Guided endodontic microsurgery in apicoectomy: a review.

The purpose of this review was twofold. The first aim was to show predictable protocols of guided endodontic microsurgery (EMS) and to describe its clinical outcomes. The second aim was to verify the accuracy of this technique compared to the traditional pathway. An electronic search of publications was established from two electronic databases, Cochrane and PubMed, by two independent researchers. The search strategy used a combination of controlled vocabulary and free-text words. Inclusion and exclusion criteria were defined by the authors before the start of the study. Inclusion criteria were: all studies published in English language; studies in vivo on humans; human cadaver studies; studies analyzing guided surgery in apicoectomy. The initial search yielded 67 citations, of which 10 were included. The studies included in this review analysis have shown two different technique both for digitization of dental arch and for surgical procedures too. Guided endodontic micro-surgery is a more predictable technique with less intra-operative and post-operative complications compared to the "freehand" technique and this procedure has shown a greater accuracy.

The health of soft tissues around four dental implants loaded immediately supporting a 4-year-old fixed screw-retained prosthesis.

The aim of this study was to assess the soft tissues health around the implant/abutment interfaces of fixed screw-retained prosthesis supported by four dental implants after at least 1-year in function. All the implants were placed between December 1, 2015 and April 30, 2019. Digital implant surgical planning was performed for all the complete-arch rehabilitations and then full-guided surgery was performed. The fixed-interim prostheses were delivered the day of the surgery and replaced by definitive prostheses after the healing period. Patients were followed-up to determinate peri-implant scores, such as Plaque Score (PS) and Bleeding on Probing (BoP). A total of 160 implants were placed in 37 patients, whereas 3 patients received both arches rehabilitated. A total of 40 complete-arch rehabilitations were performed, 26 in the maxilla and 14 in the mandible. Only 5 implants failed resulting in an overall implant survival rate of 96.9%. BoP was detected around 6 implants (3.7%) and 16 implants showed a superficial amount of plaque resulting a Plaque Score of 10%. Within the limitation of this study, it seems that the use of a fixed screw-retained prostheses supported by four dental implants to rehabilitate edentulous jaws could be a valid treatment option in the short and medium term without critical peri-implant issues. However, several perspective studies with longer follow-up are needed to achieve more predictable results.

Short implants (≤6mm) as an alternative treatment option to maxillary sinus lift.

The aim of this systematic review was to evaluate survival rate of short dental implants placed in the posterior area of the maxilla. The electronic literature search of studies published between January 1, 2010 and February 29, 2020 was performed using specific word combinations. The outcome was to meta-analyse the implant survival rate (ISR). The search generated 238 potential studies. After screening procedures, only nine randomized controlled trials fulfilled the inclusion criteria and were selected for qualitative and quantitative analysis. ISR of short implants ranged from 91.9% to 100%, while standard-length implants ISR ranged from 82.9% to 100% with a follow-up from 1 to 5 years in function. The risk ratio difference was 1.24 (95% confidence interval: 0.63-2.45, P=0.52) for short dental implants failure when compared with standard dental implants, and was not statistically significant. Based on the evidence of the included studies, short implants (≤6mm) reported high survival rates over short to medium follow-up in posterior maxilla, but the long-term success is as yet not demonstrated.

The effectiveness of subgingival irrigant ozone-based as adjuvant for non-surgical periodontal therapy in the treatment of chronic periodontitis: a review.

The aim of this review was to establish the efficacy of Ozone therapy (OT) in Periodontal disease's (PD) tratment. An electronic search of publications was established from two electronic databases: PubMed and Web of Science. The search strategy used a combination of controlled vocabulary and freetext words. Inclusion and exclusion criteria were defined by the authors before the start of the study. The inclusion criteria were: all studies published in English language; studies in vivo on humans; studies analyzing the correlation between PD and OT. The search resulted in 102 titles. Only 9 articles were included in the quantitative analysis. By the analyzed studies a strictly connection is still not evincible. More clinical trials are recommended to investigate the role of ozone, in its various types of topical administration, as a valid subgingival irrigant to achieve the goal of periodontal tissue health.

Application of the radiosurgery assisted gingival displacement technique in the aesthetic area: a case report.

