Effects of continuous chelation on the instrumentation of curved canals with a martensitic NiTi file system: an ex vivo micro-CT evaluation.

This study aimed to evaluate the influence of continuous chelation on apical transportation and centrality in shaped curved canals prepared with a martensitic file system and evaluated by micro-CT. Twenty-four lower molar canals with a curvature of 25º-40º were scanned pre-operatively with micro-CT and divided into 2 groups according to two different irrigation regimens (n = 12). Group 1 was irrigated with NaOCl, group 2 with Dual Rinse. All canals were prepared with VDW.ROTATE system. The samples were scanned post-operatively and evaluated at 1, 3 and 5 mm from the apex to determine apical transportation and canal centrality using VG Studio software. Statistical analysis was performed with SPSS software using the non-parametric Mann-Whitney test. No statistically significant differences were found between the two groups for both apical transportation and canal centrality at any of the levels studied (p < 05). The use of continuous chelation during the instrumentation of the canals with martensitic alloy files does not produce greater transportation and does not generate changes in centralization compared to NaOCl-only irrigation. Combined chelation and disinfection while shaping with martensitic NiTi can simplify the irrigation regimen without inducing iatrogenic aberrations.

Atezolizumab plus bevacizumab versus lenvatinib or sorafenib in non-viral unresectable hepatocellular carcinoma: an international propensity score matching analysis.

BACKGROUND: A growing body of evidence suggests that non-viral hepatocellular carcinoma (HCC) might benefit less from immunotherapy. MATERIALS AND METHODS: We carried out a retrospective analysis of prospectively collected data from consecutive patients with non-viral advanced HCC, treated with atezolizumab plus bevacizumab, lenvatinib, or sorafenib, in 36 centers in 4 countries (Italy, Japan, Republic of Korea, and UK). The primary endpoint was overall survival (OS) with atezolizumab plus bevacizumab versus lenvatinib. Secondary endpoints were progression-free survival (PFS) with atezolizumab plus bevacizumab versus lenvatinib, and OS and PFS with atezolizumab plus bevacizumab versus sorafenib. For the primary and secondary endpoints, we carried out the analysis on the whole population first, and then we divided the cohort into two groups: non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) population and non-NAFLD/NASH population. RESULTS: One hundred and ninety patients received atezolizumab plus bevacizumab, 569 patients received lenvatinib, and 210 patients received sorafenib. In the whole population, multivariate analysis showed that treatment with lenvatinib was associated with a longer OS [hazard ratio (HR) 0.65; 95% confidence interval (CI) 0.44-0.95; P = 0.0268] and PFS (HR 0.67; 95% CI 0.51-0.86; P = 0.002) compared to atezolizumab plus bevacizumab. In the NAFLD/NASH population, multivariate analysis confirmed that lenvatinib treatment was associated with a longer OS (HR 0.46; 95% CI 0.26-0.84; P = 0.0110) and PFS (HR 0.55; 95% CI 0.38-0.82; P = 0.031) compared to atezolizumab plus bevacizumab. In the subgroup of non-NAFLD/NASH patients, no difference in OS or PFS was observed between patients treated with lenvatinib and those treated with atezolizumab plus bevacizumab. All these results were confirmed following propensity score matching analysis. By comparing patients receiving atezolizumab plus bevacizumab versus sorafenib, no statistically significant difference in survival was observed. CONCLUSIONS: The present analysis conducted on a large number of advanced non-viral HCC patients showed for the first time that treatment with lenvatinib is associated with a significant survival benefit compared to atezolizumab plus bevacizumab, in particular in patients with NAFLD/NASH-related HCC.

Nonalcoholic steatohepatitis in hepatocarcinoma: new insights about its prognostic role in patients treated with lenvatinib.

