The efficacy of the diode laser at 800-980 nm as an aid to non-surgical therapy in periodontitis treatment: a review of literature.

The aim of this literature review is to assess the effectiveness of diode laser at a wavelength of 800-980 nm in addition to non-surgical periodontal therapy in periodontitis treatment. The authors performed an electronic research on Pubmed inserting as keywords: (laser OR laser therapy OR diode laser) and (periodontitis OR periodontal disease). The field has been narrowed to select only Randomized controlled clinical trials (RCT) performed from 2010 to 2020. The result of this research was 84 articles, of which eight were included in the review because they respect the inclusion criteria. The clinical, immunological, and microbiological parameters studied in the various clinical random trials were analysed. It has been shown that four out of eight studies have achieved greater benefits, in terms of clinical parameters, with the use of diode laser compared to Scaling and Root Planing. However, the greater increase in clinical parameters in diode laser-treated patients compared to the control group was mainly detected in the short term rather than in the long term. In terms of microbiological parameters, no improvement was detected after six months. Only one study reported six-month improvements in immunological parameters in patients treated with DL compared to the Scaling and Root Planing only group. In conclusion, considering the limitations of this review of literature, there is no evidence that the diode laser at 800-980 nm in addition to non-surgical periodontal therapy is more effective than SRP alone in the long term.

Role of mast cells in oral inflammation.

Mast cells play important roles in the maintenance of many physiological functions as well as in the pathophysiology of diseases. Mast cells are involved in the inflammatory mechanisms of many systemic diseases. In this pandemic period, their role in physiological and pathological host inflammatory reactions in tissue disruption following SARS-CoV-2 infection has been stressed. A review of the literature was carried out by entering the key words "Mast Cells" AND "Oral Diseases" AND "Role of Mast Cells in Periodontitis". The results show us that mast cells are definitely involved in many oral diseases including periodontitis. Further in vivo and in vitro studies are needed to further investigate the specific role of the cells in physiological and pathological inflammation.

Comparison of hygiene levels in metal-ceramic and stratified zirconia in prosthetic rehabilitation on teeth and implants: a retrospective clinical study of a three-year follow-up.

The aim of this retrospective clinical study was to evaluate and compare oral hygiene levels in patients subjected to fixed metal-ceramic or stratified zirconia prostheses, either on teeth or on dental implants. Twenty patients, including 10 with metal-ceramic prostheses and 10 with stratified zirconia, were engaged for the study. Considering the prosthesis positioning phase as zero time, all patients were examined twice a year for a follow-up period of 3 years. During each session, to assess oral cavity state of health, both the Plaque Index (IP) and the Bleeding Index (BOP) were recorded. All patients were instructed in home hygiene maintenance and subjected to professional oral hygiene sessions customized according to prothesis type (on natural teeth or dental implants) and materials (metal ceramic or stratified zirconia). Statistically significant evidence was found in IP values, with an increase in the initial stages in zirconia prostheses and in the final stages in metal-ceramic ones. BOP levels showed a reduction during the follow-up period, but no statistically significant differences were found between examined groups. An adequate patient education in hygiene maintenance associated with professional oral hygiene sessions with special tools could positively affect fixed prostheses' maintenance, both on natural teeth and on dental implants.

How to consider implant-prosthetic rehabilitation in elderly patients: a narrative review.

With the beginning of the twenty-first century, population aging has emerged as a major worldwide phenomenon. The dentist must respond to this demographic change by taking into consideration the possibility of restoring oral function in the elderly patient with the use of dental implants. This article aims to provide a narrative review of the literature regarding the implant survival rate in geriatric patients and the relative importance and advantages of implant-prosthetic rehabilitation through a scientific analysis of the literature through online databases and dental journals. Tooth loss can have a significant impact on patients' oral function and significantly affects quality of life, self-esteem, and nutritional status. Although many studies in the past have reported that implant success is age-dependent, more recent studies suggest that they are safe and predictable for geriatric patients, improving quality of life, with similar results to those of younger age groups. Advanced age does not necessarily represent a contraindication for implant placement and osseointegration and success is influenced by patient and site-specific factors. Aging is a process that affects each patient differently, consequently, there should be a specific therapeutic approach for everyone, which must consider the functional and cognitive status of the patient, his medical condition, and his social situation-economic and motivational.

