Craniopharyngioma: a comparison of tumor control with various treatment strategies

2010 ◽  
Vol 28 (4) ◽  
pp. E5 ◽  
Author(s):  
Isaac Yang ◽  
Michael E. Sughrue ◽  
Martin J. Rutkowski ◽  
Rajwant Kaur ◽  
Michael E. Ivan ◽  
...  
Keyword(s):  
Tumor Resection ◽  
Treatment Strategies ◽  
Group Versus ◽  
Outcome Data ◽  
Treatment Modalities ◽  
Rank Test ◽  
Tumor Control ◽  
Subtotal Resection ◽  
Log Rank Test ◽  
Significant Difference

Object Craniopharyngiomas have a propensity to recur after resection, potentially causing death through their aggressive local behavior in their critical site of origin. Recent data suggest that subtotal resection (STR) followed by adjuvant radiotherapy (XRT) may be an appealing substitute for gross-total resection (GTR), providing similar rates of tumor control without the morbidity associated with aggressive resection. Here, the authors summarize the published literature regarding rates of tumor control with various treatment modalities for craniopharyngiomas. Methods The authors performed a comprehensive search of the English language literature to identify studies publishing outcome data on patients undergoing surgery for craniopharyngioma. Rates of progression-free survival (PFS) and overall survival (OS) were determined through Kaplan-Meier analysis. Results There were 442 patients who underwent tumor resection. Among these patients, GTR was achieved in 256 cases (58%), STR in 101 cases (23%), and STR+XRT in 85 cases (19%). The 2- and 5-year PFS rates for the GTR group versus the STR+XRT group were 88 versus 91%, and 67 versus 69%, respectively. The 5- and 10-year OS rates for the GTR group versus the STR+XRT group were 98 versus 99%, and 98 versus 95%, respectively. There was no significant difference in PFS (log-rank test) or OS with GTR (log-rank test). Conclusions Given the relative rarity of craniopharyngioma, this study provides estimates of outcome for a variety of treatment combinations, as not all treatments are an option for all patients with these tumors.

Tumor control after surgery and radiotherapy for pineocytoma

2010 ◽  
Vol 113 (2) ◽  
pp. 319-324 ◽  
Author(s):  
Aaron J. Clark ◽  
Michael E. Ivan ◽  
Michael E. Sughrue ◽  
Isaac Yang ◽  
Derick Aranda ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Case Series ◽  
Group Versus ◽  
Gross Total Resection ◽  
Rank Test ◽  
Tumor Control ◽  
Adjuvant Radiation ◽  
Total Resection ◽  
Log Rank Test ◽  
Significant Difference

Object Pineocytoma is a rare tumor, and the current literature on these tumors is primarily composed of case reports and small case series. Thus, recommendations on appropriate treatment of these tumors are highly varied. Therefore, the authors performed a systematic review of the literature on tumor control after surgery for pineocytoma to determine the relative benefits of aggressive resection and postoperative adjuvant radiotherapy. Methods A comprehensive search of the published English-language literature was performed to identify studies citing outcome data of patients undergoing surgery for pineocytoma. Determination of rates of progression-free survival (PFS) was performed using Kaplan-Meier analysis. Results Sixty-four articles met the criteria of the established search protocol, which combined for a total of 166 patients. Twenty-one percent of these patients had undergone a biopsy procedure, 38% had undergone subtotal resection (STR), 42% had undergone gross-total resection, and 28% were treated with radiation therapy. The 1- and 5-year PFS rates for the resection group versus the biopsy group were 97 and 90% (1 year), and 89 and 75% (5 years), respectively (p < 0.05, log-rank test). The 1- and 5-year PFS rates for the GTR group versus the group undergoing STR combined with radiation therapy were 100 and 94% (1 year), and 100 and 84% (5 years), respectively (p < 0.05, log-rank test). There was no significant difference in PFS for STR only compared with STR in addition to radiation therapy. Conclusions Gross-total resection is the ideal treatment for pineocytoma and might represent a cure for these lesions. When gross-total resection is not possible, adjuvant radiation therapy after STR is of questionable benefit for these patients.

