1,721,111 research outputs found
Appearance of the root canal walls after preparation with NiTi rotary instruments: a comparative SEM investigations
No full textThe aim of this study was to evaluate, in vitro, with scanning electron microscope (SEM), the appearance of root canal walls shaped by three different rotary NiTi techniques and one conventional manual technique in human extracted teeth. Four different instruments were used: K3, Hero 642, RaCe and K-file. Each sample was irrigated with 5 ml of 5% NaOCl and 5 ml of 3% H2O2 and EDTA, Rc-Prep (1 ml). Each sample was prepared for SEM observation and analyzed in the coronal, middle and apical third, comparing its aspect with a predefined scale of four different parameters: presence of smear layer, pulpal debris, inorganic debris and surface profile. The apical third showed significantly more pulpal and inorganic debris, smear layer and a high number of surface profile irregularities. No significant difference was found at the coronal, middle and apical thirds between manual and rotary techniques for inorganic debris, smear layer and surface profile. Much pulpal debris were found in the apical third for K3 and RaCe compared with Hero 642 and K-file. In conclusion, mechanical rotary techniques with NiTi instruments produced quite similar results compared with a conventional manual technique using K-files. The present study demonstrated that dentin and pulpal debris, the morphology of smear layer and surface profile were only partially influenced by the type of endodontic instruments. The apical third was the anatomical area with greater amount of debris and smear layer.</p
Long-term outcome of non-surgical root canal treatment: a retrospective analysis
No full textThis study investigated the long-term clinical outcome of root canal treatment. 240 root-treated teeth (n = 61 patients) were initially classified on the basis of radiographic presence/absence of initial apical periodontitis (IAP) and clinical data. The final outcome measure was the periapical healing (healed/disease). The outcome at 6-9 months was correlated with the outcome at 10 years following treatment. Prognostic factors for the periapical healing were assessed. Extraction data were recorded. Univariate and multivariate logistic regression analysis was used to identify risk indicators for apical periodontitis (AP) development. Chi-square analysis was performed to evaluate a possible relationship between the 6-9 months outcome and the final outcome related to IAP. Mean observation time was 14 ± 3.7 years. Survival rate was 84.6% and healing rate was 79% (10-19 years). Predictors of outcome (p < .05) were considered statistically significant. Multivariate logistic regression analysis showed that initial pulpal and periapical status and the quality of root canal filling as assessed two-dimensionally were independent predictors of outcome. The 6-9 months evaluation appears to be an indicator for the final outcome of primary root canal treatment both in the presence and in the absence of IAP. An initial radiolucency associated with an unsatisfactory quality and extent of root canal filling significantly diminishes the possibility of achieving long-term radiographic success. For those with uncertain healing at 6-9 months (91%), clinicians should consider the high healing rate when estimating the prognosis and adjust the decision making accordingly
Laterally moved, coronally advanced flap: a modified surgical approach to isolated recession-type defects
No full textBACKGROUND:
Various modifications of the laterally sliding flap have been proposed to reduce the risk of gingival recession at the donor tooth site, but the reported root coverage predictability was quite low. The goal of the present study was to evaluate the effectiveness with respect to root coverage of a modified surgical approach of the laterally moved flap procedure for the treatment of an isolated type of recession defect.
METHODS:
One hundred and twenty (120) isolated gingival recessions (Miller Class I or II) with specific features of the keratinized tissue lateral to the defects were treated with a new approach to the laterally moved flap. The main surgical modifications consisted of the coronal advancement of the laterally moved flap and the different thickness during flap elevation. Clinical evaluation was made 1 year after the surgery.
RESULTS:
At the 1-year examination, 97% of the root surface was covered with soft tissue and 96 defects (80%) showed complete root coverage. A statistical and clinically significant increase of keratinized tissue was observed. These favorable results were accomplished with no change in the position of gingival margin or in the height of gingival tissue at the donor tooth/site.
