Replacement Of Restorations Research Articles

Esthetic and Functional Posterior Rehabilitation With Lithium Disilicate Ceramics for the Replacement of Gold Alloy and Metal-Ceramic Restorations: A Clinical Case With a 10-Year Follow-Up.

This case report illustrates a clinical scenario of a patient with insufficient crowns, gold onlays and localized tooth pain in the posterior teeth, treated with partial and full coverage lithium disilicate restorations. A female patient presented in the clinics, complaining about tooth pain and unesthetic metal restorations. After a thorough examination, diagnosis and treatment plan, the existing restorations were removed, and a defect-oriented preparation was done to preserve as much as possible of the remaining tooth structure. Final partial and full coverage lithium disilicate restorations were delivered. After a 10-year follow-up no biological complications were observed. Nevertheless, one major chipping was observed in one of the upper molars. This technical complication was resolved with the fabrication of a new ceramic restoration. Lithium disilicate ceramic posterior full- or partial-coverage restorations are a reliable and predictable treatment option not only for the replacement of tooth structure lost due to caries but also for the replacement of insufficient restorations. The following key factors are to be considered to pursue long-term success with ceramic restorations: patient selection, minimal invasive tooth preparation, appropriate material selection and cementation. Nevertheless, complications are to be expected, and the patient should be informed accordingly.

Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational Cross-Sectional Study With Meta-Analysis.

This web-based survey, conducted across multiple countries, sought to explore the factors that impact the decision-making of clinicians when it comes to managing defective direct restorations. A survey consisting of 14 questions was sent out to dentists in 21 countries through various online platforms. The survey consisted of two sections. The first contained five questions about demographic information, while the second involved eight clinical scenarios. In the second part, participants were tasked with deciding whether to repair or replace defective composite and amalgam restorations. Three thousand six hundred eighty dental practitioners completed the survey. For composite restorations, repair was preferred in scenarios like partial loss or fracture (RR:0.72; 95% CI: 0.58, 0.89; p = 0.002), whereas replacement was favored for secondary caries (RR:2.43; 95% CI: 1.87, 3.16; p < 0.001) and open/defective margins (RR:3.93; 95% CI: 2.68, 5.76;p < 0.001). Amalgam restorations were mostly replaced across all scenarios. The main factors influencing decision-making were caries risk, restoration size, and patient oral hygiene. Substantial heterogeneity was observed across countries. This study underscores the complexity of the decision-making process and the need for evidence-based guidelines to inform clinicians' decisions regarding restoration management. Patient-level factors predominantly influence decision-making, emphasizing the need for individualized approaches. The study reveals that the material type in the original restoration is a critical determinant, with composite restorations being repaired in specific scenarios, while amalgam restorations are consistently replaced across different countries. Key patient and tooth-level factors, such as high caries risk, poor oral hygiene, and restoration size, significantly impact clinicians' decisions, often favoring replacement over repair. These findings underscore the necessity for evidence-based guidelines to assist clinicians in making informed choices, ultimately enhancing the quality of patient care.

Minimally Invasive Approach for Anterior Dental Aesthetics: Case Report

Minimally invasive dentistry adopts a philosophy that integrates prevention, remineralization and minimal intervention for the placement and replacement of restorations. Minimally invasive dentistry reaches the treatment objective using the least invasive surgical approach, with the removal of the minimal amount of healthy tissues.This case report is aimed at reporting the treatment of a 34-year-old female patient with aesthetic concerns in the anterior teeth using a minimally invasive approach and evaluating the clinical performance after 1 year.

Repair versus replacement of defective direct dental restorations: A multinational cross-sectional study with meta-analysis

