Influence of the endodontic access cavity design and restorative technique on hard tissue removal and fracture resistance of mandibular premolars

This study assessed the influence of traditional (TradAC) and conservative access (ConsAC) with different restorative techniques on the percentage of hard tissue removed (%HTR) and on the fracture resistance of mandibular premolars. 45 premolars were scanned in a micro-computed tomography and assigned into four groups according to access (TradAC or ConsAC) and restorative technique: composite resin (CR) or fiber post (FP) + CR. After post preparation, the teeth were rescanned to determine the volume enlargement and %HTR from the crown and root canal. After restoration, the load at fracture was recorded. Data were analyzed statistically by one-way ANOVA and Tukey’s post-hoc test, ANOVA repeated measure, and chi-square tests (P<0.05). TradAC (RC or FP) resulted in the increase (Δ%) of root canal volume and hard tissue removed up to 14 mm (%) in comparison with ConsAC (RC or FP). TradAC + FP removed a greater percentage of hard tissue from the crown when compared to TradAC + CR. The percentage of hard tissue removed in the crown in the ConsAC groups was statistically lower than in the TradAC groups. The control group showed higher fracture resistance than all experimental groups, with no differences among the latter. Restorable fracture patterns were more prevalent. Traditional endodontic access cavities removed a higher percentage of dentine than conservative endodontic access cavities. However, no differences in fracture resistance were observed. Restorations using composite resin or fiber post associated with composite resin showed similar results of fracture resistance.

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Fracture resistance of simulated immature teeth after apexification with calcium silicate-based materials

European Journal of Dentistry ◽

10.4103/1305-7456.178301 ◽

2016 ◽

Vol 10 (02) ◽

pp. 188-192 ◽

Cited By ~ 9

Author(s):

Evren Ok ◽

Mustafa Altunsoy ◽

Mehmet Tanriver ◽

Ismail Davut Capar ◽

Abdussamed Kalkan ◽

...

Keyword(s):

Analysis Of Variance ◽

Calcium Silicate ◽

Fracture Resistance ◽

Composite Resin ◽

Mineral Trioxide Aggregate ◽

Control Group ◽

Fiber Post ◽

Immature Teeth ◽

Post Hoc

ABSTRACT Objective: To compare the fracture resistance of simulated immature teeth filled with an apical barrier of mineral trioxide aggregate (MTA), Biodentine, and calcium-enriched mixture (CEM). Materials and Methods: Fifty-two single-rooted human maxillary central incisors were used. For standardization, the teeth were sectioned 6 mm above and 9 mm below the cementoenamel junction to simulate immature apex. Simulations of roots into immature apices were carried out using 1.5 mm diameter drills. The specimens were then randomly divided into three experimental groups (n = 13) and one control group (n = 13). In experimental groups, MTA, Biodentine, and CEM were placed to apical 4 mm of the simulated immature roots. The samples were stored at 37°C and 100% humidity for 1 week. A load was applied on the crown of all teeth at 135° to their long axis until fracture. The data were analyzed using one-way analysis of variance and Tukey post-hoc tests. Results: No statistically significant differences were found among MTA, CEM, and Biodentine (P > 0.05), and these groups demonstrated higher fracture resistance than control group (P < 0.05). Conclusions: Using any of the MTA, Biodentine, and CEM as an apical plug and restoring with fiber post and composite resin increases the fracture resistance of immature teeth.

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Fracture Resistance of Endodontically Treated Maxillary Premolars Restored With Different Methods

Operative Dentistry ◽

10.2341/17-262-l ◽

2019 ◽

Vol 44 (1) ◽

pp. E1-E11 ◽

Cited By ~ 5

Author(s):

VA Mergulhão ◽

LS de Mendonça ◽

MS de Albuquerque ◽

R Braz

Keyword(s):

