Direct Resin Research Articles

Restoration of Root Filled Teeth; Current Opinions and Techniques

Purpose: To examine current decision-making preferences of Jordanian dentists when Restoring Root Filled Teeth (RFT). Materials and Methods: 834 Jordanian general dentists, prosthodontists and endodontists were invited to participate in a validated online survey with a 62% participation rate. Respondents were invited to answer 24 questions about their preferences for techniques and materials they use to restore RFT. The questions aimed at exploring restorative strategies commonly employed by Jordanian dentists when managing root filled teeth with extensive loss of tooth structure. Results: A minority of dentists consider direct resin restoration as the sole restoration for RFT with extensive loss of tooth structure. Full coverage metal-ceramic and all-ceramic crowns are more popular than endocrowns when restoring RFT with indirect restoration. Fiber posts are the most popular type of posts, followed by prefabricated metal posts. Glass ionomer is the most preferred cement for luting metal posts, while conventional dual resin cement with separate etch and rinse bonding strategy is the most employed when bonding fiber posts. The majority of dentists tend not to pretreat fiber posts. Loss of post/core retention or fracture of coronal tooth structure are the two most common reasons observed by dentists when RFT fail. Conclusion: Use of post and core is still preferred over more conservative approaches when restoring RFT with extensive loss of coronal tooth structure. Longevity of restorations can be enhanced by training practicing dentists on evidence-based adhesive strategies.

Anterior teeth rehabilitation with direct resin composite veneer using multiple layering technique: A case report

Cosmetic veneer has become a popular option for patients seeking to improve aesthetic in their smile. The procedure can be done through a direct or indirect technique which differs in term of material used and laboratory involvement. Despite producing a better aesthetic result than its direct technique counterpart, high-cost treatment, multiple visit requirement and invasive nature of tooth preparation are proven to be a stumbling block to the patient in some cases to choose indirect technique. Therefore, direct composite veneer technique can be offered due to its low costing and conservative concept which advocates more tooth structure preservation. This case report is about direct composite veneer for anterior teeth rehabilitation and its simple and conservative protocol.

Clinical Outcomes of Endodontic Treatments and Restorations with and without Posts Up to 18 Years

Background: The aim of this study was to collect long-term restorative and endodontic outcomes of endodontically treated teeth (ETT). Methods: 298 teeth were included in the study and were recalled up to 18 years with a media of 10.2 years. At baseline, 198 sample teeth (66.44%) showed symptoms and 164 (55%) had periapical radiolucency. The most frequently used obturation techniques were warm gutta-percha in 80% of cases, and by carrier in 20%. A total of 192 ETT were restored by direct resin composite restorations, and 106 posts were luted. Moreover, 75 (25.16%) direct restorations remained as final restorations, 137 single crowns (45.97%), 42 (14.09%) partial adhesive crowns, and 42 (14.09%) abutments of fixed bridges were the final treatments. Descriptive and inferential statistics were performed (α = 0.05). A Cox regression model was made. Results: results showed success for 92.6% of ETT up to 18 years, 2.68% (8 ETT) showed irreversible failures, and 14 (4.69%) reversible complications. Four ETT (1.34%) failed because of root fracture and the other four (1.34%) because of endodontic complications. Eight ETT (2.69%) showed non-irreversible periodontal complications and the other six (2.01%) prosthodontic complications. Accordingly, with Kaplan–Meier analysis, the survival rate after 18 years was 97.3% (Interval of Confidence (IC) 95.1–98.3). The presence of a short or long (at least 1 mm related to radiographic apex) quality endodontic filling displayed a statistically significant higher risk of complication (hazard ratio (HR) = 17.00 (IC 5.68–56.84). Furthermore, a clinically detectable not precise coronal margins predicts the presence of any clinical complication with a hazard ratio almost seven times higher than endodontically treated teeth with a proper margin (HR = 6.89 (IC 2.03–23.38)), while the presence of lucency at the baseline did not affect the risk of complication (HR = 0.575 (IC 0.205–1.61)). The presence of post, tooth position in the arch, and the type of it did not show a high-risk rate (HR = 1.85, 1.98, and 2.24, respectively). Conclusions: a correct filling (at the apex) of root canals combined with proper coronal margins allow obtaining a long-term high success rate in teeth with a periapical lesion at the baseline. The use of a post or not, when its placement is related to the residual amount of the crown, does not change the final outcome of the ETT.

