Abstract:Purpose: The purpose of the current study was to assess fracture resistance and retention of three different endocrown materials. Materials and Methods: Thirty (n=30) sound mandibular molars were endodontically treated and according to endocrown constructed material appointed arbitrarily into 3 groups (n=10 each); Group (1): IPS e.max CAD, Group (2): Vita Suprinity and Group (3): Vita Enamic. Samples of each group were additionally subdivided into2 subgroups (n=5 each) according to fracture resistance and rete… Show more
“…The leather layers were used to reduce the possibility of endocrown fracture during tightening the upper compartment clips and to increase the friction between the two surfaces. UTM was set on pull-out mode with the speed of 5 mm/min, and the pull-out force was applied until complete separation of the restoration and the tooth [ 40 ]. Fig.…”
Background
This study aimed to compare retention and fracture load in endocrowns made from translucent zirconia and zirconium lithium silicate.
Methods
Fifty-six intact human maxillary molars after being mounted in acrylic resin, were scanned to acquire biogeneric copies. Specimens underwent standard endodontic treatment and were prepared for endocrown up to 2 mm above the cementoenamel junction. The specimens were randomly divided into two groups of 28, and endocrowns were designed using biogeneric copies and milled from high-translucent zirconia disks (Zr) and zirconium lithium silicate blocks (ZLS). After cementation with dual-cure resin cement, all the specimens underwent thermomechanical aging, and pull-out retention test and compressive test were conducted (14 specimens were used for each test in each group, n = 14), and failure modes in both tests were evaluated.
Results
Independent samples t-test showed significant difference between the retention of Zr (271.5 N ± 114.31) and ZLS (654.67 N ± 223.17) groups (p value = 0.012). Compressive test results were also significantly different between Zr (7395.07 N ± 1947.42) and ZLS (1618.3 N ± 585) (p = 0.002). Failure mode of retention test was primarily adhesive failure at the cement-restoration interface in Zr group and cement-tooth interface in ZLS group. Failure modes of fracture test for Zr group were 7 non-restorable fractures and one restorable fracture while 6 specimens resisted compressive loads up to 8500 N without fracture. ZLS group showed 7 restorable and 7 non-restorable failures.
Conclusions
Zr endocrowns showed significantly lower retention and higher fracture strength. Both materials seem to be suitable for fabrication of endocrown in clinical setup.
“…The leather layers were used to reduce the possibility of endocrown fracture during tightening the upper compartment clips and to increase the friction between the two surfaces. UTM was set on pull-out mode with the speed of 5 mm/min, and the pull-out force was applied until complete separation of the restoration and the tooth [ 40 ]. Fig.…”
Background
This study aimed to compare retention and fracture load in endocrowns made from translucent zirconia and zirconium lithium silicate.
Methods
Fifty-six intact human maxillary molars after being mounted in acrylic resin, were scanned to acquire biogeneric copies. Specimens underwent standard endodontic treatment and were prepared for endocrown up to 2 mm above the cementoenamel junction. The specimens were randomly divided into two groups of 28, and endocrowns were designed using biogeneric copies and milled from high-translucent zirconia disks (Zr) and zirconium lithium silicate blocks (ZLS). After cementation with dual-cure resin cement, all the specimens underwent thermomechanical aging, and pull-out retention test and compressive test were conducted (14 specimens were used for each test in each group, n = 14), and failure modes in both tests were evaluated.
Results
Independent samples t-test showed significant difference between the retention of Zr (271.5 N ± 114.31) and ZLS (654.67 N ± 223.17) groups (p value = 0.012). Compressive test results were also significantly different between Zr (7395.07 N ± 1947.42) and ZLS (1618.3 N ± 585) (p = 0.002). Failure mode of retention test was primarily adhesive failure at the cement-restoration interface in Zr group and cement-tooth interface in ZLS group. Failure modes of fracture test for Zr group were 7 non-restorable fractures and one restorable fracture while 6 specimens resisted compressive loads up to 8500 N without fracture. ZLS group showed 7 restorable and 7 non-restorable failures.
Conclusions
Zr endocrowns showed significantly lower retention and higher fracture strength. Both materials seem to be suitable for fabrication of endocrown in clinical setup.
“…When considering the restoration of the devitalized endodontically treated teeth, dental materials should be able to replace this loss of substance in order to guarantee mechanical and functional properties, esthetics and coronal seal (15) .…”
Section: Discussionmentioning
confidence: 99%
“…The fracture resistance of the devitalized mutilated teeth is related to many factors including the root canal treatment (risk of vertical root fractures), coronal issues (quality and quantity of remaining tissues and loading context), the type, design and the material of the restorations used to restore these teeth whether the classical approach of post and core systems (post material and size, core material, ferrule effect) or endocrown adhesive restorations ( either butt joint designs or with shoulder finish line designs) (15) . Some in vitro studies reported that bonded all ceramic CAD-CAM endocrowns showed comparable fracture load values compared with conventional crowns.…”
Purpose:The aim of this study was to assess the fracture resistance of PEEK endocrowns and post-retained PEEK crowns with two preparation designs (ferrule and without ferrule). Materials and methods: Eighty sound human mandibular first premolars were selected. Teeth were divided into 4 main groups (n= 20): Group1: Were assigned for endocrown preparation with Butt joint. Group 2: Were assigned for endocrown preparation with Shoulder finish line. Group 3: Were assigned for PEEK post & core preparation without ferrule. Group 4: Were assigned for PEEK post & core preparation with ferrule. Endocrowns of both Group 1 and Group 2 were made of PEEK material veneered with composite. Both Group 3 and Group 4 were covered with PEEK crowns veneered with composite. All Restorations either PEEK post & cores or endocrowns and final crowns were sandblasted with 110 Mm aluminium oxide. Finally, cemented with self-adhesive resin cement (G-Cem cement). Results: The highest mean value was recorded in Post & core with ferrule (above CEJ) (1262.29±65.02), followed by Endocrown with Butt Joint (1101.44 ± 81.7), then Endocrown with Shoulder finish line (890.99±75.42), with the least value recorded in Post & core without ferrule (below CEJ) (726.03±71.26). Statistically, ANOVA test showed a considerable difference between groups (p=0.00). Tukey's post hoc test showed a considerable difference between each 2 groups. Conclusion: It was concluded that the mandibular premolars that were restored by PEEK Post-cores covered with crowns which designed with ferrule recorded the highest fracture resistance load.
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