Evaluation of the effect of various beverages on the color stability and microhardness of restorative materials.

OBJECTIVE: The aim of this in-vitro study was to investigate the effects of frequently consumed beverages on the color stability and microhardness of various restorative materials. MATERIALS AND METHODS: Twenty-four samples were prepared in each group to examine the effect of different beverages on coloration and surface hardness of two direct composite resins (Filtek Z250, Filtek Z550); one indirect composite resin (Solidex); and one high viscosity glass ionomer cement (Equia Forte Fil). Samples were stored in four solutions (distilled water, black tea, coffee, and cola) at room temperature for 1 week (n = 6). The color values are taken at the beginning and the color and microhardness values taken at the end of 1 week were evaluated by the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The highest color change was observed in the Equia Fil, while the least color change was observed in the Z550 group. The highest degree of color change was observed in coffee and cola groups. While the lowest values of hardness were observed in the Solidex group, the highest values of hardness were observed in the Z550 group. The highest levels of hardness change were detected in the coffee and cola groups. CONCLUSION: The color and hardness of restorative materials can be negatively affected by consumed beverages. Nanohybrid composite resins are resistant to external coloration and hardness change.

Tendências atuais no tratamento endodôntico por cirurgiões dentistas no Brasil / Current trends in endodontic treatment by dental surgeons in Brazil

Objetivo: conhecer as principais práticas adotadas atualmente por cirurgiões dentistas, clínicos gerais e endodontistas na realização do tratamento endodôntico. Material e Métodos: um questionário contendo 21 perguntas de múltipla escolha foi enviado para os profissionais, nas cinco regiões do país. As perguntas abordaram o tempo de experiência, tipos de técnicas, materiais e recursos auxiliares. Resultados: a maior parte dos respondentes são do Sudeste e Sul, endodontistas há menos de 10 anos. Realizam até 20 tratamentos/mês, utilizam localizador apical, instrumentação manual com limas de aço inoxidável associada a brocas gates glidden/largo, lupa e isolamento absoluto. O hipoclorito de sódio (2,5 a 5%) e o EDTA são os irrigantes mais utilizados juntamente com o ultrassom. O tratamento é feito em sessão única, porém o diagnóstico pulpar pode alterar o número de sessões. Quando é necessário o uso de medicação intracanal, o hidróxido de cálcio associado a outras formulações é a primeira escolha. Para obturação do sistema de canais radiculares é utilizada a técnica de condensação lateral e o cimento à base de óxido de zinco e eugenol. O selamento coronário entre sessões é feito com coltosol e com cimento de ionômero de vidro ao término do tratamento, quando os pacientes são encaminhados a outro profissional para restauração final. Atualizam-se através de artigos científicos e mostram abertura para testar novos produtos. Conclusão: a maioria dos participantes aderem a práticas atuais com uso de novas tecnologias durante o tratamento e se atualizam através da leitura de artigos científicos

Objective: to be aware of the main practices currently adopted by general dentists and endodontists when performing endodontic treatments. Material and methods: a questionnaire containing 21 multiple-choice questions was sent to professionals in the five regions of Brazil. These questions covered experience time, techniques, materials and auxiliary resources. Results: most participants are from the Southeast and South regions of Brazil and have been specialized in endodontic for less than 10 years. They perform up to 20 treatments per month, use apex locator, manual instrumentation with stainless steel files associated with gates-glidden or largo burs, magnifying loupes and absolute isolation. Sodium hypochlorite (2.5 to 5.0%) and EDTA are the most used substances for irrigation associated with ultrasound. The treatment is done in a single visit, but pulp diagnosis might alter the number of visits. When intracanal medication is required, calcium hydroxide associated with other formulations is the first choice. For root canal filling, lateral condensation technique, zinc oxide and eugenol based sealers are used. Coronal sealing between sessions is done with Coltosol® and glass ionomer cement at the end of treatment, when patients are referred to another professional for final restoration. These professionals update their knowledge with scientific articles and show availability to test new products. Conclusion: most participants have been adhering to current practices (new technologies) during treatment and has kept updated by reading scientific articles

Evaluation of physical-mechanical properties, antibacterial effect, and cytotoxicity of temporary restorative materials.