Effects of alternatively used thermal treatments on the mechanical and fracture behavior of dental resin composites with varying filler content

The purpose of this study was two-fold: (i) to investigate whether the thermal treatment of direct dental resin composites (RCs) using microwave or autoclave heating cycles would modify the materials' strength as compared to the protocol without heating (control); and (ii) to compare the mechanical performance of direct and indirect RCs. Three RCs (from 3M ESPE) were tested: one indirect (Sinfony); and two direct materials (microhybrid – Filtek Z250; and nanofilled – Filtek Z350). Specimens from the direct RCs were prepared and randomly allocated into three groups according to the thermal treatment (n = 10): Control – no thermal treatment was performed; Microwave – the wet heating was performed using a microwave oven; and Autoclave – the wet heating was performed in an autoclave oven. The indirect RC was prepared following the instructions of the manufacturer. All materials were tested using flexural strength, elastic modulus, work of fracture (Wf), microhardness, and scanning electron microscopy (SEM) analyses. Data were analyzed with ANOVA and Tukey as well as Weibull analysis (α = 0.05). The thermal treatments tended to produce slight changes in the topography of direct RCs, especially by the autoclave’ wet heating. Overall, the physico-mechanical properties changed after thermal treatment, although this effect was dependent on the type of RC and on the heating protocol. Sinfony showed the lowest modulus and hardness of the study, although it was the most compliant system (higher work of fracture). The load-deflection ability was also greater for the indirect RC. Reliability of the tested materials was similar among each other (p > 0.05). In conclusion, the alternative thermal treatments suggested here may significantly influence some aspects of the mechanical behavior of dental resin composites, with negative effects relying on both the chemical composition of the restorative material as well as on the wet heating protocol used. Clinicians should be aware of the possible effects that additional wet heating of direct resin composites using microwave or autoclave thermal protocols as performed here could have on the overall fracture and mechanical responses during loading circumstances.

Occlusal stress distribution and remaining crack propagation of a cracked tooth treated with different materials and designs: 3D finite element analysis

ObjectiveHere we used 3D finite element analysis (FEA) to analyze and directly compare stress distribution and crack propagation in identical cracked tooth models after treatment with various materials and designs. MethodsA 3D model of a cracked tooth was generated. We then applied eight restoration models, comprising combinations of three kinds of restoration designs (inlay, onlay, and crown) and four types of restoration materials (direct composite resin, indirect composite resin, ceramic, and gold). A 1000-N occlusal load was applied on the three reference points of the ball-shaped part in the direction of the longitudinal axis, causing crack line separation in the buccolingual direction. Stress distribution was analyzed on the occlusal surface, bottom level of the restoration, and mesiodistal longitudinal section. The stress on the lower margin of the crack surface was measured at 15 points on each model. ResultsCeramic inlay and onlay showed stress concentration at the restoration bottom, and low stress on the lower margin of the crack surface. Direct and indirect resin restorations exhibited low stress on the restoration bottom, and high stress on the proximal end of the lower margin of the crack surface. With a resin-unfilled gold crown, stress was concentrated on the crown bottom and the lower margin of the crack surface. Direct resin filling inside the gold crown yielded significantly decreased stress on both areas. SignificanceOur results suggest that inlay and onlay ceramic restorations, and gold crown with resin filling inside, are advantageous methods for preventing further crack propagation.

Clinical management of Hypoplasic Amelogenesis Imperfecta: a challenge for multidisciplinary team. A case report

Amelogenesis imperfecta (AI) refers to a group of rare genetic disorders that involve tooth development and are passed down through families. Hypoplasic AI phenotypes include the absence of enamel as a result of a defect in the secretory stage. This case report describes the diagnosis and treatment of a patient with hypoplastic AI. The clinical implications include sensitive teeth, functional problems, and aesthetic complaining. The diagnosis was done through history, clinical examination and imaging. The intervention was performed by Direct Resin Veneers. This treatment showed to improve occlusion, esthetics, and selfimage of the teenager. The satisfactory clinical result has made it possible to avoid more invasive and expensive treatments.

