Fracture Resistance of Esthetic Prefabricated and Custom-Made Crowns for Primary Molars After Artificial Aging.

Purpose: The purpose of this in vitro study was to compare the fracture resistance and survival of various esthetic crowns for primary molars after artificial aging via chewing simulation. Methods: A typodont tooth (mandibular primary second molar) was prepared to receive five different types of crowns as follows (n equals 10): prefabricated fiberglass (PF); CAD/CAM zirconia (CZ); CAD/CAM resin-ceramic (CR); composite- strip (CS); and prefabricated zirconia (PZ) as control. All specimens were subjected to 750,000 cycles of thermomechanical loading to artificially simulate three years of clinical service. None of the crowns from the CS group survived artificial aging. Surviving crowns were evaluated via micro-CT considering microcrack formation, and a load-to-fracture test was applied. Data were analyzed using one-way analysis of variance followed by the Duncan test. Results: Group PZ (557.4±170.1 N) and CR (669.6±255.2) were found to have comparable results (P >0.05), which were lower than the other groups (P<0.05). Group CZ resulted in the highest mean load-to-fracture value (1126.2±180.6; P <0.05). At the end of three years of artificial aging, microcracks were observed for only CS and PF groups. Conclusions: These in vitro data suggest that all tested crowns, except CS crowns, survived three years of artificial aging; however, CAD/CAM zirconia crowns may provide longer service, as they showed the highest fracture resistance with no microcrack formation.

Effects of different remineralization agents on MIH defects: a randomized clinical study.

OBJECTIVES: The aim of this study was to present a comparative evaluation of the long-term efficacy of fluoride varnish and pastes containing CPP-ACP and CPP-ACP with fluoride (CPP-ACFP) in the remineralization of creamy-white and yellow-brown defects in permanent first molars with MIH. MATERIALS AND METHODS: The study included 120 teeth with yellow-brown or creamy-white defects in 67 children (37 girls, 30 boys) aged 6-9 years (mean, 7.2) who were newly diagnosed with MIH with no substance loss or caries or prior restorative treatment. The patients were randomly divided into the experiment groups; control (oral hygiene motivation only), fluoride varnish, and pastes containing CPP-ACP and CPP-ACPF, and followed up for 24 months. The evaluations were made based on the ICDAS criteria and the measurements which were performed using the laser fluorescence method (DIAGNOdent, KaVo, Biberach, Germany) in the follow-ups. RESULTS: The research was completed with 49 patients (23 females, 26 males; mean age, 7.7) and 90 teeth. All remineralization agents increased remineralization rates in both creamy-white and yellow-brown colored defects without presenting any statistically significant difference at the end of the follow-up period (p > 0.05). However, the effects of fluoride varnishes were late to observe when compared to pastes containing CPP-ACP and CPP-ACPF. CONCLUSIONS: Pastes containing calcium and phosphate may be recommended for the longer-term preservation of teeth with yellow-brown defects which showed a post-eruptive breakdown in a shorter time. CLINICAL RELEVANCE: There is a lack of studies investigating MIH treatments in which lesion appearance was recorded. This study evaluated creamy-white and yellow-brown MIH defects separately and reported long-term results of different remineralization agents.

Comparative Evaluation of Adaptation of Esthetic Prefabricated Fiberglass and CAD/CAM Crowns for Primary Teeth: Microcomputed Tomography Analysis.

Adaptation is an important factor for the clinical success of restorations. However, no studies are available evaluating the adaptation of primary crowns. The aim of this study was to compare the adaptation of crowns fabricated by CAD/CAM technology versus prefabricated fiberglass primary crowns. Typodont maxillary central, canine, and mandibular molar teeth were prepared to serve as master dies after the size of Figaro crowns was determined (n = 10). Master dies were scanned with an intraoral scanner, and 10 identical CAD/CAM crowns were fabricated from resin-ceramic blocks. Figaro and CAD/CAM crowns were placed on the corresponding master dies and scanned via micro-CT. Three-dimensional volumetric gap measurements were performed to evaluate the overall adaptation. A total of 255 location-based linear measurements were allocated into 4 categories: marginal, cervical-axial, middle-axial, and occlusal. Statistical analyses were performed with factorial ANOVA, repeated measure ANOVA, and LSD tests (α = 0.05). CAD/CAM crowns showed significantly lower overall and location-based gap measurements than Figaro crowns regardless of tooth number (p < 0.05). For all groups, mean marginal discrepancies were lower than occlusal measurements (p < 0.05). Both crown types showed higher marginal gaps for molar teeth than for canine and central incisors with no significant difference between them (p > 0.05). CAD/CAM-fabricated crowns showed better marginal and internal adaptation than prefabricated Figaro crowns.