Cumulative survival analysis of patients with spinal myxopapillary ependymomas in the first 2 decades of life

2014 ◽  
Vol 13 (4) ◽  
pp. 400-407 ◽  
Author(s):  
Sunil Kukreja ◽  
Sudheer Ambekar ◽  
Anthony Hunkyun Sin ◽  
Anil Nanda
Keyword(s):  
Survival Analysis ◽  
Tumor Resection ◽  
Young Patients ◽  
Treatment Protocol ◽  
Complete Resection ◽  
Rank Test ◽  
Subtotal Resection ◽  
High Dose ◽  
Critical Events ◽  
Log Rank Test

Object Reports of myxopapillary ependymomas (MPEs) of the spinal cord in pediatric patients are scarce. In the literature, various authors have shared their experiences with small groups of patients, which makes it difficult to create a consensus regarding the treatment approach for spinal MPEs in young patients. The aim of this study was to perform a survival analysis of patients in the first 2 decades of life whose cases were selected from the published studies, and to examine the influence of various factors on outcomes. Methods A comprehensive search of studies published in English was performed on PubMed. Patients whose age was ≤ 20 years were included for integrative analysis. Information about age, treatment characteristics, critical events (progression, recurrence, and death), time to critical events, and follow-up duration was recorded. The degree of association of the various factors with the survival outcome was calculated by using Kaplan-Meier estimator and Cox proportional hazard model techniques. Results A total of 95 patients were included in the analysis. The overall rate of recurrence (RR) was 34.7% (n = 33), with a median time to recurrence of 36 months (range 2–100 months). Progression-free survival (PFS) and overall survival rates at 5 years were 73.7% and 98.9%, respectively. Addition of radiotherapy (RT) following resection significantly improved PFS (log-rank test, p = 0.008). In patients who underwent subtotal resection (STR), administering RT (STR + RT) improved outcome with the lowest failure rates (10.3%), superior to patients who underwent gross-total resection (GTR) alone (RR 43.1%; log-rank test, p < 0.001). Addition of RT to patients who underwent GTR was not beneficial (log-rank test, p = 0.628). In patients who had disseminated tumor at presentation, adjuvant RT controlled the disease effectively. High-dose RT (≥ 50 Gy) did not change PFS (log-rank test, p = 0.710). Conclusions Routine inclusion of RT in the treatment protocol for spinal MPEs in young patients should be considered. Complete resection is always the goal of tumor resection. However, when complete resection does not seem to be possible in complex lesions, RT should be used as an adjunct to avoid aggressive resection and to minimize inadvertent injury to the surrounding neural tissues. High-dose RT (≥ 50 Gy) did not provide additional survival benefits, although this association needs to be evaluated by prospective studies.

scholarly journals The last decade’s experience of management of central neurocytomas: Treatment strategies and new options

2021 ◽  
Vol 12 ◽  
pp. 336
Author(s):  
Alexander Konovalov ◽  
Sergey Maryashev ◽  
David Pitskhelauri ◽  
Vitaly Siomin ◽  
Andrey Golanov ◽  
...  
Keyword(s):  
Short Term Memory ◽  
Residual Disease ◽  
Obstructive Hydrocephalus ◽  
Treatment Strategies ◽  
Treatment Modalities ◽  
Tumor Control ◽  
Subtotal Resection ◽  
Ki 67 ◽  
Mortality And Morbidity ◽  
Current Series

