Estimation of cytokine levels in gingival crevicular fluid following the use of different gingival retraction systems in patients requiring fixed partial dentures - An original research.

Gingival retraction is essential to get a dry and debris free field, which enables the impression material to flow into the gingival sulcus and record the area apical to the finish line. Effective gingival retraction without damaging periodontal tissue is extremely important. Objective: To comparatively evaluate the amount of inflammation, as assessed by TNF-α in GCF induced by three different gingival retraction techniques. Methods: Ten patients with a minimum of three teeth that required biomechanical preparation for fixed prostheses and acceptable oral hygiene with no periodontal pathology were included. The patients each received an oral prophylaxis. After a washout period of 10 days patients with gingival index scores of 0 or 1 were included. Measurements of TNF-α was done at baseline, after 30 min, after 7 days and after 28 days using ELISA test kit specific to TNF-α. Results: The sample population for whom Magic Foam cord was used showed a massive reduction in the amount of TNF -α, from 78% at 7 days to 18.6% at 28 days. There was a reduction in the percentage of TNF -α produced in the samples where normal knitted cord was used and for those where Expasyl was used from 95% to 64.2% and from 70% to 48.3% respectively. Conclusion: Maximum amount of inflammatory response was seen with plain knitted gingival retraction cord. This was followed by Expasyl gingival retraction system and the least amount of inflammatory cytokine was recorded with Magic Foam retraction cord.

A newly developed patient fixation system using a dedicated mouthpiece and dental impression materials for head and neck radiotherapy: a preliminary study.

We evaluated the basic characteristics and efficacy of our newly developed patient fixation system for head and neck radiotherapy that uses a dedicated mouthpiece and dental impression materials. The present investigation demonstrated that with this system, the changes in the absorbed dose to water depending on the material of the mouthpiece were small, with a maximum of 0.32% for a 10-MV photon beam. For the dental impression material, we selected a silicone material with the lowest Hounsfield unit (HU) value that had little effect on the generation of artifacts and the quality of the X-ray beam. Multiphase magnetic resonance imaging (MRI) revealed that the head-up and -down motions in the thermoplastic shell without the mouthpiece were 5.76 ± 1.54 mm, whereas the motion with the mouthpiece decreased significantly to 1.72 ± 0.92 mm (P = 0.006). Similarly, the head-left and -right motion displacement decreased from 6.32 ± 1.86 mm without the mouthpiece to 1.80 ± 0.42 mm with the mouthpiece (P = 0.003). Regarding the tongue depressor function of the mouthpiece, the median distance from the hard palate to the surface of the tongue was 28.42 mm. The present results indicate that the new immobilization device developed herein that uses a mouthpiece and a thermoplastic shell is useful for suppressing patients' head motions and tongue positions.

Maxillary sinusitis caused by retained dental impression material: An unusual case report and literature review.

Surgical procedures in posterior area of maxillary might cause an oroantral communication and iatrogenic sinusitis. An undetected oroantral communication can cause the penetration of foreign bodies, such as dental impression materials, in the maxillary sinus, thereby contributing to persistent sinusitis. Given the occurrence of a very rare clinical and medicolegal case of persistent and drug-resistant sinusitis due to radiologically undetected fragments of silicone paste for dental impression in the maxillary antrum, a literature review was pursued through sensitive keywords in relevant databases for health sciences. All retrieved articles were considered and data about the kind of impression materials thrusted into the maxillary sinus, the diagnostic issues, the reported range of symptoms, and the occurrence of medicolegal issues were analyzed. The diagnosis resulted to be quite challenging and belatedly especially in case of healed oroantral communication and when the material retained in the maxillary sinus has similar radiodensity compared to the surrounding normal or inflammatory tissues. The case was then discussed in comparison with the reviewed literature for both clinical and medicolegal issues. Hints were provided to professionals to face the challenging diagnosis in similar rare cases and to avoid the possible related litigation.

Dosimetric Comparison of Superflab and Specially Prepared Bolus Materials Used in Radiotherapy Practice.

