding acidic challenges. Results: after statistical analysis with the Mann- Whitney, Kruskall-Wallis, and Wilcoxon tests, both products had a statistically significant decrease in dentin permeability (p < 0.001), but Biosilicate added to fluoride gel promoted a lower residual permeability than fluoride gel analysis (p < 0.001). However, almost all the acidic substances promoted a gradual increase of the permeability (p < 0.05), except for the second and third acid challenges with white wine in the specimens treated with Biosilicate. Conclusion: both were effective at decreasing permeability, however, acidic challenges resulted in the gradual increase of root dentin permeability.

Efficacy of a bioactive material and nanostructured desensitizing on dentin hypersensitivity treatment / Eficácia de um material bioativo e dessensibilizante nanoestruturado no tratamento da hipersensibilidade dentinária

Introduction: Dentin hypersensitivity is a frequent occurrence in dental practice. It is clinically characterized by acute, short, and temporary pain in response to mechanical, chemical, thermal, or osmotic stimuli resulting from dentin exposure. Objective: To compare in vivo the effect of an experimental crystalline bioactive material and nanostructured desensitizing on the pain assessment among patients with cervical dentin hypersensitivity. Material and method: Thirty patients were selected for this study, who were randomly assigned to two groups (n=15) in a split-mouth design. Each patient received two treatments: group 1 (fluoride gel and bioactive material) and group 2 (fluoride gel and nanostructured desensitizing). Pain analyses were performed using a visual analogue scale, ranging 0-10. Baseline pain measurement was performed prior to initial treatment (T0) and new measurements were carried out weekly for 3 weeks (T1, T2, and T3) before materials were reapplied. Final pain analysis was performed 3 months after initial treatment (T4). Degree of pain reduction was calculated using the formula T0 - Tperiod after treatment. The data of the pain measurements were analyzed using 2-way repeated measure ANOVA and Tukey’s test (α=0.05). Result: Regardless of evaluation period, there was no statistical difference on pain reduction between the treatments (p>0.05). The degree of pain was reduced significantly in each evaluated period for all tested treatments (p<0.05), by approximately three degrees after 3 months. Conclusion: The tested desensitizing materials were effective on dentin hypersensitivity reduction.

Introdução: A hipersensibilidade dentinária é uma ocorrência frequente na prática clínica; clinicamente caracterizada por dor aguda, curta e temporária, em resposta ao estímulo mecânico, químico, térmico ou osmótico causada pela exposição dentinária. Objetivo: Comparar in vivo o efeito de um material bioativo cristalino experimental e um dessensibilizante nanoestruturado na avaliação da dor de pacientes com hipersensibilidade dentinária cervical. Material e método: Trinta pacientes foram selecionados para este estudo, que foram randomicamente divididos em dois grupos (n=15) em um desenho experimental de boca dividida. Cada paciente recebeu dois tratamentos: grupo 1 (flúor gel e material bioativo) e grupo 2 (flúor gel e dessensibilizante nanoestruturado). As análises de dor foram realizadas usando uma escala visual analógica, variando de 0-10. A mensuração da dor inicial foi realizada previamente ao tratamento inicial (T0) e novas análises foram realizadas semanalmente durante 3 semanas (T1, T2 e T3) antes da reaplicação dos materiais. A análise final da dor foi realizada 3 meses após o início do tratamento (T4). O grau de redução de dor foi mensurado pela fórmula: T0 - Tperíodo após tratamento. Os dados das mensurações de dor foram analisados pela ANOVA para medidas repetidas 2 critérios e teste de Tukey (α=0,05). Resultado: Independente do período de avaliação, não houve diferença estatística entre todos os tratamentos na redução da dor (p>0,05). O grau de dor reduziu significativamente em cada período avaliado para todos os tratamentos testados (p<0,05), aproximadamente três graus após 3 meses. Conclusão: Os materiais dessensibilizantes testados foram efetivos na redução da hipersensibilidade dentinária.

