Involvement of the endocannabinoid system in current and recurrent periodontitis: A human study.

OBJECTIVE: The aim of the present study was to assess if the endocannabinoid system is involved differently in patients with recurrent and non-recurrent periodontal disease and if in sites that have a predisposition for reactivation, levels of anandamide (AEA) change after periodontal therapy. BACKGROUND: Periodontal disease (PD) may be due to a dysregulation of the endocannabinoid system. METHODS: Periodontal patients were recruited, treated for PD and monitored. Gingival samples from these patients with recurrent (n = 10) and non-recurrent (n = 10) periodontal disease were harvested before and after treatment and compared to those of periodontally healthy (n = 10) subjects. Levels of CB1 and CB2, AEA and CBs receptor activation were assessed in healthy and inflamed samples using immunohistochemistry, chromatography and autoradiography. In healed sites, AEA levels were also assessed. RESULTS: The number of CBs in inflamed sites of recurrent patients was significantly higher than in those with non-recurrent disease and also higher than those in healthy subjects. Inflamed sites of recurrent patients had significantly lower CBs receptor activation than those of healthy subjects. Levels of AEA in inflamed sites of non-recurrent patients were significantly higher than those found both in inflamed recurrent sites and in healthy sites. Otherwise, the amount of AEA in healthy subjects and recurrent inflamed sites was similar. After periodontal therapy, levels of AEA were significantly lower in both periodontal groups. In recurrent sites, they resulted significantly lower than in non-recurrent and even in healthy subjects. CONCLUSIONS: The endocannabinoid system seems involved differently in subjects with recurrent and non-recurrent periodontal disease.

Tamoxifen improves homeostasis in the peri-implant bone remodeling of osseointegrated titanium implants.

BACKGROUND: The purpose of this preclinical study was to evaluate the influence of tamoxifen (TAM) on the peri-implant bone remodeling of osseointegrated titanium implants in ovariectomized female rats. MATERIALS AND METHODS: Seventy-two female rats underwent bilateral ovariectomy 20 weeks before implants placement. One titanium implant was inserted in each tibia of the animals. Six weeks following the implant surgery, animals were randomly divided into two experimental groups (n = 36), which received either saline solution (SS) or tamoxifen citrate (TAM) via gavage until euthanasia. Euthanasia was performed at 30, 60, and 90 days after the first gavage. Assessments of bone to implant contact (BIC), bone ingrowth percentage (BIN), morphological description of cellular and tissue reactions, immunohistochemistry for the detection of bone morphogenetic protein 2/4 (BMP2/4), runt-related transcription factor 2 (RUNX-2), osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP), and bone chemical composition through scanning electron microscopy with energy-dispersive x-ray spectroscopy were performed. RESULTS: Tamoxifen group presented higher BIC, higher BIN, higher RUNX-2 and OCN, lower TRAP-positive cells/mm2 , and no differences regarding BMP-2/4 positive cells/mm2 than SS group in all periods. TAM group also showed higher Ca/P rate than SS group. CONCLUSION: Tamoxifen enhanced the remodeling of the bone surrounding titanium implants in ovariectomized rats.

Quantitative Evaluation of Inflammatory Markers in Peri-Implantitis and Periodontitis Tissues: Digital vs. Manual Analysis-A Proof of Concept Study.

Background and Objectives: In dentistry, the assessment of the histomorphometric features of periodontal (PD) and peri-implant (PI) lesions is important to evaluate their underlying pathogenic mechanism. The present study aimed to compare manual and digital methods of analysis in the evaluation of the inflammatory biomarkers in PI and PD lesions. Materials and Methods: PD and PI inflamed soft tissues were excised and processed for histological and immunohistochemical analyses for CD3+, CD4+, CD8+, CD15+, CD20+, CD68+, and CD138+. The obtained slides were acquired using a digital scanner. For each marker, 4 pictures per sample were extracted and the area fraction of the stained tissue was computed both manually using a 594-point counting grid (MC) and digitally using a dedicated image analysis software (DC). To assess the concordance between MC and DC, two blinded observers analysed a total of 200 pictures either with good quality of staining or with non-specific background noise. The inter and intraobserver concordance was evaluated using the intraclass coefficient and the agreement between MC and DC was assessed using the Bland-Altman plot. The time spent analysing each picture using the two methodologies by both observers was recorded. Further, the amount of each marker was compared between PI and PD with both methodologies. Results: The inter- and intraobserver concordance was excellent, except for images with background noise analysed using DC. MC and DC showed a satisfying concordance. DC was performed in half the time compared to MC. The morphological analysis showed a larger inflammatory infiltrate in PI than PD lesions. The comparison between PI and PD showed differences for CD68+ and CD138+ expression. Conclusions: DC could be used as a reliable and time-saving procedure for the immunohistochemical analysis of PD and PI soft tissues. When non-specific background noise is present, the experience of the pathologist may be still required.

Effects of Vitamin and Amino Acid-Enriched Hyaluronic Acid Gel on the Healing of Oral Mucosa: In Vivo and In Vitro Study.