Fracture Resistance ◽

Composite Resin ◽

Fracture Pattern ◽

Control Group ◽

Fisher Exact Test ◽

Fiber Post ◽

Maxillary Premolars ◽

Horizontal Fiber ◽

Ceramic Inlay

SUMMARY Purpose: The purpose of this in vitro study was to evaluate the resistance and patterns of fracture of endodontically treated maxillary premolars (ETPs) restored with different methods. Methods and Materials: Mesio-occluso-distal cavities were prepared in 50 extracted caries-free human maxillary premolars after endodontic treatment. The teeth were divided into five groups (n=10), according to the restorative method. G1: intact teeth (control group); G2: conventional composite resin; G3: conventional composite resin with a horizontal glass fiber post inserted between buccal and palatal walls; G4: bulk-fill flowable and bulk-fill restorative composites; and G5: ceramic inlay. For direct restorations, Filtek Z350 XT, Filtek Bulk Fill Flowable Restorative, and Filtek Bulk Fill Posterior Restorative were used. Indirect restorations were fabricated from a pressable lithium disilicate glass-ceramic (IPS e-max Press) and adhesively cemented (RelyX Ultimate). All specimens were subjected to thermocycling (5°C to 55°C/5000 cycles) and additionally submitted to cyclic loading 50,000 times in an Electro-Mechanical Fatigue Machine. Next, the specimens were subjected to a compressive load at a crosshead speed of 1 mm/min until fracture. The fractured specimens were analyzed to determine the fracture pattern using a stereomicroscope, and then representative specimens were carbon coated to allow for the studying of the fracture surface under scanning electron microscopy. One-way analysis of variance (ANOVA) was used to compare fracture resistance of the groups. The results of fracture patterns were submitted to the Fisher exact test (α=0.05). Results: All specimens survived fatigue. Mean (standard deviation) failure loads (N) for groups were as follows: G1: 949.6 (331.5); G2: 999.6 (352.5); G3: 934.5 (233.6); G4: 771.0 (147.4); and G5: 856.7 (237.5). The lowest fracture resistance was recorded for G4, and the highest ones were recorded for G2, followed by that of G1 and G3. One-way ANOVA did not reveal significant differences between groups (p>0.05). The highest repairable fracture rates were observed in G1 (100%) and G3 (80%). Conclusions: ETPs restored with conventional composite resin with or without horizontal fiber post, bulk-fill composite, and ceramic inlay showed fracture resistance similar to that of sound teeth. Conventional composite resin restorations exhibited the highest prevalence of unrepairable fractures, and the insertion of a horizontal fiber post decreased this prevalence. Intact teeth showed 100% of repairable fractures. It is difficult to extrapolate the results directly to a clinical situation due to the limitations of this study.

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Effect of Super-Bond C&B and self-adhesive dual-cured resin cement on the fracture resistance of roots with vertical root fracture

Journal of Dental Research Dental Clinics Dental Prospects ◽

10.15171/joddd.2019.024 ◽

2019 ◽

Vol 13 (2) ◽

pp. 153-157

Author(s):

Ezgi Doğanay Yıldız ◽

Hakan Arslan ◽

Nilay Ayaz ◽

Mustafa Gündoğdu ◽

Alper Özdoğan ◽

...

Keyword(s):

Root Canal ◽

Fracture Resistance ◽

Resin Cement ◽

Control Group ◽

Human Teeth ◽

Root Fracture ◽

Vertical Root Fracture ◽

Root Canals ◽

Chi Squared ◽

Post Hoc

Background. Vertical root fracture might occur during root canal preparation, obturation, post procedures or endodontic treatment. Methods. Fifty-four single-rooted human teeth were decoronated to obtain a standardized length. The root canals were enlarged up to #50 and obturated with gutta-percha and root canal sealer. Eighteen teeth were used as a control group, and vertical root fracture was induced in the remaining teeth. The samples were randomly divided into three groups, as follows: control group (without vertical root fracture), Super-Bond C&B group (fragments were attached with Super-Bond C&B), and self-adhesive dual-cured resin cement group (fragments were attached with self-adhesive dual-cured resin cement). Each specimen was subjected to a fracture resistance test, and data were statistically analyzed using chi-squared test, one-way ANOVA and post hoc Tukey tests (P=0.05). Results. The fracture resistance values of the control and Super-Bond C&B groups were higher than those of the self-adhesive dual-cured resin cement group (P<0.05). However, there were no significant differences between the control and Super-Bond C&B groups (P>0.05). Conclusion. Within the limitations of the present study, Super-Bond C&B was beneficial in obtaining higher fracture resistance in endodontically treated roots with vertical root fracture.