CONCLUSIONS:
The laterally moved, coronally advanced surgical technique was very effective in treating isolated gingival recessions. It combined the esthetic and root coverage advantages of the coronally advanced flap with the increase in gingival thickness and keratinized tissue associated with the laterally moved flap. The ideal gingival conditions must be present lateral to an isolated recession defect in order to render the proposed surgical technique an highly effective and predictable root coverage surgical procedure
Laser evaporation versus laser excision of oral leukoplakia: A retrospective study with long-term follow-up
No full textThe study makes a comparison between two surgical approaches for the treatment of oral leukoplakia (OL) in terms of recurrence in a well-defined cohort of patients with a long-term follow-up period
A 3-year prospective cohort study on 132 calcium phosphate-blasted implants: flap vs flapless technique
No full textPurpose: To evaluate the survival rate and marginal bone loss (MBL) of a calcium phosphate-blasted titanium implant inserted by a flap or flapless technique and to study the morphochemical characteristics of the implant surface. Materials and Methods: Sixty out of 85 patients who received one or more implants were selected as eligible for this prospective longitudinal cohort clinical study. Titanium implants (n = 132) were placed in human healthy subjects using either a flap or flapless technique, selected on the basis of the best practice. The survival rate and MBL were evaluated after 3 months (preloading stress-free healing period) and after 6, 12, 24, and 36 months in relation to implant diameter, location, sex, and smoking habits. Surface morphochemical analyses were performed by environmental scanning electron microscopy connected with energy-dispersive x-ray (ESEM/EDX). Results: The overall survival rate was 97.72%. After 3 and 36 months, MBL was 0.36 ± 0.66 mm and 1.09 ± 1.10 mm for the flapless group and 0.29 ± 0.51 mm and 1.03 ± 0.92 mm for the flap group. MBL showed a statistically significant increase with time (P = .0001), and differences were found at all times since 6 months. No statistical differences between the flapless and flap groups and sex were observed at any time, while MBL was significantly higher in the maxillary versus mandibular location (6, 12, and 24 months) and in smokers versus nonsmokers (6 months). Higher MBL in both groups was found for a smaller diameter (3.5 mm) than larger diameter (4.1, 5 mm). The surface showed a Ti-Al-V alloy displaying a uniform nanotexture. Conclusion: The implant system showed a high survival rate and markedly lower MBL considering the limits for acceptable progression. Flapless and flap techniques demonstrated similar results of MBL at the preloading healing period and at the 6 months to 3 years postloading periods. Both surgical procedures induced an early MBL during the preloading stress-free period. Implant diameter, mandibular/ maxillary location, preloading stress-free period, and smoking habits affect MBL more than the type of surgery after both short- and long-term follow-up
DNA Methylation Analysis By Bisulfite Next Generation Sequencing To Early Detect Oral Squamous Cell Carcinoma From Oral Scrapings
No full textBackground:
Oral squamous cell carcinoma (OSCC) is the most frequent neoplastic
disease in head and neck region and it is commonly preceded by potentially malignant
lesions. The discovery of highly sensitive and specific biomarkers to identify those
lesions having a high risk to undergo malignant transformation is urgently required.
Aim of the present study is to evaluate the methylation status of a list of candidate
genes from oral scraping specimens to improve the current strategies for early cancer
detection with non-invasive methods.
Design:
Oral scraping from 11 OSCC, 9 High Grade Squamous intraepithelial Lesion
(HG-SIL), 9 Low Grade SIL( LG-SIL), 9 oral lichen planus (OLP) and 8 healthy
donors were included in this study. PAP smear evaluation was done to confirm the
presence of lesional cells within the brush. DNA was purified and bisulfite treated. A
set of previously described differentially methylated genes in OSCC (
GP1BB, ZAP70,
KIF1A, p16[CDKN2A], CDH1, miR137, miR375
) were investigated by bisulfite-Next
Generation Sequencing (GSJunior, Roche, Branford, CT). ReadSeqs in Fasta format
were analyzed by QuMA (http://quma.cdb.riken.jp/). The statistical significance between
lesions and normal epithelia from the same patient and from a pool of healthy donors
were evaluated with the Mann-Whitney U-test. Additionally
TP53
mutation analysis
for exon 4-9 were performed by the same NGS platform.
Results:
ZAP70
was found to be hypermethylated in 100% of OSCC and HG-SIL cases,
in 28.5% of LG-SIL and in none of OLP.
GP1BB
hypomethylation was detected in
90.9% OSCC, in 88.8% of HG-SIL, 37.5% of LG-SIL and in none of OLP.
MIR137
was
hypermethylated in 100% of OLP, while only in 44.4% of OSCC, 50% in HG-SIL, 25%
in LG-SIL. Hypermethylation in proximal promoter of
KIF1A
was detected in 54.5%
OSCC, 33.3% HG-SIL, 50% LG-SIL and 0% in OLP. No epigenetic aberrations were
detected in normal healthy donors.
p16, CDH1
and miR375 did not revealed variations
in the methylation pattern for all the classes.