Evaluation of Residual Monomers Eluted from Pediatric Dental Restorative Materials.

Unreacted monomers eluted from resin-based restorative materials have been considered a reason of local and systemic adverse reactions. This study was designed to determine the effect of finishing and polishing procedures on the elution of Bis-GMA, TEGDMA, UDMA, and HEMA monomers from compomer and bulk-fill composite resins. Bulk-fill composite (3M ESPE GmbH, Seefeld, Germany) and compomer (Dentsply DeTrey GmbH, Konstanz, Germany) specimens with 3 × 4 mm diameters were prepared. The specimens were randomly divided into two groups, and finishing-polishing procedures were applied only to the experimental groups. Release of residual monomers was analyzed by using High-Performance Liquid Chromatography (HPLC) after 24, 48, and 72 hours. Repeated measures ANOVA and Tukey post hoc tests were used for comparisons. Finishing and polishing procedures had a significant effect on reducing the quantity of UDMA release in the Filtek™ Bulk Fill composite and Bis-GMA, HEMA, and TEGDMA in the Dyract XP compomer (p < 0.05). The restorative materials investigated here are not chemically stable after polymerization, and concentrations of eluted monomers may reach critical toxicity levels even after one restoration placement. Finishing and polishing procedures are mandatory to reduce residual monomers.

Effects of various thicknesses and levels of mineral trioxide aggregate coronal plugs on nanoleakage and fracture resistance in revascularization: An in vitro study.

The aim of this study was to evaluate the effects of mineral trioxide aggregate (MTA) applied at varying levels and thickness in the cervical region of the root on the leakage and fracture resistance of the simulated immature teeth. 3 study groups (n = 16) (Group 1: 2 mm MTA, Group 2: 4 mm MTA, Group 3: 2 mm MTA+2 mm RMGIC below cementoenamel junction) and 2 control groups (Group 4: Complete canal obturation, Group 5: No coronal plug) were used for the study. Nanoleakage was measured using a micro-computed tomography system. For the fracture resistance test, a universal testing machine was used. The amount of silver nitrate penetration decreased while MTA thicknesses increased (P < 0.001). However, the placement of MTA as a thicker layer did not make any additional contribution on the fracture resistance (P > 0.05). The 4-mm coronal MTA plug can be suggested in RETs for its superior sealing and reinforcement abilities.

Effects of Root Maturation and Thickness Variation in Coronal Mineral Trioxide Aggregate Plugs Under Traumatic Load on Stress Distribution in Regenerative Endodontic Procedures: A 3-dimensional Finite Element Analysis Study.

INTRODUCTION: Regenerative endodontic procedures (REPs) are the best biological-based treatment choice for managing necrotic immature permanent teeth. This study aimed to evaluate the stress distribution of immature maxillary permanent incisors and periodontal tissues under a traumatic load after root maturation achieved by REP with thickness variation in coronal mineral trioxide aggregate (MTA) plugs. METHODS: Five different mathematical 3-dimensional finite element analysis models of an immature permanent maxillary incisor were created. These involved immediate postoperative models after REP with varying coronal MTA plug thickness (model 1: 3-mm MTA and model 2: 5-mm MTA), postoperative models after REP with varying coronal MTA plug thickness with 15% volumetric root maturation (model 3: 3-mm MTA and model 4: 5-mm MTA), and a control model (model 5: a mature, healthy maxillary incisor). After the modeling procedures, a traumatic horizontal force load of 400 N was applied, and 3-dimensional finite element analysis was performed. The minimum principal, maximum principal, and von Mises stress criteria were calculated for evaluation. RESULTS: Regardless of the coronal MTA plug thickness, tensile stress in cervical root surfaces decreased with root maturation after REP. Using the 5-mm MTA plug reduced all types of stress in the middle third of the root. In bone tissue, the difference in MTA thickness did not affect stress values. However, stress decreased in most of the bony surfaces with root maturation after REP. CONCLUSIONS: Using the 5-mm coronal MTA plug may help in providing biomechanical advantages regarding stress transmission. Also, because root maturation after REP provided a more favorable stress distribution as mentioned, regenerative treatments can be recommended for immature permanent maxillary incisors for a good prognosis.

Resin Nanoceramic CAD/CAM Restoration of the Primary Molar: 3-Year Follow-Up Study.