Background: The purpose of the presented work is to evaluate the last decade’s experience in surgical management of central neurocytoma (CN) and elucidate on the treatment strategies and new options. Methods: The current series consists of the remaining 125 patients (70 females and 55 males) operated on during the past decade from 2008 to 2018. Most tumors were resected through transcortical (n = 76, 61%), or transcallosal (n = 40, 32%) approaches. In 5 (4%) patients with predominantly posterior location of the tumor, non-dominant superior parietal lobule approach was utilized. Both approaches (transcortical + transcallosal) were used in 4 (3%) of cases. Seven consecutive patients with large CN underwent prophylactic intraventricular stenting to prevent hydrocephalus. Results: Gross total resection was achieved in 45 patients (36%), subtotal resection (STR) in 40 (32%) cases. After surgery, 63 (50%) patients had neurocognitive problems, including disorientation, attention deficit, global amnesia, short-term memory deficits, and perceptual motor and social cognition problems. A total of 26 patients (21%) had postoperative hemorrhage in the resection bed. Obstructive hydrocephalus was noted in 25 (20%) patients. The entrapment of the occipital and/or temporal horns was observed in seven cases. None of the seven patients with prophylactic intraventricular stents required shunting. Conclusion: Although high rates of gross total or STR can be expected, the mortality and morbidity remain significant even in the modern neurosurgical era. Prophylactic intraventricular stenting in patients with large posteriorly located tumors with hydrocephalus may prevent ventricular entrapment and shunting. The main risk factors for recurrence are presence of residual disease and Ki-67 index over 5%. Recurrent symptomatic tumors should be treated surgically, whereas asymptomatic progression can be managed with stereotactic radiosurgery. Both treatment modalities are associated with low risk of complications and high tumor control rates.

Prognostic Factors in the UK LRF CLL4 Trial.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 299-299 ◽  
Author(s):  
David Graham Oscier ◽  
Rachel Wade ◽  
Jenny Orchard ◽  
Zadie Davis ◽  
Giles Best ◽  
...  
Keyword(s):  
Risk Group ◽  
Univariate Analysis ◽  
Treatment Modalities ◽  
Rank Test ◽  
P Value ◽  
Cox Regression Analysis ◽  
Log Rank Test ◽  
Significant Difference ◽  
Trisomy 12 ◽  
Vh Genes

Abstract The LRF CLL4 trial randomised 777 previously untreated patients with Binet stage progressive A, B or C disease between January 1999 and October 2004 to receive either Chlorambucil, Fludarabine or Fludarabine and Cyclophosphamide. Interphase FISH for deletions of chromosome 6q, 11q, 13q, 17p and trisomy 12, IgVH gene mutational status (98% cut off), CD38 (7% cut off) and ZAP70 (10% cut off) expression were measured at randomisation on 579, 523, 535 and 478 patients respectively. Leukemic cells from 39 patients utilised the VH3-21 gene of whom 33 had homologous CDR3’s. Among the biological markers, log rank analysis showed that >20% p53 loss, del 11q, unmutated VH genes, high CD38 and high ZAP 70 correlated with disease progression or death (Table 1) but not deletion of chromosome 6q, 13q and trisomy 12 (p=0.7, 0.3 and 0.2 respectively). There was no difference in PFS or response duration between the 52 patients with 5–20% p53 loss and the 494 patients with no p53 loss. Multivariate Cox regression analysis showed that >20% p53 loss (p<0.0001), unmutated IgVH genes (p=0.0001), deletion of 11q (p=0.02) and male gender (p=0.03) were independent risk factors for short PFS. The effects of stage and age were overridden by FISH abnormalities. High ZAP70 expression was only significant when VH gene mutation status was not included in the model. CD38 expression was only significant in univariate analysis. Table 1 Variable Progression or Death/N Univariate p-value(log rank test) Gender Male 384/573 0.002 Female 111/204 17q(p53) No 131/546 <0.00005 Yes 21/33 IgVH Unmutated 105/203 <0.00005 Mutated 225/320 del 11q No 288/463 <0.00005 Yes 87/116 ZAP70 Negative 140/242 0.003 Positive 158/236 CD38 Negative 110/201 0.0001 Positive 227/334 Among the 320 unmutated cases there was no significant difference in PFS between those with 100% homology (227 cases) and those with 99% or 98% homology to the germline sequence (93 cases). Mutated VH3-21 cases were more likely to express ZAP70 than other mutated cases, p=0.004. Excluding patients with >20% p53 loss, patients using the VH3-21 gene had similar progression free survival (PFS) to those remaining patients with unmutated VH genes and an inferior PFS to those with mutated VH genes (2p=0.0001). The adverse prognostic significance of 11q deletions was not clearly evident in an interim analysis presented at ASH ‘05. Patients can now be divided into 3 risk groups (Table 2). This risk stratification provides the basis of evaluating differing treatment modalities for each risk group in subsequent clinical trials. Table 2 Risk Group Definition Progression or Death/N Univariate p-value (log-rank test) 3 yr PFS Poor >20%p53 loss 28/33 0% Standard Unmutated VH or 11q deletion or VH3-21 208/292 <0.00001 24.7% Good Mutated VH(excl VH3–21) 79/161 55.0%

