Effectiveness of local and topical anesthesia during gingival retraction / Eficácia da anestesia local e tópica durante a retração gingival

Objective: To compare the effectiveness of local and topical anesthesia during gingival retraction in prepared abutment teeth. Material and Methods: 72 patients desiring full mouth rehabilitation or bilateral fixed partial denture in the same arch were selected based on the inclusion criteria framed and were randomly allocated into Groups A and B of 36 each. Patients in Group A received gingival retraction with topical anesthesia and Group B received gingival retraction with infiltration anesthesia. All the patients were tested for pain, discomfort and bleeding during gingival retraction. Results: There was no significant difference in pain, discomfort and gingival bleeding (P >.05) during gingival retraction using topical and local anesthetic agents. Conclusion: Topical anesthesia was equally effective as infiltration anesthesia in managing the pain, discomfort and bleeding during gingival retraction by cord packing in prepared abutment teeth. (AU)

Objetivo: Comparar a eficácia da anestesia local e tópica durante a retração gengival previa a moldagem em dentes pilares preparados. Material e Métodos: Foram selecionados 72 pacientes indicados para reabilitação bucal total ou prótese parcial fixa bilateral na mesma arcada com base nos critérios de inclusão formulados e alocados aleatoriamente nos Grupos A e B com 36 pacientes cada. Os pacientes do Grupo A receberam retração gengival com anestesia tópica e no Grupo B receberam retração gengival com anestesia infiltrativa. Todos os pacientes foram testados para dor, desconforto e sangramento durante o procedimento. Resultados: Não houve diferença significativa na dor, desconforto e sangramento gengival (P>. 05) durante a retração gengival com anestésicos tópicos e locais. Conclusão: A anestesia tópica foi tão eficaz quanto a anestesia de infiltração no controle da dor, desconforto e sangramento durante a retração gengival com fio retrator gengival em dentes pilares preparados.(AU)

Effect of Gingival Retraction Method to Lateral Gingival Displacement Width

Abstract Objective: To analyze the efficacy of retraction cord with a hemostatic agent in comparison with retraction paste on lateral gingival displacement, to achieve the success of fixed dental prostheses (FDP). Material and Methods: Test samples included 32 teeth that required treatment with metal-porcelain FDP at RSKGM FKG Universitas Indonesia. Impressions were taken before the gingival retraction procedure. From the 32 samples, 16 teeth were retracted using a combination of retraction cord and hemostatic agent, whereas the other half were retracted with retraction paste. Impressions were then taken. The sample was made using cutting die. Lateral gingival displacement width was measured on die-cast using an optical microscope Results: The mean value of group A before gingival retraction was 0.1695 mm, and after gingival retraction was 0.4705 mm. The mean value of group B before gingival retraction was 0.1767 mm, and after gingival retraction was 0.3289 mm. Lateral gingival displacement width between a combination of cord retraction and hemostatic agent group in comparison with the retraction paste group showed a significant difference (p<0.001). The combination of cord retraction and hemostatic agent group showed higher mean value Conclusion: Gingival displacement width as a result of cord retraction with the hemostatic agent was larger compared to the retraction paste. Even though both of them are still considered to be effective in providing access for impression material.

Abordagem interdisciplinar no tratamento das recessões gengivais: relato de caso / Interdisciplinary approach in the treatment of gingival recessions: case report