Erosão dentária: definição, etiologias, características clínicas e prevenção / Dental erosion: definition, etiology, clinical features and prevention ­ a literature review

O objetivo desta revisão narrativa foi expor a etiologia, o diagnóstico, as características clínicas e a prevenção da erosão, dado o ritmo da vida moderna e os padrões de beleza que impõem mudanças intangíveis nos cardápios alimentares. A erosão produz seis vezes mais remoção da estrutura dentária do que a abrasão, sendo dividida em extrínseca e intrínseca. A erosão extrínseca ocorre pelo consumo exacerbado de alimentos e bebidas ácidas, com o pH abaixo do crítico para a desmineralização. Comprimidos de vitamina C em excesso também causam desgaste dentário significativo. A erosão intrínseca (ácido clorídrico) só é neutralizada após algum tempo da ingestão do alimento, e episódios de vômito/regurgitação são os de maior potencial erosivo. Neste sentido, o enxágue com antiácidos pode neutralizar a perda do esmalte. Pacientes com bulimia nervosa possuem lesões cervicais linguais e nas incisais dos incisivos anteriores inferiores. Por outro lado, lesões oclusais e na região vestibular podem ocorrer pelo consumo extrínseco. Procedimentos que removem ou afetam a película adquirida podem levar à desmineralização. A saliva age mesmo antes do ataque ácido, como resposta do fluxo salivar aos estímulos ácidos. Dentes manchados sugerem que a erosão ácida e desgaste estão inativos, enquanto dentes livres de manchas sugerem que o processo erosivo está ativo. Entretanto, sua etiologia multifatorial não permite um diagnóstico preciso. Assim, o aconselhamento dietético, estimulação do fluxo salivar, otimização do uso do flúor, substituição de bebidas erosivas e medidas adequadas de higiene bucal são medidas preventivas. No entanto, ensaios clínicos consideráveis são necessários para confi rmar a eficácia destas propostas.

The aim of this narrative review is to highlight the etiology, diagnosis, clinical findings, and the preventive measures against erosion, given contemporary lifestyle and the beauty standards imposing intangible changes in dietary habits. Removal of tooth structure is six times higher in erosion than abrasion, being divided into intrinsic and extrinsic. Extrinsic erosion is exacerbated by consumption of acidic foods and beverages with pH below critical levels for demineralization. The excess of vitamin C tablets also cause signifi cant tooth wear. Intrinsic erosion (hydrochloric acid) is neutralized some time after meals, and episodes of vomiting/regurgitation have the most erosive potential. In this sense, rinsing with antacids can counteract the enamel loss. Patients with bulimia nervosa have lingual cervical lesions and at the incisal of mandibular anterior teeth. On the other hand, buccal and occlusal lesions can occur by extrinsic acid consumption. Procedures that remove or affect the dental pellicle can lead to demineralization. Saliva acts even before the acid attack raising the salivary flow in response to acid stimuli. Stained teeth suggest that acidic erosion and wear are inactive, while the opposite characterize active erosion. Nevertheless, its multifactorial etiology does not allow for an accurate diagnosis. Thus, dietary advice, stimulation of salivary fl ow, the fl uoride optimization use, replacement of erosive beverages, and adequate oral hygiene measures are preventive tools. However, considerable clinical trials are needed to confirm the efficacy of these proposals.

Anatomia aplicada às técnicas cirúrgicas periodontais / Anatomy applied to periodontal surgical techniques: a literature review