The objective of this study was to compare selective physical-mechanical properties, antibacterial effects and cytotoxicity of seven temporary restorative materials (TRM): five resin-based materials [Bioplic (B), Fill Magic Tempo (FM), Fermit inlay (F), Luxatemp LC (L) and Revotek LC (R)], and zinc oxide-eugenol cement (IRM) and glass ionomer cement (GIC) as the controls. Material and methods The physical-mechanical properties were evaluated by determining microleakage (ML), ultimate tensile strength (UTS) and Shore D hardness (SDH). In addition, the polymerization rate (Pr-1), depth of cure (DC), water sorption and solubility (WS/SL) were evaluated. The antimicrobial effects of the materials were assessed by biofilm accumulation of Streptococcus mutans (BT) and the direct contact test (DCT) by exposure to Enterococcus faecalis for 1 and 24 h, and cytotoxicity by MTT assay. The data were analyzed by ANOVA or Kruskall-Wallis tests, and a complementary post-hoc method (p<0.05). Results Group B, followed by FM and GIC had significantly lower percentages of microleakage in comparison with the other groups; Groups FM and L showed the highest WS, while Groups R and FM showed the significantly lowest SL values (p<0.05). Group R showed the statistically highest UTS mean and the lowest DC mean among all groups. Group F showed the lowest S. mutans biofilm accumulation (p=0.023). Only the Group L showed continued effect against E. faecalis after 1 h and 24 h in DCT. The L showed statistically lower viability cell when compared to the other groups. Conclusions These findings suggest the antibacterial effect of the temporary materials Fill Magic and Bioplic against S. mutans, while Luxatemp showed in vitro inhibition of S. mutans biofilm accumulation and E. faecalis growth. Regarding the cell viability test, Luxatemp was the most cytotoxic and Fill Magic was shown to be the least cytotoxic.

Evaluation of physical-mechanical properties, antibacterial effect, and cytotoxicity of temporary restorative materials

Abstract The objective of this study was to compare selective physical-mechanical properties, antibacterial effects and cytotoxicity of seven temporary restorative materials (TRM): five resin-based materials [Bioplic (B), Fill Magic Tempo (FM), Fermit inlay (F), Luxatemp LC (L) and Revotek LC (R)], and zinc oxide-eugenol cement (IRM) and glass ionomer cement (GIC) as the controls. Material and methods The physical-mechanical properties were evaluated by determining microleakage (ML), ultimate tensile strength (UTS) and Shore D hardness (SDH). In addition, the polymerization rate (Pr-1), depth of cure (DC), water sorption and solubility (WS/SL) were evaluated. The antimicrobial effects of the materials were assessed by biofilm accumulation of Streptococcus mutans (BT) and the direct contact test (DCT) by exposure to Enterococcus faecalis for 1 and 24 h, and cytotoxicity by MTT assay. The data were analyzed by ANOVA or Kruskall-Wallis tests, and a complementary post-hoc method (p<0.05). Results Group B, followed by FM and GIC had significantly lower percentages of microleakage in comparison with the other groups; Groups FM and L showed the highest WS, while Groups R and FM showed the significantly lowest SL values (p<0.05). Group R showed the statistically highest UTS mean and the lowest DC mean among all groups. Group F showed the lowest S. mutans biofilm accumulation (p=0.023). Only the Group L showed continued effect against E. faecalis after 1 h and 24 h in DCT. The L showed statistically lower viability cell when compared to the other groups. Conclusions These findings suggest the antibacterial effect of the temporary materials Fill Magic and Bioplic against S. mutans, while Luxatemp showed in vitro inhibition of S. mutans biofilm accumulation and E. faecalis growth. Regarding the cell viability test, Luxatemp was the most cytotoxic and Fill Magic was shown to be the least cytotoxic.

Assessment of Coronal Leakage of Temporary Restorations in Root Canal-treated Teeth: An in vitro Study.