This case report presents the clinical use of a resin nanoceramic CAD/CAM restoration of a primary second molar without successor in the form of a permanent second premolar tooth in a patient. Three-year follow-up of the case revealed that resin nanoceramic CAD/CAM restoration of the primary molar without successor achieved both aesthetics and function. Despite the high cost of treatment, this type of restoration should be considered if the retained tooth is expected to maintain functionality over the long term.

Root canal filling in primary molars without successors: Mineral trioxide aggregate versus gutta-percha/AH-Plus.

The aim of this study was to compare the clinical and radiographical success of mineral trioxide aggregate (MTA) and gutta-percha/AH-Plus used as a root canal filling material in primary second molars without successors. A total of 16 patients (9 girls, 7 boys) aged 6-13 years (mean: 10.5) were selected and randomly distributed into the treatment groups. Children were recalled for clinical and radiographic examination at 6, 12, 18, 24 and 36 months. Differences in treatment outcomes were analysed using chi-squared and Fisher's exact tests. Clinically, there was no significant difference in the success rates between the groups at the end of a 3-year follow-up period (MTA: 100%; Gutta-percha/AH-Plus: 70%) (P > 0.05). However, radiographically, there was a significant difference between the groups (MTA: 80%; gutta-percha/AH-Plus: 30%) (P < 0.05). The present study showed that MTA can be recommended for use in root canal treatment of primary molars without successors based on better radiographic success.

Review of current concepts of revascularization/revitalization.

This review focuses on the current concepts on revascularization/revitalization therapy. Revascularization/revitalization procedures performed under current protocols have reportedly achieved successful clinical and radiographical outcomes for immature permanent teeth with non-vital pulps; however, randomized prospective studies are needed to develop evidence-based methodologies for regenerative endodontic treatment.

Effect of toothbrushing on color changes of esthetic restorative materials.

PURPOSE: The aim of this study was to evaluate the effects of various drinks and toothbrushing on the color changes of esthetic restorative materials used in pediatric dentistry. MATERIALS AND METHODS: Forty specimens were prepared from each of three restorative materials (compomer [Dyract AP], glass ionomer cement [Ionofil Molar AC, Voco], composite resin [Filtek Z 250]). Specimens were divided into four groups for immersion in three different staining solutions (cherry juice, cola, chocolate milk) and distilled water. Each group was subdivided into brushing and non-brushing groups. The specimens in the brushing subgroups were brushed with toothpaste once a day using an electric toothbrush. Color was measured using a colorimeter, and color changes were calculated between baseline and 1, 7, 30, 60 days. Data was analyzed using Kruskal-Wallis, Mann-Whitney U, Wilcoxon, and Wilcoxon Signed Rank tests. RESULTS: All the solutions evaluated yielded color changes, and these changes were significantly greater for composite resin than for glass ionomer cement or compomer (p < 0.006). Brushing significantly decreased the color changes of restorative materials (p < 0.004). CONCLUSION: Brushing significantly influenced the color stability of esthetic restorative materials. The results of this study also showed that glass ionomer cements and compomers had higher color stability than composite resins. CLINICAL SIGNIFICANCE: The color stability values after brushing may better reflect the discoloration of the esthetic restorative materials. Any color stability study model should consider the effects of toothbrushing that can remove the adsorbed colorants. The results of this study also showed that glass ionomer cements and compomers can be used in anterior restorations of children with their higher color stability than composite resins.

Late developing supernumeraries in a case of nonsyndromic multiple supernumerary teeth.

Objective. This case report presents 3-year follow-up of a case of nonsyndromic multiple supernumerary teeth (NSMST) with 11 supernumerary teeth, 2 of which showed subsequent formation. Case Report. A 10-year-old girl was referred to the dental clinic with the chief complaint of delayed eruption. Radiographic examination showed 9 retained supernumerary teeth. The treatment plan consisted of extraction of the supernumerary teeth and associated primary teeth in order to allow the permanent teeth to erupt. After 2 years of follow-up, 2 additional supernumerary teeth were observed. Conclusion. Regular follow-up for late forming supernumeraries is crucial for NSMST cases.

Efficacy of platelet-rich plasma as a scaffold in regenerative endodontic treatment.