BACKGROUND: Hepatocellular carcinoma (HCC) treatment remains a big challenge in the field of oncology. The liver disease (viral or not viral) underlying HCC turned out to be crucial in determining the biologic behavior of the tumor, including its response to treatment. The aim of this analysis was to investigate the role of the etiology of the underlying liver disease in survival outcomes. PATIENTS AND METHODS: We conducted a multicenter retrospective study on a large cohort of patients treated with lenvatinib as first-line therapy for advanced HCC from both Eastern and Western institutions. Univariate and multivariate analyses were performed. RESULTS: Among the 1232 lenvatinib-treated HCC patients, 453 (36.8%) were hepatitis C virus positive, 268 hepatitis B virus positive (21.8%), 236 nonalcoholic steatohepatitis (NASH) correlate (19.2%) and 275 had other etiologies (22.3%). The median progression-free survival (mPFS) was 6.2 months [95% confidence interval (CI) 5.9-6.7 months] and the median overall survival (mOS) was 15.8 months (95% CI 14.9-17.2 months). In the univariate analysis for OS NASH-HCC was associated with longer mOS [22.2 versus 15.1 months; hazard ratio (HR) 0.69; 95% CI 0.56-0.85; P = 0.0006]. In the univariate analysis for PFS NASH-HCC was associated with longer mPFS (7.5 versus 6.5 months; HR 0.84; 95% CI 0.71-0.99; P = 0.0436). The multivariate analysis confirmed NASH-HCC (HR 0.64; 95% CI 0.48-0.86; P = 0.0028) as an independent prognostic factor for OS, along with albumin-bilirubin (ALBI) grade, extrahepatic spread, neutrophil-to-lymphocyte ratio, portal vein thrombosis, Eastern Cooperative Oncology Group (ECOG) performance status and alpha-fetoprotein. An interaction test was performed between sorafenib and lenvatinib cohorts and the results highlighted the positive predictive role of NASH in favor of the lenvatinib arm (P = 0.0047). CONCLUSION: NASH has been identified as an independent prognostic factor in a large cohort of patients with advanced HCC treated with lenvatinib, thereby suggesting the role of the etiology in the selection of patients for tyrosine kinase treatment. If validated, this result could provide new insights useful to improve the management of these patients.

Identification of lenvatinib prognostic index via recursive partitioning analysis in advanced hepatocellular carcinoma.

BACKGROUND: After the advent of new treatment options for advanced hepatocellular carcinoma (HCC), the identification of prognostic factors is crucial for the selection of the most appropriate therapy for each patient. PATIENTS AND METHODS: With the aim to fill this gap, we applied recursive partitioning analysis (RPA) to a cohort of 404 patients treated with lenvatinib. RESULTS: The application of RPA resulted in a classification based on five variables that originated a new prognostic score, the lenvatinib prognostic index (LEP) index, identifying three groups: low risk [patients with prognostic nutritional index (PNI) >43.3 and previous trans-arterial chemoembolization (TACE)]; medium risk [patients with PNI >43.3 but without previous TACE and patients with PNI <43.3, albumin-bilirubin (ALBI) grade 1 and Barcelona Clinic Liver Cancer stage B (BCLC-B)]; high risk [patients with PNI <43.3 and ALBI grade 2 and patients with PNI <43.3, albumin-bilirubin (ALBI) grade 1 and Barcelona Clinic Liver Cancer stage C (BCLC-C)]. Median overall survival was 29.8 months [95% confidence interval (CI) 22.8-29.8 months] in low risk patients (n = 128), 17.0 months (95% CI 15.0-24.0 months) in medium risk (n = 162) and 8.9 months (95% CI 8.0-10.7 months) in high risk (n = 114); low risk hazard ratio (HR) 1 (reference group), medium risk HR 1.95 (95% CI 1.38-2.74), high risk HR 4.84 (95% CI 3.16-7.43); P < 0.0001. The LEP index was validated in a cohort of 127 Italian patients treated with lenvatinib. While the same classification did not show a prognostic value in a cohort of 311 patients treated with sorafenib, we also show a possible predictive role in favor of lenvatinib in the low risk group. CONCLUSIONS: LEP index is a promising, easy-to-use tool that may be used to stratify patients undergoing systemic treatment of advanced HCC.

External cervical resorption: part 2 - management.