scholarly journals Clinical evaluation of the failure rate of metallic brackets bonded with orthodontic composites

2012 ◽  
Vol 23 (4) ◽  
pp. 399-402 ◽  
Author(s):  
Fábio Lourenço Romano ◽  
Rodrigo Alexandre Valério ◽  
Jaciara Miranda Gomes-Silva ◽  
José Tarcísio Lima Ferreira ◽  
Gisele Faria ◽  
...  
Keyword(s):  
Failure Rate ◽  
Orthodontic Treatment ◽  
Color Change ◽  
Rank Test ◽  
Initial Alignment ◽  
Bond Failure ◽  
Log Rank Test ◽  
Significant Difference ◽  
Mandibular Teeth

The purpose of the present study was to evaluate in vivo the failure rate of metallic brackets bonded with two orthodontic composites. Nineteen patients with ages ranging from 10.5 to 38.7 years needing corrective orthodontic treatment were selected for study. The enamel surfaces from second premolars to second premolars were treated with Transbond Plus-Self Etching Primer (3M Unitek). Next, 380 orthodontic brackets were bonded on maxillary and mandibular teeth, as follows: 190 with Transbond XT composite (3M Unitek) (control) and 190 with Transbond Plus Color Change (3M Unitek) (experimental) in contralateral quadrants. The bonded brackets were light cured for 40 s, and initial alignment archwires were inserted. Bond failure rates were recorded over a six-month period. At the end of the evaluation, six bond failures occurred, three for each composite. Kaplan-Meyer method and log-rank test (Mantel-Cox) was used for statistical analysis, and no statistically significant difference was found between the materials (p=0.999). Both Transbond XT and Transbond Plus Color Change composites had low debonding rates over the study period.

Effectiveness of the Bactiseal Universal Shunt for reducing shunt infection in a sub-Saharan African context: a retrospective cohort study in 160 Ugandan children

2014 ◽  
Vol 13 (2) ◽  
pp. 140-144 ◽  
Author(s):  
Jordan D. Lane ◽  
John Mugamba ◽  
Peter Ssenyonga ◽  
Benjamin C. Warf
Keyword(s):  
Cohort Study ◽  
Low Income ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Shunt Infection ◽  
Low Income Countries ◽  
Rank Test ◽  
Log Rank Test ◽  
Significant Difference ◽  
Chi Square Analysis