Objetivo: o artigo faz uma revisão literária com abordagem interdisciplinar acerca do tratamento das recessões gengivais, por meio de relato de caso, exemplificando características clínicas e protocolo de resolução. Relato de caso: paciente com queixa principal de insatisfação estética na região dos dentes 11 e 21,em que se observou a presença de recessões gengivais rasas associadas à esses, sendo maior a do incisivo central superior esquerdo com a presença de coroas provisórias acrílicas com contornos fisiológicos inadequados e núcleos metálicos fundidos. O plano de tratamento indicado inicialmente foi deslize coronal do retalho com enxerto de tecido conjuntivo na região dos dentes 11 e 21, com objetivo de recobrimento radicular e confecção de novas coroas provisórias. Considerações finais: a técnica cirúrgica do envelope, associada ao enxerto de tecido conjuntivo, promoveu ganho clínico de inserção e recobrimento radicular, representando uma alternativa viável e altamente previsível para o tratamento das recessões gengivais, principalmente aquelas relacionadas aos defeitos classe I e II de Miller. O tratamento interdisciplinar associando cirurgia periodontal e tratamento protético contribuiu para o aumento de espessura da mucosa ceratinizada e a estabilidade da margem gengival respectivamente; coroas provisórias confeccionadas com contornos fisiológicos dão suporte à margem gengival e, consequentemente, favorecem a saúde periodontal.(AU)

Objective: The study presents a literature review with an interdisciplinary approach to the treatment of gingival recessions, by means of a case report, exemplifying their clinical characteristics and resolution protocol. Case report: Patient with the major complaint of aesthetic dissatisfaction in the region of teeth 11 and 21, which showed the presence of shallow gingival recession associated with said teeth. The greatest recession was in the upper left central incisor with the presence of temporary acrylic crowns, inadequate physiological contours, and molten metal nuclei. The initial treatment plan was the coronal slide of the flap with connective tissue graft in the region of teeth 11 and 21 to cover the root and the production of new temporary crowns. Final Considerations: The surgical technique of the envelope associated with the connective tissue graft promoted the clinical gain of insertion and root coverage, representing a viable and highly predictable alternative for the treatment of gingival recessions, especially those related to Miller class I and II defects. The interdisciplinary treatment associating periodontal surgery and prosthetic treatment contributed to increase the thickness of keratinized mucosa and to the stability of the gingival margin, respectively. Temporary crowns produced with physiological contours support the gingival margin and consequently favor periodontal health.(AU)

A survey on the use of various gingival displacement techniques in fixed partial denture by the prosthodontists in vadodara city

Aims: To evaluate the use of various gingival displacement techniques prior to impression making in fixed partial dentures by the Prosthodontists in Vadodara. Settings and Design: Questionnaire based survey among prosthodontists in Vadodara city. Methods and Material: All the prosthodontists practitioners and those prosthodontists in academic institutes in Vadodara City, Gujarat, were surveyed through a questionnaire regarding their usage of gingival displacement technique and their reasons and methods of using gingival displacement technique for fixed partial denture. The results were analysed through discriminant statistical analysis. Results: Among all the Prosthodontists in Vadodara city, 62% prefer the use of gingival displacement technique for successful clinical practice while 38 % of them do not follow the procedure believing it does not make major difference in clinical practice. Conclusions: Those Prosthodontists who preferred the use of gingival displacement technique were able to detect many advantages of using it in their daily fixed partial denture practice and the percentage of prosthodontists not following gingival displacement technique blamed it as a time consuming affair and was not feasible on economic grounds for the class of patient they treated.

Técnicas de afastamento gengival em prótese dental: revisão da literatura / Gingival retraction methods in dental prosthesis: literature review

A proposta desta revisão da literatura foi avaliar as técnicas empregadas no afastamento gengival para prótese dental incluindo métodos mecânicos, químicos-mecânicos e cirúrgicos. A técnica de afastamento gengival deve ser previamente avaliada pelo profissional e a sua indicação, dependerá de cada situação clínica. Nesta revisão foram apresentadas as vantagens e desvantagens das técnicas de afastamento gengival incluindo fio afastador embebido ou não em soluções químicas, técnicas cirúrgicas, procedimentos a base de laser, curetagem gengival e eletro cirurgia. Após a realização desta revisão verificamos que o método químico-mecânico é o mais utilizado pelos profissionais. Atualmente podemos considerar que mesmo com a utilização de tecnologias mais elaboradas, como por exemplo scanners intraorais, quando o término do preparo dental estiver ao nível gengival ou subgengival se faz necessário o afastamento gengival. Para atingir o sucesso de uma prótese dental e importante coexistir uma harmonia entre a prótese e os tecidos periodontais circunvizinhos. (AU)