Em algumas situações clínicas, durante o tratamento da doença periodontal ou de defeitos relacionados à posição, quantidade e espessura dos tecidos gengivais, se faz necessária a aplicação de técnicas cirúrgicas para intervenção terapêutica dessas diferentes condições. Porém, para a correta execução desses procedimentos, o conhecimento anatômico se faz extremamente necessário, pois, em algumas situações, estruturas nobres podem estar presentes na área de intervenção cirúrgica. Dessa forma, o objetivo deste estudo foi realizar uma revisão das estruturas anatômicas da cavidade oral que podem interferir na aplicação de técnicas cirúrgicas periodontais. Dentre os procedimentos cirúrgicos praticados em Periodontia, os retalhos, os enxertos e a cirurgia de cunha distal são os mais críticos para a possível lesão de estruturas nobres. Estruturas vasculares, nervos e ductos de glândulas salivares encontram-se associados às regiões próximas da gengiva inserida, que é a área de interesse em uma abordagem cirúrgica periodontal. Dessa forma, o completo conhecimento da presença e localização dessas estruturas auxilia na prevenção de acidentes cirúrgicos durante a cirurgia periodontal.

In some clinical situation during the periodontitis treatment and/or morphological mucogingival defect treatment related with the position, size and thickness of the gingival tissue, the application of surgical techniques for treating these different conditions is necessary. However, for the correct execution of these procedures, the anatomical knowledge of structures is necessary due the fact that in some situations noble structures may be present in the surgical field. Thus, the aim of this study was to review the anatomical structures of the oral cavity. That can interfere the periodontal surgery techniques. Among the surgical procedures practiced in Periodontics, the opening of flaps, grafts and distal wedge surgeries are the most critical for the possible injury to noble structures. Vessels, nerves, ducts of salivary glands are adjacent with regions of the attached gingiva, which is the area of interest in a periodontal surgical approach. Thus, the complete knowledge of the presence and location of these structures helps in preventing surgical accidents during periodontal surgery.

A microscopic analysis of the effects of root surface scaling with different power parameters of Er,Cr:YSGG laser.

The aim of this study was to evaluate the effects of different power parameters of an Erbium, Cromium: Yttrium, Scandium, Gallium, Garnet laser (Er,Cr:YSGG laser) on the morphology, attachment of blood components (ABC), roughness, and wear on irradiated root surfaces. Sixty-five incisive bovine teeth were used in this study, 35 of which were used for the analysis of root surface morphology and ABC. The remaining 30 teeth were used for roughness and root wear analysis. The samples were randomly allocated into seven groups: G1: Er,Cr:YSGG laser, 0.5 W; G2: Er,Cr:YSGG laser, 1.0 W; G3: Er,Cr:YSGG laser, 1.5 W; G4: Er,Cr:YSGG laser, 2.0 W; G5: Er,Cr:YSGG laser, 2.5 W; G6: Er,Cr:YSGG laser, 3.0 W; G7: scaling and root planning (SRP) with manual curettes. The root surfaces irradiated by Er,Cr:YSGG at 1.0 W and scaling with manual curettes presented the highest degrees of ABC. The samples irradiated by the Er,Cr:YSGG laser were rougher than the samples treated by the manual curette, and increasing the laser power parameters caused more root wear and greater roughness on the root surface. The Er,Cr:YSGG laser is safe to use for periodontal treatment, but it is not appropriate to use irradiation greater than 1.0 W for this purpose.

Análise dos troncos radiculares, abertura das raízes e projeções cervicais de esmalte de furcas de molares superiores e inferiores. Estudo in vitro / Analysis of root trunks, opening of roots and cervical projections enamel furcas of upper and lower molars. In vitro study

O tratamento periodontal de dentes que apresentam lesão de furca, muitas vezes, tem resultados imprevisíveis devido a diversos fatores que podem dificultar a terapia ou influenciar no progresso da doença periodontal. Destes, o comprimento do tronco radicular pode contribuir para a lesão precoce das furcas ou mesmo trazer complicações para a aplicação do tratamento. A abertura das raízes pode orientar o tipo de tratamento a ser instituído e as projeções cervicais de esmalte podem dificultar a instrumentação da região, ou mesmo atuar como nicho de retenção de placa. Assim, o propósito deste estudo foi medir, por meio de um paquímetro digital, os troncos radiculares de 400 molares de banco, tanto os primeiros como os segundos, e tanto os superiores como os inferiores, assim como analisar, por meio de índice apropriado, o tipo da projeção cervical de esmalte e, por meio de classificação apropriada, a abertura das raízes, com o objetivo de orientar no diagnóstico e no plano de tratamento. Concluiu-se que há variação das medidas de tronco radicular entre as faces dos dentes avaliados e que uma maior projeção cervical de esmalte (PCE) correlaciona-se com uma diminuição do comprimento de tronco radicular na amostra avaliada, assim como os primeiros molares apresentam maior ocorrência de raízes com grau de abertura maior do que os segundos molares.