Why ceramic? When you can use composite. Indirect restoration of tooth in a more biomimetic way using heat treated direct resin composite

Direct resin composites have a greater degree of conversion, physical properties, color, and resistance to abrasion when heat treated. So, it is best suited for indirect use as heat-treated direct resin using oven, autoclave or porcelain furnace, or microwave. We have chosen direct resin composite as a suitable material and heat-treated it for endo crown fabrication or aesthetic indirect restoration. The reason for such technique is supported by various research studies, and case reports available have shown positive results, and it is also considered as a biomimetic method.

Oral rehabilitation in a child with early childhood caries: a case report

ABSTRACT The aim of the current study is to present a treatment approach in a case of severe early childhood caries (ECC). A 5-year-old girl was referred to the Pediatric Dentistry Division with multiple premature tooth loss, masticatory difficulties, prolonged breast-feeding, and low quality of life, who was diagnosed with severe ECC. A three-phased treatment plan was implemented: 1. Disease control – consisting of behavioral changes in oral hygiene habits, diet guidance, professional biofilm removal followed by fluoride application and temporary restorations; 2. Infection control – teeth extractions and pulpotomy; and 3. Functional rehabilitation – direct and semi-indirect resin restorations, a removable partial and total prostheses in the lower and upper jaws, respectively. In conclusion, the proposed multidisciplinary approach resulted in a positive impact on the patient’s nutrition and growth, speech production, communication, self-image, and social functioning leading to an improved quality of life.

Color stability and surface roughness of resin based direct and indirect restorative materials

Purpose: This study investigated discoloration and surface roughness (Ra) of resin-based computer aided design (CAD)/computer aided manufacturing (CAM) blocks and direct and indirect resin composites after staining with coffee. Materials & Methods: Using a Teflon mold, 60 disc shaped specimens (8×2 mm2) were fabricated from direct (Estelite Asteria and GrandioSO) and indirect (Gradia Plus) resin composites, and 30 resin CAD/CAM specimens (12×14×2 mm3) were prepared from resin composite CAD/CAM blocks (Vita Enamic, Brilliant Crios, and Cerasmart) (n=10). A contact type profilometer was used to determine the Ra of all 60 polished samples. All specimens were thermocycled between 5 and 55°C for 3000 cycles, and immersed in coffee solution (37°C) for 1 and 7 days. A spectrophotometer was used to determine the color change (∆E00) with the CIEDE2000 formula after the specimens were re-polished. One-way analysis of variance (ANOVA) and Tukey multiple comparison test was performed to analyze the data (p<0.05). Results: The lowest degree of discoloration among the materials tested was found in Vita Enamic resin CAD/CAM block (p<0.001), whereas the highest degree of discoloration was found in the Gradia Plus indirect composite (p<0.001). There was no significant difference was seen between the initial surface roughness values (Ra) among the groups (p=0.249). No significant improvement was observed in the color of the groups except for the Cerasmart resin block after after polishing. Conclusion: Direct resin composites have a higher discoloration potential over resin-based CAD/CAM blocks, whereas they are less prone to discoloration than indirect resin composites

Anterior Aesthetic rehabilitation in a patient with suspectedamelogenesis imperfecta (AI)

Amelogenesis imperfecta (AI) is a genetic condition affecting the enamel of teeth with no system ic involvement. In this condition, patients can present changes in thickness, colour and shape of enamel, which leads to compromising the aesthetics and appearance of the patient along with impaored masticatory functions. Various treatment modalities are available for rehabilitation of such patients, like prosthetic procedures. This report shows a suspected case of AI and describes the clinical procedures of anterior aesthetic and functional rehabilitation of a young adult patient with involving the use of direct resin composite restorations and the use of all ceramic prosthesis. The overall result is remarkably different from the original appearance is a huge boost to the moral confidence of the patient.

