Influence of Endodontic Treatment and Retreatment on the Fatigue Failure Load, Numbers of Cycles for Failure, and Survival Rates of Human Canine Teeth

Background The aim of this study was to assess the clinical impact of non-surgical root canal treatments (NSRCT) performed with different treatment protocols on the probability of tooth survival without untoward events and to identify predictors influencing the outcome. Methods During the period from July 1999 to October 2016, 5,858 patients were identified in which 9,967 NSRCTs were performed. The treatments were followed up and divided into three groups. In Group 1 root canal treatment was performed with hand instruments, in Group 2 with multiple file rotary instruments and passive ultrasonic irrigation (PUI), and Group 3 was treated with Reciproc instruments and PUI. Untoward events were defined as orthograde retreatment, apicoectomy or extraction of the tooth after initial treatment. Weibull regression was used to analyse the data. Results A total of 9,938 cases could be included into the analyses. The results showed 5-years predicted survival rates without untoward events of 73.9% (95% CI [71.7%–76.1%]), 75.1% (95% CI [71.7%–78.0%]) and 78.4% (95% CI [75.1%–81.4%]) for study group 1 (N = 5,580), 2 (N = 1,700) and 3 (N = 2,658), respectively. The differences between Group 1 and 3 were statistically significant (p < 0.006). Higher age of the patient (per year increase) and number of earlier NSRCTs (per unit increase) reduce the survival without untoward events statistically significant (both p < 0.02), while treatment of premolars had a statistically significant lower hazard ratio [0.89 (95% CI [0.79–0.99]; p = 0.030)] compared to treatment of molars and anterior teeth. A higher number of supportive periodontal treatments (per unit increase) improved tooth survival without untoward events highly significant (p < 0.0001). Discussion More recent endodontic treatment protocols involving reciprocating instruments and PUI appear to be associated with higher tooth survival rates without untoward events compared to hand instruments.

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Fatigue Failure Load of Lithium Disilicate Restorations Cemented on a Chairside Titanium‐Base

Journal of Prosthodontics ◽

10.1111/jopr.12911 ◽

2018 ◽

Vol 28 (9) ◽

pp. 973-981 ◽

Cited By ~ 3

Author(s):

Peerapat Kaweewongprasert ◽

Kamolphob Phasuk ◽

John A. Levon ◽

George J. Eckert ◽

Sabrina Feitosa ◽

...

Keyword(s):

Fatigue Failure ◽

Failure Load ◽

Lithium Disilicate

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Fatigue Failure Load of Restored Premolars: Effect of Etching the Intaglio Surface of Ceramic Inlays With Hydrofluoric Acid at Different Concentrations

Operative Dentistry ◽

10.2341/16-345-l ◽

2018 ◽

Vol 43 (2) ◽

pp. E81-E91

Author(s):

T Missau ◽

AB Venturini ◽

GKR Pereira ◽

C Prochnow ◽

LF Valandro ◽

...

Keyword(s):

Fatigue Failure ◽

Hydrofluoric Acid ◽

Computer Aided Design ◽

Failure Load ◽

Acrylic Resin ◽

Test Machine ◽

Staircase Method ◽

Ceramic Inlays ◽

Computer Aided ◽

Failure Loads

SUMMARY The aim of this study was to evaluate the effect of etching, with different hydrofluoric acid concentrations at the intaglio surface of feldspathic ceramic inlays, on the fatigue failure load of restored premolars. A total of 60 upper premolars were embedded in plastic cylinders with acrylic resin (up to 3 mm below the cement-enamel junction) and prepared using a device specially designed for that purpose. Teeth were randomly assigned to three groups (n=20): HF1, HF5, and HF10 (etching with hydrofluoric acid for 60 seconds at concentrations of 1%, 5%, and 10%, respectively). Preparations were scanned and restorations were milled by a computer-aided design / computer-aided manufacturing system. The inner surfaces of the inlays were etched and received an application of a silane coupling agent; the dentin and enamel were treated appropriately for the luting system (RelyX ARC, 3M-ESPE). The restorations were cemented and the fatigue failure load (in N) was determined using the staircase method (10 Hz; 105 cycles in each step). The initial load (585.5 N) was applied on the slopes of the cusps (labial and palatal/lingual, simultaneously) through a cylinder attached to the test machine (Instron ElectroPuls E3000). The tested samples were analyzed under a stereomicroscope for failure analysis. Fatigue data were analyzed by one-way analysis of variance. There was no statistical difference among the fatigue failure loads (in N): HF1 (448.5±79.1), HF5 (360.7±55.4), and HF10 (409.5±121.1). Regarding the fracture mode, there was a predominance of interfacial fracture (50%), followed by cusp fracture (34.6%). It may be concluded that the etching with hydrofluoric acid at the tested concentrations (1%, 5%, and 10%) does not influence the fatigue failure load of feldspathic ceramic inlays cemented on premolars.

