Use of electrical field for biofilm implant removal

OBJECTIVE

New methods for biofilm removal are being investigated. A recent new one involves the use of the electric field for biofilm removal. In particular, electrolytic cleaning works on the adhesion forces of the biofilm on the surfaces, with few studies showing promising results in decontamination and implant re-integration in the bone. This study aims at assessing the effect of a new decontamination device that implies the electric field for implant-biofilm removal.

MATERIALS AND METHODS

Three implants affected by peri-implantitis were selected for the study. After the treatment, the implants were observed by the Scanning Electron Microscopy.

RESULTS

All three samples showed no microbial biofilm in the application area, while the rest of the surface observed was covered with microbial biofilm, with an intensely thickened bacterial population.

CONCLUSIONS

Peri-mucositis and peri-implantitis prevention and early treatments are essential for implant maintenance, thus saving the surrounding hard and soft tissues. The technological innovation is providing electrolytic devices which act not only on the microbial population but on the biofilm adhesion to the implant surface, with promising results for a new and valid therapeutic option.

Soft tissue augmentation by means of silicon expanders prior to bone volume increase: a case series

In guided bone regeneration (GBR) interventions, the incorrect manipulation of the soft tissues may lead to exposure of graft due to insufficient amount of tissue needed for a free-tension flap closure. The aim of this investigation was to evaluate the clinical and radiographical effectiveness of soft tissue augmentation in aesthetic areas. A total of 6 patients were treated in the Department of Medical, Oral and Biotechnological Sciences, University "G. D'Annunzio" of Chieti-Pescara, with a radiographical follow-up at 1 year from the loading. At the follow up, no soft tissue dehiscence was observed This study presented an innovative approach for soft tissue augmentation prior to bone regeneration in aesthetic areas. Augmentation of soft tissue with a silicon expander device before bone regeneration is a simple technique and also allows to obtain greater bone tissue in selective cases.

Add-on peginterferon alfa-2a to nucleos(t)ide analogue therapy for Caucasian patients with hepatitis B 'e' antigen-negative chronic hepatitis B genotype D

Nucleos(t)ide analogues (NAs) and peginterferon have complementary effects in chronic hepatitis B, but it is unclear whether combination therapy improves responses in genotype D-infected patients. We conducted an open-label study of peginterferon alfa-2a 180 μg/wk added to ongoing NA therapy in hepatitis B e antigen (HBeAg)-negative, genotype D-infected patients with hepatitis B virus DNA <20 IU/mL. The primary endpoint was proportion of patients with ≥50% decline in serum HBsAg by the end of the 48-week add-on phase. Seventy patients received treatment, 11 were withdrawn at week 24 for no decrease in HBsAg, and 14 withdrew for other reasons. Response rate (per-protocol population) was 67.4% (29/43) at week 48 (95% confidence interval [CI]: 51, 81) and 50.9% (28/55) at week 96 (95% CI: 38, 66). Median serum HBsAg decreased throughout peginterferon alfa-2a treatment and was significantly lower than baseline at weeks 48, 72 and 96 (P < 0.001). Decreases in HBsAg of ≥0.5-log₁₀ and ≥1-log₁₀ were documented in 19 (44.2%) and 6 (14.0%) patients at week 48 and 6 (10.9%) and 17 (30.9%) patients at week 96. The proportion of patients with HBsAg <1000, <500, <100 and <10 IU/mL at ≥1 timepoint during treatment was 78.6% (n = 44), 57.1% (n = 32), 21.4% (n = 12) and 7.1% (n = 4). Interferon gamma-induced protein 10 increased from baseline up to week 48, with week 12 levels significantly associated with response at week 48. Addition of peginterferon alfa-2a to ongoing NA therapy significantly decreased HBsAg levels in HBeAg-negative patients with genotype D infection (ClinicalTrials.gov NCT01706575).