INTRODUCTION: Coronal leakage is one of the constant concerns in routine dental practice. It is one of the factors responsible for the failure of root canal therapy. Permanent restorations should be given as soon as possible after the completion of root canal therapy. If unavoidable, provisional restoration should be given in such a way that it maximally reduced the leakage of microorganisms and fluids from the external environment into the canal space. Hence, we evaluated the effect of saliva on the coronal leakage of temporary restorations. MATERIALS AND METHODS: Biomechanical preparation of the root canals of 204 fresh mandibular first premolar teeth was done using endodontic files with intermittent irrigation of sodium hypochlorite solution and ethylenediaminetetraacetic acid. Alternate irrigation with normal saline was done periodically. After preparation, drying of the canals was done using paper points followed by sealing of the apical foramen. For the assessment of the microleakage, Siqueira et al apparatus and method was used. All the specimens were divided into four groups based on the provisional restorative material used. All the groups were further divided into three subgroups based on the presence and absence of intracanal medicaments. Verissimo et al's criteria were used to check the turbidity at 1-, 2-, 3-, and 4-week interval respectively. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. Chi-square test was used to measure the level of significance, and p < 0.05 was considered to be significant. RESULTS: In group I, all the subgroups' specimens showed significant difference at 1 week's time. Only the subgroup with no intracanal medicaments in Cavit-containing provisional restoration showed nonsignificant alterations. Statistically significant alterations were seen at 1, 2, and 3 weeks' interval in all the subgroups except for one with intracanal medicaments. CONCLUSION: All the temporary restorative materials were not able to prevent microleakage after 1 week's time, with worst bacterial resistance shown by Ketac Molar and ionomer restorative material. Future studies are advocated for better prognosis of root canal therapy.

In vitro color and roughness stability of different temporary restorative materials.

OBJECTIVE: The aim of this study was to evaluate the effects of staining solutions on the color stability and roughness of different provisional resin material. MATERIAL AND METHODS: Three different materials were tested (two polymethylmethacrylate and one bis-acryl composite resins) in cola and coffee and for 1 and 4 weeks. 240 specimens were used - half of them polished and other half not. Color measurements were made before and after immersions using CIE L*a*b*. Surface roughness was measured using profilometer. Data was analyzed by ANOVA and Tukey HSD multiple comparison tests. RESULTS: The highest ΔE values were observed in the coffee. Unpolished and polished bis-acryl resin showed the highest ΔE values (p<0.00) in both intervals. The i-TEMP had the lowest or one of the least color changes. The time factor had influence on the color stability of provisional materials (p<0.01). The highest Ra values of polished specimens were observed in the cola; i-TEMP exposed the best result (p<0.00). The Pearson Correlation test showed a strong correlation between ΔE and Ra in provisional restorative materials in coffee and weak-moderate correlation in cola. CONCLUSIONS: The higher color stability of polished and unpolished specimens was shown by polymethylmethacrylate than bis-acryl resins. All polished specimens shown better color stability properties than unpolished except for the hot polymerization provisional materials (i-CAB). Polished polymethylmethacrylate showed better results of average roughness in comparison with bis-acryl resin. Cold-polymerization polymethylmethacrylate had better results of color and roughness stability than hot-polymerization polymethylmethacrylate.

A temporary filling material during endodontic treatment may cause tooth fractures in two-surface class II cavities in vitro.

OBJECTIVES: To investigate the effect of a zinc oxide/zinc sulphate-based cement as a temporary filling material during root canal treatment on the occurrence of cracks within the filling material or the tooth. MATERIALS AND METHODS: Root canals of 122 extracted human molars were prepared using ProTaper instruments. Standardized occlusal-distal cavities were prepared. After placing calcium hydroxide into the root canals, the teeth were divided randomly into four groups containing 33 specimens each. In the Coltosol group, the cavity was completely filled with Coltosol® F. In the Coltosol-Clearfil group, a 2-mm layer of Coltosol® F was placed into the apical part of the pulp chamber, and in the Clearfil group, a foam pellet was placed into the coronal pulp chamber. The remaining cavities were filled with Clearfil™. In the control group, the cavities were not restored. The teeth were stored at 37 °C for 14 days and examined every 24 h under a stereomicroscope. RESULTS: Fractures of the filling and/or the tooth were only observed in the Coltosol group. All Coltosol® F restorations had cracks after 24 h. Tooth fractures were found in 25 (76 %) teeth. Among these teeth, 21 (84 %) had crown fractures, four (16 %) had root-crown fractures. All root-crown fractures were vertical. CONCLUSION: Coltosol® F when used alone led to tooth fractures in two-surface class II cavities in teeth undergoing root canal treatment. CLINICAL RELEVANCE: Coltosol® F solely used as restorative material may lead to tooth fractures in two-surface class II cavities.