Effective management of external cervical resorption (ECR) depends on accurate assessment of the true nature and accessibility of ECR; this has been discussed in part 1 of this 2 part article. This aim of this article was firstly, to review the literature in relation to the management of ECR and secondly, based on the available evidence, describe different strategies for the management of ECR. In cases where ECR is supracrestal, superficial and with limited circumferential spread, a surgical repair without root canal treatment is the preferred approach. With more extensive ECR lesions, vital pulp therapy or root canal treatment may also be indicated. Internal repair is indicated where there is limited resorptive damage to the external aspect of the tooth and/or where an external (surgical) approach is not possible due to the inaccessible nature of subcrestal ECR. In these cases, root canal treatment will also need to be carried out. Intentional reimplantation is indicated in cases where a surgical or internal approach is not practical. An atraumatic extraction technique and short extraoral period followed by 2-week splinting are important prognostic factors. Periodic reviews may be indicated in cases where active management is not pragmatic. Finally, extraction of the affected tooth may be the only option in untreatable cases where there are aesthetic, functional and/or symptomatic issues.

Self-Limiting versus Conventional Caries Removal: A Randomized Clinical Trial.

A single-blind randomized controlled clinical trial in patients with deep caries and symptoms of reversible pulpitis compared outcomes from a self-limiting excavation protocol using chemomechanical Carisolv gel/operating microscope (self-limiting) versus selective removal to leathery dentin using rotary burs (control). This was followed by pulp protection with mineral trioxide aggregate (MTA) and restoration with glass ionomer cement and resin composite, all in a single visit. The pulp sensibility and periapical health of teeth were assessed after 12 mo, in addition to the differences in bacterial tissue concentration postexcavation. Apical radiolucencies were assessed using cone beam computed tomography/periapical radiographs (CBCT/PAs) taken at baseline 0 mo (M0) and 12 mo (M12). In total, 101 restorations in 86 patients were placed and paired subsurface, and deep (postexcavation) dentin samples were obtained. DNA was extracted and bacteria-specific 16S ribosomal RNA gene quantitative polymerase chain reaction was performed. No significant difference was found in bacterial copy numbers normalized to mass of dentin ("bacterial tissue concentration") between the self-limiting (96.3% reduction) and control protocols (97.1%, P = 0.33). The probability of 12-mo success was 4 times (odds ratio [OR] = 4.33; confidence interval [CI], 1.2-15.6; P = 0.025) higher in the self-limiting protocol compared to the control (conventional excavation technique), with pulp survival rates of 73.3% and 90%, respectively ( P = 0.049). Molars had a 4 times higher probability of success compared to premolars (OR, 4.17; CI, 1.17-14.9; P = 0.028), and symptom severity did not statistically predict outcome (OR, 0.41; CI, 0.12-13.9, P = 0.153). CBCT detected significantly more periapical (PA) lesions than PA radiographs at the baseline visit ( P < 0.001). In conclusion, the self-limiting caries excavation protocol under magnification increased pulp survival rate compared to rotary bur excavation ( ClinicalTrials.gov NCT03071588).

Pooled analysis of 1-year recall data from three root canal treatment outcome studies undertaken using cone beam computed tomography.

AIM: To provide an estimate of the proportion of successful outcomes of primary and secondary root canal treatments (retreatments) determined by periapical radiographs and cone beam computed tomography (CBCT), a pooled analysis of the data collected from three previous prospective clinical outcome studies was undertaken. METHODOLOGY: The analysis pooled the 1-year results for 354 teeth, including 123 primary treatments and 231 retreatments. All root canals were instrumented with ProTaper Universal and filled using a warm vertical condensation technique. Comparisons of favourable results between root canal treatments and retreatments and between different tooth types were made using chi-square/Fisher's exact test. RESULTS: The overall percentage of favourable results was 91% using periapical radiographs and 80% for CBCT (P < 0.001). With CBCT, the percentage of favourable results for primary treatments (84.7%) was not significantly different (P = 0.316) from that of retreatments (77.9%). When assessed by tooth group, the overall percentage of favourable results with CBCT was 75.5%, 90.6% and 91.1% for molar, premolar and anterior teeth, respectively. When CBCT is used to assess the outcome, the proportion of favourable outcomes in molars was significantly lower than that of premolars and anterior teeth (P < 0.05). Teeth with root fillings terminating more than 2 mm short of the radiographic apex had less favourable outcomes (73%) compared to long (83%) and adequate root filling length (84%). CONCLUSIONS: The proportions of favourable outcomes of primary root canal treatments and retreatments assessed with CBCT were lower when compared to periapical radiographs, and also lower than those historically reported by periapical radiograph-based outcome studies. Considering the very high favourable outcome of anterior teeth and premolars compared to molar teeth, future studies assessing the effect of new materials and techniques on the outcome of root canal treatments should be based on preoperative and postoperative CBCT images, and focus on molar teeth.