ObjectivesWhen dental practitioners encounter a defective restoration, they are faced with a crucial decision whether to repair or replace it. This study aims to explore international preferences for repair procedures and the clinical steps taken during the repair process. MethodAn 11-question survey was distributed to dentists across 21 countries via different platforms. The survey comprised two sections: the first included five questions aimed at gathering demographic information, while the second consisted of six questions focusing on participants' practices related to the repair of composite or amalgam restorations A meta-analysis was employed to ascertain the pooled odds ratio of repairing versus replacement. The statistical analysis was carried out using the RevMan 5.3 program and forest plots were generated using the same program to visualize the results. ResultsThe survey was completed by 3680 dental practitioners. The results indicated a strong tendency to repair defective composite restorations (OR: 14.23; 95 % CI: 7.40, 27.35, p < 0.001). In terms of amalgam, there was a significant tendency to replace the restorations (OR: 0.19; 95 % CI: 0.12, 0.30, p < 0.001). When repairing restorations, the most common protocols were etching with orthophosphoric acid and creating an enamel bevel, regardless of the restorative material used. ConclusionThe findings of this study indicate that there exists a knowledge gap among dental practitioners regarding restoration repair. It is imperative that dental practitioners receive proper education and training on restoration repair, to ensure the usage of adequate protocols and restoration survival. Clinical significanceA significant portion of dental practitioners lack the necessary knowledge and education required for the repair of restorations. Therefore, it is imperative to establish guidelines aimed at enhancing the management of defective restorations, along with protocols for clinical interventions. This includes the incorporation of proper courses in undergraduate, graduate, and continuing education programs.

Longevity of composite restorations in posterior teeth placed by dental students: a 12-year retrospective study.

To evaluate the longevity of resin composite restorations placed in posterior teeth by dental students, using data from electronic records from 2008 to 2019. Demographic (gender and age) and clinical variables (dental group, position in dental arch, and the number of restored surfaces) were evaluated. The 5-year follow-up was assessed according to the day the restoration was placed. Kaplan-Meier curves were generated to calculate the annual failure rate. Data were analyzed by Chi-Square, Kruskal-Wallis, and Mann-Whitney tests (α = 0.05). In total, 3.883 records relative to return periodicity were analyzed. The final sample consisted of 900 restorations from 479 patients. The majority were females, aged between 31 and 60. In total, 256 failures were reported (success rate = 78%), showing an annual failure rate of 2.05%. The main reasons for failures were restoration replacement (55.5%), endodontics (21.9%), prosthetics (14.5%) and extraction (8.2%). There was a higher risk of failure in restorations involving three or more surfaces (p = 0.000) and in patients over 60 years (p < 0.001). In females (p = 0.030), molars (p = 0.044), and maxillary teeth (p = 0.038) failed in a shorter time. Resin composite restorations placed in permanent posterior teeth by dental students had high survival rates. The main reason for failure was the replacement of restorations. The age group and the number of restored surfaces significantly affected the success of the restorations. The electronic health records over 12 years showed that 78% of the resin restorations in posterior teeth placed by dental students were successful for a minimum of five years.

In vitro evaluation of the bleaching effect on the change of color match of omnichroma composite resin

Aim To in vitro evaluate the bleaching effect on the color match of Omnichroma composite resin restorations to the teeth color. Materials and methods Thirty freshly extracted intact human premolars were collected and mounted in acrylic resin blocks (only roots were embedded). The shade of the selected teeth was measured by (VITA Easyshade V). Class V cavities (4 mm width, 2 mm length, and 2 mm depth) were prepared 2 mm coronal to cement-enamel junction on the cervical third of the facial surface of each tooth. Specimens were randomly divided into two equal groups (n = 15): group I: was restored with nano hybrid Tetric N- ceram while group II: was restored with Omnichroma supra-nano filled composite resin using their respective adhesives. All the specimens were thermocycled for 500 cycles from 5 to 55°C with 15 s dwell time, and 20 s transfer time. The initial data of color measurements for tooth and restoration surfaces were recorded after thermocycling using VITA Easy Shade V. Specimens were then bleached using 40% HP by White smile power whitening YF according to the manufacturer instructions and kept in artificial saliva for 1 week before color re-measuring. All data were collected, tabulated, and statistically analyzed at 95% significance level using a software statistical package for social sciences (SPSS version 26). Results Before bleaching, higher mean ΔΕ values were recorded for the teeth (3.38 and 2.74) compared to (2.24 and 1.82) of the restorations in group I (Tetric N) and group II (Omnichroma) respectively with no statistically significant difference (P = 0.26 and 0.43) in either of the groups denoting the color match between the restorations and the teeth in both groups. After bleaching there was a highly statistically significant difference (P = 0.039) between the mean ΔΕ values of teeth (5.56) and restorations (3.23) in group I, denoting the color mismatch. While in group II there was no significant difference (P = 0.249) between the values of teeth (5.25) and restorations (4.49) denoting the persistence of the color match after bleaching. No significant difference was found between the ΔΕ values of teeth used in both groups neither before (P = 0.62) nor after bleaching (P = 0.802). While there was a significant difference between the recorded values of the restorations after bleaching (P = 0.026) although the difference was not significant before bleaching (P = 0.619). Bleaching significantly affected the teeth color (P = 0.013 and 0.038), and the restoration color (P = 0.049 and 0.012) in groups I and II, respectively. Conclusions Omnichroma class V composite restorations matched the shades of teeth before and after bleaching where it was changed to a lighter shade with the teeth enamel that was within the acceptable clinical range. The color matching of the Tetric N restorations after bleaching was lost where the teeth were lighter in a clinically detectable manner, which necessitates restoration replacement.

