Dental cavity liners for Class I and Class II resin-based composite restorations.

BACKGROUND: Resin-based composite (RBC) is currently accepted as a viable material for the restoration of caries for posterior permanent teeth requiring surgical treatment. Despite the fact that the thermal conductivity of the RBC restorative material closely approximates that of natural tooth structure, postoperative hypersensitivity is sometimes still an issue. Dental cavity liners have historically been used to protect the pulp from the toxic effects of some dental restorative materials and to prevent the pain of thermal conductivity by placing an insulating layer between restorative material and the remaining tooth structure. This is an update of the Cochrane Review first published in 2016. OBJECTIVES: The objective of this review was to assess the effects of using dental cavity liners in the placement of Class I and Class II resin-based composite posterior restorations in permanent teeth in children and adults. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 12 November 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 10) in the Cochrane Library (searched 12 November 2018), MEDLINE Ovid (1946 to 12 November 2018), Embase Ovid (1980 to 12 November 2018) and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 12 November 2018). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We included randomized controlled trials assessing the effects of the use of liners under Class I and Class II posterior resin-based composite restorations in permanent teeth (in both adults and children). We included both parallel and split-mouth designs. DATA COLLECTION AND ANALYSIS: We utilized standard methodological procedures prescribed by Cochrane for data collection and analysis. Two review authors screened the search results and assessed the eligibility of studies for inclusion against the review inclusion criteria. We conducted risk of bias assessments and data extraction independently and in duplicate. Where information was unclear we contacted study authors for clarification. MAIN RESULTS: Eight studies, recruiting over 700 participants, compared the use of dental cavity liners to no liners for Class I and Class II resin-based composite restorations.Seven studies evaluated postoperative hypersensitivity measured by various methods. All studies were at unclear or high risk of bias. There was inconsistent evidence regarding postoperative hypersensitivity (either measured using cold response or patient-reported), with a benefit shown at some, but not all, time points (low-quality evidence).Four trials measured restoration longevity. Two of the studies were judged to be at high risk and two at unclear risk of bias. No difference in restoration failure rates were shown at 1 year follow-up, with no failures reported in either group for three of the four studies; the fourth study had a risk ratio (RR) 1.00 (95% confidence interval (CI) 0.07 to 15.00) (low-quality evidence). Three studies evaluated restoration longevity at 2 years follow-up and, again, no failures were shown in either group.No adverse events were reported in any of the included studies. AUTHORS' CONCLUSIONS: There is inconsistent, low-quality evidence regarding the difference in postoperative hypersensitivity subsequent to placing a dental cavity liner under Class I and Class II posterior resin-based composite restorations in permanent posterior teeth in adults or children 15 years or older. Furthermore, no evidence was found to demonstrate a difference in the longevity of restorations placed with or without dental cavity liners.

Influence of Shrinkage and Viscosity of Flowable Composite Liners on Cervical Microleakage of Class II Restorations: A Micro-CT Analysis.

This study determined the influence of shrinkage and viscosity of flowable composite liners on the cervical microleakage of Class II restorations using micro-CT. Seven composites of varying viscosities were selected and included five giomers (Shofu Beautifil II [BF], Flow Plus F00 and F03 [F00 and F03], Flow F02 and F10 [F02 and F10]) and 2 nano-filled composites (3M-ESPE Filtek Z350 [Z350] and Filtek Z350 Flowable [Z350F]). Polymerization shrinkage (n=7) was assessed with the Acuvol volumetric shrinkage analyzer while complex viscosity was determined with the advanced rheometric expansion system at 25°C. Standardized Class II restorations incorporating 1-mm horizontal layers of different flowable liners and 3-mm oblique layers of BF or Z350 were subjected to a silver nitrate test for 24 hours and examined using micro-CT. Microleakage was determined at 0.1-mm intervals from the buccal to lingual surfaces providing 30 sites per specimen and scored accordingly. Statistical analysis was performed with the one-way ANOVA, Kruskal-Wallis test, and Spearman's rho correlation at a significance level of p<0.05. Mean volumetric shrinkage ranged from 5.33±0.17% to 2.35±0.02% for F02 to Z350, respectively. The flowable materials had significantly higher shrinkage than did their sculptable counterparts (BF and Z350). Complex viscosities ranged from 9.65 to 4.20 (Z350 and F10, respectively) at a frequency of 10 rad/s and from 8.16 to 3.28 (Z350 and F03, respectively) for 100 rad/s. Giomer restorations had significantly less leakage than did those restored with nano-filled composites. No microleakage was observed with restorations lined with F02 or F10. The use of flowable liners reduced cervical microleakage of Class II restorations. Interfacial integrity of Class II restorations was significantly correlated with liner viscosity, filler volume, and shrinkage.