The aim of this review was to assess the use of gingival retraction methods in the fixed tooth supported prosthesis including mechanical, chemicals-mechanical and surgical methods. The choice of the best gingival retraction technique should be considered previously by the professional and it depends of each individual clinical conditions. In this review were discussed the advantages and the disadvantages of each gingival retraction technique including mechanical, chemical and surgical methods. In this review, we could understand that chemicals-mechanical technical is the most indicate by dentists. Nowadays, we can consider that even with the hightech use in dental area, such as intraoral scanners, when the margin of the restoration is placed sub-gingivally the gingival retraction should be considered. For the successful in dental prosthesis, a healthy coexistence between the restoration and their surrounding periodontal structure should be the goal of a prosthodontist. (AU)

Healing of the periimplant mucosal tissue injury after placing retraction cord subgingivally in beagle dogs / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This work aims to observe the healing of periimplant mucosal tissue injury in beagle dogs after subgingival retraction cord placement by examining the gingival index (GI), quantity of gingival crevicular fluid (GCF), and the proinflammatory cytokine in the GCF.</p><p><b>METHODS</b>In eight beagle dogs, the fourth mandibular premolars on the left side were extracted (n=8); after two months of healing, bone-level implants were installed. A plaque control regimen was performed throughout the duration of the experiment. After three months, retraction cords were placed subgingivally for 5 min before the cement-retained implant-supported crowns were cemented. GI, GCF quantity, and levels of tumor necrosis factor-alpha (TNF-α) in GCF were assessed before application and on days 1, 3, 7, 14, 28, and 56 after application.</p><p><b>RESULTS</b>GI, quantity of GCF, and TNF-α were significantly increased on days 1, 3, and 7 compared with those at the baseline and on days 14, 28, and 56 (P<0.05), and no statistically significant differences were observed among those on days 14, 28, and 56 and the baseline (P>0.05).</p><p><b>CONCLUSIONS</b>Under the circumstances of good oral hygiene, acute injury caused by placing retraction cord subgingivally in periimplant mucosal tissue of bone-level implant is reversible. GI, the quantity of GCF, and TNF-α on day 14 return to the baseline levels.</p>

Comparason of the clinical efficacy of different gingival retraction methods / 实用口腔医学杂志

Objective: To evaluate the effects of 4 gingival retraction methods. Methods: 48 premolars were selected from 12 periodontal healthy volunteers and were randomly divided into 4 groups(n = 12 teeth) and treated with different gingival retraction methods: Ultrapak E(group UL) and three kinds of cordless gingival retraction, including Expasy1 (group EX), Astringent Retraction Paste (group AS) and Racegel(group RA). Perfusing plaster models were prapaired after useing putty-wash impression technique. A 3D digital model was reconstructed by a 3-shape model scanner for each patient. Data were collected before and after gingival retraction and analysed by the Geomagic Studio 2013 in the mesial, middle, and distal sides of the selected teeth. Results: Effective width of gingival retraction were all obtained in the 4 groups. The most effective effects were observed in group UL, followed by group EX, group AS and group RA, among the groups, F = 1 114. 4, P＜ 0. 000 1. Conclusion: Cordless gingival retraction technic can achieve effective gingival retraction.

Observation of 120 cases of teeth with severe wedge-shaped defect treated with glass fiber post combined ;with gingival retraction / 中国基层医药

Objective To observe the effect of glass fiber post combined with gingival retraction in the treat-ment of teeth with severe wedge -shaped defect.Methods 53 patients with 120 teeth treated for severe wedge -shaped defect were selected.All the teeth were given root canal treatment,glass fiber post was applied after root canal prepared and resin was applied to fill wedge-shaped defect after gingival retraction.All the teeth were followed up for 2-3 years.Results In 2-3 years follow-up after treatment,there was no adverse outcome such as crown fracture or root fracture,neither filling material falling off in all the 53 patients with 120 teeth.The effect was good and satis-fied.Conclusion The indication should be strictly grasped and then it is convenient to apply glass fiber post com-bined with gingival retraction to treat premolar with severe wedge -shaped defect,and complete coronal restoration should be avoided to reduce the cost of health care.