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Effect of Posts on the Fracture Resistance of Load-cycled Endodontically-treated Premolars Restored with Direct Composite Resin

The Journal of Contemporary Dental Practice ◽

10.5005/jcdp-10-3-10 ◽

2009 ◽

Vol 10 (3) ◽

pp. 10-17 ◽

Cited By ~ 3

Author(s):

Sara Majidinia ◽

Marjaneh Ghavamnasiri ◽

Hila Hajizadeh ◽

Mohammad Sadegh Namazikhah ◽

Mohammad Javad Moghaddas

Keyword(s):

Fracture Resistance ◽

Failure Modes ◽

Composite Resin ◽

Control Group ◽

Quartz Fiber ◽

Chi Square ◽

Mean Values ◽

Chi Square Test ◽

Composite Resin Restoration

Abstract Aim The aim of this study was to investigate the fracture resistance and failure mode of premolars restored with composite resin using various prefabricated posts. Methods and Materials Sixty sound maxillary premolars were divided into four equal sized groups. All but the control group received endodontic treatment followed by placement of mesiodistocclusal (MOD) composite restorations (Tetric Ceram) as follows: Group T = no post, Group DT = fiber reinforced composite (FRC) post (DT Light), Group FL = prefabricated metal post (Filpost). The control group (C) had no cavities prepared. After thermal and load cycling, static load was applied at a 30° angle until fracture. Failure modes were categorized as restorable and non-restorable. Data were analyzed using the analysis of variance (ANOVA) and Duncan tests (α = 0.05). Results The mean values of fracture loads (N) for all groups were: C (880±258); T (691±239); DT (865±269); and FL (388±167). Statistically significant differences (P<0.05) were observed for all groups except between groups C and DT. The Chi Square test showed failure modes in groups C and DT were mostly restorable. The most non-restorable fractures were observed in group FT. Conclusion Intact teeth and the teeth restored with composite and quartz fiber posts had a similar fracture resistance and the failure modes were mostly restorable. The lowest fracture resistance and the most nonrestorable failures were observed in conjunction with metal posts. Clinical Significance The results of this in vitro study suggest the use of a quartz fiber post used in conjunction with an MOD composite resin restoration improves fracture resistance in an endodontically treated premolar. Citation Hajizadeh H, Namazikhah MS, Moghaddas MJ, Ghavamnasiri M, Majidinia S. Effect of Posts on the Fracture Resistance of Load-cycled Endodontically-treated Premolars Restored with Direct Composite Resin. J Contemp Dent Pract 2009 May; (10)3:010-017.

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Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Restored with Resin Fiber Post and Stainless Steel Post: An In Vitro Study

Dental Journal of Advance Studies ◽

10.1055/s-0038-1672019 ◽

2015 ◽

Vol 03 (02) ◽

pp. 080-084

Author(s):

Vijay Singh ◽

Poonam Bogra ◽

Saurabh Gupta ◽

Navneet Kukreja ◽

Neha Gupta

Keyword(s):

Stainless Steel ◽

Fracture Resistance ◽

Testing Machine ◽

Compressive Force ◽

Control Group ◽

Fiber Post ◽

Endodontically Treated Teeth ◽

Group I ◽

Significant Difference

AbstractFracture resistance of endodontically treated teeth restored with post. Aims: This study aims to compare the fracture resistance of endodontically treated teeth restored with resin fiber and stainless steel post. Commercially available prefabricated resin fiber post(Dentsply Maillefer Easy Post), prefabricated stainless steel post(Coltene/Whaledent Parapost) were used. Methods and Material: Forty five maxillary central incisors were obturated and divided into 3 groups: Control Group (Group I) without any post (n = 15), Resin Fiber Post Group (Group II) (n = 15) and Stainless Steel Post Group (Group III) (n = 15). In all Groups except control group, post space was prepared; a post was cemented, and a core build-up was provided. All the specimens were subjected to compressive force under a universal testing machine until fracture. Statistical analysis used: The results were analyzed using the variable analysis test (ANOVA). Results: One-way analysis of variance revealed significant difference among test groups. The control group demonstrated highest fracture resistance (925.2183 N), followed by the resin fiber post group (486.7265 N) and stainless steel post group (423.539N). Conclusions: Teeth restored with resin fiber post showed higher fracture resistance values than prefabricated stainless steel post.

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The effectiveness of mindfulness on quality of life of women with premature menopause: a quasi-experimental study

10.21203/rs.2.22532/v1 ◽

2020 ◽

Author(s):

Fatemeh Pyri ◽

Parvin Abedi ◽

Elham Maraghi ◽

Maryam Gholamzadeh Jashreh

Keyword(s):