The use of digital tools offers a new perspective to daily clinical activities even though sometimes different clinical approaches are necessary. This case report of a maxillary anterior rehabilitation demonstrates the application of a gingival displacement technique to enhance the recording of subgingival finish line by means of an intraoral optical scanner (IOS). The temporary restoration was used as a guide for the radiosurgery tip in order to displace the gingiva in a guided and mini-invasive approach. It was then possible to create the space between the tooth structure and the soft tissues for the light beam of the IOS to properly detect the finish lines of the dental preparation. Six single porcelain fused to zirconia crowns were delivered. This technique could be considered as a solution of complex cases with subgingival dental preparation to be detected by means of an IOS.

Radiosurgery in dentistry: a review.

The aim of the present study was to analyse the clinical potential of radiosurgery applied to modern dentistry through a revision of the indexed literature. Radiosurgery represents a recent form of electrosurgery working at a frequency of 3.0-4.0 MHz. The depth of penetration of the waves is inversely proportional to the frequency. Radiowaves working at high frequency express a lower penetration with a consequent lower tissue alteration. The authors analyzed the literature in order to give to the scientific community an overview of the possible applications of radiosurgery in the clinical dental practice and their effectiveness. Radiosurgery can be used in prosthodontics, in periodontal and implant surgery, in the treatment of trigeminal neuralgia, in the treatment of obstructive sleep apnea syndromes (OSAS) and in endodontics. Our analysis shows that although there are few articles in indixed literature on the applications of radiosurgery in dentistry, thanks to the benefits that derive from it, radiosurgery will spread more in the daily clinical practice of the dentists.

Influence of implant scanbody material and operator on scanning fluency and polygonal mesh numbers of digital impression: an in vitro study.

The purpose of this study is to evaluate the influence of implant scanbody (ISB) material and operator on scanning fluency and polygonal mesh numbers of a confocal microscopy intraoral scanning (IOS). An edentulous maxillary master model with 6 implant analogues was assembled. Thereafter 3 ISBs featured with same geometry but different materials (polyetheretherketone (PK), titanium (T) and PK with a titanium base (PKT)) were produce and scanned according to a randomized sequence by three different operators. The confocal microscopy IOS resulted in 45 STL test files that were processed to a dedicate software to obtain the request data. The overall analysis of fluency (imm/sec) showed the following results: mean 11.997 imm/sec, SD 2.355. The multivariate analysis showed statistical significance of material (p<.0001) and operator (p<.0001) influence. The univariate analysis referred to polygonal mesh numbers expressed the following results: mean 30327.8, SD 2432.5. The multivariate analysis stressed how there is a related effect to materials (p<.0001) and operator (p=0.0205). PKT represented the material with the best results for both. Analyzing the overall distribution histogram for scanning fluency, the IOS device seems to work with higher frequency at level of 13 imm/sec. The distribution of the measurements in the reference histograms showed an effect related to both variables referring to scanning fluency as well as to polygonal mesh numbers. Operator can be considered as a random effect; regarding the materials, the difference between PKT and PK can be related to the different base material. The dissimilar optical properties of T justify the different behavior.

The oxygen uptake slow component at submaximal intensities in breaststroke swimming.

The present work proposed to study the oxygen uptake slow component (VO2 SC) of breaststroke swimmers at four different intensities of submaximal exercise, via mathematical modeling of a multi-exponential function. The slow component (SC) was also assessed with two different fixed interval methods and the three methods were compared. Twelve male swimmers performed a test comprising four submaximal 300 m bouts at different intensities where all expired gases were collected breath by breath. Multi-exponential modeling showed values above 450 ml·min-1 of the SC in the two last bouts of exercise (those with intensities above the lactate threshold). A significant effect of the method that was used to calculate the VO2 SC was revealed. Higher mean values were observed when using mathematical modeling compared with the fixed interval 3rd min method (F=7.111; p=0.012; η2=0.587); furthermore, differences were detected among the two fixed interval methods. No significant relationship was found between the SC determined by any method and the blood lactate measured at each of the four exercise intensities. In addition, no significant association between the SC and peak oxygen uptake was found. It was concluded that in trained breaststroke swimmers, the presence of the VO2 SC may be observed at intensities above that corresponding to the 3.5 mM-1 threshold. Moreover, mathematical modeling of the oxygen uptake on-kinetics tended to show a higher slow component as compared to fixed interval methods.

Determinants of high-affinity binding and receptor activation in the N-terminus of CCL-19 (MIP-3 beta).