Object Antibiotic-impregnated shunts have yet to find widespread use in the developing world, largely due to cost. Given potential differences in the microbial spectrum, their effectiveness in preventing shunt infection for populations in low-income countries may differ and has not been demonstrated. This study is the first to compare the efficacy of a Bactiseal shunt system with a non–antibiotic-impregnated system in a developing country. Methods The Bactiseal Universal Shunt (BUS) was placed in 80 consecutive Ugandan children who required a shunt. In this retrospective cohort study, the outcome for that group was compared with the outcome for the immediately preceding 80 consecutive children in whom a Chhabra shunt had been placed. The primary end points were shunt failure, shunt infection, and death. Shunt survival was analyzed using the Kaplan-Meier method. Significance of differences between groups was tested using the log-rank test, chi-square analysis, Fisher's exact test, and t-test. Results There was no difference between groups in regard to age, sex, or etiology of hydrocephalus. Mean follow-up for cases of nonfailure was 7.6 months (median 7.8 months, interquartile range 6.5–9.5 months). There was no significant difference between groups for any end point. The BUS group had fewer infections (4 vs 11), but the difference was not significant (p = 0.086, log-rank test). Gram-positive cocci were the most common culturable pathogens in the Chhabra group, while the only positive culture in the BUS group was a gram-negative rod. Conclusions These results provide equipoise for a randomized controlled trial in the same population and this has been initiated. It is possible that the observed trends may become significant in a larger study. The more complex task will involve determining not only the efficacy, but also the cost-effectiveness of using antibiotic-impregnated shunt components in limited-resource settings.

scholarly journals Silent infarct is a risk factor for infarct recurrence in adults with sickle cell anemia

Neurology ◽  
2018 ◽  
Vol 91 (8) ◽  
pp. e781-e784 ◽  
Author(s):  
Lori C. Jordan ◽  
Adetola A. Kassim ◽  
Manus J. Donahue ◽  
Meher R. Juttukonda ◽  
Sumit Pruthi ◽  
...  
Keyword(s):  
Risk Factor ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Cox Regression ◽  
Brain Mri ◽  
Treatment Strategies ◽  
Significant Risk ◽  
Rank Test ◽  
Event Analysis ◽  
Log Rank Test

ObjectiveBecause of the high prevalence of silent cerebral infarcts (SCIs) in adults with sickle cell anemia (SCA) and lack of information to guide treatment strategies, we evaluated the risk of recurrent SCIs and overt stroke in adults with SCA with preexisting SCI.MethodsThis observational study included adults with SCA (HbSS or Sβ0 thalassemia) aged 18 to 40 years. Participants received 3-tesla brain MRI and a detailed neurologic examination. Time-to-event analysis assessed those with or without baseline SCI and with new or progressive infarcts. The incidence rate of new events was compared by log-rank test. Univariable Cox regression assessed the association of SCI with infarct progression.ResultsAmong adults with SCA with 2 MRIs and at least 6 months between MRIs (n = 54, mean interval = 2.5 years), 43% had SCI at baseline. Of participants with baseline SCI, 30% had new or progressive SCI over 2.5 years compared to 6% with no SCI at baseline; no participant had an overt stroke. New SCIs at follow-up were present in 12.9 per 100 patient-years with existing SCI compared with 2.4 per 100 patient-years without prior SCI (log-rank test, p = 0.021). No statistically significant differences were seen among those with or without baseline SCI in use of hydroxyurea therapy, hydroxyurea dose, or other stroke risk factors. The presence of SCI was associated with increased hazard of a new or progressive infarct (hazard ratio 5.27, 95% confidence interval 1.09–25.51, p = 0.039).ConclusionsSilent infarcts in adults with SCA are common and are a significant risk factor for future silent infarcts.

CDKN2A or CDKN2B homozygous deletion with high-immune infiltration as a favorable prognostic factor for lung adenocarcinoma.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e20543-e20543
Author(s):  
Benxu Tan ◽  
Yonghong Chen ◽  
Lei Xia ◽  
Xian Yu ◽  
Yusheng Huang ◽  
...  
Keyword(s):  
Prognostic Factor ◽  
Lung Adenocarcinoma ◽  
Homozygous Deletion ◽  
Hazard Ratio ◽  
Gene Set Enrichment Analysis ◽  
Rank Test ◽  
Immune Infiltration ◽  
Log Rank Test ◽  
Significant Difference ◽  
Wild Group