Quality Of Life ◽

Experimental Study ◽

Hot Flashes ◽

Repeated Measure ◽

Control Group ◽

Premature Menopause ◽

Chi Square ◽

Quasi Experimental

Abstract Background: Premature menopause may impair the quality of life and expose women to disorders such as cardiovascular disease, osteoporosis, and depression. This study aimed to evaluate the effectiveness of mindfulness on the quality of life of women with premature menopause. Methods: This was a quasi-experimental study in which 62 women were recruited and randomly allocated in two groups of mindfulness and control. The mindfulness group received eight sessions of training. A demographic questionnaire, Menopause-Specific Quality of Life (MENQOL) and a checklist (for assessing frequency and intensity of hot flashes) were used to collect data. The quality of life, frequency, and intensity of hot flashes measured at baseline, after eight weeks and in three months follow-up. The Independent t-test, the chi-square test, and the repeated measure test were used for analyzing data. Results: The score of quality of life was significantly improved after the intervention and in three months follow-up in the mindfulness group compared to the control group (p<0.001). The scores of vasomotor, psychological, physical, and sexual domains also improved significantly in the mindfulness group compared to the control group. The severity and the frequency of hot flashes were significantly reduced in the mindfulness group in comparison to the control group. Conclusion: The results of this study showed that eight weeks of mindfulness training could significantly improve the quality of life and also could reduce the frequency and intensity of hot flashes in women with premature menopause. Using mindfulness for women with premature menopause is recommended.

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Fracture Resistance of Immature Incisors Following Root Filling with Various Bioactive Endodontic Cements Using an Experimental Bovine Tooth Model

European Journal of Dentistry ◽

10.1055/s-0039-1695654 ◽

2019 ◽

Vol 13 (02) ◽

pp. 156-160 ◽

Cited By ~ 1

Author(s):

Pegah Sarraf ◽

Mohammad Hossein Nekoofar ◽

Mohammad Saeed Sheykhrezae ◽

Paul M. H. Dummer

Keyword(s):

Root Canal ◽

Fracture Resistance ◽

Acrylic Resin ◽

Control Group ◽

Control Groups ◽

Cem Cement ◽

Filling Materials ◽

Gutta Percha ◽

Significant Difference ◽

And Control

Abstract Objective The aim of this study was to compare the fracture resistance of immature bovine roots when using ProRoot MTA, CEM Cement, and Biodentine as root filling materials. Materials and Methods An immature bovine tooth model was developed by removing the coronal and apical portions of 70 bovine incisors 8 mm above and 12 mm below the cementoenamel junction (CEJ). The specimens were then divided into five groups: ProRoot MTA, CEM Cement, Biodentine, gutta-percha/AH26 sealer, and control. All groups received a 5-mm apical plug with a temporary restorative material. Then, the remaining root canal space was filled with one of the afore-mentioned materials. After setting, the specimens were mounted in acrylic resin. Then, 3 mm coronal to the CEJ from the buccal side of the teeth and at a 135°angle to the long axis, the specimens were loaded until fracture. Results The specimens in the Biodentine (2196 N) and ProRoot MTA (2103 N) groups had significantly greater fracture resistance in comparison to the control group (p = 0.01). No significant difference was found between CEM Cement, gutta-percha and sealer AH26, and control groups. No significant differences occurred between the four experimental groups (p = 0.45). Conclusion Filling the root canal space with ProRoot MTA and Biodentine contributed to higher fracture resistance values.

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Effect of Fiber Post and Cusp Coverage on Fracture Resistance of Endodontically Treated Maxillary Premolars Directly Restored with Composite Resin

Journal of Endodontics ◽

10.1016/j.joen.2009.07.010 ◽

2009 ◽

Vol 35 (10) ◽

pp. 1428-1432 ◽

Cited By ~ 33

Author(s):

Narmin Mohammadi ◽

Mehdi Abed Kahnamoii ◽

Parnian Karimi Yeganeh ◽

Elmira Jafari Navimipour

Keyword(s):

Fracture Resistance ◽

Composite Resin ◽

Fiber Post ◽

Maxillary Premolars

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Micro-CT Evaluation of Root Filling Removal after Three Stages of Retreatment Procedure

Brazilian Dental Journal ◽

10.1590/0103-6440201300061 ◽

2015 ◽

Vol 26 (6) ◽

pp. 612-618 ◽

Cited By ~ 11

Author(s):

Ricardo Abreu da Rosa ◽

Manuela Favarin Santini ◽

Bruno Cavalini Cavenago ◽

Jefferson Ricardo Pereira ◽

Marco Antônio Húngaro Duarte ◽

...