Uso de resina bisacrílica en la resolución estética en adolescente: caso clínico / The use of bisacrylic resin for the esthetic resolution in an adolescent: report of a clinical case

La estética constituye uno de los motivos de consulta de urgencia más frecuentes durante la adolescencia. Recientemente, fueron introducidos en el mercado, productos a base de resinas bisacrílicas. Tienen como componente principal metacrilatos multifuncionales con relleno de vidrio y/o sílice que constituyen la principal diferencia con los acrílicos convencionales. El objetivo de este trabajo es presentar un caso clínico de un paciente de 10 años de edad, resuelto en la Cátedra de Odontología Integral Niños de la Facultad de Odontología, Universidad de Buenos Aires, utilizando para la confección de restauraciones dentales temporales, una resina bisacrílica autopolimerizable.

Aesthetics is one of the most frequent reasons for urgent consultation during adolescence. Recently, products based on bisacrylic resins have been introduced on the market. They have as main component multifunctional methacrylates with filling of glass and / or silica that constitute the main difference with conventional acrylics. The objective of this work is to present a clinical case of a 10-year-old patient, resolved in the Chair of Integral Dentistry of the Faculty of Dentistry, University of Buenos Aires, using for the preparation of temporary dental restorations a bisacrylic resin self-cured.

Evaluation of color stability of different temporary restorative materials / Avaliação da estabilidade de cor de diferentes materiais restauradores provisórios

Introduction: Temporary restorative materials are widely used, however, little is know about their color stability. Objective: to evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage. Material and method: Four materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) and 30 test specimens (15 mm in diameter and 2 mm thick) per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee) and storage time intervals (2, 5, 7 and 15 days). Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%. Result: Acrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767). As regards solutions tested, coffee showed the highest color change values (p<0.001), and the longer the storage time interval, the greater was the color change in all the temporaryrestorative materials analyzed (p<0.001). Conclusion: Acrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.

Introdução: Os materiais restauradores provisórios são amplamente utilizados, porém pouco se sabe a respeito de sua estabilidade de cor. Objetivo: Avaliar a estabilidade de cor de materiais restauradores provisórios: resina acrílica e resinas bisacrílicas, após a imersão em soluções pigmentantes, durante diferentes períodos de armazenamento. Material e método: Quatro materiais foram testados (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) sendo confeccionadas 30 amostras (15 mm de diâmetro e 2 mm de espessura) por material. Estes foram divididos de acordo com o meio de imersão (saliva artificial, saliva + refrigerante tipo cola e saliva + café) e período de armazenamento (2, 5, 7 e 15 dias). As mensurações de cor foram realizadas antes e após as imersões, com auxílio de um espectrofotômetro, através do sistema CIE L*a*b*. Os dados foram analisados com análise de variância (ANOVA) e Tukey, com nível de significância à 5%. Resultado: A resina acrílica apresentou maior estabilidade de cor quando comparada às resinas bisacrílicas (p<0,001). Comparando as resinas bisacrílicas, não foi observado diferença significativa entre as resinas Structur e Luxatemp (p=0,767). Em relação as soluções testadas, o café apresentou os maiores valores de alteração de cor (p<0,001), sendo que quanto maior o período de armazenamento, maior foi a alteração de cor de todos os materiais provisórios analisados (p<0,001). Conclusão: A resina acrílica apresentou maior estabilidade de cor, quando comparada às bisacrílicas. O café causou a maior alteração de cor, e o tempo de imersão foi determinante na estabilidade de cor dos materiais provisórios analisados.

Effect of liquid polishing materials on the stainability of bis-acryl interim restorative material in vitro.

STATEMENT OF PROBLEM: The discoloration of interim restorations may negatively affect a patient's perception of treatment. PURPOSE: The purpose of this study was to investigate the effect of liquid polishing materials on the color stability of bis-acryl interim restorative material. MATERIAL AND METHODS: One hundred twenty specimens (10×2 mm) of a bis-acryl interim restorative material were divided into 3 groups. Group CO (control) was not subjected to any liquid polishing material. Groups GC and BC were polished with 2 liquid polishing materials. The specimens were then divided into 4 subgroups (n=10) and stored for 24 hours at 37°C in different staining solutions: coffee, coffee with sugar, cola, and distilled water. The color of the specimens was measured at baseline and after immersion with a spectrophotometer by using the CIE L*a*b* system, and color changes (ΔE) were calculated. The means of color change for each specimen were analyzed by 2-way and 1-way ANOVA tests. Post hoc comparisons were made with the Tukey HSD and Tamhane T2 tests. RESULTS: The application of liquid polishing materials significantly decreased the staining of autopolymerized bis-acryl interim restorative material (P<.01). Coffee with sugar resulted in higher ΔE values than coffee without sugar or cola. CONCLUSIONS: The use of liquid polishing materials significantly decreased staining when compared with bis-acryl specimens without liquid polish. The presence of sugar in coffee increased color change compared with coffee without sugar for all groups evaluated.