CC chemokine receptor 7 (CCR-7) is expressed on mature dendritic cells and T-cells. Its ligands, CCL-19 (MIP-3beta) and CCL-21 (SLC), play an important role in the migration of these cells to secondary lymphoid organs where they are predominantly expressed. For most chemokines, the N-terminal domain preceding the first two conserved cysteines is involved in stabilizing the active conformation of its cognate receptors. We have chemically synthesized N-terminal analogues of CCL-19 with the aid of a native chemical ligation method to investigate structure function requirements of this ligand domain by performing ligand binding, GTP-gammaS binding, and chemotaxis assays. Successive truncations of the N-terminus of CCL-19 reduced the affinity of the receptor for the ligand in a size-dependent manner. Furthermore, Ala substitutions of Asn(3), Asp(4), and Asp(7) show that the side chains of these residues are important for high-affinity binding of CCL-19 to CCR-7. The effects observed were mirrored in both GTP-gammaS binding and chemotaxis assays, highlighting the functional importance of this ligand domain. We also describe two partial agonists of CCR-7 ([Nle(72)]CCL-19(6-77) and Ac-[Nle(72)]CCL-19(7-77)), and identify the first analogue of CCL-19 (Ac-[Nle(72)]CCL-19(8-77)) that acts as a functional antagonist in vitro (K(B) approximately 350 nM for GTP-gammaS binding assays). As mutations of both Glu(6) and Asp(7) to Ala did not dissociate effects on ligand binding from receptor activation, it is likely that the backbone of these two residues is crucial for agonist activity.

Protein kinase C contributes to desensitization of ANG II signaling in adult rat cardiac fibroblasts.

We have studied G(q)-linked ANG II signaling [inositol phosphate (IP) accumulation, Ca(2+) mobilization] in primary cultures of rat cardiac fibroblasts (CFs) and have found that ANG II initiates a protein kinase C (PKC)-mediated negative feedback loop that rapidly terminates the ANG II response. Pharmacological inhibition of PKC by staurosporine and GF-109203X doubled IP production over that achieved in response to ANG II alone. Inhibition of PKC also led to larger Ca(2+) transients in response to ANG II, suggesting that Ca(2+) mobilization was proportional to G(q)-phospholipase C-IP(3) activity under the conditions studied. Depletion of cellular PKC by overnight treatment with phorbol 12-myristate 13-acetate (PMA) similarly augmented ANG II-induced IP production. Acute activation of PKC by PMA halved IP formation, with an EC(50) approximately 1 nM; 4alpha-PMA was inactive. Time course data demonstrated that ANG II-mediated IP production fully desensitized within 30 s; PKC inhibition reduced the rate and extent of this desensitization. In cells desensitized to ANG II, a purinergic agonist still mobilized intracellular Ca(2+), indicating that desensitization was homologous. The ANG II-induced Ca(2+) signal was fully resensitized within 30 min. The data demonstrate that a large portion of the IP-Ca(2+) responses of rat CFs to ANG II are short-lived because of rapid, PKC-mediated desensitization.

The chemokine fractalkine inhibits Fas-mediated cell death of brain microglia.

Fractalkine is a CX3C-family chemokine, highly and constitutively expressed on the neuronal cell surface, for which a clear CNS physiological function has yet to be determined. Its cognate receptor, CX3CR-1, is constitutively expressed on microglia, the brain-resident macrophages; however, these cells do not express fractalkine. We now show that treatment of microglia with fractalkine maintains cell survival and inhibits Fas ligand-induced cell death in vitro. Biochemical characterization indicates that this occurs via mechanisms that may include 1) activation of the phosphatidylinositol-3 kinase/protein kinase B pathway, resulting in phosphorylation and blockade of the proapoptotic functions of BAD; 2) up-regulation of the antiapoptotic protein Bcl-xL; and 3) inhibition of the cleavage of BH3-interacting domain death agonist (BID). The observation that fractalkine serves as a survival factor for primary microglia in part by modulating the protein levels and the phosphorylation status of Bcl-2 family proteins reveals a novel physiological role for chemokines. These results, therefore, suggest that the interaction between fractalkine and CX3CR-1 may play an important role in promoting and preserving microglial cell survival in the CNS.

[Report on surgical strategy in reoperation of esophageal achalasia]. / Cenni di strategia operatoria nei reinterventi per acalasia esofagea.

Surgical therapy for achalasia of the esophagus gives good results in only 80-90% of cases. Several reasons could be responsible for this 10-20% failure; the most frequent causes are inadequate cardiomyotomy and reflux esophagitis. We report our experience and our procedure in the management of recurrent achalasia. The most important controversies are also discussed.