The influence of restorative material and glass fiber posts on fracture strength of endodontically treated premolars after extensive structure loss.

OBJECTIVE: The aim of this in vitro study was to investigate the fracture strength and cuspal deflection of endodontically treated premolars restored using different composite resins along with or without fiber post application. MATERIALS AND METHOD: Eighty intact premolars were randomly divided into eight groups (n = 10); CO group: intact teeth (control), OPR group: mesio-occlusal-distal-palatal (MODP) preparation (OPR) + endodontic treatment (ET), TC group: MODP preparation + ET + Tetric N-Ceram, TB group: MODP preparation + ET + Tetric EvoCeram Bulk Fill, SO group: MODP preparation + ET + SonicFill 2, TC-P group: MODP preparation + ET + Hahnenkratt glass fiber post + Tetric N-Ceram, TB-P group: MODP preparation + ET + Hahnenkratt glass fiber + Tetric EvoCeram Bulk Fill, and SO-P Group: MODP preparation + ET + Hahnenkratt glass fiber post + SonicFill 2. After thermocycling, specimens were subjected to a compressive load until fracture. Data were analyzed using analysis of variance and Tukey tests (P < 0.05). RESULTS: The mean fracture strength of groups which received post treatment showed similar fracture strength values [TC-P (931.6 ± 97.9), TB-P (882.0 ± 59.7), SO-P (862.0 ± 143.0) (P > 0.05)] and was significantly higher than OPR (530.6 ± 41.7), TC (841.2 ± 93.1), TB (774.5 ± 101.8), and SO (735.0 ± 178.01) groups (P < 0.05). No significant difference was detected among groups considering cuspal deflection (P > 0.05). The fiber post insertion resulted in more unfavorable fractures. CONCLUSION: Endodontically treated teeth restored with fiber post and bulk-fill or conventional composite resins demonstrated fracture strength values similar to intact teeth.

Long-term survival of different deep dentin caries treatments: A 5-year clinical study.

OBJECTIVE: The aim of this in-vivo study was to evaluate the long-term clinical survival of different deep dentin caries treatment options. MATERIALS AND METHODS: : In total, 391 patients with at least one permanent tooth with clinically diagnosed deep dentin caries were inspected. Two hundred and fourteen patients were examined at recall visits. Inclusion criteria were teeth with deep caries lesions with pulp vitality but absence of spontaneous pain and periapical alterations. The subjects received either stepwise removal (SWR), complete caries removal (CCR), or direct pulp capping (DPC). The radiological and clinical exams were performed after a mean observation time of 62 months. Success was defined as pulp sensitivity to vitality test and absence of periapical lesions as well as a clinical symptom. Data were statistically analyzed using Kaplan-Meier and log-rank (Mantel-Cox) tests (α = 0.05). RESULTS: Of the total 214 patients evaluated, 126 received SWR, 88 received CCR, and 67 received DPC treatment. One hundred and twenty-seven restorations were amalgam and 141 were composite. The mean observation period was 62 months. Survival rates were 85.7%, 90.9%, and 59.7% for SWR, CCR, and DPC, respectively (P = 0.001). Success rates of amalgam restorations (86.6%) were similar to composite restorations (83%), and both were found to be successful (P = 0.401). CONCLUSION: SWR treatment should be considered to preserve pulp vitality of deep dentin lesions instead of CCR or DPC. CLINICAL RELEVANCE: SWR method for deep dentin caries management had acceptable results over 5 years.

Comparative Evaluation of Marginal Adaptation and Fracture Strength of Different Ceramic Inlays Produced by CEREC Omnicam and Heat-Pressed Technique.

OBJECTIVE: The aim of this in vitro study was to evaluate marginal adaptation and fracture strength of inlays produced by CEREC Omnicam using different types of blocs and heat-pressed technique. Methods: Seventy-five extracted human mandibular molars were divided randomly into 5 groups (n=15). 60 molars in four groups received MOD inlay preparations. Experimental groups were CO: Intact teeth, EC: IPS e.max CAD and CEREC, LU: Lava Ultimate and CEREC, EL: IPS Empress CAD and CEREC, EP: IPS Empress Esthetic ingots and heat-pressed technique. Marginal gap measurements were taken with a stereomicroscope. Restorations were cemented with Variolink N and stored in distilled water at 37°C for 24 hours. All samples were subjected to thermocycling. The fracture strength of specimens was determined at a 0.5 mm/min crosshead speed until fracture. Fracture modes were determined. Statistical analyses were performed using one-way analysis of variance for fracture strength data and Kruskal-Wallis for marginal gap data (p=0.05). RESULTS: The mean marginal gap size of EC, LU, EL, and EP were 33.54 µm, 33.77 µm, 34.23 µm, and 85.34 µm, respectively. EP had statistically higher values than other groups. The fracture strength values were significantly higher in the intact teeth group (3959,00 ± 1279,79 N) than those of restored groups EC (2408,00 ± 607,97 N), LU (2206,73 ± 675,16), EL (2573.27 ± 644,73) ve EP (2879,53 ± 897,30). CONCLUSION: Inlays fabricated using CEREC Omnicam demonstrated better marginal adaptation than inlays produced with heat-pressed technique, whereas fracture strength values of inlays fabricated with different type of blocks using CEREC Omnicam exhibited similarity to those fabricated with heat-pressed technique.