Anti-discoloration system: a new chlorhexidine mouthwash.

Chlorhexidine is defined as biocompatible, which is why it is used as a mouthrinse for the patient before starting dental procedures (2). It has the ability to bind well to teeth and mucous membranes and is released for twelve hours, which is why it is used as a treatment for gingivitis and also in post-operative wound healing. The long-term side effects of chlorhexidine are pigmentations. To remedy this, various types of antidiscoloration have been tried out over time. Nowadays there are other types of anti-discoloration systems such as, for example, in our study we used a test group containing an anti-discoloration system called SPPD. A single-center, prospective, double-blind randomized clinical trial on 84 patients. The investigated treatments consisted of 4 mouthwashes (CHX 0.12% SPDD alcohol free; CHX 0.20% SPDD alcohol free; CHX 0.12% alcohol free with ADS; CHX 0.20% alcohol free with ADS). Despite the limitations of the study, all the mouthwashes tested showed good efficacy in reducing the amount of plaque. Comparing the two experimental concentrations (0.12% and 0.20%) tested here demonstrates that the 0.20% chlorhexidine concentration slightly surpasses its 0.12% equivalent with regard to the PI and BI parameters. The SPDD is an innovative anti-discoloration system and gives the mouthwash a great taste.

Frequent and Persistent Salivary Gland Ectasia and Oral Disease After COVID-19.

The clinical picture of coronavirus disease 2019 (COVID-19) in various target organs has been extensively studied and described. However, relatively little is known about the characteristics of oral cavity involvement. This is surprising, considering that oral mucosal and salivary gland cells are known targets for the direct replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and that the presence of the virus in saliva is a source of transmission of the infection. The aim of our study was to investigate the presence and prevalence of oral manifestations in COVID-19 survivors. We profiled the oral involvement in 122 COVID-19 survivors that were hospitalized and followed up at a single-referral university hospital in Milan, Italy, between July 23, 2020 and September 7, 2020, after a median (interquartile range) time from hospital discharge of 104 (95 to 132) d. We found that oral manifestations, specifically salivary gland ectasia, were unexpectedly common, with oral manifestations being detected in 83.9% while salivary gland ectasia in 43% of COVID-19 survivors. Salivary gland ectasia reflected the hyperinflammatory response to SARS-CoV-2, as demonstrated by the significant relationship with C-reactive protein (CRP) and lactate dehydrogenase (LDH) levels at hospital admission, and with the use of antibiotics during acute disease. Both LDH levels and antibiotic administration survived as independent predictors of salivary gland ectasia at multivariable analysis. Temporomandibular joint abnormalities, facial pain, and masticatory muscle weakness were also common. Overall, this retrospective and prospective cohort study of COVID-19 survivors revealed that residual damage of the oral cavity persists in the vast majority of patients far beyond clinical recovery, and suggests that the oral cavity represents a preferential target for SARS-CoV-2 infection. Further studies are needed to clarify the connection between SARS-CoV-2 infection and oral disorders.

Role of induced pluripotent stem cells (IPSCS) in bone tissue regeneration in dentistry: a narrative review.

Several conditions as trauma, cancer surgical resection, fractures, congenital malformations and periodontitis could bring alveolar bone defects. To avoid more invasive and less predictable regenerative procedures, Stem cells of different origins as pluripotent Embryonic Stem Cells (ESCs), undifferentiated multipotent Mesenchymal Stem Cells (MSCs) and Induced Pluripotent Stem Cells (iPSCs) were proposed as possible alternative. IPSCs have potential for proliferation and differentiate into all derivatives of the three primary germ layers: ectoderm, endoderm and mesoderm. According with their ability to involve in several cells type, Induced Pluripotent Stem Cells (iPSCs) could be proposed as alternative in regeneration either of mineralized tooth components or supporting tissue. The aim of this brief review is to describe clinical applications of Induced Pluripotent Stem Cells (iPSCs) in oral bone regeneration to employ their use in tissue regeneration in dentistry.