The smear layer created by scaling and root planing is physiologically eliminated in a biphasic process.

Mechanical instrumentation of the root surface causes the formation of a smear layer, which is a physical barrier that can affect periodontal regeneration. Although different procedures have been proposed to remove the smear layer, there is no information concerning how long the smear layer persists on root surfaces after instrumentation in vivo. This study assessed the presence of the smear layer on root surfaces over a 28-day period after subgingival instrumentation with hand instruments. Fifty human teeth that were referred for extraction because of advanced periodontal disease were scaled and root planed (SRP) by a single experienced operator. Ten teeth were randomly assigned to be extracted 7, 14, 21, and 28 days after SRP. Another 10 teeth were extracted immediately after instrumentation (Day 0, control group). The subgingival area of the instrumented roots was evaluated with scanning electron microscopy. Representative photomicrographs were assessed by a blinded and calibrated examiner according to a scoring system. A rapid and significant (p < 0.05, Z test) initial reduction in the amount of smear layer was observed at 7 days, and a further significant (p < 0.05) decrease was observed 28 days after SRP. Interestingly, even 28 days after SRP, the smear layer was still present on root surfaces. This study showed that the physiological elimination of the smear layer occurred in a biphasic manner: a rapid initial reduction was observed 7 days after instrumentation, which was followed by a slow process leading to a significant decrease 28 days after instrumentation.

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.

The smear layer created by scaling and root planing is physiologically eliminated in a biphasic process

Mechanical instrumentation of the root surface causes the formation of a smear layer, which is a physical barrier that can affect periodontal regeneration. Although different procedures have been proposed to remove the smear layer, there is no information concerning how long the smear layer persists on root surfaces after instrumentation in vivo. This study assessed the presence of the smear layer on root surfaces over a 28-day period after subgingival instrumentation with hand instruments. Fifty human teeth that were referred for extraction because of advanced periodontal disease were scaled and root planed (SRP) by a single experienced operator. Ten teeth were randomly assigned to be extracted 7, 14, 21, and 28 days after SRP. Another 10 teeth were extracted immediately after instrumentation (Day 0, control group). The subgingival area of the instrumented roots was evaluated with scanning electron microscopy. Representative photomicrographs were assessed by a blinded and calibrated examiner according to a scoring system. A rapid and significant (p < 0.05, Z test) initial reduction in the amount of smear layer was observed at 7 days, and a further significant (p < 0.05) decrease was observed 28 days after SRP. Interestingly, even 28 days after SRP, the smear layer was still present on root surfaces. This study showed that the physiological elimination of the smear layer occurred in a biphasic manner: a rapid initial reduction was observed 7 days after instrumentation, which was followed by a slow process leading to a significant decrease 28 days after instrumentation.

Preventive effect of a high fluoride toothpaste and arginine-carbonate toothpaste on dentinal tubules exposure followed by acid challenge: a dentine permeability evaluation.