e20543 Background: CDKN2A and CDKN2B both acted as tumor suppressor genes by regulating the cell cycle, which in humans were located at chromosome 9, band p21.3. The frequencies of homozygous deletion (HomDel) in CDKN2A and CDKN2B in lung adenocarcinoma (LUAD) were 12.5% and 12.1%, respectively. However, the genomic, immunogenomic features and impact on the prognosis of LUAD patients with CDKN2A/B HomDel were still unclear. Methods: The cohort of this study was from The Cancer Genome Atlas (TCGA). A total of 508 LUAD patients, including 99 CDKN2A/B HomDel (homdel) and 509 CDKN2A/B wild (wild). This study explored the difference of genomic and immunogenomic landscape between homdel and wild by analysis of whole-exome sequencing (WES) and RNA sequencing data. Results: The most frequently mutated genes were TP53, TTN, MUC16, and CSMD3. Their frequencies in homdel and wild are 46% and 48%, 43% and 46%, 35% and 41%, 33% and 38%, respectively. There was no significant difference of tumor mutational burden (TMB) between homdel and wild (median TMB, 133 in homdel vs 177 in wild; Wilcoxon test, p = 0.11), and clinical characteristics including age, gender, smoking history, and tumor stage were not significantly different between homdel and wild. Homdel had a shorter overall survival (OS) than wild (Log-rank test, p = 0.04, Hazard Ratio: 0.7, 95% CI: 0.49-1.02), but there was no significant difference in progression-free survival (PFS) (Log-rank test, p = 0.05, Hazard Ratio: 0.73, 95% CI: 0.51-1.04). We used single sample gene set enrichment analysis (ssGSEA) to calculate the enrichment score (ES) of 25 immune-related pathways such as antigen presentation and T cell-mediated immunity, and then used the consensus clustering algorithm (ConsensusClusterPlus) to cluster homdel and wild respectively, and both clustered into low and high immune infiltration groups. For the high immune infiltration and low immune infiltration in homdel and wild, high immune infiltration had a longer OS (Log-rank test, p = 0.009, Hazard Ratio: 2.19, 95% CI: 1.22-3.94) and PFS (Log-rank test, p = 0.044, Hazard Ratio: 1.8, 95% CI: 1.01-3.2) than low immune infiltration in homdel. However, there was no significant heterogeneity between high and immune infiltration in terms of PFS (Log-rank test, p = 0.28, Hazard Ratio: 1.21, 95% CI: 0.87-1.68) and OS (Log-rank test, p = 0.96, Hazard Ratio: 1.01, 95% CI: 0.71-1.44) in the wild group, the wild group had longer OS than homdel group with low immune infiltration (Log-rank test, p = 0.003, Hazard Ratio: 0.5, 95% CI: 0.29-0.88), while had the same OS with homdel with high immune infiltration, irrespective of immune infiltration. And so was PFS (Log-rank test, p = 0.005, Hazard Ratio: 0.48, 95% CI: 0.27-0.82). Conclusions: CDKN2A/B homdel was an unfavorable prognostic factor for LUAD, but which with high immune infiltration might improve patient survival time.

Does Age Itself Have an Adverse Effect on Survivorship of Meniscal Allograft Transplantation? A Cartilage Status and Time From Previous Meniscectomy–Matched Cohort Study

2020 ◽  
Vol 48 (7) ◽  
pp. 1696-1701 ◽  
Author(s):  
Ju-Ho Song ◽  
Seong-Il Bin ◽  
Jong-Min Kim ◽  
Bum-Sik Lee ◽  
Dong-Wook Son
Keyword(s):  
Clinical Outcomes ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Rank Test ◽  
Meniscal Allograft Transplantation ◽  
Log Rank Test ◽  
Meniscal Allograft ◽  
Age Related ◽  
Significant Difference ◽  
Operating Characteristic Curve