Keyword(s):

Root Canal ◽

Filling Material ◽

Micro Ct ◽

Micro Computed Tomography ◽

Root Canal Filling ◽

Tomography System ◽

Filling Materials ◽

Ct Evaluation ◽

Ah Plus ◽

Post Hoc

The aim of this study was to quantify the residual filling material after filling removal, re-preparation with rotary or reciprocating files and passive ultrasonic irrigation (PUI). Twenty maxillary molars were prepared using ProTaper instruments up to F1. The teeth were filled with AH Plus and ProTaper gutta-percha points using the single-cone technique. Thereafter, the specimens were scanned using a micro-computed tomography system (Micro-CT #1). Then, the root canal filling was removed using ProTaper Retreatment files, and a new scan was performed (Micro-CT #2). The specimens were divided into two groups according to the instrument used for re-preparation: ProTaper rotary or WaveOne reciprocating files (Micro-CT #3). Finally, PUI was performed, and a new micro-CT scan was performed (Micro-CT #4). Intragroup and intergroup analyses were performed using Friedman and Dunn's post hoc test and the Kruskal-Wallis and Dunn post hoc tests, respectively. Palatal canal presented the highest volume of residual filling material in all stages of endodontic retreatment (p<0.05). The main reduction of filling volume was achieved after using ProTaper Retreament (p<0.05). The amount of remaining filling material after using ProTaper Retreatment was similar to that achieved with rotary and reciprocating files and after PUI (p>0.05). Rotary and reciprocating files achieved similar removal of the root canal filling (p>0.05). The greatest reduction in filling material was achieved after using ProTaper Retreatment files. Rotary and reciprocating instruments and PUI did not improve the removal of root canal filling materials.

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The Effects of Cavity Preparation and Composite Resin on Bond Strength and Stress Distribution Using the Microtensile Bond Test

Operative Dentistry ◽

10.2341/16-338-l ◽

2018 ◽

Vol 43 (1) ◽

pp. 81-89 ◽

Cited By ~ 4

Author(s):

SSL Braga ◽

LRS Oliveira ◽

RB Rodrigues ◽

AA Bicalho ◽

VR Novais ◽

...

Keyword(s):

Stress Distribution ◽

Bond Strength ◽

Failure Modes ◽

Composite Resin ◽

Shrinkage Stress ◽

Cavity Preparation ◽

Chi Square ◽

Chi Square Test ◽

Post Hoc ◽

Made In

SUMMARY Objectives: To evaluate the effect of flowable bulk-fill or conventional composite resin on bond strength and stress distribution in flat or mesio-occlusal-distal (MOD) cavity preparations using the microtensile bond strength (μTBS) test. Methods: Forty human molars were divided into two groups and received either standardized MOD or flat cavity preparations. Restorations were made using the conventional composite resin Z350 (Filtek Z350XT, 3M-ESPE, St Paul, MN, USA) or flowable bulk-fill (FBF) composite resin (Filtek Bulk Fill Flowable, 3M-ESPE). Postgel shrinkage was measured using the strain gauge technique (n=10). The Z350 buildup was made in two increments of 2.0 mm, and the FBF was made in a single increment of 4.0 mm. Six rectangular sticks were obtained for each tooth, and each section was used for μTBS testing at 1.0 mm/min. Polymerization shrinkage was modeled using postgel shrinkage data. The μTBS data were analyzed statistically using a two-way analysis of variance (ANOVA), and the postgel shrinkage data were analyzed using a one-way ANOVA with Tukey post hoc test. The failure modes were analyzed using a chi-square test (α=0.05). Results: Our results show that both the type of cavity preparation and the composite resin used affect the bond strength and stress distribution. The Z350 composite resin had a higher postgel shrinkage than the FBF composite resin. The μTBS of the MOD preparation was influenced by the type of composite resin used. Irrespective of composite resin, flat cavity preparations resulted in higher μTBS than MOD preparations (p<0.001). Specifically, in flat-prepared cavities, FBF composite resin had a similar μTBS relative to Z350 composite resin. However, in MOD-prepared cavities, those with FBF composite resin had higher μTBS values than those with Z350 composite resin. Adhesive failure was prevalent for all tested groups. The MOD preparation resulted in higher shrinkage stress than the flat preparation, irrespective of composite resin. For MOD-prepared cavities, FBF composite resin resulted in lower stress than Z350 composite resin. However, no differences were found for flat-prepared cavities. Conclusions: FBF composite resin had lower shrinkage stress than Z350 conventional composite resin. The μTBS of the MOD preparation was influenced by the composite resin type. Flat cavity preparations had no influence on stress and μTBS. However, for MOD preparation, composite resin with higher shrinkage stress resulted in lower μTBS values.

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