Strain analysis and fracture resistance of zirconium FPDs with pier abutments using different designs
Mohammed Mohammed Ali Al-samhari;
Abstract
This research was designed to study the strain analysis and fracture resistance of zirconium FPDs with pier abutments using different designs.
A right maxillary first premolar and first molar were removed from the upper arch of an acrylic typodent. The socket of the upper lateral was closed with pink modeling wax to simulate an edentulous area of a missing first premolar and first molar bounded by maxillary right canine, second premolar (pier), and second molar acrylic teeth. Each tooth was prepared to receive a full coverage all-ceramic retainer.
A total of 30 all-ceramic zirconia bridges were constructed and divided according to bridge design in to three groups(10 bridges each);fixed-fixed design (10 samples),non-rigid design (10 samples),and cantilever design (10 samples).
Each group was made to measure;1 strain gauge analysis at 300 N, 2 strain gauge analysis at fracture load, 3 fracture resistance loading.
The fitting surface of the retainers were sandblasted with 50 μm AL2O3 at maximum pressure of 2.5 bar for 30 seconds at an approximate distance 2 cm.
Thirty epoxy resin (Chemapoxy 150 Transparent) dies were fabricated by introducing the polymerizing resin into a polyvinylsiloxane mold (KERR Extrude Medium) of the master dies. The adhesive resin Metacem was used for cementation of the restorations. The restorations were seated slowly with gentle finger pressure then seated in the lower compartment of cement loading device under (1.5 Kg) load for one minute. Excess luting material was removed with sponge pellets immediately, and each cement surface/margin was light cured for 40 seconds.
Summary and conclusion
118
The samples were subjected to aging process as they were stored in acidic medium (citric acid) with pH. 6 and cyclic loading (dry type) for 500,000 cycles with forces ranges from 20-50 N.
The samples were subjected to vertical loading using a universal-testing machine (LIoyd Instrument LR 5K). The cross-head speed was 1 mm/min. the very first discontinuity resulting from an early crack, debonding or catastrophic failure of bridge and/or die was detected. 4 KYOWA strain gauges were bonded at four points; point A, at lingual –mesial surface of the distal retainer, point B, at lingual –distal surface of the pier retainer, point C, at lingual –mesial surface of the pier retainer, point D, at lingual –mesial surface of the anterior retainer using strain gauge cement. The strain induced in the samples during 300 N and fracture resistance testing was measured by a KYOWA strain meter.
Data of this study were presented as mean as mean and standard deviation (SD) values. Data were explored for normality using test of normality. A low significance value (less than 0.05) of test indicates that the distribution of the data differs significantly from a normal distribution. Fracture resistance and strain data showed a normal distribution so parametric tests were used for the comparisons. One way Analysis of Variance (ANOVA) was used to compare between three types of designs. Tukey҆s post-hoc test was used for pair-wise comparison between the
A right maxillary first premolar and first molar were removed from the upper arch of an acrylic typodent. The socket of the upper lateral was closed with pink modeling wax to simulate an edentulous area of a missing first premolar and first molar bounded by maxillary right canine, second premolar (pier), and second molar acrylic teeth. Each tooth was prepared to receive a full coverage all-ceramic retainer.
A total of 30 all-ceramic zirconia bridges were constructed and divided according to bridge design in to three groups(10 bridges each);fixed-fixed design (10 samples),non-rigid design (10 samples),and cantilever design (10 samples).
Each group was made to measure;1 strain gauge analysis at 300 N, 2 strain gauge analysis at fracture load, 3 fracture resistance loading.
The fitting surface of the retainers were sandblasted with 50 μm AL2O3 at maximum pressure of 2.5 bar for 30 seconds at an approximate distance 2 cm.
Thirty epoxy resin (Chemapoxy 150 Transparent) dies were fabricated by introducing the polymerizing resin into a polyvinylsiloxane mold (KERR Extrude Medium) of the master dies. The adhesive resin Metacem was used for cementation of the restorations. The restorations were seated slowly with gentle finger pressure then seated in the lower compartment of cement loading device under (1.5 Kg) load for one minute. Excess luting material was removed with sponge pellets immediately, and each cement surface/margin was light cured for 40 seconds.
Summary and conclusion
118
The samples were subjected to aging process as they were stored in acidic medium (citric acid) with pH. 6 and cyclic loading (dry type) for 500,000 cycles with forces ranges from 20-50 N.
The samples were subjected to vertical loading using a universal-testing machine (LIoyd Instrument LR 5K). The cross-head speed was 1 mm/min. the very first discontinuity resulting from an early crack, debonding or catastrophic failure of bridge and/or die was detected. 4 KYOWA strain gauges were bonded at four points; point A, at lingual –mesial surface of the distal retainer, point B, at lingual –distal surface of the pier retainer, point C, at lingual –mesial surface of the pier retainer, point D, at lingual –mesial surface of the anterior retainer using strain gauge cement. The strain induced in the samples during 300 N and fracture resistance testing was measured by a KYOWA strain meter.
Data of this study were presented as mean as mean and standard deviation (SD) values. Data were explored for normality using test of normality. A low significance value (less than 0.05) of test indicates that the distribution of the data differs significantly from a normal distribution. Fracture resistance and strain data showed a normal distribution so parametric tests were used for the comparisons. One way Analysis of Variance (ANOVA) was used to compare between three types of designs. Tukey҆s post-hoc test was used for pair-wise comparison between the
Other data
| Title | Strain analysis and fracture resistance of zirconium FPDs with pier abutments using different designs | Other Titles | تحليل التشوه الداخلى ومقاومه الكسر للتصاميم المختلفه من الجسور الزركونيه المستخدمه في تعويض حالات فقدان الاسنان مع وجود سن البيير الداعم بحث | Authors | Mohammed Mohammed Ali Al-samhari | Issue Date | 2014 |
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