External cervical resorption: a three-dimensional classification.

This article describes a novel three-dimensional classification for external cervical resorption (ECR). The European Society of Endodontology and American Association of Endodontists & American Academy of Oral & Maxillofacial Radiology position statements advise that Cone beam computed tomography should be considered for the assessment and/or management of root resorption if it appears to be clinically amenable to treatment following clinical and conventional radiographic examination. The new classification takes into account the ECR lesion height (1: at CEJ level or coronal to the bone crest (supracrestal), 2: extends into the coronal third of the root and apical to the bone crest (subcrestal), 3: extends into the mid-third of the root, 4: extends into the apical third of the root), circumferential spread (A: ≤90° B: ≤180° C: ≤270° D: >270°) and proximity to the root canal (d: lesion confined to dentine, p: probable pulpal involvement), thus classifying ECR in three dimensions. At present, there is no classification to accurately describe ECR. This novel and clinically relevant three-dimensional classification should allow effective and accurate communication of ECR lesions between colleagues. It will also allow the effect of the nature of ECR on the outcome of treatment to be assessed objectively.

Rapid Bacterial Detection during Endodontic Treatment.

Bacteria present in the root canal (RC) space following an RC treatment (RCT) can lead to persistent infections, resulting in treatment failure and the need for reintervention or extraction. Currently, there are no standardized methods in use to clinically detect bacterial presence within RC spaces. The use of paper point sampling and fluorescence staining was shown to be a rapid method, able to detect residual bacteria following treatment. The study demonstrated that Calcein acetoxymethyl (AM) proved to be a suitable dye for detecting vital bacteria within mature endodontic biofilms, with an improved sensitivity over colony-forming unit counting in a stressed biofilm model. Furthermore, in a clinical trial with primary RCTs, 53 infected teeth were sampled in vivo, and increased detection of vital cells was found when compared with colony-forming unit counting, highlighting the sensitivity of the technique in detecting low cell numbers. By combining fluorescent staining and microspectroscopy with software-based spectral analysis, successful detection of vital cells from RCs was possible after 5 min of Calcein AM incubation. Application of this technology during RCT has the potential to reduce persistent infections through vital cell detection and additional treatment. Furthermore, this technique could be applied to antimicrobial research and disinfection control in clinical settings ( ClinicalTrials.gov NCT03055975).

Long-term outcomes of direct acting antivirals in post-transplant advanced hepatitis C virus recurrence and fibrosing cholestatic hepatitis.

Long-term functional outcomes of sofosbuvir-based antiviral treatment were evaluated in a cohort study involving 16 Italian centres within the international compassionate use programme for post-transplant hepatitis C virus (HCV) recurrence. Seventy-three patients with cirrhosis (n=52) or fibrosing cholestatic hepatitis (FCH, n=21) received 24-week sofosbuvir with ribavirin±pegylated interferon or interferon-free sofosbuvir-based regimen with daclatasvir/simeprevir+ribavirin. The patients were observed for a median time of 103 (82-112) weeks. Twelve of 73 (16.4%) died (10 non-FCH, 2 FCH) and two underwent re-LT. Sustained virological response was achieved in 46 of 66 (69.7%): 31 of 47 (66%) non-FCH and 15 of 19 (79%) FCH patients. All relapsers were successfully retreated. Comparing the data of baseline with last follow-up, MELD and Child-Turcotte-Pugh scores improved both in non-FCH (15.3±6.5 vs 10.5±3.8, P<.0001 and 8.4±2.1 vs 5.7±1.3, P<.0001, respectively) and FCH (17.3±5.9 vs 10.1±2.8, P=.001 and 8.2±1.6 vs 5.5±1, P=.001, respectively). Short-treatment mortality was higher in patients with baseline MELD≥25 than in those with MELD<25 (42.9% vs 4.8%, P=.011). Long-term mortality was 53.3% among patients with baseline MELD≥20 and 7.5% among those with MELD<20 (P<.0001). Among deceased patients 75% were Child-Turcotte-Pugh class C at baseline, while among survivors 83.9% were class A or B (P<.0001). Direct acting antivirals-based treatments for severe post-transplant hepatitis C recurrence, comprising fibrosing cholestatic hepatitis, significantly improve liver function, even without viral clearance and permit an excellent long-term survival. The setting of severe HCV recurrence may require the identification of "too-sick-to-treat patients" to avoid futile treatments.