The effects of surgical preparation techniques and implant macro-geometry on primary stability: An in vitro study

Background

The attainment of a good primary stability is a necessary condition to ensure the success of osseointegration in implantology. In type IV cancellous bone, however, it is possible that a reduced primary stability can lead to an increased rate of failure. The aim of this study was therefore to determine, with the help of the resonance frequency (Osstell mentor), which technique of implant site preparation (piezo surgery, conventional, under-preparation, bone compaction, osteodistraction) and macro-geometry is able to improve implant stability in type IV cancellous bone.

Material and Methods

10 pig ribs were prepared with a surgical pre-drilled guide, calibrated for a correct implant positioning. On each rib, 5 implant sites (one for each technique) were prepared. Successively, 50 conical implants (Tekka Global D) were inserted and measured with the resonance frequency to evaluate the primary stability. Data collected were analyzed by analysis of variance (ANOVA) to test whether the Implant Stability Quotient (ISQ) values of the five techniques were significantly different.

Results

The results showed that no significant differences among the ISQ values of the five techniques used were found. Also, no significant differences in the macro-geometry of the two types of compared implants were observed. However, the macro-geometry of Tekka implants, characterized by a double condensing thread, seems to provide greater ISQ values than those of single thread implants when using the same technique.

Conclusions

In light of these preliminary data, it is conceivable that in cases of reduced stability, such as those occurring with a type IV bone, all means ameliorating the primary stability and accelerating the osseointegration can be utilized.

Key words:Implant primary stability, resonance frequency analysis, implant site preparation.

"All on short" prosthetic-implant supported rehabilitations

Objectives

Short implants are increasing their popularity among clinicians who want to fulfill the constant demanding of fixed prosthetic solutions in edentulous jaws. The aim of this report was to propose a new possibility to project and realize an occlusal guided implant cross-arch prosthesis supported by ultra-short implants, describing it presented an edentulous mandible case report.

Methods

A 61-year-old, Caucasian, female patient who attended the dental clinic of the University of L'Aquila presented with edentulous posterior inferior jaw and periodontitis and periimplantitis processes in the anterior mandible. The remaining tooth and the affected implant were removed. Six 4-mm-long implants were placed to support a cross-arch metal-resin prosthesis.

Results

At 1-year follow-up clinical and radiological assessment showed a good osseointegration of the fixtures and the patient was satisfied with the prosthesis solution.

Conclusion

The method, even if it requires further validation, seems to be a valid aid in solving lower edentulous clinical cases, and appears less complex and with more indications of other proposals presented in the current clinical literature. Our case report differs from the current technique All-on-Four, which uses four implants in the mandible to support over-denture prosthesis, assuring a very promising clinical result.

Behaviour of dental pulp stem cells on different types of innovative mesoporous and nanoporous silicon scaffolds with different functionalizations of the surfaces

Dental pulp stem cells (DPSCs) are stem cells found in the dental pulp. The ability of DPSCs to differentiate towards odontoblastic and osteoblastic phenotype was reported first in the literature, then in the following years, numerous studies on odontogenesis were carried out, starting from mesenchymal stem cells isolated from tissues of dental and oral origin. The aim of this research was to evaluate the behaviour of DPSCs grown on silicon nanoporous and mesoporous matrices and differentiated towards the osteogenic phenotype, but also to investigate the use of DPSCs in pilot studies focused on the biological compatibility of innovative dental biomaterials. Twenty-eight silicon samples were created with standardized procedures. These scaffolds were divided into samples made of silicon bulk, nanoporous silicon, mesoporous silicon, nanoporous silicon functionalized with (3-Aminopropyl) Trimethoxysilane (APTMS) and methanol (MeOH), nanoporous silicon functionalized with (3-Aminopropyl) Trimethoxysilane (APTMS)/toluene, mesoporous silicon functionalized with (3-Aminopropyl) Trimethoxysilane (APTMS) and methanol (MeOH) andmesoporous silicon functionalized with (3-Aminopropyl) Trimethoxysilane (APTMS)/toluene. DPSC proliferation on the tested silicon scaffolds was analyzed at 3 and 5 days. The assay showed that DPSCs proliferated better on mesoporous scaffolds functionalized with APTMS/toluene compared to a silicon one. These results show that the functionalization of silicon scaffold with APTMS/toluene supports the growth of DPSCs and could be used for future applications in tissue engineering.