A Comparative Study of Direct Resin Veneers and Porcelain Veneers in the Esthetic Restoration of Anterior Teeth with Dental Fluorosis

A Comparative Study of Direct Resin Veneers and Porcelain Veneers in the Esthetic Restoration of Anterior Teeth with Dental Fluorosis

Survival Rates of Unrestorable Fracture of Endodontically Treated Anterior Teeth Restored with Resin Composites or Crowns: A Retrospective Cohort Study.

Current guidelines for the restoration of endodontically treated anterior teeth (ETT) are based on laboratory results and insufficient clinical findings. This retrospective cohort study aimed to compare the survival rates of ETT with unrestorable fracture restored with direct resin composite (DRC) or full coverage crown (FCC), and identify predisposing factors. Dental records and radiographs of ETT restored with DRC or FCC were collected from the dental charts of patients who received endodontic treatments and attended recall(s) from 2007 to 2019. Clinical/radiographic data and incidence of unrestorable fracture were recorded. Survival rates of ETT with unrestorable fracture treated with DRC and FCC were analyzed using Kaplan-Meier survival analysis and log-rank test, whereas predisposing factors were identified using Cox proportional-hazard model. Moreover, the survival rates of maxillary ETT with different sites of remaining cervical tooth structure were analyzed. A total of 263 ETT with 157 DRC and 106 FCC were recruited. At an average recall period of 38 months, the survival rate of ETT restored with FCC was significantly higher (99.1%) than DRC (90.4%) (P<0.05). The predisposing factors of ETT with FCC were not identified; however, the identified predisposing factors of ETT with DRC were: (i) considered less than three walls of remaining cervical tooth structure, (ii) the ratio between root dentin thickness and root canal width at the cervical region was less than 1:1:1, (iii) loss of posterior-teeth support, and (iv) parafunctional habits. Maxillary ETT with complete or palatal structure had a significantly higher survival rate than those without the palatal structure (P<0.05). Based on the findings of the current cohort study, the survival rate of ETT with unrestorable fracture restored with FCC was significantly higher than DRC. However, ETT without predisposing factors were not susceptible to fracture and could be successfully restored with DRC.

Effect of Polymerization Time and Shade on the Depth of Cure of Nano-Hybrid Resin Composites

AbstractObjective The effect of polymerization time and resin shade on the depth of cure (DOC) of two nano-hybrid resin composites (Filtek Z250 XT and IPS Empress Direct) was evaluated and compared.Materials and Methods Sixty specimens were prepared from two shades (A1 and A3) of the resin composites. The specimens were allocated into two groups that were further divided into three subgroups depending on the polymerization time (20, 40, and 60 sec; n = 5). After that, the DOC was evaluated by calculating the polymerized part of the specimen’s thickness to the nearest (0.01 mm) using a high-accuracy micrometer. Each specimen was measured three times, and the corresponding mean reading (in mm) was divided by two to obtain the DOC. The data were analyzed using SPSS software, version 20. Descriptive statistics followed by three-way analysis of variance was applied. Multiple comparisons were made using Scheffe post hoc tests (α = 0.05).Results Filtek Z250 XT-A1-60sec presented with the greatest DOC (7.42 ± 0.47 mm), and the lowest DOC was obtained with IPS Empress-A3-20sec (2.31 ± 0.21 mm). The mean DOC of Filtek Z250 XT and IPS Empress Direct resin composites were 6.18 mm and 3.59 mm, respectively. Statistically significant (p &lt; 0.05) difference was observed between the resin composites. The interaction between independent factors, namely composites, resin shade, and polymerization time, revealed that interaction between them contributed significantly to the DOC (p ≤0.05). However, the interaction between resin shade and the polymerization time was insignificant (p = 0.148).Conclusion Filtek Z250 XT demonstrated greater DOC than IPS Empress Direct resin composite. An increase in polymerization time significantly enhanced the DOC of the resin composites irrespective of the resin shade. Regardless of the resin composite tested, DOC was lower for darker shades (A3).