Dental cavity liners for Class I and Class II resin-based composite restorations.

BACKGROUND: Resin-based composite (RBC) is currently accepted as a viable material for the restoration of caries for posterior permanent teeth requiring surgical treatment. Despite the fact that the thermal conductivity of the RBC restorative material closely approximates that of natural tooth structure, postoperative hypersensitivity is sometimes still an issue. Dental cavity liners have historically been used to protect the pulp from the toxic effects of some dental restorative materials and to prevent the pain of thermal conductivity by placing an insulating layer between restorative material and the remaining tooth structure. OBJECTIVES: The objective of this review was to assess the effects of using dental cavity liners in the placement of Class I and Class II resin-based composite posterior restorations in permanent teeth in children and adults. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 25 May 2016), the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 4) in the Cochrane Library (searched 25 May 2016), MEDLINE Ovid (1946 to 25 May 2016), Embase Ovid (1980 to 25 May 2016) and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 25 May 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We included randomized controlled trials assessing the effects of the use of liners under Class I and Class II posterior resin-based composite restorations in permanent teeth (in both adults and children). We included both parallel and split-mouth designs. DATA COLLECTION AND ANALYSIS: We utilized standard methodological procedures prescribed by Cochrane for data collection and analysis. Two review authors screened the search results and assessed the eligibility of studies for inclusion against the review inclusion criteria. We conducted risk of bias assessments and data extraction independently and in duplicate. Where information was unclear we contacted study authors for clarification. MAIN RESULTS: Eight studies, recruiting over 700 participants, compared the use of dental cavity liners to no liners for Class I and Class II resin-based composite restorations.Seven studies evaluated postoperative hypersensitivity measured by various methods. All studies were at unclear or high risk of bias. There was inconsistent evidence regarding postoperative hypersensitivity (either measured using cold response or patient-reported), with a benefit shown at some, but not all, time points (low-quality evidence).Four trials measured restoration longevity. Two of the studies were judged to be at high risk and two at unclear risk of bias. No difference in restoration failure rates were shown at one year follow-up, with no failures reported in either group for three of the four studies; the fourth study had a risk ratio (RR) 1.00 (95% confidence interval (CI) 0.07 to 15.00) (low-quality evidence). Three studies evaluated restoration longevity at two years follow-up and, again, no failures were shown in either group.No adverse events were reported in any of the included studies. AUTHORS' CONCLUSIONS: There is inconsistent, low-quality evidence regarding the difference in postoperative hypersensitivity subsequent to placing a dental cavity liner under Class I and Class II posterior resin-based composite restorations in permanent posterior teeth in adults or children 15 years or older. Furthermore, no evidence was found to demonstrate a difference in the longevity of restorations placed with or without dental cavity liners.

Resistencia a la fractura in vitro de incrustaciones cerámicas usando dos materiales como bases cavitarias / in vitro fractures strength of ceramic inlays, using two types of cavity bases

Las bases cavitarias son usadas en odontología restauradora,varios materiales se recomiendan como base cavitaria en incrustaciones cerámicas. Objetivo: Comparar la resistencia a la fractura in vitro de una cerámica (disilicato de litio) como material restaurativo usando diferentes bases cavitarias en inlays en premolares. Material y métodos: Se elaboraron cavidades estandarizadas para inlays cerámicas MOD en 30 premolares. Se asignaron aleatoriamente tres grupos (n = 10): grupo 1: sin base cavitaria; grupo 2: base ionómero de vidrio reforzado con resina (VitrebondTM, 3M); grupo 3: base resina compuesta (FiltekTM Z350 XT, 3M). Las incrustaciones fueron fabricadas con disilicato de litio (IPS e.max®, Ivoclar) cementadas con (RelyXTM, 3M) y almacenadas en agua bidestilada (37 oC por 24 horas). Semidió la resistencia a la fractura en una máquina universal de pruebas mecánicas (MTS® Alliance RT/30) a una velocidad de 0.5 mm/minuto,fracturadas las muestras se registró bajo microscopia estereoscópica elmodo de fallo. Los datos se analizaron usando ANOVA de una vía y comparaciones post hoc con la prueba Scheffé. (Programa IBM SPSS STATISTICS 21.0). Resultados: El grupo control (sin base) obtuvo la media más alta (105.16 Kgf ± 11.41) siendo estadísticamente significativa con relación al grupo 2 (77.04 ± 19.69). El grupo 3 obtuvo una media (94.81 ± 10.65) siendo estadísticamente diferente del grupo 2 (p = .001). El modo de fallo más común fue el patrón IV (60 por ciento). Conclusiones: La resistencia a la fractura de inlays cerámicas de disilicato de litio es mayor en cavidades sin base cavitaria...

