The epidemiology of oral cancer during the COVID-19 pandemic in Northern Italy: Incidence, survival, prevalence.

Despite novel treatment approaches, oral cancer survival has not improved significantly and the disease often presents a disabling path for patients. The aim of this work was to describe the epidemiological data of oral cancers in a province of northern Italy. Incident cases in the period 1996-2020 and EU population standardized rates were reported for Oral Cavity cancer (OC) and OroPharyngeal cancer (OP). Annual percent changes (APC) were estimated with joint point analysis. The 5-year survival was calculated in three different periods: 1996-2000, 2001-2010 and 2011-2015. From 1996 to 2020, 771 cases of oral cancers (442 OC and 329 OP) were recorded with the age-standardized incidence rate 7.28 (10.74 in males and 3.97 in females): 3.82 for OC and 3.47 for OP. In males there is a significant increase in the incidence of OP up to 2017 (APC 11; 95% CI, 4.9-17.5), which then decreases; in females the rates are constant. In 2020 (the era of Covid-19), we did not see a decline in incidence compared to 2019. The 5-year survival (for cases diagnosed in 2011-2015) was 55.6%, 56.5% and 56% for OC, OP and OC + OP, respectively; it was somewhat higher in females and was undergoing some changes over the course of years. The number of prevalent cases as of 1 January 2021 is 314 (175 OC, 139 OP). The study showed a decline in cancers in men, particularly for OP; survival shows improvement in the long-term examined; Covid-19 had no negative impact on 2020 diagnoses.

Multicenter Retrospective Analysis of Implant Overdentures Delivered with Different Design and Attachment Systems: Results Between One and 17 Years of Follow-Up.

PURPOSE: To analyze implant and prosthetic survival rates, complications, patient satisfaction, and biological parameters of patients rehabilitated with implant overdentures (IOV) on splinted and nonsplinted implants and different attachment systems, in function for one to 17 years. METHODS: This retrospective study evaluated data collected from patients rehabilitated with implant overdentures between January 2001 and December 2016 in nine different centers. Outcome measures were implant and prosthetic success rates, mechanical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. RESULTS: A total of 581 implants were installed in 194 patients. Patients were followed for a mean period of 60.6 months (range 6⁻206). Eighty-nine patients received 296 low profile attachment (OT Equator), 62 patients received 124 ball attachments, and 43 patients received 107 Locator attachments. In eighty-three patients the implants were splinted with computer aided design/computer aided manufacturing (CAD/CAM) or casted bar. At the last follow-up, 10 implants failed in eight patients. Statistical significance was found for failed prostheses (P = 0.0723) and complications (P = 0.0165), with better values for splinted implants. No statistically significant differences were found in proportion of implant and prosthetic failure (P > 0.05). At a five-year follow-up, proportion of complications (P = 0.0289) and failed prostheses (P = 0.0069) were statistically higher for IOV on Locator attachments. No difference was founded in MBL at one- and two-year follow-up between different attachment systems (P > 0.05). Statistically significant improvement in all the OHIP categories was reported in all the patients, after one year of function. CONCLUSIONS: Implant overdenture showed high implant and prosthetic survival rates, low complications, high patient satisfaction, and good biological parameters in the long-term follow-up. Splinting the implants may reduce number of mechanical complications. Locator attachments showed higher number of complications. Further studies are needed to confirm these preliminary results.

Clinical evaluation of a novel dental implant system as single implants under immediate loading conditions - 4-month post-loading results from a multicentre randomised controlled trial.

PURPOSE: To evaluate the safety and clinical effectiveness of a novel dental implant system (GENESIS Implant System, Keystone Dental, Massachusetts, USA) using another dental implant system by the same manufacturer as a control (PRIMA Implant System, Keystone Dental). MATERIALS AND METHODS: A total of 53 patients requiring at least two single crowns had their sites randomised according to a split-mouth design to receive both implant systems at six centres. If implants could be placed with a torque superior to 40 Ncm they were to be loaded immediately with provisional crowns, otherwise after 3 months of submerged healing. Provisional crowns were replaced by definitive crowns 4 months after initial loading, when the follow-up period for the initial part of this study was completed. Outcome measures were crown/implant failures, complications, pink esthetic score (PES), peri-implant marginal bone level changes, plaque score, marginal bleeding, patients and preference of the clinician. RESULTS: In total 53 PRIMA and 53 GENESIS implants were placed. Three patients dropped out but all of the remaining patients were followed up to 4-months post-loading. No PRIMA implant failed whereas four GENESIS implants failed. Only two complications were reported for PRIMA implants. There were no statistically significant differences for crown/implant failures (difference in proportions = 0.080; P (McNemar test) = 0.125) and complications (difference in proportions = -0.04; P (McNemar test) = 0.500) between the implant systems. There were no differences at 4-months post-loading for plaque (difference = -0.54, 95% CI: -3.01 to 1.93; P (Paired t-test) = 0.660), marginal bleeding (difference = -3.8, 95% CI: -7.63 to 0.019; P (Paired t-test) = 0.051), PES (difference = 0.47, 95% CI: -0.56 to 1.50; P (Paired t-test) = 0.365) and marginal bone level changes (difference in mm = -0.04, 95% CI: -0.33 to 0.26; P (Paired t-test) = 0.795). The majority of the patients (46) had no preference regarding the two implant systems evaluated. Three operators preferred GENESIS implants, two had no preference and one preferred GENESIS in medium and soft bone and PRIMA in hard bone. CONCLUSIONS: No statistically significant differences were observed between the systems' implant types, although four GENESIS implants failed versus none of the PRIMA type. Longer follow-ups of wider patient populations are needed to better understand whether there is an effective advantage with one of the two implant designs. Conflict-of-interest statement: This research project was originally funded by Keystone Italia, Dental spa (Verona, Italy), the manufacturer of the implants evaluated in this investigation. However, when Keystone Italia received the data of the present manuscript, they refused to honour the financial agreement for the present publication. Therefore, no further follow-ups of this trial will be considered. A legal action was initiated against Keystone Italia. The data belonged to the authors and by no means was the manufacturer allowed to interfere with the conduct of the trial or the publication of the results.

Dimensional tolerances and assembly accuracy of dental implants and machined versus cast-on abutments.

BACKGROUND: The clinical application of prosthetic components obtained by different manufacturing processes lacks technological foundation: the dimensional tolerance of individual parts and their assembly accuracy are not known. The rotational misfit (RM) of the hexagonal connection is critical in single-tooth implant restorations, but no standard control procedures are available for its evaluation. PURPOSE: The research aimed at proposing a new protocol for the dimensional assessment of implant-abutment connections, based on noncontact measurement and statistical data processing. The procedure was applied to machined- and cast-on abutments, as well of the matching implants. MATERIALS AND METHODS: Three groups of five abutments each were studied: machined titanium abutments, pre-machined calcinable abutments before casting procedures and the same specimens after casting. A group of five corresponding implants was considered as well. Twice the apothem was measured on each hexagon through an optical measuring microscope. The data were processed to obtain the international tolerance (IT) grade. The RM was then calculated using the apothems of the external and the internal hexagon. RESULTS: All the components were classified between IT8 and IT9, and the maximum RM was around 3-4° for all the assemblies, inferior to the critical limits for the screw joint stability. CONCLUSION: An original measuring protocol was developed, independent of parts assembly and based on ITs. An objective dimensional characterization of prosthetic components and assemblies has been achieved, which is the basis for their reliability in clinical applications.