Dental Implants with Anti-Biofilm Properties: A Pilot Study for Developing a New Sericin-Based Coating.

AIM: several strategies have been tested in recent years to prevent bacterial colonization of dental implants. Sericin, one of the two main silk proteins, possesses relevant biological activities and also literature reports about its potential antibacterial properties, but results are discordant and not yet definitive. The aim of this study was to evaluate the effectiveness of different experimental protocols in order to obtain a sericin-based coating on medical grade titanium (Ti) able to reduce microbial adhesion to the dental implant surface. MATERIALS AND METHODS: different strategies for covalent bonding of sericin to Ti were pursued throughout a multi-step procedure on Ti-6Al-4V disks. The surface of grade 5 Ti was initially immersed in NaOH solution to obtain the exposure of functional -OH groups. Two different silanization strategies were then tested using aminopropyltriethoxysilane (APTES). Eventually, the bonding between silanized Ti-6Al-4V and sericin was obtained with two different crosslinking processes: glutaraldehyde (GLU) or carbodiimide/N-Hydroxy-succinimide (EDC/NHS). Micro-morphological and compositional analyses were performed on the samples at each intermediate step to assess the most effective coating strategy able to optimize the silanization and bioconjugation processes. Microbiological tests on the coated Ti-6Al-4V disks were conducted in vitro using a standard biofilm producer strain of Staphylococcus aureus (ATCC 6538) to quantify the inhibition of microbial biofilm formation (anti-biofilm efficacy) at 24 hours. RESULTS: both silanization techniques resulted in a significant increase of silicon (Si) on the Ti-6Al-4V surfaces etched with NaOH. Differences were found between GLU and EDC/NHS bioconjugation strategies in terms of composition, surface micro-morphology and anti-biofilm efficacy. Ti-6Al-4V samples coated with GLU-bound sericin after silanization obtained via vapor phase deposition proved that this technique is the most convenient and effective coating strategy, resulting in a bacterial inhibition of about 53% in respect to the uncoated Ti-6Al-4V disks. CONCLUSIONS: The coating with glutaraldehyde-bound sericin after silanization in the vapor phase showed promising bacterial inhibition values with a significant reduction of S. aureus biofilm. Further studies including higher number of replicates and more peri-implant-relevant microorganisms are needed to evaluate the applicability of this experimental protocol to dental implants.

Dental Implants With a Platform-Switched Morse Taper Connection and an Osteo Growth Induction Surface.

AIM: The aim of this study was to analyze the clinical outcomes after using an innovative implant system characterized by a modern platform-switched Morse taper connection and an osteo growth induction titanium surface (a particular type of SLA surface). Peri-implant bone loss (PBL) and implant success rate were examined after a 1- to 3-year follow-up. METHODS: The study was conducted as a cross-sectional analysis on all patients treated from January 2011 to December 2014 using CLC CONIC implants. Implants were divided into 3 main groups, based on the duration of the follow-up (1 year, 2 years, and 3 years), then subgrouped by diameter, length, and type of prosthetic rehabilitation to compare differences in PBL. X-rays were taken at the time of surgery, at prosthetic loading, at 1 year, and then annually thereafter. Previously-established success criteria were used to assess the implants. Frequency analyses and comparisons between the means (with 95% CI) were conducted for the statistical analysis of the data collected. RESULTS: One hundred twenty patients met inclusion and exclusion criteria, and completed the follow-up, and were thus eligible for the study, with a total of 261 CLC CONIC implants. The mean follow-up was 22.45 months. No implants failed, giving an overall success rate of 100%. The average PBL at 1-year follow-up was 0.047 mm, at 2 years it was 0.128 mm, and at 3 years it was 0.236 mm. CONCLUSIONS: The CLC CONIC implant system had a high success rate after 1 to 3 years of follow-up, in line with previous reports in the scientific literature. Combining platform switching with the Morse taper connection enabled stable bone levels to be achieved in the short to medium term.

A Conservative Approach to a Peripheral Ameloblastoma.

Peripheral Ameloblastoma (PA) is the rarest variant of ameloblastoma. It differs from the other subtypes of ameloblastoma in its localization: it arises in the soft tissues of the oral cavity coating the tooth bearing bones. Generally, it manifests nonaggressive behavior and it can be treated with complete removal by local conservative excision. In this study we report a case of PA of the maxilla in a 78-year-old female patient and we describe the four different histopathological patterns revealed by histological examination. After local excision and diagnosis, we planned a long term follow-up: in one year no recurrence had been reported. The choice of treatment is illustrated in Discussion.