The smokeless tobacco: a survey in a cohort of young Italians through a social-media questionnaire.

This observational survey aimed to demonstrate the use of the Snus kind of smokeless tobacco, among young Italian adults from alpine areas. A customized anonymous questionnaire was purposely created using the Google Forms platform and made it available for 4 weeks through social media supports to a cohort of young adults living in a mountain area in Italy. Out of four hundred recipients, 332 interviewees returned the survey. Participants had a mean age of 22.8, range 17-40 years. One hundred fifty regular consumers used Snus for more than 5 years. Gingival changes were reported in 92 subjects, associated with gingival bleeding in 14 subjects. 79 subjects reported discoloration of the mucosa. The 50% of the habitual users developed an addiction to Snus and 90% didn't smoke conventional cigarettes. In Italian young adults the use of Snus tobacco could be an adjunctive risk factor for the oral mucosa. It is essential to extend and spread the awareness about this addictive habit among dental professionals, to give to the patients a reliable and effective oral and systemic education.

Palatal prosthetic rehabilitation in patients affected by cocaine-induced midline destructive lesions.

Cocaine is one of the most popular illicit drugs in Europe and cocaine-induced midline destructive lesions (CIMDL) represent a rare but destructive consequence of its intranasal use. The extent of lesions can vary remarkably and may include palate perforations with consequent oronasal reflux and hypernasal speech. The therapeutic options encompass surgery, with local and distant flaps, and prosthetic rehabilitation with palatal obturators. We retrospectively reviewed a case series of 6 patients affected by palatal perforation as part of CIMDL, who were treated with a dental or implant-retained palatal obturator at San Raffaele Dentistry Department between 2015 and 2020. In addition, we reviewed the available literature on CIMDL and the prosthetic rehabilitation of palatal perforations in this context. The most frequent symptoms reported were hypernasal speech, oro-nasal reflux, halitosis, and difficulty in interpersonal relationships. Palatal obturators were always successful in the relief of the majority of symptoms, but the duration of the benefit was strongly related to progression of the lesion, and in some cases a close follow-up and continuous modifications of the prosthesis were necessary. In conclusion prosthetic approach is a valid option for the symptomatic relief in CIMDL-related palate perforation. Nevertheless, the short-lasting efficacy for patients with active disease can be the reason for unsatisfactory results.

Management of the delicate phase of the temporary crown: an in vitro study.

The fundamental moment of prosthetic rehabilitation is the "temporary". Although the meaning of the term diminishes its importance, the provisional has fundamental biological, aesthetic and functional functions. The oral cavity must maintain an adequate level of oral hygiene to carry out this delicate phase in the best possible way; a result achieved only with the collaboration of the prosthetic dentist with the hygienist and the patient, as if they were a biological system in motion. The different methods of hygiene are effective in maintaining a good level of oral health; but they could, if too aggressive, affect the prosthetic restoration. Our objective in vitro is to understand, after applying a known bacterial load, which hygiene method is the most effective in removing bacterial biofilm but at the same time is less aggressive towards resinous material.

The association between minor recurrent aphthous stomatitis (RAS), children's poor oral condition, and underlying negative psychosocial habits and attitudes towards oral hygiene.