Effect of cement type, relining procedure, and length of cementation on pull-out bond strength of fiber posts.

INTRODUCTION: As opposed to the cementation metal posts, the cementation of fiber posts has several details that can significantly influence the success of post retention. This study evaluated the effect of the relining procedure, the cement type, and the luted length of the post on fiber posts retention. METHODS: One hundred eighty bovine incisors were selected to assess post retention; after endodontic treatment, the canals were flared with diamonds burs. Post holes were prepared in lengths of 5, 7.5, and 10 mm; the fiber posts were relined with composite resin and luted with RelyX ARC, RelyX Unicem, or RelyX Luting 2. All cements are manufactured by 3M ESPE (St. Paul, MN). Samples were subjected to a pull-out bond strength test in a universal testing machine; the results (N) were submitted to a three-way analysis of variance and the Tukey post hoc test (alpha = 0.05). RESULTS: The improvement of post retention occurred with the increase of the post length luted into the root canal; the relining procedure improved the pull-out bond strength. RelyX Unicem and RelyX ARC showed similar values of retention, both showing higher values than RelyX Luting 2. CONCLUSION: Post length, the relining procedure, and the cement type are all important factors for improving the retention of fiber posts.

Microhardness of glass ionomer cements indicated for the ART technique according to surface protection treatment and storage time.

The aim of this study was to assess the microhardness of 5 glass ionomer cements (GIC) - Vidrion R (V, SS White), Fuji IX (F, GC Corp.), Magic Glass ART (MG, Vigodent), Maxxion R (MR, FGM) and ChemFlex (CF, Dentsply) - in the presence or absence of a surface protection treatment, and after different storage periods. For each GIC, 36 test specimens were made, divided into 3 groups according to the surface protection treatment applied - no protection, varnish or nail varnish. The specimens were stored in distilled water for 24 h, 7 and 30 days and the microhardness tests were performed at these times. The data obtained were submitted to the ANOVA for repeated measures and Tukey tests (alpha = 5%). The results revealed that the mean microhardness values of the GICs were, in decreasing order, as follows: F > CF = MR > MG > V; that surface protection was significant for MR, at 24 h, without protection (64.2 + or - 3.6a), protected with GIC varnish (59.6 + or - 3.4b) and protected with nail varnish (62.7 + or - 2.8ab); for F, at 7 days, without protection (97.8 + or - 3.7ab), protected with varnish (95.9 + or - 3.2b) and protected with nail varnish (100.8 + or - 3.4a); and at 30 days, for F, without protection (98.8 + or - 2.6b), protected with varnish (103.3 + or - 4.4a) and protected with nail varnish (101 + or - 4.1ab) and, for V, without protection (46 + or - 1.3b), protected with varnish (49.6 + or - 1.7ab) and protected with nail varnish (51.1 + or - 2.6a). The increase in storage time produced an increase in microhardness. It was concluded that the different GICs, surface protection treatments and storage times could alter the microhardness values.