Tratamento de recessão gengival com utilização da técnica de tunelização associada ao enxerto conjuntivo subepitelial ­ controle clínico de seis anos / Treatment of gingival recession with the tunneling technique and the subepithelial connective tissue graft ­ a 6-year clinical follow-up

O recobrimento radicular é indicado por razões estéticas, para reduzir a hipersensibilidade de raiz e para criar ou aumentar tecido queratinizado. Várias técnicas cirúrgicas têm sido descritas, com a decisão dependendo de parâmetros clínicos anatômicos e técnicos. A principal meta terapêutica é alcançar uma cobertura completa da raiz com um resultado estético satisfatório. Uma abordagem previsível para o recobrimento radicular é a técnica de tunelização associada ao enxerto de tecido conjuntivo subepitelial, matriz dérmica acelular (MDA) ou outros biomateriais. Neste relato de caso com controle clínico de seis anos foi realizada a recuperação do tecido gengival perdido na região do dente 13, com o uso de uma técnica minimamente invasiva: a técnica de túnel associado ao enxerto de tecido conjuntivo subepitelial. Esta associação resultou em um importante ganho de inserção e, além do recobrimento radicular, foram melhoradas a hipersensibilidade e a estética na região.

The root coverage is indicated for aesthetic reasons, to reduce root hypersensitivity and to create or to increase keratinized tissue. Several surgical techniques have been described, with the decision depending on anatomical clinical and technical parameters. The main therapeutic goal is to achieve full coverage of the root with a satisfactory cosmetic result. A predictable approach to root coverage is a tunneling technique associated with subpeithelial connective tissue graft, acellular dermal matrix (ADM) or other biomaterials. In this case report with a 6-year clinical follow-up, the gingival tissue lost at the tooth 13 region was recovered using a minimally invasive technique (tunneling + subepithelial connective tissue graft). This association contributed to a signifi cant attachment level recovery and, besides root coverage, hypersensitivity and esthetics were improved in the operated site.

Gingival recession: its causes and types, and the importance of orthodontic treatment

abstract Gingival recession has direct causes and predisposing factors. Orthodontic treatment is able to prevent recession and even contribute to its treatment, with or without periodontal approach, depending on the type and severity of gingival tissue damage. There is no evidence on the fact that orthodontic treatment alone might induce gingival recession, although it might lead the affected teeth (usually mandibular incisors or maxillary canines) to be involved in situations that act as predisposing factors, allowing direct causes to act and, therefore, trigger recession, especially when the buccal bone plate is very thin or presents with dehiscence. Several aspects regarding the relationship between orthodontic treatment and gingival recession have been addressed, and so has the importance of the periosteum to the mechanism of gingival recession formation. Clinical as well as experimental trials on the subject would help to clarify this matter, of which understanding is not very deep in the related literature.

Resumo As recessões gengivais têm causas diretas e fatores predisponentes. O tratamento ortodôntico pode prevenir as recessões e, até, contribuir para o seu tratamento, com ou sem uma abordagem por parte do periodontista, dependendo do tipo e da severidade do comprometimento dos tecidos gengivais. Não há evidências de que o tratamento ortodôntico possa induzir, de forma primária, as recessões gengivais, muito embora possa levar os dentes envolvidos (comumente, os incisivos inferiores e os caninos superiores) a situações que ajam como fatores predisponentes para que as causas diretas possam atuar e produzir recessões - em especial, quando deixa-se uma tábua óssea vestibular muito fina ou, até, com deiscência. Vários aspectos da relação entre o tratamento ortodôntico e as recessões gengivais já foram abordados, assim como a importância do periósteo no mecanismo de formação delas. Trabalhos clínicos e experimentais sobre o assunto ajudariam a esclarecer o assunto, que ainda se apresenta muito pouco aprofundado na literatura pertinente.