BACKGROUND: Minor Recurrent Aphthous Stomatitis (RAS) represents a disease which is very difficult to prevent. This case-control study focused on possible associations between minor Recurrent Aphthous Stomatitis in children, their oral health, and underlying behavioral indexes of children's attitudes and habits pertaining to (home) oral hygiene, with the further goal of enabling the dentist to prevent these specific kind of lesions, both from a clinical and a broader psychosocial perspective. METHODS: Four hundred one school-children (5-10 years old) in Milan (Italy) were submitted to an intra-oral examination, and interviewed with the aid of a brief psychosocial questionnaire. RESULTS: At the clinical level, statistically significant associations were observed between the presence of decayed teeth and minor Recurrent Aphthous Stomatitis (Odds Ratio: 3.15; 95% CI: lower limit 1.06; upper limit: 9.36; Z-test: 2.07, p = 0.039; Chi-square = 4.71, p = 0.030), and between the Decayed Missing or Filled Teeth (DMFT) index and minor aphthous stomatitis (Odds Ratio: 3.30; 95% CI: lower limit 1.13; upper limit: 9.67; Z-test = 2.18, p = 0.029; Chi-square = 5.27; p = 0.022), both results pointing to a significant increase-by circa 3 times-in the risk of developing minor Recurrent Aphthous Stomatitis in children exposed to the two above-identified factors (i.e., the presence of decayed teeth and a clearly compromised oral condition, as signaled by the DMFT index), if compared with the risk run by their non-exposed counterparts. At the psychosocial level of analysis, statistically significant associations were observed (1) between children's practice of spontaneously brushing teeth when not at home and a comparatively lower (i.e. better) Decayed Missing or Filled Teeth index (Chi-square: 8.95; p = 0.011), and (2) between receiving parental aid (e.g., proper brushing instructions) while practicing home oral hygiene and a significantly reduced presence of decayed teeth (Chi-square = 5.40; p = .067; Spearman's Rho, p = .038). Further, significant associations were also observed between children's reported severity of dental pain and both (a) the presence of decayed teeth (Chi-square = 10.80; p = 0.011), and (b) children's (poor) oral health condition as expressed by the Decayed Missing or Filled Teeth index (Chi-square = 6.29; p = 0.043). Interestingly, specific lifestyles and social status, showed no systematic association to other clinical or psychological/psychosocial indices. CONCLUSIONS: These systematic relations suggest that, in the presence of Recurrent Aphthous Stomatitis in pediatric patients, the dentist should carefully monitor children for potential carious lesions, implement protocols of prevention to control Recurrent Aphthous Stomatitis disease in children affected by caries, and also be particularly aware of the right or wrong habits children may acquire in the course of continued social exchange with their caregivers and peers.

Non-linear eigensolver-based alternative to traditional SCF methods.

The self-consistent procedure in electronic structure calculations is revisited using a highly efficient and robust algorithm for solving the non-linear eigenvector problem, i.e., H({ψ})ψ = Eψ. This new scheme is derived from a generalization of the FEAST eigenvalue algorithm to account for the non-linearity of the Hamiltonian with the occupied eigenvectors. Using a series of numerical examples and the density functional theory-Kohn/Sham model, it will be shown that our approach can outperform the traditional SCF mixing-scheme techniques by providing a higher converge rate, convergence to the correct solution regardless of the choice of the initial guess, and a significant reduction of the eigenvalue solve time in simulations.

Adjunctive effect of chlorhexidine antiseptics in mechanical periodontal treatment: first results of a preliminary case series.

OBJECTIVES: The aim of the present case series was to evaluate the clinical and microbiological effects of a single session of mechanical and manual scaling and root planing (SRP) combined with the use of two different chlorhexidine formulations in the treatment for generalized chronic periodontitis. METHODS: Ten patients affected by chronic periodontal disease with periodontal probing depth (PPD) ≥ 5 mm were treated with SRP plus local chlorhexidine. In each patient, similar teeth, treated with SRP with the adjunctive use of chlorhexidine digluconate and dihydrochloride or chlorhexidine gluconate, respectively, were selected and assigned to a test and a control group. In both groups, PPD, bleeding on probing (BOP) parameters, total bacterial counts (TBC) and quality of periodontal bacteria at time 0 and 6 weeks after treatment were measured. RESULTS: PPD significantly decreased over time both in the test and in the control group; however, no significant differences between the two groups were observed. BOP and TBC were significantly lower in the test than in the control group 6 weeks after treatment. In the post-treatment revaluation, a significant decrease both in the treatment and in the control group, for each of the single periodontal pathogens, was observed. CONCLUSION: In this study--a preliminary case series with small sample size and short follow-up--the adjunctive use of chlorhexidine (CHX) to SRP resulted in clinical and microbiological benefits in the treatment for generalized chronic periodontitis. A CHX gel formulation consisting of CHX digluconate and CHX dihydrochloride seems to lead some additional benefits over SRP plus CHX gluconate in the short term. Additional investigations are needed to evaluate the effectiveness of this antiseptic therapy.