A temporary filling material used for coronal sealing during endodontic treatment may cause tooth fractures in large Class II cavities in vitro.

AIM: To investigate the use of a zinc oxide/zinc sulphate-based cement (Coltosol(®) F, Coltène Whaledent, Cuyahoga Falls, OH, USA) as a temporary filling material during multiple-visit root canal treatments and the occurrence of cracks within the filling material or the tooth. METHODOLOGY: Root canals of one hundred and twenty-two extracted human molars were prepared using ProTaper instruments up to size F2. After root canal preparation, standardized mesial-occlusal-distal cavities were prepared. The buccal-lingual/palatal width of the cavities was 4.5 mm), so that the remaining cavity walls had a mean thickness of 3.5 mm. Teeth were checked for cracks and fracture lines using a stereomicroscope with 10× magnification. A calcium hydroxide slurry was used as an intracanal dressing. The teeth were divided into three groups. In the Coltosol group, the cavity was filled with Coltosol(®) F. In the Coltosol-Clearfil group, a 2-mm layer of Coltosol(®) F was placed into the coronal pulp chamber, the remaining cavity was filled with Clearfil(™) . In the Clearfil group, a foam pellet was placed onto the orifices of the root canals, the remaining cavity was filled with Clearfil(™) . In the control group, the cavities were left without any filling material. The teeth were stored in water at 37 °C for 14 days and examined every 24 h under a stereomicroscope for fracture lines occurring on the tooth surface or in the filling material. RESULTS: In the Coltosol group, fractures within the filling material were observed in 28 (85%) of 33 teeth. 13 (39%) teeth had tooth fractures. Amongst these teeth, 8 (61%) had root fractures, 1 (8%) had a crown fracture and 4 (31%) had a root-crown fracture. CONCLUSION: Coltosol(®) F, when used alone as a restorative material, led to tooth fractures in Class II cavities in teeth undergoing root canal treatment. Tooth fractures may occur 4 days after placement of the filling.

Effects of surface treatment and artificial aging on the shear bond strength of orthodontic brackets bonded to four different provisional restorations.

OBJECTIVE: To evaluate the combined effects of material type, surface treatment, and thermocycling on the bond strength of orthodontic brackets to materials used for the fabrication of provisional crowns. MATERIALS AND METHODS: Four materials were included in this study (ProTemp, Trim Plus, Trim II, and Superpont C+B). Sixty cylindrical specimens (1 × 3 cm) were prepared from each material and equally divided into three groups. The first group was ground with silica carbide paper, the second was polished with pumice, and the last group was sandblasted with 50-µm aluminum oxide particles. Stainless-steel maxillary central incisor brackets (Victory Series, 3M) were bonded to the provisional material specimens with Transbond XT light-cured composite resin, and half of the specimens from each group were thermocycled 500 times in 5°C and 55°C water baths. Then the brackets were debonded with shear testing, and the results were statistically analyzed by three-way analysis of variance and Tukey's multiple-comparison tests at α  =  0.05. Adhesive Remnant Index (ARI) was also identified. RESULTS: Before and after thermocycling, ProTemp materials showed the highest shear bond strength with orthodontic brackets (10.3 and 13.1 MPa, respectively). The statistical analysis indicated an interaction among the three independent variables (P < .05) and statistically significant differences in bond strength among provisional materials (P < .001), surface treatments (P < .001), and thermocycling (P < .05). According to the ARI, most groups demonstrated adhesive failure. CONCLUSIONS: The provisional material type, surface treatment, and artificial aging have a significant effect on bond strength. Sandblasting treatment exerts a beneficial effect on shear bond strength.

Color stability and flexural strength of poly (methyl methacrylate) and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to beverages and food dye: an in vitro study.