Retalho deslocado coronalmente com a utilização de enxerto conjuntivo subepitelial e Emdogain para recobrimento radicular ­ controle clínico de cinco anos / Coronally repositioned flap with subepithelial connective tissue graft and Emdogain for root coverage ­ a 5 year follow-up case report

Uma situação desafiadora na Odontologia é a recessão gengival. Seu tratamento deve ser capaz de promover um completo recobrimento do defeito da recessão com mínima profundidade de sondagem pós-tratamento, além de promover resultados de cor e textura na área recoberta compatível com a dos tecidos moles adjacentes. Algumas situações clínicas prévias devem ser observadas quando do exame do paciente, dentre elas: a etiologia da lesão, o grau de classificação e a existência de lesões cariosas na raiz exposta. Uma abordagem previsível para o recobrimento radicular é o retalho deslocado coronalmente associado ao enxerto de tecido conjuntivo subepitelial. As proteínas derivadas da matriz do esmalte vêm sendo utilizadas associadas a técnicas de recobrimento com o intuito de aumentar o potencial regenerativo da região. Neste relato, com controle clínico de cinco anos, foi realizada a recuperação do tecido gengival perdido na região do dente 31, com o uso da técnica do retalho deslocado coronalmente associado ao enxerto de tecido conjuntivo subepitelial e ao Emdogain. Esta associação resultou em um importante ganho de inserção, além da melhora estética na região para o paciente.

A challenging situation in dentistry is gingival recession. Its treatment should be able to promote a complete coverage of the recession defect with minimum post-treatment probing depth, in addition to promoting color and texture results in the covered area compatible with the adjacent soft tissue. Some previous medical conditions must be observed when examining the patient, among them the etiology, the degree of classifi cation and the existence of caries on the exposed root. A predictable approach to root coverage is the coronally repositioned flap associated with subepithelial connective tissue grafting. The enamel derived matrix has been associated with coverage techniques in order to increase the regenerative potential. In this 5 year case report, the lost gingival tissue was recovered at the region of tooth 31 using a coronally advanced fl ap associated to STG and Emdogain. There were esthetic improvements and better attachment levels observed in the clinical results.

Coverage of Miller class I and II gingival recessions treated with subepithelial connective tissue graft, acellular dermal matrix, and enamel matrix proteins. Pilot study / Recobrimento de recessões gengival classe I e II de Miller com enxerto de tecido conjuntivo subepitelial, matriz dérmica acelular, e proteína derivada da matriz do esmalte. Estudo piloto

Objective: The aim of this study was to compare clinical findings obtained in the treatment of gingival recessions using subepithelial connective tissue graft (SECT), acellular dermal matrix (ADM), and enamel matrix proteins (EMP). Material and method: Twelve patients with Miller class I and II recession in the canines or upper premolars were randomly divided into groups to receive treatments using SECT, ADM, or EMP. Clinical measurements were performed before and three months after surgical procedures. The data evaluated were as follows: percentage of root coverage, height and width of gingival recession, probe depth, clinical attachment level, and height and thickness of keratinized gingiva. The Kruskal-Wallis test complemented by Dunn's test was used to perform the between-group, analysis and the Wilcoxon test was used to perform the within-groups analysis. The tests were applied at the 95% confidence level. Result: The SECT and ADM groups had a higher percentage of root coverage and greater reduction in the height and width of gingival recessions compared to the EMP group (p< 0.05). Conclusion: The SECT and ADM are more effective in treating gingival recessions than EMP.