Transitioning from injectable resin composite restorations to resin composite CAD/CAM veneers: A clinical report.

To describe a shift from injectable resin composite technique to composite resin computer-aided design and computer-aided manufacturing (CAD/CAM) veneers in addressing esthetic concerns associated with diastemas between anterior lower teeth in a clinical case. Among several techniques proposed for direct resin composite restoration, the "Injectable resin composite technique" has gained popularity for its time-efficiency, reduced technique sensitivity, and diminished reliance on clinician skills. However, challenges such as staining and the need for frequent polishing follow-ups may prompt the consideration of more stable alternatives such as indirect veneer restorations. While ceramic veneers offer superior mechanical and optical properties, resin ceramic veneers, especially those milled from CAD/CAM resin ceramic blocks, offer advantages such as rapid, cost-effective production, simplified intra-oral repairs, less susceptibility to fracture, superior stress absorption, and requires minimal tooth preparation, making them an appealing option for many patients. Moreover, a fully-digital approach not only streamlines the process but also saves time and labor while ensuring the delivery of high-quality restorations to patients. In addressing a patient's dissatisfaction with constant polishing of direct resin composite restorations, a shift to resin composite CAD/CAM veneers was implemented. Utilizing a fully-digital approach with CAD/CAM resin ceramic restorations successfully restored both esthetics and function. While the injectable resin composite technique achieves immediate esthetic results, its low color stability necessitates frequent polishing sessions. The replacement of direct resin composite restorations with CAD/CAM resin composite veneers becomes a viable option for patients seeking more stable restorations that require fewer follow-ups. This transition addresses both esthetic concerns and the need for enduring solutions in restorative dentistry.

Longevity of dental restorations in Sjogren’s disease patients using electronic dental and health record data

BackgroundDecreased salivary secretion is not only a risk factor for carious lesions in Sjögren’s disease (SD) but also an indicator of deterioration of teeth with every restorative replacement. This study determined the longevity of direct dental restorations placed in patients with SD using matched electronic dental record (EDR) and electronic health record (EHR) data.MethodsWe conducted a retrospective cohort study using EDR and EHR data of Indiana University School of Dentistry patients who have a SD diagnosis in their EHR. Treatment history of patients during 15 years with SD (cases) and their matched controls with at least one direct dental restoration were retrieved from the EDR. Descriptive statistics summarized the study population characteristics. Cox regression models with random effects analyzed differences between cases and controls for time to direct restoration failure. Further the model explored the effect of covariates such as age, sex, race, dental insurance, medical insurance, medical diagnosis, medication use, preventive dental visits per year, and the number of tooth surfaces on time to restoration failure.ResultsAt least one completed direct restoration was present for 102 cases and 42 controls resulting in a cohort of 144 patients’ EDR and EHR data. The cases were distributed as 21 positives, 57 negatives, and 24 uncertain cases based on clinical findings. The average age was 56, about 93% were females, 54% were White, 74% had no dental insurance, 61% had public medical insurance, < 1 preventive dental visit per year, 94% used medications and 93% had a medical diagnosis that potentially causes dry mouth within the overall study cohort. About 529 direct dental restorations were present in cases with SD and 140 restorations in corresponding controls. Hazard ratios of 2.99 (1.48–6.03; p = 0.002) and 3.30 (1.49–7.31, p-value: 0.003) showed significantly decreased time to restoration failure among cases and positive for SD cases compared to controls, respectively. Except for the number of tooth surfaces, no other covariates had a significant influence on the survival time.ConclusionConsidering the rapid failure of dental restorations, appropriate post-treatment assessment, management, and evaluation should be implemented while planning restorative dental procedures among cases with SD. Since survival time is decreased with an increase in the number of surfaces, guidelines for restorative procedures should be formulated specifically for patients with SD.