OBJECTIVE: This study compares standard commercial bolus material (Superflab) to custom prepared silicone dental impression material (CDIM) and play dough material (PDM) with respect to dosimetric properties and applicability by using ion chamber measurement and calculated dose values. MATERIALS AND METHODS: The CDIM bolus was prepared by mixing dental impression silicone material with enough water to maintain a density of about 1.0 g/cm3. The prepared bolus material is applied on an RW3 solid phantom by covering 10x10 cm2 area with 0.5-1 cm thickness. Ion chamber measurements were performed separately with and without bolus material application. The setup was scanned in CT and the same procedure was repeated in the TPS using the scan data, in which the Pencil Beam Convolution dose calculation algorithm was used. To compare the effect of bolus material on tissue, the Superflab bolus and CDIM bolus were applied with 1 cm of thickness on postmastectomy scar and dose calculations on TPS were performed. RESULTS: After comparison of the dosimetric values for Superflab, CDIM and PDM, we obtained statistically meaningful results between superflab and CDIM. For PDM, the results obtained with TPS and ion chamber measurements indicated that, it is not suitable to use in radiotherapy application due to its material properties. For the simulated skin dose values obtained at five random points on the scar tissue, the comparison of Superflab and CDIM TPS calculation results were not statistically significant. CONCLUSION: The CDIM is easy to prepare and apply on irregular mastectomy scar tissue and it prevents formation of air gaps in the application surface. Especially for curved anatomical regions such as scar tissue, inclusion of the bolus material in treatment planning protocol will reduce dose uncertainty in application. It is safe to use CDIM as an alternative to Superflab in radiotherapy application, whereas PDM is not useful in clinical practice due to its material properties.

The effect of disinfectants on the accuracy, quality and surface structure of impression materials and gypsum casts: A comparative study using light microscopy, scanning electron microscopy and micro computed tomography.

The aim of this study was to compare the effect of several commercially available disinfectants on the accuracy of various types of impression materials and their compatibility with gypsum including surface quality and structure evaluation. Four alginate and three elastomeric impression materials in combination with disinfectants Aseptoprint Liquid, Zeta 7 solution, Silosept and Dentaclean Form were tested. The dimensional changes, detail reproduction, the compatibility with gypsum and surface/subsurface morphology were evaluated using light microscopy, scanning electron microscopy and micro computed tomography. Two alginate materials disinfected in Dentaclean Form exhibited the most significant differences (p<0.0001). The loss of detail on some alginate impressions in combination with this disinfectant including deterioration and change of morphology of gypsum surfaces was observed. Porosity in subsurface area and exposed large particles were detected. It was confirmed that the desired properties of impressions may be negatively affected in combination with some disinfectants.

Estabilidade dimensional de moldes obtidos com alginato de armazenamento tardio / Dimensional stability of molds obtained with late storage alginate

Resumo Introdução Recentemente, vêm surgindo no mercado alguns alginatos de armazenamento prolongado. Não há, no entanto, um consenso na literatura a respeito da estabilidade dimensional destes materiais durante este armazenamento Objetivo Avaliar, por meio de método prático experimental, a estabilidade dimensional de um alginato de armazenamento tardio. Material e método O material de moldagem utilizado foi o alginato Hydrogum 5 (Zhermack). Uma matriz metálica cilíndrica foi utilizada para a realização das moldagens, com 38 mm de diâmetro externo, 30 mm de diâmetro interno e cuja superfície superior apresenta três linhas paralelas entre si com 25 mm de comprimento e 20, 50 e 75 µm de largura. Após o tempo de geleificação do material de moldagem, 16 moldes foram colocados em um umidificador e essas amostras foram fotografadas utilizando-se uma câmera digital (Canon EOS Rebel 3Ti, Canon) associada a um software para análise das imagens obtidas (ImageJ 1.52a, U.S. National Institutes of Health; DI). A calibragem da régua foi 10 cm e, posteriormente, três linhas foram medidas três vezes, para se obter uma média dos comprimentos das linhas. As amostras foram fotografadas nos seguintes intervalos: imediatamente, 24, 48, 72, 96 e 120 horas. Resultado Os dados mostraram diferenças estatisticamente significantes para o fator tempo quando comparada a leitura imediata com os demais períodos de tempo de leitura (p<0,001) e quando comparada a leitura após 24 h de armazenagem com os demais períodos de tempo (p<0,001). Não houve diferença estatística (p>0,05) quando os tempos de armazenamento de 48 h, 72 h, 96 h e 120 h foram comparados entre si. Todos os valores encontravam-se dentro dos valores preconizados pela ISO 21563:2013. Conclusão Os moldes dos alginatos testados podem ser armazenados por até cinco dias em 100% de umidade relativa.