Microhardness of glass ionomer cements indicated for the ART technique according to surface protection treatment and storage time

The aim of this study was to assess the microhardness of 5 glass ionomer cements (GIC) - Vidrion R (V, SS White), Fuji IX (F, GC Corp.), Magic Glass ART (MG, Vigodent), Maxxion R (MR, FGM) and ChemFlex (CF, Dentsply) - in the presence or absence of a surface protection treatment, and after different storage periods. For each GIC, 36 test specimens were made, divided into 3 groups according to the surface protection treatment applied - no protection, varnish or nail varnish. The specimens were stored in distilled water for 24 h, 7 and 30 days and the microhardness tests were performed at these times. The data obtained were submitted to the ANOVA for repeated measures and Tukey tests (á = 5 percent). The results revealed that the mean microhardness values of the GICs were, in decreasing order, as follows: F > CF = MR > MG > V; that surface protection was significant for MR, at 24 h, without protection (64.2 ± 3.6a), protected with GIC varnish (59.6 ± 3.4b) and protected with nail varnish (62.7 ± 2.8ab); for F, at 7 days, without protection (97.8 ± 3.7ab), protected with varnish (95.9 ± 3.2b) and protected with nail varnish (100.8 ± 3.4a); and at 30 days, for F, without protection (98.8 ± 2.6b), protected with varnish (103.3 ± 4.4a) and protected with nail varnish (101 ± 4.1ab) and, for V, without protection (46 ± 1.3b), protected with varnish (49.6 ± 1.7ab) and protected with nail varnish (51.1 ± 2.6a). The increase in storage time produced an increase in microhardness. It was concluded that the different GICs, surface protection treatments and storage times could alter the microhardness values.

An effective method for spreading flowable composites in resin-based restorations.

UNLABELLED: Cavity lining with flowable composites has been suggested for better marginal adaptation and a reduction in interfacial stress and post-operative sensitivity. The following in vitro study compares the spreading of flowable composite that lines the inner wall of a test cavity using an explorer and a specially designed smooth, oscillating, off-center rotating bur spun at 300 to 600 rpm. Two commercial flowable materials were used in this study. RESULTS: With use of the rotating bur, a more consistent, uniform cavity lining was achieved. This was not possible using the dental explorer. CONCLUSION: The specially designed rotating bur provides an effective way for clinicians to form a uniform cavity lining.

Importancia clínica de los barnices fluorados / Clinical importance of fluoridated varnishes

Los barnices fluorados fueron introducidos en los años 60's. en los países escandinavos. En los últimos años se ha intensificado su uso, sobre todo por el conocimiento actual del modo de acción del flúor. Las ventajas del barniz de flúor sobre otros compuestos fluorados es su habilidad para permanecer por tiempo prolongado sobre la superficie del esmalte, favoreciendo el intercambio iónico entre la placa y el esmalte. Estudios in vitro han demostrado que la liberación de flúor después de la aplicación de barniz se mantiene por aproximadamente 4 meses. Existen diversas marcas comerciales, siendo las más conocidas Duraphat, Duraflor (basadas en NsF) y Flúor Protector. Los estudios clínicos han demostrado reducción de caries dental en dentición primaria, dentición permanente, superficies oclusales y proximales y reducción de calcificaciones durante el tratamiento ortodóntico. Además, la aplicación de barniz de flúor, no ha mostrado ningún tipo de toxicidad aguda o crónica. Los protocolos de aplicación dependen en gran manera del riesgo de caries individual y al uso de otros fluoruros. La técnica de aplicación de barniz de flúor es muy rápida y sencilla. La evidencia científica sugiere promover el uso del barniz de flúor como una herramienta más en la prevención de caries dental

Efectividad de dos barnices en la remineralización de la mancha blanca / Effectiveness of two varnishes in the remineralization of white spots

El objetivo de este trabajo es evaluar clínicamente la efectividad de la remineralización de las manchas blancas (MB) utilizando dos barnices fluorados. Se diagnosticaron 90 superficie sde MB. Los pacientes fueron divididos en tres grupos, GA: tratado con laca fluorada (FNa al 6 por ciento y F2Ca al 6 por ciento; Bifluorid 11/VOCO), GB: tratado con barniz fluorado (FNa al 5 por ciento, Fluoridin N 5/VOCO) y GC: control. Se realizaron tres topicaciones a los 0, 15 y 30 días La remineralización fue evaluada a los 15, 30 y 90 días. El grupo control no mostró remineralización en ninguno de los controles realizados (p menor 0.05. Para el tratamiento con laca (GA), se observó remineralización a los 15 días luego de la 1ra. topicación (p menor 0.01). Mientras que para el barniz (GB) la misma fue registrada a los 30 días (p menor 0.05). El tratamiento de las superficies dentarias con laca fluorada resulta ser más efectivo luego de la primera topicación con respecto al tratamiento con barniz fluorado