AIM: To evaluate the color stability and flexural strength of poly (methyl methacrylate) (PMMA) and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to tea, coffee, cola, and food dye. MATERIALS AND METHODS: Two provisional crown and bridge resins, one DPI self-cure tooth molding powder (PMMA) (Group A), and one Protemp 4 Temporization Material (bis-acrylic composite) (Group B) were used. Disk-shaped specimens for color stability testing (n = 30 for each material) and bar-shaped specimens for flexural strength testing (n = 30 for each material) were fabricated using a metal mold. The specimens were immersed in artificial saliva, artificial saliva + tea, artificial saliva + coffee, artificial saliva + cola, and artificial saliva + food dye solutions and stored in an incubator at 37°C. Color measurements were taken before immersion, and then after 3 and 7 days of immersion. Flexural strength was evaluated after 7 days of immersion. RESULTS: Group A showed significantly higher color stability as compared to Group B, and artificial saliva + coffee solution had the most staining capacity for the resins. Test solutions had no effect on the flexural strength of Group A, but Group B specimens immersed in artificial saliva + cola showed significantly lower flexural strength values as compared to the control group. CONCLUSION: The findings of the study showed that for materials used in the study, PMMA was more color stable than bis-acrylic composite based resin. Also, material based on PMMA was more resistant to damage from dietary beverages as compared to bis-acrylic composite based provisional crown and bridge resin.

Impact of three radiographic methods in the outcome of nonsurgical endodontic treatment: a five-year follow-up.

INTRODUCTION: The periapical film radiograph (PFR) and digital periapical radiograph (DPR) techniques have some limitations in the visualization of small periapical lesions (PLs) when compared with cone-beam computed tomography (CBCT). However, the evidence supporting their effectiveness is very limited. This retrospective longitudinal cohort study evaluated the outcome of endodontic treatments measured/monitored by PFR, DPR, and CBCT during a 5-year follow-up and also determined the prognostic factors that influenced treatment success. METHODS: A total of 132 teeth (208 roots) with vital pulps received endodontic treatment. The periapical indexes with scores ≥2 for PFR and DPR and ≥1 for CBCT indicated the presence of PLs. Prognostic factors were determined by bivariate and multivariate analyses. Statistical significance was defined at a P level <.05. RESULTS: CBCT detected a higher number of PLs (18.7%, n = 39 roots), followed by DPR (7.7%, n = 16 roots) and PFR (5.7%, n = 12 roots). Likewise, CBCT was more sensitive than PFR and DPR in detecting deficiencies in extension and density of the root canal filling (P ≤ .001). Of the 17 prognostic factors evaluated, 4 were significantly associated with poor outcome to the treatment (P < .05): root canal curvature, disinfection of gutta-percha, presence of missed canals, and the quality of definitive coronal restoration. CONCLUSIONS: The success outcome of endodontic treatment after 5 years in teeth with vital pulps varied with each radiographic method: 94.3%/PFR, 92.3%/DPR, and 81.3%/CBCT.

In vitro color stability of provisional restorative materials.

BACKGROUND: Discoloration of provisional restorations can result in esthetic problems which are critically important in, for example, anterior areas and may compromise the acceptability of the restoration. AIMS: The purpose of this study was to investigate the effect of tea on provisional restorative materials. SETTING AND DESIGN: This study was designed to measure the degree of color change of three acrylic resin provisional materials, before and after immersion in artificial saliva and artificial saliva-tea solution for 2 and 4 weeks. MATERIALS AND METHODS: Three types of acrylic provisional materials (duralay, tempron, acropars TRP), were studied. Twenty disks (20 ± 0.1 mm by 2 ± 0.05 mm) were fabricated from each material. Specimens were polished with acrylic bur using pumice and diamond polishing paste. Base line color was measured using a spectrophotometer. Ten disks were stored in artificial saliva and 10 were stored in a solution of artificial saliva and tea at room temperature. Color measurements were made after 2 and 4 weeks of immersion. STATISTICAL ANALYSIS USED: Differences in color changes were compared by two way ANOVA, across the six groups, followed by a Turkey-Kramer's multiple comparison test. RESULTS: For specimens immersed in artificial saliva, the color change of methyl methacrylate materials; duralay (ΔE=4.94) and tempron (ΔE=6.54), was significantly more than butyl methacrylate material; acropars (ΔE=4.10). After immersion in an artificial saliva- tea solution, tempron exhibited less color change (ΔE=8.50) compared to duralay (ΔE=10.93) and acropars (ΔE=15.64). CONCLUSION: Color stability of methyl methacrylate is higher than butyl methacrylates so if provisional materials are used for extended periods of time; tempron is preferred.