Evidence that muscle cells do not express the histidine-rich glycoprotein associated with AMP deaminase but can internalise the plasma protein.

Histidine-rich glycoprotein (HRG) is synthesized by liver and is present at relatively high concentration in the plasma of vertebrates. We have previously described the association of a HRG-like molecule to purified rabbit skeletal muscle AMP deaminase (AMPD). We also provided the first evidence for the presence of a HRG-like protein in human skeletal muscle where a positive correlation between HRG content and total determined AMPD activity has been shown. In the present paper we investigate the origin of skeletal muscle HRG. The screening of a human skeletal muscle cDNA expression library using an anti-HRG antibody failed to reveal any positive clone. The RT-PCR analysis, performed on human skeletal muscle RNA as well as on RNA from the rhabdomyosarcoma (RD) cell line, failed to show any mRNA specific for the plasma HRG or for the putative muscle variant. When the RD cells were incubated with human plasma HRG, a time-dependent increase of the HRG immunoreactivity was detected both at the plasma membrane level and intracellularly. The internalisation of HRG was inhibited by the addition of heparin. The above data strongly suggest that skeletal muscle cells do not synthesize the muscle variant of HRG but instead can actively internalise it from plasma.

Characterization, evolution and chromosomal distribution of two satellite DNA sequence families in Lathyrus species.

DNA clones containing highly repetitive DNA sequences were selected from partial libraries of Lathyrus sativus and L. sylvestris. Two satellite DNA sequence families were isolated from the genome of the former species. A first family was made up of repeats that varied in length from 54-56 bp, and shared 51.7-94.8% nucleotide sequence similarity. The repeats of the second sequence family were 52-62 bp in length, and shared a 58.5-78.5% nucleotide sequence similarity. All the repeat units contained in a clone from L. sylvestris were 41 bp in length and showed an almost perfect structural conservation (95.1-100% nucleotide sequence similarity). The evolution of the first sequence family from L. sativus and of that isolated from L. sylvestris was studied by dot-blot hybridization to the genomic DNA of these species and 3 other Lathyrus species, L. clymenum, L. latifolius and L. odoratus. The former repeats were found to be species-specific and their redundancy was calculated to be 2.9 x 10(7). The satellite DNA sequence isolated from L. sylvestris was present also in L.latifolius, with a redundancy of 1.4 x 10(7) and 1.1 x 10(7), respectively. Fluorescent in situ hybridization (FISH) was used to investigate the chromosomal distribution of the two sequence families and of 45S and 5S ribosomal genes. The species-specific sequences of L. sativus were located around the centromere of chromosome pair IV, where they occupied a very broad region, and, in a much smaller amount, close to the centromere in the short arm of pair II. Sequences related to the repeat units isolated from L. sylvestris were found, both in this species and L. latifolius, in all of the chromosome pairs at terminal and interstitial regions, where they co-localize with the vast majority of DAPI bands. The pattern of distribution of the satellite DNA sequences investigated, together with that of DAPI bands and ribosomal DNA, allowed each chromosome pair of the 3 complements studied to be identified unambiguously.

A self-consistent transport model for molecular conduction based on extended Hückel theory with full three-dimensional electrostatics.