Background: The aging process is accompanied by several conditions that could affect the outcome of meniscal allograft transplantation (MAT). These conditions have made it difficult for clinicians to determine the effect of chronologic age on survivorship after MAT. Hypothesis: Advanced age does not have an adverse effect on survivorship of MAT when controlling for age-related factors, such as cartilage status and time from previous meniscectomy. Study Design: Cohort study; Level of evidence, 3. Methods: The records of 264 consecutive patients who underwent primary medial or lateral MAT were reviewed. To check whether there was a difference in MAT survivorship according to age, a cutoff value was calculated from a time-dependent receiver operating characteristic curve. Survival rates, as well as clinical improvement as determined using the Lysholm score, were compared between groups divided by the cutoff value. Patients were matched for cartilage status and elapsed time from previous meniscectomy. Differences in survivorship and clinical outcomes were assessed between the matched groups. Results: A time-dependent receiver operating characteristic curve showed that the difference in MAT survivorship was maximized with a cutoff age of 43 years. Kaplan-Meier analysis showed a significant difference in MAT survivorship between the older and younger groups (log-rank test, P = .01). However, after matching for cartilage status and time from previous meniscectomy, which left 56 patients per group, there was no significant difference in MAT survivorship (log-rank test, P = .10) between the groups. Regarding clinical outcomes, the mean Lysholm scores were not significantly different between the older and younger groups ( P = .19, before matching; P = .39, after matching). Conclusion: MAT survivorship was more affected by age-related prognostic factors, such as cartilage status and time from previous meniscectomy, than age itself. Clinical outcomes did not show differences according to age, either.

scholarly journals In Vitro Fatigue Resistance of Teeth Restored With Bulk Fill versus Conventional Composite Resin

2016 ◽  
Vol 27 (4) ◽  
pp. 452-457 ◽  
Author(s):  
Gabrielle Branco Rauber ◽  
Jussara Karina Bernardon ◽  
Luiz Clovis Cardoso Vieira ◽  
Hamilton Pires Maia ◽  
Françoá Horn ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Composite Resin ◽  
Survival Curve ◽  
Maximum Force ◽  
Lower Percentage ◽  
Rank Test ◽  
Log Rank Test ◽  
Kaplan Meier ◽  
Significant Difference ◽  
Meier Survival Curve

Abstract The aim of this study was to compare the fatigue resistance of restored teeth with bulk fill composite resin, conventional composite resin with incremental insertion and unprepared sound teeth. Twenty-eight extracted maxillary premolars were selected and divided into 4 groups based on composite resin and insertion technique: control (C), conventional composite resin with incremental insertion (I) and bulk fill composite resin with three (BF3) or single increment (BF1). The restored specimens were submitted to fatigue resistance test with a 5 Hz frequency. An initial application of 5,000 sinusoidal load cycles with a minimum force of 50 N and a maximum force of 200 N was used. Next, were applied stages of 30,000 load cycles with the maximum force increasing gradually: 400, 600, 800, 1000, 1200 and 1400 N. The test was concluded when 185,000 load cycles were achieved or the specimen failed. The fatigue resistance data were recorded for comparison, using the Kaplan-Meier survival curve and analyzed by log-rank test at 0.05 significance. Fractures were classified based on the position of the failure - above or below the cementoenamel junction (CEJ). Statistical analysis of the Kaplan-Meier survival curve and log-rank test showed a significant difference between groups (p=0.001). The fracture analysis demonstrated that only 28.58% of failures were below the CEJ in group C, while for groups I, BF1 and BF3 they were 42.85%, 85.71% and 85.71%, respectively. Teeth restored with composite bulk fill in both techniques present similar fatigue resistance values compared with those restored with a conventional incremental insertion of composite, while the fatigue strength values of unprepared sound teeth were higher. Furthermore, unprepared sound teeth showed a lower percentage of fractures below the CEJ.

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