Influence of treatment modalities of prepared teeth on retention of cast metal copings bonded with self-adhesive resin cements.

OBJECTIVE: To evaluate the influence of different conditioning methods of prepared teeth on the retention of cast metal copings bonded with two self-adhesive resin cements. METHOD AND MATERIALS: Mandibular first molars (n = 80) were prepared to receive metal copings. Sixteen molars were stored in water without interim copings as a control group (CG), while 64 molars were covered with interim copings. Eighty cast copings were laboratory fabricated from Ni-Cr alloy. Interim copings were removed, and 64 molars were cleaned and divided into four groups (n = 16) according to pretreatment methods of prepared molars: no pretreatment (T-NT) and conditioning with self-etching adhesive (T-SE), polyacrylic acid (T-PA), or ethylenediaminetetraacetic acid (EDTA) (T-ED). Each group was further subdivided into two subgroups (n = 8) according to luting cements. RelyX Unicem and seT self-adhesive resin cements were used for cementation of copings. Specimens were stored in water at 37°C for 6 months and then cyclically loaded and thermal cycled. Retentive stress in N was recorded for each specimen. Statistical analyses were conducted with two- and one-way ANOVA and Tukey HSD test. RESULTS: Retentive stress ranged from 526.7 to 692.9 N for RelyX Unicem and 339.8 to 492.3 N for seT. There were no statistically significant differences between the mean retentive stress of the CG, T-SE, and T-PA groups (P > .05). The mean retentive stress of group CG was significantly higher than mean retentive stress of groups T-NT and T-ED (P < .05). The mean retentive stress of the control and test groups bonded with RelyX Unicem was significantly higher than the mean retentive stress of the same groups bonded with seT. CONCLUSION: Conditioning of prepared teeth using polyacrylic acid or self-etching adhesive significantly increased the retentive stress of cast metal copings.

Is endodontic treatment performed under general anaesthesia technically acceptable?

OBJECTIVES: Undertaking endodontic treatment under general anaesthesia (GA) is often described as difficult and hazardous, but no study reports on safe and efficacious conditions for endodontic treatment under GA. This study aims to evaluate whether compromises made for the endodontic treatment of permanent teeth under GA are acceptable. It describes the quality of endodontic treatment undertaken in two series of consecutive patients treated either under GA or local anaesthesia (LA). MATERIALS AND METHODS: Post-operative data sheets and periapical radiographs were collected for 255 permanent teeth treated under GA during a 4-year period (GA group, 125 patients with special needs) and for 246 permanent teeth treated under local anaesthesia over 7 months (LA group, 180 healthy patients). The radiographic criteria for quality of endodontic treatment (RCQET) were considered satisfactory when (1) the root filling was within 2 mm of the apex; (2) the filling displayed no voids or defects; and (3) all the visible canals had been obturated. The type of tooth, pulpal status and periapical status were considered independent variables for RCQET. RESULTS: The proportion of satisfactory RCQET reached 63% in both groups and differed by type of tooth, being significantly lower for molars than for other teeth. CONCLUSION: From a technical point of view, compromises made for the endodontic treatment of permanent teeth under GA are acceptable. Further studies should be conducted to evaluate the long-term success of endodontic treatment performed under GA. CLINICAL RELEVANCE: This study supports the feasibility of endodontic treatment for patients treated under GA.

The effectiveness of using different pulp-capping agents on the healing response of the pulp.

BACKGROUND: Some of the disadvantages of calcium hydroxide Ca(OH) 2 as pulp-capping material are related to the inflammatory response, and its poor sealing ability. Cyanoacrylate glue was proposed in this study as pulp-capping agent because of its sealing ability, and diprogenta, on the other hand, was proposed because of its anti-microbial and anti-inflammatory effects. The aim of this study is to evaluate and compare the histopathological response of the pulp toward cyanoacrylate and diprogenta in direct pulp capping (DPC). MATERIALS AND METHODS: Cyanoacrylate, diprogenta, and calcium hydroxide were applied on 20 permanent teeth of 6 rabbits divided into four groups, each contains five teeth, as follow: G1: Diprogenta and calcium hydroxide. G2: Cyanoacrylate. G3: Diprogenta and cyanoacrylate. G4: Calcium hydroxide (control group). RESULTS: A remarkable dentin bridge formation was found in all groups. No pulp necrosis was found in any tooth of the four groups. Pathological reactions of the pulp were found in 25%, 40%, 20%, and 100% of groups 1, 2, 3, and 4, respectively. Differences between study and control groups were found statistically significant ( P < 0.05). CONCLUSION: All materials used in this study were biocompatible and suggested to be studied further on human teeth. These materials when used in combination with Ca(OH) 2 , may give better results.