Resistencia flexural de composites sobre distintas bases / Flexural strength of composites on different base materials

El objetivo de este trabajo fue evaluar la resistencia flexural de un bloque de composite cuando es ubicado sobre tres bases diferentes. Fueron confeccionadas probetas en las que la medida de su espesor (2 mm.) estaba representada por una capa de 1 mm. confeccionada con un cemento de ionómero vítreo convencional, un cemento de ionómero vítreo modificado con resinas y un compómero, y el resto por un composite de alto contenido cerámico. Se determinó su resistencia flexural sometiéndolos a cargas sobre la superficie correspondiente al composite. Los valores medios en MPa obtenidos fueron 27,5; 84, 3 y 104,3 para las probetas con base de ionómero, ionómero modificado y compómero, respectivamente. Las diferencias fueron estadísticamente significativas, por lo que puede concluirse que la resistencia flexural de un bloque de composite ubicado sobre un relleno cavitario es influida por las propiedades mecánicas del material empleado para confeccionar este último

Influencias del bisel de la apicectomía en la microfiltración de la obturación retrógrada / Influences of the apicoectomy bevel on the retrograde obturation microleakage

Al practicar la apicectomía en cirugía periapical quedan expuestos túbulos dentinarios en la superficie del bisel que, según la zona del ápice donde se talle el mismo, comunicarán el espacio periapical con la restauración, facilitándose la microfiltración. La finalidad de este estudio ha sido evaluar la microfiltración que experimentan nueve materiales (amalgama sola, con barniz de copal, con barniz Dentin Protecto(R) y con Panavia(R); ionómero de vidrio autopolimerizable convencional, ionómero de vidrio con partículas de plata, ionómero fotopolimerizable, composite y gutapercha termosellada) y determinar las posibles influencias del bisel vestibular o lingual en el grado de microfiltración. Tras practicar una bisel de 25 grados no se han encontrado diferencias entre la filtración por vestibular y lingual. Se ha puesto de manifiesto que las variaciones de filtración entre vestibular y lingual están influenciadas por el tipo de material

El hidróxido de calcio y su empleo en odontología / The use of calcium hydroxide in dentistry

La odontología moderna y actual no solamente se preocupa de diagnosticar y tratar las afecciones bucodentales, eliminando las causas que provocan desequilibrio orgánico, sino que también actúa protegiendo las estructuras y tejidos remanentes con un sinfín de medicamentos, sustancias y materiales. Estos elementos tienen la particularidad de poseer doble función: protectora y aislante, a la vez de promover la recuperación y consiguiente reparación de los tejidos dentarios sobre los cuales actúa. Este es precisamente el caso del hidróxido de calcio, un material cuya singular característica, la biocompatibilidad y sus otras propiedades benéficas para las piezas dentarias, fueron analizadas y comprobadas a través de los años y de las experiencias que le dan un lugar indiscutible dentro de los materiales de uso odontológico

Estudio "in vitro" de microfiltración usando distintos sistemas de obturación en restauraciones clase II / In vitro study of dental leakage in class II restorations using different methods

El presente estudio tuvo el propósito de evaluar los niveles de microfiltración utilizando diversos materiales dentales restauradores. Se utilizaron 40 piezas dentarias (entre molares y premolares) en las que se realizaron cavidades clase II, las cuales fueron restauradas con amalgama STANDALLOY; resina Z-100 y adhesivo dentinario SCOTCHBOND MP; y ionómero-resina VITREMER. Del grupo restaurado con amalgama, a un subgrupo se le aplicó previamente barniz cavitario SCI-PHARM, mientras que al otro, flúor gel acidulado KERR. Todos los grupos fueron sometidos a ciclaje térmico, luego de lo cual fueron sometidos a azul de metileno por 12 horas. Se procedió a cortar los especímenes por la mitad para luego ser evaluados al estereomicroscopio. Los resultados mostraron que existía diferencia altamente significativa en los niveles de microfiltración de los 4 grupos. Se concluyó que los grupos con amalgama-flúor y amalgama-barniz eran los que permitían mayor microfiltración mientras que el grupo con ionómero-resina VITREMER fue el que se comportó mejor evitando la microfiltración