Objetivo: O objetivo desse estudo foi de comparar os achados clínicos obtidos no tratamento de recessões gengivais utilizando o enxerto de tecido conjuntivo subepitelial (SECT), a matriz dérmica acelular (ADM) e as proteínas derivadas da matriz do esmalte (EMP). Material e método: Doze pacientes que apresentavam recessões gengival classe I e II de Miller nos caninos e pré-molares superiores foram randomicamente alocados para receber o SECT, ADM ou EMP. Análises clínicas foram executadas antes e 3 meses após os procedimentos cirúrgicos. Foram avaliados os seguintes parâmetros: porcentagem de recobrimento radicular, altura e comprimento da recessão gengival, profundidade de bolsa a sondagem, nível clínico de inserção, altura e espessura da gengiva queratinizada. O teste de Kruskal-Wallis complementado pelo teste de Dunn foram usados para avaliar as diferenças entre os grupos em cada período enquanto que o teste de Wilcoxon foi utilizado para avaliar as diferenças dentro de cada grupo variando-se o período de avaliação. Os teste foram aplicados com nível de confiança de 95%. Resultado: Os grupos SECT e ADM apresentaram maior porcentagem de recobrimento radicular e maior redução da altura e comprimento das recessões do que o grupo EMP (p<0,05). Conclusão: O SECT e a ADM são mais efetivos no tratamento de recessões gengivais que o EMP.

Clinical investigation of three gingival retraction methods / 实用口腔医学杂志

270 patients underwent single crown prosthodontics were randomly divided into 3 groups(n =90)and received gingival retraction with single-cord,double-cord and gingival retraction paste respectively.The prosthesis quality of the 3 groups was not statistically significant (P =3.209).The patient satisfaction was more and the gingival retraction time of the paste group was shorter than those of the cord groups(P<0.05).

Afastamento gengival: técnicas e materiais / Gingival retraction: techniques and materials

Este trabalho teve como objetivo levar o leitor a uma revisão da literatura sobre os diferentes métodos de afastamento gengival, suas técnicas, indicações e contraindicações. Foram abordadas as variações dos métodos e técnicas, a fim de facilitar a escolha mais adequada às diferentes situações clínicas. São feitas considerações sobre as soluções químicas, os fios utilizados para o afastamento gengival, as pastas adstringentes, bem como a combinação entre eles. Foram elaborados quadros comparativos entre os diferentes métodos de afastamento gengival, entre as soluções químicas mais utilizadas e entre as diferentes marcas comerciais existentes.

This paper aims to take the reader on a review of literature about the diff erent methods of gingival retraction, their techniques, indications and contraindications. Variations of the methods and techniques were discussed in order to facilitate the most appropriate choice for diff erent clinical situations. Some considerations were made about the chemical solutions, the gingival retraction cords, as well as their combination. Comparative tables among the diff erent gingival retraction methods, the most used chemical solutions, and the diff erent trademarks were prepared.

Study of the relation between platelet count and periodontal condition in patients with immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is a disease associated to the decrease of platelet count in peripheral blood, with repercussion on the oral cavity, due to the potential risk of spontaneous bleeding or provoking it. The aim of this work was evaluate the relation between the platelet count of chronic IPT patients and their periodontal condition. Thereunto, 31 patients were evaluated; 15 with this pathology (group 1) and 16 Dentistry students with no hematologic disease (group 2). Both groups were examined in their periodontal condition through gingival condition index (G), periodontal attachment loss (P) and gingival recession (R), as well as blood tests were performed to verify the platelet count, further a questionnaire on the socioeconomic aspects, access to dentistry services and mouth health self-perception. It was observed that 68.8% of IPT patients' mouth sextants presented some degree of gingivitis, despite some 16.8% manifested loss of periodontal insertion. Gingival retraction occurred in only 2 patients of the group 1, and the average measure for this event in this group was 0.22mm. The questionnaires applied allowed characterizing the sample of the group 1 as low income and low education in relation to the group 2, but with need of dental treatment. We concluded, therefore, there was no direct relation between the platelet count of IPT individuals when the intraoral test was performed, and their periodontal conditions received the indexes "G", "P" e "R".