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Fatigue failure load of feldspathic ceramic crowns after hydrofluoric acid etching at different concentrations

Journal of Prosthetic Dentistry ◽

10.1016/j.prosdent.2017.03.021 ◽

2018 ◽

Vol 119 (2) ◽

pp. 278-285 ◽

Cited By ~ 14

Author(s):

Andressa B. Venturini ◽

Catina Prochnow ◽

Liliana G. May ◽

Cornelis J. Kleverlaan ◽

Luiz Felipe Valandro

Keyword(s):

Fatigue Failure ◽

Hydrofluoric Acid ◽

Failure Load ◽

Acid Etching ◽

Ceramic Crowns

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Fatigue Failure Load of a Bonded Simplified Monolithic Feldspathic Ceramic: Influence of Hydrofluoric Acid Etching and Thermocycling

Operative Dentistry ◽

10.2341/19-069-l ◽

2020 ◽

Vol 45 (1) ◽

pp. E21-E31 ◽

Cited By ~ 1

Author(s):

LF Guilardi ◽

GKR Pereira ◽

AS Vallau ◽

IA Silva ◽

JC Giordani ◽

...

Keyword(s):

Fatigue Failure ◽

Fatigue Resistance ◽

Hydrofluoric Acid ◽

Failure Load ◽

Statistical Tests ◽

Resin Cement ◽

Ceramic Surface ◽

Adhesive Cementation ◽

Ceramic Restorations ◽

O 10

SUMMARY Objective: To evaluate the effect of hydrofluoric acid (HF) etching and thermocycling (Tc) on fatigue failure load of feldspathic ceramic restorations cemented with two resin cements. Methods: Disc-shaped feldspathic ceramic (Vitablocs Mark II; Ø=10 mm, 1.0-mm thick) and G10 epoxy resin (Ø=10 mm, 2.5-mm thick) specimens were made and randomly allocated considering three factors: ceramic etching (ie, with vs without 10% HF plus silane application), resin cement (ie, self-adhesive [RelyX U200; U200] or conventional [Multilink Automix; MA]), and Tc (ie, with vs without 5-55°C/12,000 cycles). Adhesive cementation followed each manufacturer's instructions. The fatigue test (n=20) was based on the staircase approach (250,000 cycles; 20 Hz). Contact angle, surface topography, and fractography analysis were also executed. Specific statistical tests were employed for each outcome (α=0.05). Results: The interaction of HF and Tc factors decreased the fatigue resistance for both cements (U200 542.63>U200/HF-Tc 495.00; MA 544.47>MA/HF-Tc 506.84). Comparing the cements associated with HF or Tc, there was statistical superiority for MA (U200-Tc 537.37<MA-Tc 561.32; U200/HF 535.79<MA/HF 557.11), and no statistical difference was detected when only cement type or its association with HF-Tc was compared (U200 542.63=MA 544.47; U200/HF-Tc 495.00=MA/HF-Tc 506.84). The fracture always originated from defects at the ceramic-intaglio surface as radial cracks. Conclusion: HF etching plus silane agent increased the ceramic surface free energy and its wettability, but it did not provide better results in terms of fatigue resistance compared with silane agent application only. The association of HF etching and aging significantly reduced the fatigue resistance of the material, regardless of the resin cement used.

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