Assessment of Prevalence and Causative Factors for Replacement of Composite and Amalgam Restorations: An Observational Study

ABSTRACT Aim: This study intends to evaluate the frequency and causes of replacement for failed amalgam and composite dental restorations. Methodology: A cross-sectional study comprising female patients with failed permanent composite and amalgam restorations aged 15–60 years old was carried out at the dental clinics of Qassim University. Using a self-structured proforma, demographic data and causes for restoration failure were recorded. The effectiveness of the restorations was assessed by using the Ryge criteria after performing clinical and radiographic examinations. The Statistical Package for Social Science was used for the statistical analysis. Results: It is found that 84.6% of the 299 unsuccessful restorations examined were composite, and 15.4% were amalgam. The main reason for dental failure for both amalgam (95.6%) and composite (93.28%) restorations was secondary caries. Failure of amalgam restoration was largely caused by poor marginal adaptation. With varied incidences between amalgam and composite restorations, typical complaints included discomfort, sensitivity, pain, and food impaction with soreness. The main justification for replacement in amalgam restorations was sensitivity. Repair and replacement rates were similar for amalgam, composite, and mandibular/maxillary restorations. Moreover, 21.1% of individuals overall reported no symptoms, with 8.7% in the amalgam group and 23.3% in the composite group with significant differences (χ 2 = 34.28, P = 0.001). Conclusion: According to the current study, secondary caries was found to be the main reason for both amalgam and composite restoration failure. The main problems reported were sensitivity, discomfort, and pain with amalgam showing more sensitivity-related failures.

Complicated caries of permanent teeth in children: status of the problem and modern solution ways

The issue of improving dental care protocols for children with multiple (decompensated) and complicated caries of permanent teeth, their full rehabilitation is particularly relevant, especially in periods of social cataclysms (the COVID-19 pandemic, martial law, etc.). The purpose of this study was an assessment of the dental caries experience, analysis of modern approaches to diagnosis, treatment, prevention and rehabilitation of complicated caries of permanent teeth among children in Kyiv. The material of the study was data from medical histories of 236 children aged 7-18 years. During the analysis of the obtained data, the dental caries experience, % of cases of toothache complaints and part of the need for replacement or correction of restorations after the treatment of complicated caries were calculated. The prevalence of caries of permanent teeth among 7-18-year-old children (n=236) in the period 2020-2023 was 42-95%, the dental caries experience – 1.73-6.4, the frequency of diagnosis of complicated caries – 4.8-37,1%, the prevalence of toothache – 31%, the part of the need for replacement of restorations after treatment of complicated caries – 62%. The obtained indicators confirm the absence of a downward trend compared to similar data for more than 15 years of observation. Diagnosis, treatment and full rehabilitation of complicated caries of permanent teeth in children is complex, multi-stage and requires the practical experience and patience of a dentist and the usage of the most modern materials and technologies. To date, there are no clear scientifically based protocols for the restoration of permanent teeth, in particular with incomplete root formation, after endodontic treatment. The usage of modern technologies of orthopedic dentistry and materials science (3D scanner, 3D printer, T-scan, polymers) will allow to significantly improve the quality of comprehensive treatment and rehabilitation of children with complications of caries of permanent teeth.