Effect of dentin-cleaning techniques on the shear bond strength of self-adhesive resin luting cement to dentin.

OBJECTIVE: This in vitro study evaluated the influence of different cleansing techniques on the bond strength of self-adhesive cement to dentin. METHODS AND MATERIALS: A total of 33 noncarious human molars were sectioned mesiodistally and embedded in chemically cured resin with the buccal or lingual surfaces facing upward. Superficial dentin was exposed and resin disk provisional restorations were cemented to the dentin surfaces with noneugenol provisional cement and were stored in distilled water at 37°C. After seven days, the provisional restorations were removed and 13 specimens were randomly assigned to each of the five groups (n=13), according to the following cleansing treatments: G1-excavator (control); G2-0.12% chlorhexidine digluconate; G3-40% polyacrylic acid; G4-mixture of flour pumice and water; and G5-sandblasting with 50 µm aluminum oxide particles at a pressure of 87 psi. Resin composite disks (Filtek Supreme Plus, 3M ESPE Dental Products, St Paul, MN, USA) 4.7 (±0.1) mm in diameter and 3.0 (±0.5) mm in height were cemented with self-adhesive cement (RelyX Unicem, 3M ESPE), photocured, and stored in distilled water at 37°C for 24 hours. Shear bond strength testing was conducted using a universal test machine at a crosshead speed of 0.5 mm/min until failure. RESULTS: Data were analyzed using analysis of variance (ANOVA) and the Tukey-B rank order test. Sandblasting with aluminum oxide (11.32 ± 1.70 MPa) produced significantly higher shear bond strength values compared with any other treatment groups (p<0.05). No significant differences were found between G1-control (7.74 ± 1.72 MPa), G2-chlorhexidine (6.37 ± 1.47 MPa), and G4-pumice (7.33 ± 2.85 MPa) (p<0.05).

Comparação da resistência de cimentos restauradores provisórios utilizados em Endodontia / Comparison of compressive strength of different temporary filling materials used on root canal treatment

O selamento provisório da abertura coronária, entre sessões do tratamento endodôntico, éum procedimento de rotina e de suma importância para o sucesso do tratamento, no qualdeve possuir características tais como resistência e bom selamento periférico entre outras.Este trabalho avaliou in vitro a resistência de diferentes cimentos restauradores provisóriosutilizados em Endodontia - Cimpat Branco, Cimpat Rosa, Villevie, Tempore, IRM, Citodure Coltosol. Para referida pesquisa foram confeccionados através de uma forma feita emsilicona, três corpos de prova de cada material totalizando uma amostragem de 21 corpos.Todos os cimentos foram encubados em 37°C a 100% de umidade por 7 dias. As amostrasforam levadas para uma prensa de compressão simples e através do cálculo se obtevea força máxima de resistência. Os resultados obtidos mostraram que houve diferençaestatisticamente significante ao nível de 5% entre os cimentos testados, sendo que o IRMapresentou o melhor resultado, e o Tempore demonstrou o pior resultado de resistência.

The temporary sealing of the coronary opening among sessions of the endodontic treatmentis a routine procedure and important pace for the success of the treatment, where itneeds to have characteristics such as compressive strength and good sealing ability andothers. This in vitro study evaluated the compressive strength of different temporary fillingmaterials used on root canal treatment - white Cimpat, pink Cimpat, Villevie, Tempore,IRM, Citodur and Coltosol. It was made a form to prepare 3 samples of each material,resulting 21 samples, what were incubed at 37°C in 100% humidity for 7 days. After period,the samples were put in a machine of simple compression, through a formula resulted tocompressive strength. The results showed statistical difference between groups (á<0.05).IRM showed better result, and Tempore showed worst result.