Hepatocellular carcinoma recurrence in patients with curative resection or ablation: impact of HCV eradication does not depend on the use of interferon.

BACKGROUND: In HCV-infected cirrhotic patients with successfully treated early hepatocellular carcinoma (HCC), the time to HCC recurrence and the effects of sustained viral eradication (SVR) by interferon (IFN)-based or IFN-free regimens on HCC recurrence remain unclear. AIM: To perform an indirect comparison of time to recurrence (TTR) in patients with successfully treated early HCC and active HCV infection with those of patients with SVR by IFN-based and by IFN-free regimens. METHODS: We evaluated 443 patients with HCV-related cirrhosis and Barcelona Clinic Liver Cancer Stage A/0 HCC who had a complete radiological response after curative resection or ablation. Active HCV infection was present in 328, selected from the Italian Liver Cancer group cohort; 58 patients had SVR achieved by IFN-free regimens after HCC cure, and 57 patients had SVR achieved by IFN-based regimens after HCC cure. Individual data of patients in the last two groups were extracted from available publications. RESULTS: TTR by Kaplan-Meier curve was significantly lower in patients with active HCV infection compared with those with SVR both by IFN-free (P = 0.02) and by IFN-based (P < 0.001) treatments. TTR was similar in patients with SVR by IFN-free or by IFN-based (P = 0.49) strategies. CONCLUSION: In HCV-infected, successfully treated patients with early HCC, SVR obtained by IFN-based or IFN-free regimens significantly reduce tumour recurrence without differences related to the anti-viral strategy used.

Safety and efficacy of direct-acting antivirals for the treatment of chronic hepatitis C in a real-world population aged 65 years and older.

The availability of direct-acting antiviral agents (DAA) regimens has expanded the pool of patients eligible for treatment. However, data on the virologic response and tolerability of DAAs in elderly patients are lacking. We evaluated the efficacy and safety of DAAs in patients with advanced fibrosis/cirrhosis in real-life practice with the focus on those aged ≥65 years. Between January and December 2015, all consecutive patients with HCV-related advanced fibrosis/cirrhosis treated with DAA at eleven tertiary referral centres in Emilia Romagna (Italy) were enrolled. Regimen choice was based on viral genotype and stage of disease, according to guidelines. The primary end point was sustained virologic response 12 weeks after the end of treatment (SVR12). Overall, 282 of 556 (50.7%) patients evaluated were elderly, most of them with cirrhosis. Antiviral therapy was stopped prematurely in four (1.4%) patients. Two patients, both with cirrhosis, died during treatment due to worsening of liver/renal function. SVR12 was achieved by 94.7% and was comparable to that obtained in patients aged <65 (P=.074). Similar data were also reported in subgroup of patients aged ≥75 years. All patients with advanced fibrosis achieved virologic response. SVR12 was 80.8% in Child-Pugh-Turcotte (CTP)-B cirrhosis and 95.4% in CTP-A (P=.013). According to genotype, the SVR12 was achieved in 172 of 181 (95%) with genotype 1b cirrhosis and in 44 of 48 (91.7%) with genotype 2 cirrhosis. In conclusions, in a real-world setting, DAAs are safe and effective in elderly patients with HCV-related advanced fibrosis/cirrhosis, but SVR12 is lower with worsening CTP class.