Color stability of two different resin matrix ceramics: randomized clinical trial

BackgroundOne of the most common causes of aesthetic failure and restoration replacement is the tooth restorations color mismatch specifically after aging.MethodsOne hundred and two participants with endodontically treated first molar were selected clinically. The patients were randomly splited into two groups and restored either with Cerasmart hybrid ceramic or Vita Enamic polymer infiltrated ceramic network (PICN) crowns and cemented using dual cure adhesive cement. The color difference (ΔE) values after cementation at 0 (Baseline), 6, and 12 months of use were obtained by quantification of L*, a*, and b* values with a digital spectrophotometer. Mann–Whitney test used to compare between tested groups at each time point and between (α = 0.05).ResultsAt 6 months follow-up intervals, Vita Enamic group showed the highest significant ∆L* (p = 0.035) and ∆a* (p < 0.001) compared to Cerasmart group. ∆b* and ∆E showed no significant difference between both groups (p > 0.05). Furthermore, all color parameters of both groups showed statistically significant difference at 12 months follow-up intervals. After 12 months, Vita Enamic restorations presented higher color change compared to Cerasmart restorations with a (p-value of 0.0120). When comparing the total color difference ∆Et through-out the follow-up intervals of Vita Enamic & Cerasmart groups, there were insignificant difference (p = 0.263).ConclusionBoth hybrid materials demonstrated comparable color stability after 1 year of clinical service within clinical acceptance range. However, Cerasmart demonstrated a better colour stability after 1 year.Trial registrationClinicalTrials.gov (ID: NCT05501808) 15/8/ 2022- ‘retrospectively registered’.

Patient care in the restorative clinic of a public dental school after COVID-19 lockdown

Aim: This study, with the aim of checking some of the changes in patients’ daily habits and their reasons for needing restorative treatment was conducted at a public university immediately on return to attendance after the COVID-19 pandemic lockdown. Methods: This survey consisted of interviews held by applying 2 questionnaires to students and patients. A single researcher collected data in all the restorative dentistry clinics at the university after the return to face-to-face activities in the period between 02/02/2021 and 07/30/2021. Data obtained by means of the questionnaires were submitted to descriptive analysis. Results: Ninety (90) participants answered the patient questionnaire. When considering possible associations between being in social isolation or not, significant values were found for changed type of diet (p=0.0011), frequency of eating (p=0.011) and toothbrushing (p=0.034). Data about 417 restorations were collected and among the reasons for restorative intervention, 33.03% were restoration replacement, 31.87% treatment of primary caries and 24.40% of dental wear/non-carious lesions. Conclusion: Patients who isolated themselves during the pandemic tended to change their eating habits and frequency of oral hygiene. Toothache was the main reason for seeking dental treatment and the replacement of pre-existing restorations was the main reason for restorative treatments.

Degradation and Failure Phenomena at the Dentin Bonding Interface.

Damage in the bonding interface is a significant factor that leads to premature failure of dental bonded restorations. The imperfectly bonded dentin-adhesive interface is susceptible to hydrolytic degradation and bacterial and enzyme attack, severely jeopardizing restorations' longevity. Developing caries around previously made restorations, also called "recurrent or secondary caries," is a significant health problem. The replacement of restorations is the most prevailing treatment in dental clinics, leading to the so-called "tooth death spiral". In other words, every time a restoration is replaced, more tooth tissue is removed, increasing the size of the restorations until the tooth is eventually lost. This process leads to high financial costs and detriment to patients' quality of life. Since the complexity of the oral cavity makes prevention a challenging task, novel strategies in Dental Materials and Operative fields are required. This article briefly overviews the physiological dentin substrate, features of dentin bonding, challenges and clinical relevance. We discussed the anatomy of the dental bonding interface, aspects of the degradation at the resin-dentin interface, extrinsic and intrinsic factors affecting dental bonding longevity, perspectives on resin and collagen degradation and how these subjects are connected. In this narrative review, we also outlined the recent progress in overcoming dental bonding challenges through bioinspiration, nanotechnology and advanced techniques to reduce degradation and improve dental bonding longevity.

Perception of Minimum Interventional Dentistry among Dental Undergraduate Students and Interns.

