Alessandra Reis

In-Office Whitening

In this chapter, the step-by-step procedure of in-office whitening (or in-office bleaching) and the efficacy and side effects of this bleaching modality will be presented. Other characteristics of this protocol such as the number of clinical appointments required to achieve effective whitening, concentration of the bleaching products, the effects of dentin dehydration and demineralization on the final outcome, as well as bleaching-induced tooth sensitivity will be addressed. At the end, some frequently asked questions will be answered.

Effect of sealing infected dentin with glass ionomer cement on the abundance and localization of MMP‐2, MMP‐8, and MMP‐9 in young permanent molars in vivo

BACKGROUNDnThe study of MMPs behavior in carious lesions contributes to the understanding of the mechanisms involved in dentin reorganization after restoration.nnnAIMnTo compare the abundance and localization of MMPs 2, 8, and 9 in infected dentin before and after restoration.nnnDESIGNnThe sample consisted of 23 young permanent molars with active deep carious lesions. Infected carious dentin samples were collected from the same tooth at baseline and 60xa0days after cavity lining with GIC and composite resin restoration and processed for immunohistochemistry assays. After digital images were obtained, two calibrated operators analyzed the samples according to the immunostaining intensity and the MMPs localization. Chi-square test was used for statistical analysis.nnnRESULTSnThe intensity of immunostaining for MMP-8 was reduced after 60xa0days (Pxa0=xa00.02), and no difference was observed for MMP-2 (Pxa0=xa00.32) and MMP-9 (Pxa0=xa00.14). The MMPs distribution was generalized in the intertubular dentin and absent or located in the intratubular dentin, regardless of the period.nnnCONCLUSIONnThe sealing of infected carious dentin in young permanent molars reduced the expression of MMP-8, which is consistent with the initial remodeling process of the dentin matrix.

Effect of dentin roughness on the adhesive performance in non-carious cervical lesions: a double-blind randomized clinical trial

OBJECTIVEnThis double-blind randomized clinical trial evaluates the influence of dentin roughening (RO) on the clinical behavior of a new universal multi-mode adhesive (Tetric N-Bond Universal; Ivoclar-Vivadent) applied as self-etch and as etch-and-rinse in non-carious cervical lesions (NCCLs).nnnMETHODSnA total of 192 restorations were randomly placed in 48 patients according to the following groups: ER - Etch-and-rinse (no preparation); SE - self-etch (no preparation); ER+RO and; SE+RO. The resin composite Empress Direct (Ivoclar-Vivadent) was placed incrementally. The restorations were evaluated after one week (baseline), 6 and 18 months, using the FDI and USPHS criteria. Statistical analyses were performed using appropriate tests (α=0.05).nnnRESULTSnFifteen restorations were lost at 18 months (3 for SE, 2 for ER, 5 for SE+RO and 5 for ER+RO) (p >0.05 between groups). Post-operative sensitivity wasnt observed in any of the recall periods. Eighty-four restorations were considered to have minor discrepancies in marginal adaptation at the 18-month recall using the FDI criteria (24 for SE, 18 for ER, 22 for SE+RO and 20 for ER+RO; p >0.05 between groups). Nineteen restorations were considered to have minor discrepancies in marginal discoloration at the 18-month recall (10 for SE, 03 for ER, 05 for SE+RO and 01 for ER+RO; p >0.05 between groups).nnnCONCLUSIONnThe dentin roughening before application of Tetric N-Bond Universal as self-etch and etch-and-rinse didnt affect the clinical behavior of composite restorations placed in NCCLs.

Clinical, mineral and ultrastructural changes in carious dentin of primary molars after restoration

INTRODUCTIONnPartial caries removal has been shown to be an effective method to treat deep carious lesions in deciduous teeth. Nevertheless, the possibility of keeping infected dentin in the cavity still requires additional investigation. The objective of this research was to describe changes in primary infected dentin after restoration with glass ionomer cement.nnnMETHODSnDentin from 45 primary molars with deep and active carious lesions was evaluated using clinical and laboratory criteria, before and 60 days after restoration. The clinical analysis evaluated dentin colour (CO), dentin consistency (COS) and laser fluorescence (LF). The laboratory procedures assessed bacterial contamination and mineral content (MC), and evaluated the dentin ultrastructure and collagen content. Data on CO, COS, LF and colony forming units were analysed using the Wilcoxon signed-rank test; MC, bacterial counts and collagen evaluations were evaluated using the Students t-test.nnnRESULTSnAfter 60 days, lower values of LF were observed, together with a lower bacterial count, and a higher COS was found, with an increase in calcium, phosphorus and collagen contents. Differences were not detected for CO or for fluorine content. Baseline samples showed enlarged tubules with bacterial invasion; 60-day samples showed better organised tissue, with a more compact intertubular dentin and narrower tubules.nnnCONCLUSIONnIt is concluded that appropriate cavity sealing can promote beneficial changes in deep carious lesions of primary teeth, even in the presence of infected dentin.