Abstract Introduction Recently, some extended-pour alginate impression materials have been placed in the market. However, there is no consensus in the literature regarding the dimensional stability of these materials during these storage. Objective To evaluate, through the experimental model, the durability and velocity with respect to dimensional alteration, analyzing the material and detecting distortions. Material and method The material for molding in this test was alginate (Hydrogum 5, Zhermack). A cylindrical metallic matrix was used to make the moldings with: 38 mm of external diameter, 30 mm of internal diameter and superior of the upper series of the card 3d transport lines with each 25 mm in length and 20, 50 and 75μm in width. After the time of jellification / polymerization of the molding material, 16 molds were inserted in a doser and were photographed with a digital camera (Canon EOS Rebel 3Ti, Canon) associated with a software for analysis of sacred images (ImageJ 1.52a, US National Institutes of Health, DI). The calibration of the ruler was performed in 10 cm and then in 3 lines were means 3 (three) times to obtain a mean of the lengths of the lines. The photographs were taken at the following intervals: immediately, 24, 48, 72, 96 and 120 hours after being cast. Result The data were found when compared with the other parts of the reading time (p <0.001) and when compared to the execution after 24 hours of locomotion with the other parts of the time (p <0.001). The rest time of 48 hours, 72 hours, 96 hours and 120 hours were compared to each other. Conclusion The molds of the tested alginates can be stored for 5 days in 100% relative sauce.

Accuracy of partially edentulous arch impressions obtained from different alginates and storage times

Purposes: This study aimed to assess the dimensional accuracy of five commercial alginates verified in stone casts. Methods: Each alginate impression (Cavex ColorChange, Cavex Holland BV; Jeltrate Plus, Dentsply; Hydrogum, Zhermack; Kromopan 100, Lascod; Ezact Kromm, Vigodent) was performed on partially edentulous standard stainless steel mandibular arch cast with reference points on teeth 33, 43, 37 and 47. On the stainless steel cast, the anteroposterior (33-37 and 43-47) and transverse (33-43 and 37-47) distances were measured in a stereomicroscope at 30x magnification and 0.5 µm accuracy. The distances between these points were measured three times, obtaining an average, which was analyzed statistically and compared with the distances obtained from the stone casts. For each alginate the casts were poured gypsum (n = 5) immediately and after a period of 1, 2, 3 and 5 days of the impression procedure. Results: The dimensional accuracy values of stone and stainless steel casts were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). The results showed significant differences between the alginates; however, no differences in dimensional accuracy were found among the different storage times of alginate impression. Conclusions: It can be concluded that the alginate impressions can be stored for up to 5 days (AU)

Transferência precisa da morfologia do tecido mole peri-implantar em prótese anterior: relato de caso / Accurate transposition of peri-implant soft tissue morphology in anterior prosthesis: case report

O perfil de emergência em próteses implantossuportadas é a porção da restauração que emerge coronalmente do implante até a gengiva marginal livre, visando conferir suporte e estabilidade ao tecido mole peri-implantar, mimetizando o dente natural. As restaurações com contornos apropriados têm um efeito significativo na higiene bucal, saúde do tecido peri-implantar e estética. O maior desafio para a confecção de próteses implantossuportadas definitivas está na duplicação do perfil de emergência obtido com a prótese provisória para o modelo de trabalho, sendo que há várias técnicas publicadas, porém não há um consenso na literatura sobre qual método é mais preciso. O objetivo do presente estudo é apresentar, por meio do relato de um caso clínico, uma técnica de moldagem do perfil de emergência e tecido peri-implantar...