We present a transport model for molecular conduction involving an extended Hückel theoretical treatment of the molecular chemistry combined with a nonequilibrium Green's function treatment of quantum transport. The self-consistent potential is approximated by CNDO (complete neglect of differential overlap) method and the electrostatic effects of metallic leads (bias and image charges) are included through a three-dimensional finite element method. This allows us to capture spatial details of the electrostatic potential profile, including effects of charging, screening, and complicated electrode configurations employing only a single adjustable parameter to locate the Fermi energy. As this model is based on semiempirical methods it is computationally inexpensive and flexible compared to ab initio models, yet at the same time it is able to capture salient qualitative features as well as several relevant quantitative details of transport. We apply our model to investigate recent experimental data on alkane dithiol molecules obtained in a nanopore setup. We also present a comparison study of single molecule transistors and identify electronic properties that control their performance.

Role of stress-activated mitogen-activated protein kinase (p38) in beta 2-integrin-dependent neutrophil adhesion and the adhesion-dependent oxidative burst.

Bacterial LPS elicits both rapid activation of the stress-activated MAP kinase p38 in polymorphonuclear leukocytes (PMN) and rapid adhesion of the PMN to ligands for the leukocyte integrin CD11b/CD18. The functional correlation between these two events was examined. The time course for tyrosine phosphorylation of p38 in PMN in response to 10 ng/ml LPS in 1% normal human serum was consistent with participation in signaling for leukocyte integrin-dependent adhesion, with transient phosphorylation peaking at 10 to 20 min. The concentration dependence of p38 phosphorylation also resembled that for PMN adhesion, with <1 ng/ml LPS eliciting a response. Phosphorylation was inhibited by mAb 60b against CD14, but not by mAb 26ic, a nonblocking anti-CD14. The function of p38 in integrin-dependent adhesion and the adhesion-dependent oxidative burst was tested using a specific inhibitor of p38, SB203580. SB203580 inhibited adhesion by diminishing the initial rate of adherence in response to both LPS and TNF, with a half-maximal concentration in the range of 0.1 to 0.6 microM. It did not, however, block adhesion in response to formyl peptide or PMA. The p38 inhibitor also blocked the adhesion-dependent oxidative burst with a half-maximal concentration similar to that for adhesion. Timed delivery of the compound during the lag phase preceding H2O2 production suggested that p38 kinase activity was required throughout the lag but not after the oxidase was assembled. These results suggest that p38 functions in PMN to signal leukocyte integrin-dependent adhesion and the subsequent massive production of reactive oxygen intermediates.

Variation of repetitive DNA sequences in progenies of regenerated plants of Pisum sativum.

The frequency variation of highly repeated (HR) DNA sequences was studied in plants regenerated through in vitro culture of macerated vegetative apices of Pisum sativum and their progenies. Feulgen cytophotometry showed that regenerated plants (R1) have 6-7% more DNA per nucleus than control plants; this difference is maintained in the subsequent generation (R2). Slot-blot analyses using isolated highly repeated sequences as probe indicated that an increased frequency of these sequences occurs in regenerated plants and their progenies. These results were confirmed by a series of experiments: (a) metaphase chromosomes were longer in R2 than in control plants; (b) cytophotometric analyses of chromatin structure after Feulgen-staining showed that condensed chromatin is more represented in R2 than in control plants; and (c) thermal denaturation of isolated HR sequences indicated that a new HR family appears in R1 and is maintained in R2 plants. These results suggest that, in this species, the DNA extrasynthesized during in vitro culture is, at least in part, integrated in the chromosomes and transmitted to the progeny.

Cytophotometric determination of heterochromatin base composition in interphase nuclei of plant cells.

The use of DNA base-specific fluorochromes and static cytophotometry at different thresholds of fluorescence intensity is proposed for studying the base composition of differently condensed chromatin fractions in plant interphase nuclei. Results are reported of such analyses on nuclei from leaflets of Posidonia oceanica and Helianthus annuus, which confirm other findings obtained on the same materials by biochemical and molecular methods.