BACKGROUND: Considering the current high use of high fluoride toothpastes, the aim of the study was to quantify alterations in the root dentine permeability submitted to treatment with a high fluoride toothpaste and 8% arginine, calcium carbonate, sodium monofluorophosphate toothpaste as a preventive treatment for dentinal tubules exposure followed by acid challenge. METHODS: Thirty-third molars were sectioned below the cementoenamel. The root segments were connected to a hydraulic pressure apparatus to measure dentine permeability after the following sequential steps (n = 10 per group): I) Baseline; II) treatment with phosphoric acid for 30 s (maximum permeability); III) Toothbrushing (1 min) according to the experimental groups (G1- control; G2- 5000 ppm fluoride toothpaste; G3- 8% arginine-calcium carbonate toothpaste); IV) acid challenge for 5 min (orange juice). The data were converted into percentage, considering stage II as 100%. RESULTS: The results have shown a statistically significant decreasing on dentine permeability after treatment with toothpaste (Friedman test and Dunn's post hoc test). Comparison among groups demonstrated a high increasing on dentine permeability when acid challenge was performed after toothbrushing with distilled water (control group) (Kruskal-Wallis and Dunn's post hoc test). CONCLUSION: The toothpaste treatment may provide sufficient resistance on dentine surface, preventing dentinal tubules exposure after acid challenge.

Blood clot stabilization on root dentin conditioned by the combination of tetracycline and EDTA

AIM: To assess the combined use of tetracycline (TTC) and ethylenediaminetetraacetic acid (EDTA) on clot formation, considering that EDTA may neutralize TTC acidity. METHODS: Planed human tooth roots were treated with saline solution, EDTA, TTC and their combination (EDTA followed by TTC and TTC before EDTA). Fresh human blood was applied on the conditioned surfaces to check clot adhesion and stabilization. A previously calibrated (kappa = 0.93) and blinded examiner scored scanning electron micrographs of the samples. Statistical analyses were performed using one-way ANOVA and Tukey's test. RESULTS: Application of TTC before EDTA presented the best results with the highest number of cells adhered to the root surface (p=0.046). Use of EDTA alone and EDTA before TTC disturbed clot stabilization when compared to control group (p<0.01). CONCLUSIONS: The use of TTC before EDTA seems to be able to keep blood cells viable to establish an organized clot and could be used by clinicians together with the conventional mechanical root scaling and planing...

Análise da morfologia e da adesão de elementos sanguíneos em superfícies radiculares instrumentadas com ultrassom piezoelétrico: estudo in vitro / Morphology and adhesion on blood components in root surfaces treated by a piezoelectric ultrasonic: an in vitro study

Objective: The aim of this study was to evaluate the morphology and adhesion of blood components on root surfaces instrumented with piezoelectric ultrasonic Piezon Master Surgery. Methods: 10 teeth were used in this study. The teeth had their proximal divided into four areas that received different treatments: Group 1: untreated control Group 2: scaling with manual instrument; Group 3: scaling with ultrasound; Group 4: Scaling with manual instruments and ultrasound. We obtained 20 samples, 10 of which were used to analyze the morphology and the other 10 were used for analysis of adhesion of blood components. The specimens were analyzed by scanning electron microscopy. Photomicrographs were analyzed by the scores of adhesion of blood components and the index of root morphology. The results were statistically by the Kruskall-Wallis and Mann-Whitney with a significance level of 95%. Results: The morphological analysis showed that the Group 1 had a surface unchanged in relation to other groups (Group 1 X Group 2 = 0.0025;Group 1 X Group 3 = 0.0003; Group 1 X Group 4 = 0.0003) and Group 2 presented a smoother surface compared to Group 1 and groupsinstrumented with ultrasound (Group 2 X Group 3 = 0.0025; Group 2 X Group 4 = 0.0025) there were no statistical differences betweenthe Groups 3 and 4. analysis of adhesion of blood components showed that the Groups 2, 3 and 4 had no statistically significant differencesbetween themselves, but more biocompatible surfaces promoted the surface untreated control (Group 1 X Group 2 = 0.02; Group 1 X Group3 = 0.04; Group 1 X Group 4 = 0.005). Conclusion: The instrumentation with piezoelectric ultrasonic promoted an irregular root surface, but did not negatively affect the adhesion of blood components.