Background: The philosophy of minimum interventional dentistry (MID) is to integrate prevention, remineralization, and minimal intervention for the placement and replacement of restorations. All branches of dentistry play an important role in practicing MID, and their primary goal is to realize that any restoration is of less biological significance than the healthy original tissue Objectives: The objective of this study was to assess the perception of MID among dental undergraduate students and interns in terms of knowledge, attitude, and practice at the College of Dentistry. Materials and Methods: This cross-sectional study was conducted among undergraduate students and interns at the College of Dentistry, Qassim University, Saudi Arabia. A self-administered questionnaire was distributed, which included basic demographic profiles and questions about the knowledge, attitude, and practices toward MID. The data were tabulated in MS Excel, and all statistical analyses were performed using SPSS version 21. Results: A total of 163 dental students were recruited, with senior students comprising 73% and interns comprising 27%. Male students were slightly more prevalent (50.9%) than female students (49.1%). About 37.6% of participants received training about MID during educational courses, while 10.3% received it during their internship. A statistical test revealed that the prevalence of interns who were trained in performing MID was significantly higher (p < 0.001). Conclusions: The majority of the participants demonstrated proper knowledge, attitude, and practice in different aspects of MID. Interns reported a higher rate of knowledge, attitude, and practice in MID compared to undergraduate students. However, more education and hands-on training about MID concepts during the college curriculum are necessary to attain better knowledge, attitude, and practices that could be useful for more conservative clinical practice.

Repair Versus Replacement of Failed Restorations

Detailed criteria are needed to establish what constitutes failures which call for replacement or repair of restorations. Many factors play a role in the selection of repair as an alternative to replacement of failed restorations, including the clinical condition, the restorative material involved, and cost/benefit assessments. The advantages of repair of localised defects include saving of tooth structure and increased longevity of restorations at a low cost.

Clinical evaluation of reasons for replacement of amalgam vs composite posterior restorations

BackgroundThe aim of the present study is to evaluate the most common reasons for replacing posterior amalgam and resin composite restorations in patients attending the university dental restorative clinics. MethodsA total of 318 restorations which needed to be replaced were clinically and radiographically evaluated in a period of nine months. The frequencies of reasons for replacing posterior amalgam and resin composite restorations were calculated; secondary caries, restoration/tooth fracture, marginal discoloration/ditching, proximal overhang/open margin, loss of anatomy, pain/sensitivity, and esthetics. ResultsThe sample population comprised of 191 females and 106 males. The majority of the sample population fell in the age group of 40–50 years (n = 110). 318 restorations (n = 318) were examined in this study. 82% of examined teeth were restored with amalgam (n = 261), while posterior composite restorations comprised 18% of the examined teeth (n = 57). Among all restorations demanded to be replaced by the patients (n = 318), aesthetic need was the most common reason (n = 98), followed by Ditching or discoloration (n = 64), secondary caries (n = 57), and fracture (n = 44). Loss of anatomy was the least common cause to replace both amalgam and resin composite restorations (n = 5). The different reasons of failure were all significant between amalgam and resin composite restorations as shown in (Fig. 1) (p < 0.005). The most common reason for amalgam replacement was aesthetic. The most common reason for composite replacement was secondary caries and marginal ditching. ConclusionBoth amalgam and composite had different reasons for replacement. Amalgam had lesser risk of developing secondary caries and higher longevity than composite.

Teaching of composite restoration repair in Brazilian dental schools

ObjectivesThe aim was to investigate aspects of the teaching of restoration repair as a minimally invasive alternative to replacing defective direct composite restorations in undergraduate curricula teaching programs in Brazilian dental schools. MethodsA 14-item validated survey questionnaire was mailed to directors/coordinators of operative/restorative dentistry teachers of Brazilian Dental Schools. Data were collected on demographic characteristics of the teachers and institutions, together with questions on the teaching of the repair of defective resin-based composite restorations as part of the school curriculum; the rationale behind the teaching; the nature of the teaching (preclinical and/or clinical); how techniques were taught, indications for repair, operative techniques, materials used, patient acceptability and expected longevity of completed repairs. ResultsTwo hundred and twenty-two (94%) directors/ coordinators of dental curricula in Brazil were contacted. One hundred and thirty-one directors/coordinators (59%) replied, providing the e-mail address from the teacher responsible for the operative/restorative dentistry program in their school. Of these, 104 responded to the questionnaire (79% response rate). Ninety-three (89%) of the participating schools reported teaching composite repairs as an alternative to replacing restorations. Of the theoretical content, 43% was taught at preclinical and clinical levels, whereas most practical experience (53%) was acquired at clinical levels. Eighty-eight schools (95%) reported tooth substance preservation being the main reason for teaching repair techniques. All schools that taught repairs reported high patient acceptability. ConclusionsThe teaching of composite restoration repair as an alternative to restoration replacement is established in undergraduate programs in most of the Brazilian dental schools surveyed. Clinical significanceThe reasons for teaching restoration repair in Brazil were found to be quite unanimous among teachers, especially regarding the preservation of tooth structure. Variations were found in the clinical indications for repair, suggesting the need for further investigations. Monitoring repaired restorations should be encouraged and could contribute to future studies.