Clinical Performance of Root Surface Restorations

This chapter describes the clinical performance of restorations placed in root caries lesions. The prevalence of root caries and other types of cervical lesions, caused by abfraction, erosion, and abrasion (non-carious cervical lesions) are high, mainly in the elderly; and therefore, restorative procedures are indicated. We will revise the restorative materials used to restore these types of lesions and present evidence-based findings to provide clinicians with better evidence for choosing them. Additionally, some steps of the restorative procedure for the placement of resin-based composites will be revised and common clinical questions related to these steps will be answered based on high evidence level, produced by randomized clinical trials and systematic reviews of the literature.

Adhesion to Root Dentin: A Challenging Task

The treatment of severely destroyed teeth involves quite often the placement of a fiberglass post into the root canal space as a means of retention for the final restorative procedure. The bonding of fiberglass posts into the root canal is a very challenging task in which several factors may influence the final outcome. This chapter summarizes (1) the several limiting factors that require the clinician’s expertise to minimize bonding failures and (2) suggestions to overcome these limitations in a clinical setting.

Methods for Increasing the Longevity of Adhesion to Root Canal Dentin

All bonding protocols undergo degradation over time, and this may be one of the reasons why fiberglass post is prone to debonding during clinical service. The understanding of the mechanisms behind such degradation is crucial for clinicians to implement alternatives to minimize the degradation process and prolong the lifetime of post-retained restoration. This chapter will describe the degradation mechanisms that adhesive interfaces created in the root canal are prone to and also discuss clinical alternatives that can be incorporated into the clinical protocol to maximize the bonding longevity.

Effect of chlorhexidine concentration on the bond strength to dentin in primary teeth

Purpose: To evaluate the effect of the use of 0.5% and 2% chlorhexidine digluconate on the immediate bond strength of a conventional adhesive system to dentin in primary teeth. nMethods: Twenty-one healthy primary molars were divided into three groups (n=7), being one control (A) and two experimental groups (B and C). After dentin exposure, in Group (A) the adhesive procedure was performed using 37% phosphoric acid gel (15 s); dentin was washed (15 s), air dried (30 s) and rehydrated with water. Groups B and C followed similar procedures but for re-hydration with 0.5% and 2% chlorhexidine, respectively, for 30 s. A resin composite block was built simulating a restoration, and the teeth were stored in distilled water at 37°C for 24 h before the microtensile bond strength test. The bond strength data were analyzed by analysis of variance. nResults: No statistically significant difference in bond strength was found among the tested groups (P>0.05) nConclusion: The 0.5% and 2% concentrations of chlorhexidine presented similar behavior and caused no adverse effects on the bond strength to dentin in primary teeth.

Use of flowable composite as intermediary layer in non-carious cervical lesions restored with composite resin: 48-month follow-up

Purpose: In this case report study, the clinical performance of a microhybrid resin composite was compared with lined class V restorations or with restorations performed without a flowable resin composite, over a 48-month period. nCase description: The patient of this case report presented 2 pairs of equivalent cervical abfraction lesions, under occlusion. Four restorations were placed in teeth 34, 35, 44 and 45. The restorations were divided into groups (Single Bond + Filtek-Flow + Filtek Z250 or Single Bond + Filtek Z250) and the materials were applied according to the manufactures instructions. Two previously calibrated operators placed the restorations and two other independent examiners evaluated the restorations at baseline and after 48 months, according to the USPHS criteria and modified criteria for color match. nConclusion: After 48 months of evaluation the lesions restored with Filtek-Flow as a liner under Filtek Z250 did not show better clinical performance than the restorations without Filtek-Flow. All the groups showed a trend toward dark yellowing after 48 months.

Efecto Del Tiempo De Exposición Sobre La Eficacia De Polimerización Con Unidades Equipadas Con Luz Emitida Por Diodos-Led´s

Objetive: Evaluate The Top And Bottom Hardness Of Two Composites Cured Using Polymerizing Units Equipped With Light Emitting Diodes (LED ´s), (LEDemetron, Elipar Free Light, Coltolux LED) And One Quartz Tungsten Halogen Device (Optilux) Under Different Exposure Times (20, 40 Y 60 Seconds). Methods: Five Matrix Mold With 5mm In Diameter And 2 Mm In Depth Was Made To Obtained Dic Shaped Specimens For Each Experimental Group, GI: Z250 Color B 0.5 And GII : Charisma SL. The Specimens Were Cured By One Of The Ligth Curing Units For 20, 40 Or 60 Sec., And The Hardness Was Measured With A Vickers Hardness Measuring Instrument (50gr/30 Sec). Data Were Subjected To ANOVA And Tukey ´s Test (p=0.05). Results: The Units LED Were As Effective As The Quartz Tungsten Halogen Device For Curing Both Composites. A Significant Increase In The Microhardness Values Were Observed For All Light When The Exposure Time Was Changed From 20 Sec To 40 Sec. The Z250 Composite Showed Hardness Values That Were Usually Higher Than Those Of The Charisma Composite Under Similar Experimental Condition. Conclusions: LED Are As Efficient For Curing Composites As The Quarts Tungsten Halogen Device As Long As Na Exposure Time Of 40 Sec Or Higher.