DENTAL PULP STEM CELLS AND HUMAN PERIAPICAL CYST MESENCHYMAL STEM CELLS IN BONE TISSUE REGENERATION: COMPARISON OF BASAL AND OSTEOGENIC DIFFERENTIATED GENE EXPRESSION OF A NEWLY DISCOVERED MESENCHYMAL STEM CELL LINEAGE

Bone regeneration is an interesting field of biomedicine. The most recent studies are aimed to achieve a bone regeneration using mesenchymal stem cells (MSCs) taken from more accessible sites: oral and dental tissues have been widely investigated as a rich accessible source of MSCs. Dental Pulp Stem Cells (DPSCs) and human Periapical Cysts Mesenchymal Stem Cells (hPCy-MSCs) represent the new generation MSCs. The aim of this study is to compare the gene expression of these two innovative cell types to highlight the advantages of their use in bone regeneration. The harvesting, culturing and differentiating of cells isolated from dental pulp as well as from periapical cystic tissue were carried out as described in previously published reports. qRT-PCR analyses were performed on osteogenic genes in undifferentiated and osteogenic differentiated cells of DPSC and hPCy-MSC lineage. Real-time RT-PCR data suggested that both DPSCs and hPCy-MSCs cultured in osteogenic media are able to differentiate into osteoblast/odontoblast-like cells: however, some differences indicated that DPSCs seem to be directed more towards dentinogenesis, while hPCy-MSCs seem to be directed more towards osteogenesis.

Comparison between PRP, PRGF and PRF: lights and shadows in three similar but different protocols

OBJECTIVE

The main goal of the modern surgery is to get a low invasiveness and a high rate of clinical healing: in the last years, it has been introduced the concept of a "regenerative surgery", and many techniques has been widely described in the literature. The most used are PRP, PRGF and PRF techniques. Aim of this research is to compare the three protocol of PRP, PRF and PRGF in their essential features, so to suggest to the practitioners the best blood product to use in the regenerative surgery.

DISCUSSION AND CONCLUSIONS

Among the advantages that shows the PRF, compared to PRP and PRGF, we can cite a greater simplicity of production for the absence of manipulation that leads to a reduced possibility of alteration of the protocol due to an error of the operator. The special texture of the PRF and its biological features shows clearly an interesting surgical versatility and all the characteristics that can support a faster tissues regeneration and high-quality clinical outcomes.

Transdermal penetration of diclofenac after multiple epicutaneous administration

OBJECTIVE

To test whether therapeutic diclofenac concentrations are attained in skeletal muscle tissue beneath the application site of an epicutaneously administered diclofenac foam formulation.

METHODS

Diclofenac foam (5%) was administered epicutaneously at the thigh 80 mg/200 cm2 twice daily for a period of 7 days in healthy volunteers (n=12). On Day 8, 2 microdialysis probes were inserted into skeletal muscle tissue beneath the application site and an 80 mg dose was administered epicutaneously. Concentration versus time profiles in plasma and skeletal muscle were followed for 10 hours.

RESULTS

Concentration versus time profiles were obtained for plasma and interstitial muscle fluid in all experiments. Mean Cmax in plasma was 18.75+/-4.97 ng/ml. Corresponding interstitial concentrations in skeletal muscle were significantly higher, 219.68+/-66.36 ng/ml (p=0.01). Plasma concentrations were not correlated to tissue concentrations (r=-0.08).

CONCLUSION

There is significant direct penetration of diclofenac into skeletal muscle following multiple epicutaneous administration. However, the concentration attained in individual subjects is not predictable and may be strongly influenced by individual skin properties.