Years of life that could be saved from prevention of hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) causes premature death and loss of life expectancy worldwide. Its primary and secondary prevention can result in a significant number of years of life saved. AIM: To assess how many years of life are lost after HCC diagnosis. METHODS: Data from 5346 patients with first HCC diagnosis were used to estimate lifespan and number of years of life lost after tumour onset, using a semi-parametric extrapolation having as reference an age-, sex- and year-of-onset-matched population derived from national life tables. RESULTS: Between 1986 and 2014, HCC lead to an average of 11.5 years-of-life lost for each patient. The youngest age-quartile group (18-61 years) had the highest number of years-of-life lost, representing approximately 41% of the overall benefit obtainable from prevention. Advancements in HCC management have progressively reduced the number of years-of-life lost from 12.6 years in 1986-1999, to 10.7 in 2000-2006 and 7.4 years in 2007-2014. Currently, an HCC diagnosis when a single tumour <2 cm results in 3.7 years-of-life lost while the diagnosis when a single tumour ≥ 2 cm or 2/3 nodules still within the Milan criteria, results in 5.0 years-of-life lost, representing the loss of only approximately 5.5% and 7.2%, respectively, of the entire lifespan from birth. CONCLUSIONS: Hepatocellular carcinoma occurrence results in the loss of a considerable number of years-of-life, especially for younger patients. In recent years, the increased possibility of effectively treating this tumour has improved life expectancy, thus reducing years-of-life lost.

The detection of simulated periapical lesions in human dry mandibles with cone-beam computed tomography: a dose reduction study.

AIM: To assess in an ex vivo model the accuracy of detection of simulated periapical lesions using two cone-beam computed tomography (CBCT) dose modes and periapical radiography. METHODOLOGY: Small and large artificial periapical lesions were created with burs at the base of the socket of eleven mandibular molars, in seven human dry mandibles. Digital periapical radiographs, 360° and 180° rotations CBCT scans with standard dose and dose reduction (DR) modes were obtained before and after periapical lesions were prepared. Six blinded examiners scored the presence/absence of lesions. Inter- and intra-examiner reliability were determined. Sensitivity, specificity, positive predictive values and negative predictive values and receiver operating characteristic (ROC) area under the curve (overall accuracy) were determined for each modality. RESULTS: The mean sensitivity and specificity of both CBCT rotations with dose reduction mode were higher compared to that of standard dose CBCT scans. The ROC Az mean values for periapical radiographs, 360° scan with standard dose and dose reduction and 180° scans with standard dose and dose reduction were 0.62, 0.94, 0.95, 0.95 and 0.97, respectively. No significant difference in the diagnostic accuracy of CBCT scans taken with standard and dose reduction modes, whilst their accuracy was significantly higher than periapical radiographs. CONCLUSIONS: Using dose reduction with 360° and 180° CBCT scans demonstrated good diagnostic accuracy in the detection of simulated periapical lesions whilst reducing the radiation dose by 54% and 51%, respectively, compared to conventional settings. Clinical evaluation is now needed to determine whether this is applicable to patients.

Comparison between alcohol- and hepatitis C virus-related hepatocellular carcinoma: clinical presentation, treatment and outcome.

BACKGROUND: Hepatitis C virus (HCV) and alcohol abuse are the main risk factors for hepatocellular carcinoma (HCC) in Western countries. AIM: To investigate the role of alcoholic aetiology on clinical presentation, treatment and outcome of HCC as well as on each Barcelona Clinic Liver Cancer (BCLC) stage, as compared to HCV-related HCCs. METHODS: A total of 1642 HCV and 573 alcoholic patients from the Italian Liver Cancer (ITA.LI.CA) database, diagnosed with HCC between January 2000 and December 2012 were compared for age, gender, type of diagnosis, tumour burden, portal vein thrombosis (PVT), oesophageal varices, liver function tests, alpha-fetoprotein, BCLC, treatment and survival. Aetiology was tested as predictor of survival in multivariate Cox regression models and according to HCC stages. RESULTS: Cirrhosis was present in 96% of cases in both groups. Alcoholic patients were younger, more likely male, with HCC diagnosed outside surveillance, in intermediate/terminal BCLC stage and had worse liver function. After adjustment for the lead-time, median (95% CI) overall survival (OS) was 27.4 months (21.5-33.2) in alcoholic and 33.6 months (30.7-36.5) in HCV patients (P = 0.021). The prognostic role of aetiology disappeared when survival was assessed in each BCLC stage and in the Cox regression multivariate models. CONCLUSIONS: Alcoholic aetiology affects survival of HCC patients through its negative effects on secondary prevention and cancer presentation but not through a greater cancer aggressiveness or worse treatment result. In fact, survival adjusted for confounding factors was similar in alcoholic and HCV patients.