INTRODUCTION: Current research is concerned with discovering better scaffolds for use in regenerative endodontic treatment. This study aimed to clinically and radiographically evaluate the efficacy of platelet-rich plasma (PRP) used as a scaffold in regenerative endodontic treatment and compare it with that of a conventional blood clot (BC) scaffold. METHODS: A total of 20 necrotic, single-rooted immature teeth were randomly distributed into 2 groups. After disinfecting the root canal space with triple antibiotic paste (1:1:1 ciprofloxacin, metronidazole, and cefaclor), a tissue scaffold was created by using either PRP or BC and covered with white mineral trioxide aggregate. Clinical and radiographic follow-up examinations were performed once every 3 months during an 18-month period. Differences in root area were calculated from preoperative and postoperative radiographs. Fisher exact and Mann-Whitney U tests were used to evaluate differences between groups, with P value <.05 considered to be statistically significant. RESULTS: All 20 teeth were clinically asymptomatic during 18-month follow-up period; however, 1 tooth in the BC group exhibited periapical pathosis and was judged radiographically unsuccessful. Complete apical closure was observed in a mean of 8.1 months in the PRP group compared with 9 months in the BC group. The PRP group exhibited 9.86% increase in root area, compared with 12.6% increase in the BC group. The difference in success rates between the groups was not statistically significant (P > .05). CONCLUSIONS: PRP successfully created a scaffold for regenerative endodontic treatment; however, treatment outcomes did not differ significantly between PRP and conventional BC scaffold.

Resistance to leakage of various thicknesses of apical plugs of Bioaggregate using liquid filtration model.

AIM: The aim of this study was to compare the resistance to leakage of different thicknesses of Bioaggregate (BA) and 4-mm-thick white mineral trioxide aggregate (WMTA) in an apexification model using liquid filtration. METHODS: 32 extracted mandibular premolar teeth were sectioned at the cemento-enamel junction and 3-4 mm from the tooth apex to obtain 12-mm-long root segments. The apical and coronal thirds were prepared with size two through six Gates Glidden burs. The teeth were divided into four groups according to material and thickness, as follows: Group 1: 2-mm BA; Group 2: 4-mm BA; Group 3: 12-mm (total length) BA; Group 4: 4-mm WMTA (control). The empty parts of the roots in Groups 1, 2, and 4 were filled with gutta-percha and root canal sealer, and leakage was measured using fluid filtration. The data were analyzed using the Kruskal-Wallis H-test. RESULTS: No statistical differences in microleakage were observed between Groups 1, 2, and 4 (P > 0.05). Group 3 (roots filled completely with BA) showed significantly less leakage than the other groups tested (P < 0.01). CONCLUSIONS: The findings of this study showed that 12 mm of BA exhibited the best resistance to leakage. At the same time, 2-4 mm of BA showed similar results when compared to 4-mm MTA. In light of these results, this study suggests that BA may be a good candidate for further clinical studies when used as an apical barrier for apexification.

Dental management of patients with epidermolysis bullosa.

Epidermolysis Bullosa (EB) is a group of rare, genetic skin disorders characterized by fragility and blistering to minimal trauma. All oral surfaces may be involved, including the tongue, buccal mucosa, palate, floor of the mouth and gingiva. Common oral findings of the disease include microstomia, intraoral ulcerations and bullae formation, ankyloglossia, tongue atrophy, elimination of buccal and vestibular sulci, lingual depapillation and atrophy of the palatal folds. In these case reports; systemic findings, oral manifestations and preventive measures are described for 3 patients with EB, all of whom required extensive oral management. Early dental management and preventive care to minimize caries development and improve oral health is very important for patients with EB. Pediatric dentists play an especially important role in early intervention. In describing the dental management of three EB cases, this article stresses the importance of an aggressive dental preventive programme with strict oral hygiene instructions for patients and parents along with frequent professional cleaning and fluoride therapy.

Comparative evaluation of Ca(OH)2 plus points and Ca(OH)2 paste in apexification.

AIM: The aim of this study was to compare calcium hydroxide plus points (CHPPs) with the conventional calcium hydroxide paste (CHP) clinically and radiographically as materials used in apexification treatment. MATERIAL AND METHODS: Sixteen children, each with at least one necrotic permanent central incisor requiring apexification treatment, were selected for this study. Twenty-two selected teeth were divided into two test groups (10 CHP and 12 CHPP). The children were recalled for clinical evaluations every 3 weeks, and their radiographical evaluations were carried out every 3 months. Mann-Whitney U and Fisher's exact tests were used to evaluate the differences between the groups. RESULTS: The follow-up evaluations revealed that the success rate was 100% for CHP and 92% for CHPP. No statistically significant difference between the groups was observed (P > 0.05). CONCLUSIONS: CHPP-treated central incisors requiring apexification demonstrated good success. CHPP can be used for cases in which traditional Ca(OH)(2) apexification is indicated as it has a similar outcome with CHP.