Objetivo: Avaliar a morfologia e a adesão de células sanguíneas em superfícies radiculares instrumentadas com o ultrassom piezoelétrico Piezon Master Surgery. Métodos: Foram utilizados nesse estudo 10 dentes que tiveram suas proximais divididas em 4 áreas que receberam diferentes tratamentos: Grupo 1: controle sem tratamento; Grupo 2: raspagem com instrumento manual; Grupo 3: raspagem com ultrassom; Grupo 4: associação instrumento manual e ultrassom. Foram obtidas 20 amostras, sendo que 10 foram utilizadas para análise da morfologia e as outras 10 foram utilizadas para a análise de adesão de elementos sanguíneos. Os espécimes foram analisados em microscópio eletrônico de varredura. As fotomicrografias foram analisadas através dos scores de adesão de elementos sanguíneos e pelo índice de morfologia radicular e os resultados foram analisados estatisticamente através dos testes de Kruskall-Wallis e de Mann-Whitney com nível de significância de 95%.Resultados: A Análise morfológica demonstrou que o Grupo 1 apresentou uma superfície inalterada em relação aos outros grupos (Grupo 1 X Grupo 2 = 0.0025; Grupo 1 X Grupo 3 = 0.0003; Grupo 1 X Grupo 4 = 0.0003), e o Grupo 2 apresentou uma superfície mais lisa em relação ao Grupo 1e aos grupos instrumentados com ultrassom (Grupo 2 X Grupo 3 = 0.0025; Grupo 2 X Grupo 4 = 0.0025). Não houve diferenças estatísticasentre os Grupos 3 e Grupo 4. A análise de adesão de elementos sanguíneos demonstrou que o Grupo 2, Grupo 3 e Grupo 4 não apresentaram diferenças estatisticamente significantes entre si, porém promoveram superfícies mais biocompatíveis que a superfície controle sem tratamento (Grupo 1 X Grupo 2 = 0.02; Grupo 1 X Grupo 3 = 0.04;Grupo 1 X Grupo 4 = 0.005). Conclusão: A instrumentação com ultrassom promoveu uma superfície radicular irregular, porém não afetou negativamente a adesão de elementos sanguíneos.

In vitro evaluation of Biosilicate® dissolution on dentin surface: a SEM analysis / Avaliação in vitro da dissolução do Biosilicato® sobre a superfície dentinária: análise por meio da microscopia eletrônica de varredura

Introduction: Biomaterials such as bioactive glasses and glass-ceramics have been proposed for the treatment of dentinal hypersensitivity. Objective: to evaluate by scanning electron microscopy (SEM), the dissolution of a novel bioactive glass-ceramic (Biosilicate® 1-20 µm particles) on dentin surface samples, with different application methods and different dilution medium used for applying Biosilicate®. Material and Method: 280 dentin samples were randomly divided into four groups: (1) Biosilicate® plus fluoride gel applied with Robinson brush; (2) Biosilicate® plus fluoride gel applied with microbrush; (3) Biosilicate® plus distilled water applied with Robinson brush; (4) Biosilicate® plus distilled water applied with microbrush. After treatment, the samples were immersed in saliva at different periods (0, 15 and 30 minutes, 1, 2, 12 and 24 hours). Two photomicrographs were obtained from each sample and were further analyzed by a blind calibrated examiner according to a "Particle Dissolution Index" created for this study. Result: The data were analyzed using the Mann-Whitney, Kruskal-Wallis and Dunn's tests. There was no statistical difference among the degrees of dissolution between the 4 groups in any period. Conclusion: Biosilicate® can be incorporated in both substances without differences in the degree of dissolution of the particles in any of the evaluated periods and the application of dentine can be performed with both methods evaluated.