Cervical margin relocation - basic principles and influence on the periodontal tissues

INTRODUCTION: Cervical margin relocation (CMR) involves the placement of a base layer of direct resin composite material in order to elevate the cavity margins located below the gingiva. CMR is applied prior to the cementation of bonded restorations. AIM: The aim of this review is to briefly present the basic principles of the CMR technique and to assess whether the execution of this method before the cementation of bonded restorations is beneficial to the long-term outcome of the treatment and to the periodontal tissues according to the literature. MATERIALS AND METHODS: This review includes articles searched without date restriction in the Medline/PubMed database along with bibliographic data. A variety of keywords and their combinations were used: margin relocation, proximal box elevation, indirect restorations, adhesion, marginal adaptation, marginal sealing, deep margin elevation. RESULTS: The review is based upon 41 references. The literature data provided information on the basic principles of cervical margin relocation and its relation to periodontal health. CONCLUSION: Further research, scientific evidence and longer follow-up results are needed in order to conclude that CMR is entirely beneficial to the long-term outcome of the treatment and to the periodontal tissues.

A systematic approach to contouring and polishing anterior resin composite restorations: A checklist manifesto.

This article presents a systematic, step-by-step checklist approach to be used for contouring and polishing anterior resin composite restorations to achieve maximum esthetics efficiently. This checklist is intended to be used to take the guesswork out and streamline the process to predictably, practically, and repeatedly contour and polish anterior resin composite restorations. The practitioner's knowledge of basic dental anatomy combined with this step-by-step checklist facilitates identifying and modifying the final restoration to an anatomically correct form, thus satisfying the most esthetically demanding patients. This approach is demonstrated with case presentation of direct resin veneers in a young female, which resulted in an improved smile that satisfied her esthetic desires. The use of standardized protocols facilitates and expedites daily procedures in dentistry. Specifically, this checklist protocol, which is geared towards contouring and polishing anterior direct resin composite restorations. The clinical technique presented in this article shows the advantages of using a step-by-step checklist approach to predictably and efficiently obtain ideal esthetics when performing anterior resin composite restorations.

Biobased Resins Using Lignin and Glyoxal

The utilization of lignin and glyoxal as potentially sustainable and less hazardous building blocks for phenolic resins is an emerging research field. Lignin thereby serves as a partial, macromolecular substitute for phenol, while glyoxal fulfills the role of an aldehyde cross-linker. In the first part of this perspective, the industrial context of lignin and glyoxal will be expounded with a focus on their origin and production processes. In the framework of phenolic resins, the use of lignin and glyoxal can be categorized into two research domains: (i) glyoxalation to improve the reactivity of lignin prior to resin synthesis and (ii) direct resin synthesis using lignin and glyoxal with glyoxal immediately serving as the cross-linker. This perspective provides a comprehensive overview of the progress made in both domains, pinpointing the opportunities, blind spots, and challenges that lay ahead.

Restabelecimento do sorriso com restaurações em resina composta após clareamento dental: relato de caso

INTRODUÇÃO: Atualmente, os pacientes almejam um sorriso harmônico e natural, e procedimentos minimamente invasivos devem ser priorizados. Dentre esses, o clareamento dental associado às restaurações diretas com resina composta são tratamentos indicados para alteração de cor e forma dental, devolvendo estética e função. OBJETIVO: O presente trabalho tem como objetivo apresentar, através de um relato de caso clínico, o restabelecimento de um sorriso possibilitado pelo clareamento dental e restaurações diretas em resina composta. RELATO DE CASO: Paciente do sexo feminino, 33 anos, compareceu em consulta clínica se queixando da estética do seu sorriso após a remoção do aparelho ortodôntico. Os dentes apresentavam alteração de cor e forma, e assim, foram planejados clareamento dental e restaurações diretas em resina composta. O clareamento dental foi realizado pela técnica combinada e após 14 dias, as restaurações em resina composta nos incisivos, caninos e pré-molares superiores foram confeccionadas. CONCLUSÃO: O tratamento clareador e as restaurações em resina composta são abordagens conservadoras que possibilitaram o restabelecimento estético do sorriso.