The detection of periapical pathoses using digital periapical radiography and cone beam computed tomography in endodontically retreated teeth - part 2: a 1 year post-treatment follow-up.

AIM: Part 2 of this prospective clinical study aimed to compare the 1-year outcome of root canal retreatments, when individual roots and teeth were assessed by periapical radiographs and cone beam computed tomography (CBCT). METHODOLOGY: Subjects participating in this study had been referred for management of an endodontic problem associated with one or more root filled teeth. Root canal retreatment was performed by Specialists or postgraduate students under the direct supervision of Specialist endodontic staff. A total of 98 teeth (84 patients) were reassessed clinically and radiographically 1 year after completion of root canal retreatment. The postoperative periapical radiographs and CBCT scans were compared with their respective pre-treatment (diagnostic) periapical radiographs and CBCT scans. The increase or decrease in size of existing periapical radiolucencies and development of new radiolucencies were assessed by a consensus panel consisting of two calibrated examiners. They also determined an appropriate management plan for each case based on the radiographical findings. Comparison of the outcome diagnosis of individual roots and teeth and case management, when assessed by periapical radiographs and CBCT scans, was performed using chi-squared and McNemar's tests. RESULTS: An overall favourable result of 93% success for teeth (96% roots) was recorded when the assessment was undertaken by periapicals compared with 77% success for teeth (87% roots) when assessed by CBCT. A significant difference in outcome diagnosis of single paired roots (P < 0.0001) and teeth (P = 0.0001) was observed when comparing periapicals to CBCT for the cohort of teeth as a whole. When comparing the future management plan on the basis of radiographic information alone, there was a significant difference between periapicals and CBCT-based management (P = 0.01). CONCLUSION: Diagnosis using CBCT revealed a significantly lower number of favourable outcomes than periapicals in root canal retreatment. This significantly affected the future management of cases attending for a review.

Synergistic effect of 2% chlorhexidine combined with proteolytic enzymes on biofilm disruption and killing.

AIM: To investigate the dynamics of a disinfection regimen using 1% trypsin and 1% proteinase K in combination with 2% chlorhexidine (with or without ultrasonics) using a nutrient-stressed endodontic multispecies model biofilm. METHODOLOGY: Nutrient-stressed biofilms (Propionibacterium acnes, Staphylococcus epidermidis, Actinomyces radicidentis, Streptococcus mitis and Enterococcus faecalis OMGS 3202) were grown in prepared root canals of single-rooted teeth. The treatment groups included 1% trypsin and 2% chlorhexidine (CHX), 1% proteinase K and 2% CHX (with and without ultrasonics). 2% CHX was the positive control and untreated group, and sterile saline (with and without ultrasonics) was the negative control. The biofilms were investigated using confocal laser scanning microscopy (CLSM) with live/dead staining and quantitative microbial culture. RESULTS: The trypsin and CHX group with ultrasonics was significantly more effective in reducing viable counts and the substratum coverage than those of all other groups (P < 0.05). The viable counts of the proteinase K and CHX group used with (4.26 ± 0.58 log10  cfu mL(-1) ) or without ultrasonics (5.05 ± 1.36 log10  cfu mL(-1) ) were significantly reduced (P < 0.05) as compared with the untreated control (7.67 ± 0.84 log10  cfu mL(-1) ) and saline groups used with (6.57 ± 0.73 log10  cfu mL(-1) ) and without ultrasonics (6.74 ± 0.10 log10  cfu mL(-1) ). The CHX group was less effective in biofilm disruption compared to when used in combination with trypsin and proteinase K. CONCLUSION: The trypsin and CHX group with ultrasonics was significantly more effective at reducing bacterial viable counts and disrupting biofilm.