Cytotoxic effects of the extractions of three gingival retraction cords with different extraction time / 实用口腔医学杂志

Objective:To evaluate the toxic effect of 3 different gingival retraction cords.Methods:DMEMextraction of DL-adren-aline HCl,aluminium sulphate and non-drug retraction cords with the extraction time of 5,10,15 and 30 min were respectively pre-pared and were used to culture human gingival fibroblasts(HGFs)in vitro respectively.Cell proliferation was tested by MTT assay. Cell apoptosis was examined by Annexin/PI method.Results:The 3 gingival retraction cord extractions inhibited the roliferation,pro-moted the apoptosis of HGFs(P <0.05),the effects were related to the extraction time.Conclusion:The 3 retraction cords have time-dependant cytotoxity.

The effects of gingival retraction in the restoration of subgingival non-carious cervical lesions / 实用口腔医学杂志

120 teeth with wedge-shaped defects at subgingival depth of 0 ~2 mm were selected and divided into 3 groups(n =40).Gingival retraction code and EXPASYL gingival retraction paste were used for gingival retraction in the 2 retraction groups,and none retraction was used in the control group.After restoration of the defects,all cases were followed up for 1 year and 2 years.The results were evaluated by modified USPHS criteria.No significant difference was detected for 1 year and 2 year successful rates between the extraction groups(P >0.05).The successful rate in extraction groups was higher than that in the control group(P ＜0.05).

Effect of conventional and experimental gingival retraction solutions on the tensile strength and inhibition of polymerization of four types of impression materials

In the present study, two types of tests (tensile strength test and polymerization inhibition test) were performed to evaluate the physical and chemical properties of four impression materials [a polysulfide (Permlastic), a polyether (Impregum), a condensation silicone (Xantopren) and a polyvinylsiloxane (Aquasil) ,3; when polymerized in contact with of one conventional (Hemostop) and two experimental (Vislin and Afrin) gingival retraction solutions. For the tensile strength test, the impression materials were mixed and packed into a steel plate with perforations that had residues of the gingival retraction solutions. After polymerization, the specimens were tested in tensile strength in a universal testing machine. For the polymerization inhibition test, specimens were obtained after taking impressions from a matrix with perforations that contained 1 drop of the gingival retraction solutions. Two independent examiners decided on whether or not impression material remnants remained unpolymerized, indicating interference of the chemical solutions. Based on the analysis of the results of both tests, the following conclusions were reached: 1. The tensile strength of the polysulfide decreased after contact with Hemostop and Afrin. 2. None of the chemical solutions inhibited the polymerization of the polysulfide; 3. The polyether presented lower tensile strength after polymerization in contact with the three gingival retraction agents; 4. The polyether had its polymerization inhibited only by Hemostop; 5. None of the chemical solutions affected the tensile strength of the condensation silicone; 6. Only Hemostop inhibited the polymerization of the condensation silicone; 7. The polyvinylsiloxane specimens polymerized in contact with Hemostop had significantly lower tensile strength; 8. Neither of the chemical solutions (Afrin and Vislin) affected the tensile strength of the polyvinylsiloxane and the condensation silicone; 9. Results of ...

Contrast study on the clinical effects of electrosurgical retraction and secondary gingival retraction / 重庆医科大学学报

Objective:To observe and compare the clinical effects of electrosurgical retraction and secondary gingival retraction in fixed prosthodontics.Methods:68 teeth of 36 patients undergoing crown and bridge restoration were randomly distributed into 2 groups.Secondary gingival retraction and electrosurgical retraction were adopted to perform gingival retraction,take impression in sequence and make master cast respectively.Then,the time of gingival retraction and shoulder of preformed teeth,gingival condition and master cast were evaluated after gingival retraction.Results:25 of 33 teeth performed with secondary gingival retraction reached satisfactory level,while 8 teeth were unsatisfactory,with the satisfactory rate of 75.8%.28 of 35 teeth performed with electrosurgical retraction were satisfactory,but 7 teeth were not satisfactory,with the satisfactory rate of 80.0%.Time of gingival retraction by this two methods showed significant statistical difference,while the effects have no statistical difference.Conclusion:Electrosurgical retraction is a relatively good way of gingival retraction and worthy of clinical application because of easy and simple handling,easy exposure of clear dividing line between soft and hard tissue,satisfactory effects of gingival retraction,and quick recovery after surgery.