Comparison between color stability of zirconia and lithium disilicate

The most widely used glass-ceramic is lithium disilicate (LD) because of its remarkable optical qualities, high strength, and simplicity of manufacture. Greater marginal strength, reduced porosity, and net-shaped manufacturing by pressing are further benefits of LD. The development of yttrium stabilized trigonal zirconia polycrystalline (Y-TZP) ceramics is the result of the pursuit for a material with both mechanical capabilities, like the resistance provided by metallic restoration, and the distinctive optical characteristics of glass-ceramic. The main drawback is the fragile veneering ceramics, which are prone to chipping, debonding, and breakage. There is evidence that extrinsic variables such beverages, mouthwashes, acid solutions, dental brushing, and increased temperatures might cause ceramic surfaces to deteriorate. The composition and surface shape of ceramic materials have an impact on the extrinsic pigment absorption or adsorption from the oral cavity. The main causes for the clinical replacement of anterior restorations, according to prior research, are poor color matching and color instabilities. Monolithic zirconia is more prone to staining from chlorhexidine, green tea, and coffee. In monolithic zirconia, the aging-related color changes are more pronounced. The color of the background substructure influences how zirconia restorations look overall. In terms of color stability and translucency, LD ceramic has also been proven to be more aesthetically pleasing. In comparison to monolithic zirconia, bilayer zirconia with feldspar veneering ceramic displayed reduced discoloration overall. It has been noted that monolithic zirconia is more susceptible to low-temperature degradation than the core Y-TZP. The use of current literature to infer outcomes has several limitations because in most vitro investigations, thermocycling has been carried out in water rather than oral cavity saliva and the influence of sunlight exposure, salivary proteins, food coloring, tobacco, different enzymes, and surface-related factors on the color stability is yet to be examined.

"EFFICIENCY OF REPLACEMENT OF TONGUE DEFECTS AND RESTORATION OF CHEWING AND SWALLOWING FUNCTIONS"

"EFFICIENCY OF REPLACEMENT OF TONGUE DEFECTS AND RESTORATION OF CHEWING AND SWALLOWING FUNCTIONS"

Postoperative Sensitivity of Composite Replacement of Amalgam Restoration: A Randomized Clinical Trial

This randomized clinical trial aimed to evaluate the postoperative sensitivity of different resin composite/adhesive materials, placed either by an incremental or bulk-fill technique in posterior resin composite replacement of amalgam restorations. A total of 47 patients with good overall health and at least four class I or class II amalgam restorations to be replaced participated in this study. The characteristics of 188 cavities were registered and randomly restored using incremental (Z350XT, 3M) or bulk-fill (Filtek Bulk Fill, 3M; Sonic Fill, Kerr; and Opus Bulk Fill, FGM) technique. The postoperative sensitivity was assessed using a Visual Analog Scale (0-100) after 24 hours, 7 days, and 30 days. Pain scores were temporally analyzed using Friedman test followed by Dunn post hoc test (α=0.05). The frequency of tests was calculated according to the frequency and percentage of the McNemar test. The restorative technique and the bulk-fill system used did not affect the postoperative sensitivity, except for Filtek Bulk Fill group, which presented less postoperative sensitivity after 24 hours (p=0.037). Regardless of the restorative material, the postoperative sensitivity decreased after 24 hours, and no differences were found after 7 and 30 days. After 1 week, the filling technique and the bulk-fill system have no influence on the postoperative sensitivity.