Reflectance and transmittance of flowable dental resin composite predicted by the two-flux model: on the importance of analyzing the effective measurement geometry

Flowable direct resin composite materials used in the dental domain are among materials that scatter light rather weakly, giving to millimeter-thick samples a certain translucent aspect. In order to predict the spectral reflectance and the color of such samples, the two-flux theory, i.e., Kubelka-Munk model (with Saunderson correction), remains the standard approach used in the dental domain, in spite of its known limitations when scattering is too weak. The present study, however, shows that a careful analysis of the light signal effectively measured on weakly scattering samples with instruments based, as usually recommended, on the d:8° measurement geometry, and a subsequent reevaluation of the parameters used in the Saunderson correction formulas with respect to the effective measurement geometry, can considerably improve the prediction accuracy of the model in both reflectance and transmittance modes, as confirmed by experiments carried out with samples of dental flowable resin composite material of different thicknesses. This broadens the applicability domain of the model, and might satisfy users preferring the simplicity of the two-flux model and the affordable equipment it needs to more relevant but more complex light scattering theories.

Comparison of conventional ceramic laminate veneers, partial laminate veneers and direct composite resin restorations in fracture strength after aging

ObjectivesThe objectives of this study were to test the fracture strength in vitro of laminate veneers, partial laminate veneers and composite restorations after aging and analyze the failure mode. MethodsForty extracted, sound human teeth were selected and divided into four groups: 1) Control group (CG); 2) Conventional Laminate Veneer (CLV); 3) Partial Laminate Veneer (PLV); 4) Direct Composite Resin (DCR). Laminate veneer preparations with incisal overlap were made in group CLV whereas only incisal preparations were made with a 1 mm bevel in group PLV and DCR. The indirect restorations were luted with a resin composite and the DCR group was restored with a direct resin composite restoration. The restored teeth were subsequently aged by thermocycling (20.000 cycles, 5–55 degrees C). Subsequently, the fracture strength was tested by a load to failure test at 135° on the incisal edge. A failure analysis was performed using light microscopy. The results were analyzed using Shapiro-Wilk and Kruska-Wallis test. ResultsAfter thermocycling, one sample from group CLV presented a premature adhesive failure and was excluded. Three restorations from groups PLV and DCR presented small cracks but were taken to the fracture test. After aging mean fracture load + SD (N) were: Group DCR (n = 10): 385 ± 225; Group CG (n = 10): 271 ± 100; Group PLV (n = 10): 266 ± 69; Group CLV (n = 9): 264 ± 66. Fracture strength means from groups CLV and PLV did not differ statistically from each other nor from control (p = 0.05). In the group CLV the root fracture was the most occurring fracture. In groups PLV and DCR, material cohesive failures and a mix (adhesive, tooth and material cohesive) failures were most observed. SignificanceThis in vitro study showed for the first time that partial laminate veneers can exhibit fracture strength values similar to direct composite restorations or conventional ceramic laminate veneers. All three restorative procedures presented clinically acceptable values of fracture strength. Even though three samples from groups PLV and three from DCR presented small cracks after thermocycling, these cracks do not appear to have a negative effect on the fracture strength.

Microstructural analysis of restorative materials submitted to acid exposure

The study aimed to evaluate, through surface roughness and microhardness tests, the amount of damage caused by hydrochloric acid to restorative materials. Five different materials were used: direct composite resin (Z 350), indirect composite resin (Resilab Master), conventional glass-ionomer cement (GIC) (Vidrion R), resin modified GIC (Vitremer) and ceramic (Empress II). Twenty one specimens of each material were constructed and had their initial roughness and microhardness evaluated. Sixteen specimens of each material were immersed in a gastric fluid without enzymes simulating acid episodes. Other 5 specimens of each material were immersed in artificial saliva (control groups). After 7 days of immersion, the specimens had their surfaces evaluated again. Then, after another 21 days of immersion the specimens were submitted to a third mensuration. One specimen at each stage of the research was subjected to analysis in scanning electronic microscopy. The samples demonstrated changes in roughness and microhardness after the immersion of the restorative materials in the acid solution. The roughness results showed that for both glass ionomer cements, there was a significant difference between the first and last reading, with an increase in their roughness. In ceramic and direct resin materials, no significant difference among the periods was observed. Concerning to microhardness, the behavior of the materials showed a tendency towards decreasing hardness. The results showed the degradation of the restorative materials when exposed to acid episodes.