The emergence profile for implant-supported prostheses is the portion of the restoration that emerges coronally from the implant to the free gingival margin, giving support and stability to peri-implant soft tissues and mimicking the natural tooth. Restorations with appropriate contour have a significant effect on oral hygiene, health and esthetics of peri-implant tissues. The greatest challenge involved in manufacturing permanent prosthesis is the duplication of the emergence profile obtained with the provisional restoration secured to the cast. Several techniques have been published, but no consensus has been reached on the literature regarding which method is the most accurate. The objective of this study is to present a technique for molding the emergency profile and peri-implant tissues by presenting a clinical case...

Influence of retentive areas associated to onlay preparations on the dimensional stability of silicone impression materials

This study evaluated the effect of retentive areas on onlay preparations on the dimensional alterations in condensation and addition silicone materials. A standard model with an onlay preparation was made. Each impression material was used through the double or simultaneous impression technique (n=25), resulting in a hundred impressions of the same model. Impressions were poured with type IV dental stone. Digital images were taken with a light microscope and the distances between the reference points created on the plaster dies were compared with the ones on the standard model. In the occlusal, mesial-medium and mesial-cervical segments, the double impression (DI) with condensation silicone presented similar values compared to the standard model. The values of the addition silicone with DI were similar to the standard model only in the mesial-occlusal segment. In the other segments (distal-cervical, distal-medium and distal-occlusal), all groups were statistically different from the control. It could be concluded that addition and condensation silicone impressions provided plaster dies with significant dimensional alterations in most of the evaluated areas when compared to the standard model. The retentive areas related to the onlay preparation influenced the dimensional stability of the addition and condensation silicone impressions.

Este estudo avaliou as alteracoes dimensionais de silicones de condensacao e adicao usados em duas tecnicas como resultado de areas retentivas de preparos do tipo onlay. Um modelo padrao foi feito e vinte e cinco moldagens realizadas com os dois materiais, atraves da tecnica de dupla impressao ou impressao simultanea, e cada material resultou em 50 modelos de gesso. Imagens digitais foram feitas com um microscopio de luz e as distancias entre os pontos de referencia criados no modelo de gesso foram comparados aos pontos de referencia no modelo padrao. Nos segmentos oclusais, medio-mesial e cervico-mesial, a tecnica de dupla impressao (DI) com silicone de condensacao apresentou valores similares comparados ao modelo padrao. Os valores do silicone de adicao com DI foram similares ao modelo padrao somente no segmento mesio-oclusal. Nos outros segmentos (disto-cervical, medio-distal e disto-oclusal), todos os grupos foram estatisticamente diferentes do controle. Pode- se concluir que moldagens com silicone de adicao e condensacao conferem modelos de gesso com alteracoes dimensionais significativas na maioria das areas avaliadas, quando comparadas ao modelo padrao. As areas retentivas relacionadas ao preparo de onlay influenciaram na estabilidade dimensional das moldagens atraves dos silicones de condensacao e adicao.

The effect of glutaraldehyde disinfectant on the dimension stability of four high polymer impression materials / 实用口腔医学杂志

Objective:To measure the effect of disinfection on dimension stability of four high polymer impression materials which were separately immersed in 20 ml/L glutaraldehyde solution.Methods:Fifteen plaster replication models of four high polymer impression materials(Impregum Penta polyether, Express-Putty silicone, Silagum-Putty silicone, GC EXAFINE silicone) were made on the same metal master cast respectively. Vertical and horizontal dimensions between landmarks on the masters and plaster casts were measured with an optical microscope,one-way ANOVA was used to compare the measurements among the materials.Results:The difference between the masters and Casts in horizontal distances measured on Express-Putty silicone impression material produced models was longer than those on other high polymer impression materials produced ones after disinfection for 20 minutes and beyond clinical requirement. Compared with metal master cast, the difference became significant when these four silicone impression materials were disinfected for 40 minutes. Conclusion: Among the four kinds of impression materials, the Express-Putty silicone material is relatively the most accurate one after disinfection for 20 minutes.