Introdução: Biomateriais, tais como vidros bioativos e vidros cerâmicos têm sido propostos para o tratamento da hipersensibilidade dentinária. Objetivo: Avaliar por microscopia eletrônica de varredura (SEM), a dissolução de uma nova vitrocerâmica bioativa (Biosilicato®, partículas de 1-20 µm) na superfície de amostras de dentina, com diferentes métodos de aplicação e de meio de diluição diferente, usado para aplicação de Biosilicato®. Material e Método: 280 amostras de dentina foram divididas aleatoriamente em quatro grupos: (1) Biosilicato® mais flúor gel aplicado com escova de Robinson, (2) Biosilicato® mais flúor gel aplicado com microbrush, (3) Biosilicato® mais água destilada aplicado com escova de Robinson; (4) Biosilicato® mais água destilada aplicado com microbrush. Após o tratamento, as amostras foram imersas em saliva, em diferentes períodos (0, 30 e 15 minutos, 1, 2, 12 e 24 horas). Duas fotomicrografias foram obtidas a partir de cada amostra e foram analisadas por um examinador calibrado cego de acordo com um "Índice de Dissolução de Partículas", criado para este estudo. Resultado: Os dados foram analisados usando o teste de Mann-Whitney, Kruskal-Wallis e Dunn. Não houve diferença estatística entre os graus de dissolução entre os quatro grupos em qualquer período. Conclusão: Biosilicato® pode ser incorporado em ambas às substâncias, sem diferenças no grau de dissolução das partículas em qualquer dos períodos de avaliação e a aplicação sobre da dentina pode ser realizada com os dois métodos avaliados.

Comparação in vitro da eficácia de diferentes formulações do gel de EDTA 24% no condicionamento da superfície radicular / In vitro comparison of different 24% EDTA gel formulations efficacy on root surface conditioning

Introdução: A biomodificação radicular visa a alterar a superfície radicular para auxiliar no reparo das estruturas periodontais de suporte destruídas pela doença periodontal. Objetivo: Avaliar por meio de microscopia eletrônica de varredura a eficácia do condicionamento químico com gel de EDTA 24% na remoção de smear layer e na exposição de fibras colágenas, verificando-se diferentes marcas comerciais, modos e tempos de aplicação. Material e Método: Um total de 225 amostras foram obtidas e distribuídas aleatoriamente em cinco grupos: soro fisiológico (controle); EDTA 24% (Farmácia Santa Paula); EDTA-T 24% (Farmácia Santa Paula); EDTA 24% (PrefGel; Straumann); EDTA 24% (Biodinâmica). As amostras de cada grupo foram redistribuídas aleatoriamente em subgrupos (n = 5) e condicionadas com os diferentes géis de EDTA nos tempos de 1, 2 e 3 minutos, e nos modos de aplicação tópica, fricção vigorosa e fricção suave. Os testes de Kruskal-Wallis e Dunn (p < 0,05) foram utilizados e aplicados separadamente para os fatores: marca comercial, tempo e modo de aplicação. Resultado: A análise estatística revelou que o gel de EDTA 24% da Biodinâmica promoveu a menor remoção de smear layer. Não foram detectadas diferenças estatísticas para os tempos de aplicação. O modo de aplicação fricção suave resultou em menor quantidade de smear layer residual. Conclusão: Todos os géis de EDTA 24% utilizados foram eficazes na remoção de smear layer e na exposição de fibras colágenas, independentemente do tempo de aplicação; no entanto, o modo de fricção suave foi mais efetivo. Na análise comparativa entre os produtos, o EDTA da Biodinâmica foi menos efetivo, já que promoveu menor remoção de smear layer e exposição de fibras colágenas.