Conclusions:
In our preliminary results, Bisulfite-NGS analysis of
GP1BB, ZAP70
and
miR137
promoters from oral scrapings allows to discriminate OSCC and HG-SIL from
LG-SIL, OLP and normal oral mucosa. HG-SILs share the same epigenetic modifications
of OSCC. These data confirm that CpG methylation changes may play a role in oral cancer progression and that DNA methylation analysis may have significant utility in
early detection of OSCC. Furthermore the method here proposed is non invasive and
can be applied to screen patients
Intratumoral Heterogeneity in Recurrent Metastatic Squamous Cell Carcinoma of the Oral Cavity: New Perspectives Afforded by Multiregion DNA Sequencing and mtDNA Analysis
No full textPurpose: Improvements in sequencing technologies have shown that genetic differences among neoplastic cells can reflect clonal expansion. Intratumor heterogeneity (ITH) has been suggested to explain differences in prognosis and treatment response, indicating that personalized medicine is the goal of the future. This study evaluated ITH in 5 patients with recurrent metastatic oral squamous cell carcinoma (OSCC) and tracked the evolution from non-neoplastic tissue to neoplastic events developing after primary tumor formation. Patients and Methods: Representative regions were macrodissected from specimens obtained from patients with OSCC of the tongue (n = 4) and floor of the mouth (n = 1). ITH and tumor evolution were explored by analyzing DNA mutations disclosed by next-generation sequencing of specific driver genes combined with changes in the mtDNA D-loop hypervariable region. Phylogenetic trees were generated employing MAFFT tool with UPGMA/Jukes-Cantor serving as the substitute model. Results: High levels of heterogeneity were observed within and among tumors. ITH emerged as metastatic and recurrent events progressed, but the evolutionary patterns differed. In some patients, specific subclones persisted during tumor relapse. Neighboring tissue also was heterogeneous at the premalignant level. Conclusions: A multiregion approach yielded more representative data than did single samples when tumors were subjected to molecular investigation. Persistent mutations that might be targeted by individualized medicine were thus exposed. Mitochondrial DNA is a useful adjunct tool when studying the phylogenetic evolution of subclones. The clinical implications of “field” heterogeneity should be studied in depth
Podoplanin expression as a predictive marker of dysplasia in oral leukoplakia
No full textRecent studies have emphasized the role of podoplanin in oral lesions at risk of malignant transformation. We investigated a group of oral leukoplakias (OLs) to determine a possible relation between altered podoplanin expression and dysplasia, and to compare the results with those obtained by other, widely used biomarkers
Ki67 Overexpression in mucosa distant from oral carcinoma: A poor prognostic factor in patients with long-term follow-up
No full textPurpose The aggressive behavior of oral squamous cell carcinoma (OSCC) has recently been related to the mucosa surrounding the primary mass, consisting of genetically altered cells that might be responsible for cancer progression. The aim of the study was to determine whether an abnormal cell turnover in clinically and histologically “normal” mucosa distant from the primary tumor is associated with a poor prognosis in terms of locoregional control (LRC) of disease and disease-specific survival (DSS). Material and methods This prospective study monitored 55 OSCC patients. Cell turnover in areas clinically and histologically distant from the tumor mass was evaluated by immunohistochemical expression of Ki67. A Ki67 value >20% was considered “high.” Results The mean follow-up period of the population studied was 53.7 ± 32.4 months (range 12–110 months). Multivariate analysis showed that the Ki67 value in distant mucosa was a powerful independent prognostic factor for LRC. In addition, high Ki67 expression in distant mucosa was the only variable statistically related to worse LRC (χ2 = 9.5; p = 0.002) and DSS (χ2 = 5.51; p = 0.02) in T1-2N0 OSCCs. Conclusions The present study confirmed the role of Ki67 in tumor-distant areas as a prognostic marker for OSCC patients
Paraesthesia after Local Anaesthetics: An Analysis of Reports to the FDA Adverse Event Reporting System
No full textThis study was aimed to evaluate the possible alert signals of paraesthesia by local anaesthetics, focusing on those used in dentistry. A case/non-case study of spontaneous adverse events recorded in FAERS (FDA Adverse Event Reporting System) between 2004 and 2011 was performed. Cases were represented by the reports of reactions grouped under the term 'Paraesthesias and dysaesthesias' involving local anaesthetics (ATC: N01B*); non-cases were all other reports of the same drugs. Reporting odds ratios (ROR) with the relevant 95% confidence intervals (95CI) were calculated. Alert signal was considered when number of cases >3 and lower limit of ROR 95CI > 1. To estimate the specificity of signals for dentistry, the analysis was restricted to the specific term "Oral Paraesthesia" and to reports concerning dental practice. Overall, 528 reports of 'Paraesthesias and dysaesthesias' were retrieved, corresponding to 573 drug-reaction pairs (247 lidocaine, 99 bupivacaine, 85 articaine, 30 prilocaine, 112 others). The signal was significant only for articaine (ROR=18.38; 95CI = 13.95-24.21) and prilocaine (2.66; 1.82-3.90). The analysis of the specific term "Oral Paraesthesia" retrieved 82 reports corresponding to 90 drug-reaction pairs (37 articaine, 19 lidocaine, 14 prilocaine, 7 bupivacaine, 13 others) and confirmed the signal for articaine (58.77; 37.82-91.31) and prilocaine (8.73; 4.89-15.57). The analysis of reports concerning dental procedures retrieved a signal for articaine, both for any procedures (8.84; 2.79-27.97) and for non-surgical ones (15.79; 1.87-133.46). In conclusion, among local anaesthetics, only articaine and prilocaine generated a signal of paraesthesia, especially when used in dentistry
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