Introduction: The main goal of root biomodification is to modify the root surface in order to improve the repair of periodontal tissues destroyed by periodontal disease. Objective: To evaluate the conditioning efficacy of 24% EDTA gel of different trademarks, considering the variables time and application method, by scanning electron microscopy. Material and Method: 225 samples were randomly assigned to five groups: sterile saline solution (control); 24% EDTA (Santa Paula Pharmacy); 24% EDTA-T (Santa Paula Pharmacy); 24% EDTA (PrefGel - Straumann); 24% EDTA (Biodinâmica). For each experimental group the gels were applied for 1, 2 or 3 minutes by topical application; vigorous or smooth friction. The Kruskal-Wallis and Dunn tests (p < 0,05) were used and individually applied to the variables commercial brand, time and type of application. Result: The statistical analysis showed that 24% EDTA Biodinâmica gel promoted less smear layer removal compared to the other groups. No significant differences could be detected among the different times of application. The smooth friction resulted in lower amount of residual smear layer. Conclusion: All 24% EDTA gels tested were able to remove smear layer and to expose dentinal tubules irrespective of application time; however, the application method by smooth friction was more effective than the other ones. The comparative analysis demonstrated that the Biodinâmica gel was the least effective product, promoting less smear layer removal and exposure of collagen fibers than the other EDTA gels.

Influence of nicotine and cotinine impregnation on the first step of periodontal regeneration: clot stabilization.

This study analyzes the clot stabilization on root surfaces of teeth impregnated with cotinine and nicotine and the influence of the scaling in the adhesion of blood components, observing the influence of new exposition to nicotine and/or cotinine after scaling. Fifteen human teeth extracted due to periodontal disease of non-smokers patients were selected and manually scaled. Four dentin blocks were obtained from each tooth (n = 60). Samples received blood application or reimpregnation with nicotine and/or cotinine, depending on the groups. Group 1: PBS immersion + root scaling + blood; group 2: nicotine + root scaling + blood; group 3: nicotine + root scaling + nicotine reapplication + blood; group 4: cotinine + root scaling + blood; group 5: cotinine + root scaling + cotinine reapplication+ blood; group 6: nicotine and cotinine + root scaling + nicotine and cotinine + blood. Samples were kept in 2 ml of each substance for 24 hours. Each group received a blood drop and was analyzed by SEM. The higher amount of blood components was present in teeth exposed to cotinine and the groups submitted to scaling and blood application in comparison with groups that received reapplication of toxic substances after scaling. The greater toxic effect on root dentin surface was after the exposure to nicotine and cotinine. Results suggest that periodontal healing may be delayed in smokers due to the direct inhibition of clot stabilization on the root surface when nicotine and cotinine are present concomitantly.

Wound healing of dehiscence defects following different root conditioning modalities: an experimental study in dogs.

OBJECTIVE: The purpose of this study was to investigate the periodontal healing pattern of dehiscence-type defects following different chemical root conditioning modalities. MATERIALS AND METHODS: Buccal osseous dehiscence defects were created on six teeth of seven dogs. After dental plaque accumulation, defects were treated with sterile saline solution (control group) or one chemical conditioning modality: citric acid (CA group), ethylenediaminetetraacetic acid (EDTA group), tetracycline (TTC group), citric acid + tetracycline (CA + TTC group), or tetracycline + citric acid (TTC + CA group). After 3 months of healing, clinical parameters were evaluated, and the animals were killed. Histological sections were processed, and a computer-assisted histometric analysis was used to evaluate the formation of new cementum, new bone, and epithelial apical migration. RESULTS: All treatments yielded significant improvements in terms of probing depth decrease and clinical attachment level gain compared to baseline values; however, without significant differences among the groups (p > 0.05; one-way ANOVA). The highest amount of new cementum was noted in the EDTA group (3.72 ± 0.83 mm, 77.6 %), while the lowest amount of new bone was observed in the TTC group (0.7 ± 0.94 mm, 14.3 %). However, no statistically significant differences could be observed among the groups regarding epithelial apical migration, new cementum, and alveolar bone formation (p > 0.05). CONCLUSION: Chemical root surface conditioning did not promote any significant improvement in periodontal healing pattern of dehiscence-type defects in dogs. CLINICAL RELEVANCE: Chemical root surface conditioning after surgical debridement did not promote positive or negative effects on periodontal healing pattern of dehiscence-type defects.