Background and Objectives: Wound healing is a dynamic process that can be compromised in patients with chronic and metabolic conditions or unhealthy lifestyles. Numerous medical substances designed for topical use, charged with compounds that promote the healing process, have been developed to improve wound healing, especially in compromised subjects. The present study aimed to extend our understanding of the in vivo effects of a hyaluronic acid gel charged with amino acids (HAplus gel, Aminogam gel® Errekappa Euroterapici spa, Milan, Italy) and study the in vitro effects of the same gel charged with additional substances in an attempt to optimize its formulation. Materials and Methods: In a randomized controlled split-mouth clinical and histological trial, HAplus gel was tested on the gingival tissue of the lower third molar post-extraction socket. The gingiva was collected at the time of extraction (T0) and ten days after the extraction (T1) to be histologically analyzed. During the second stage of the study, culture media with HAplus gel and vitamin C and E at different concentrations (TEST) were tested on human gingival fibroblasts and compared to the HAplus-enriched medium (HA-Control). Results: Histological and immunohistochemical analysis of collected gingiva showed higher microvascular density and collagen fibers organized in closely packed and well-oriented bundles in sites treated with HAplus gel. In the in vitro study, all TEST groups showed an increased viability from 24 h to 48 h. After 24 h, the viability percentage in all experimental groups was below 100% of the HA-Control, demonstrating a mild toxicity. After 48 h from seeding, the TEST groups' viability grew significantly compared to HA-Control. Conclusions: These encouraging preliminary results suggest that the use of HAplus gel enriched with vitamins C and E may be beneficial in patients with conditions that impair soft tissue healing.

CEMP-1 Levels in Periodontal Wound Fluid during the Early Phase of Healing: Prospective Clinical Trial.

OBJECTIVES: Cementogenesis seems to be significantly compromised during tissue inflammation. In dental practice, surgical procedures are performed with the aim to regenerate periodontium including cementum. However, inflammation that occurs during the initial healing phases after surgery may impair regeneration of this tissues. The aim of the present study was to assess if surgical procedures designed to regenerate periodontium might affect levels of cementum protein-1 (CEMP-1) in periodontal wound fluid during early phase of healing. MATERIALS AND METHODS: In 36 patients, 18 intrabony periodontal defects were treated with regenerative therapy (REG group) and 18 suprabony periodontal defects were treated with open flap debridement (OFD group). In the experimental sites, gingival crevicular fluid was collected immediately before surgery, and periodontal wound fluid was collected 4, 7, 14, and 21 days after surgery. CEMP-1 levels were detected by indirect enzyme-linked immunosorbent assay technique. RESULTS: At the analysis, it resulted that there was a significant average difference in CEMP-1 values between the REG and OFD groups at baseline (p = 0.041), the CEMP-1-modeled average in the OFD group was lower by 0.45 ng/ml. There was a significant trend in CEMP-1 over time, and this trend was different among the 2 groups: the REG group showed a statistically significant rising CEMP-1 trend (0.18 ng/ml a week p = 0.012), while the OFD had a trend that was significantly lower (-0.22 ng/ml a week compared to the REG group trend p = 0.023), the OFD group lost on average 0.05 ng/ml a week. In REG sites, GCF protein levels resulted also related to clinical parameters. CONCLUSIONS: During the initial inflammatory phase of periodontal healing, CEMP-1 levels decrease regardless of the surgical protocol applied. The surgical procedures used to regenerate periodontal tissue are able to reverse this trend and to induce significant increase of CEMP-1 in periodontal wound fluid after the first week postop.

Electromyographic analysis of the oral phase of swallowing in subjects with and without atypical swallowing: A case-control study.

BACKGROUND: Swallowing is a complex physiologic function developing mostly in the first years of life. After 6 years old, if mature deglutition is not achieved, swallowing persists as "atypical swallowing" (AS). OBJECTIVE: The aim of this study was to detect any electromyographical differences in the muscular activation pattern in patients with and without AS. MATERIALS AND METHODS: 38 adolescents and young adults were selected for this study: 20 with atypical swallowing (AS group) and 18 without (C group). Standardised surface electromyographic analysis was performed by the same operator to detect the activity of masseter (MM), temporalis (TA) and submental (SM) muscles. A Student t test for unpaired data was carried out to detect differences between the AS and C groups. A 1-way ANOVA was performed to detect any differences between the three couples of muscles. RESULTS: When compared to controls, AS patients showed a significantly longer duration of activity for each couple of muscles and for the whole duration of swallowing act (P < 0.0001) as well as lower intensity of the SM activity (P < 0.05) than controls. Within the AS and C groups, masticatory muscles (MM and TA) showed lower duration of activation (P < 0.01) and lower intensity of the spike (P < 0.0001) than SM. Within the C group, masticatory muscles also reached their activation spike earlier (1-way ANOVA, P < 0.01) than SM. CONCLUSION: Two different muscular performance models have been defined: patients with AS showed a longer activity of all the muscles involved with a lower intensity of SM activity than that of controls.

Predictor factors for long-term outcomes stability of coronally advanced flap with or without connective tissue graft in the treatment of single maxillary gingival recessions: 9 years results of a randomized controlled clinical trial.

AIM: To assess the clinical outcomes 9 years after the surgical treatment of single maxillary gingival recessions and identify predictors for long-term gingival margin stability. MATERIALS AND METHODS: Twenty-five gingival recessions (Miller Class I and II) were randomly treated with Coronally Advanced Flap (CAF) plus Connective Tissue Graft (CTG) or CAF alone. Outcomes included complete root coverage (CRC), recession reduction (REC), keratinized tissue (KT) gain and dentin hypersensitivity, and were evaluated at 6 months, 1 and 9 years. Multilevel analysis was performed to identify predictors for long-term gingival margin stability. RESULTS: Baseline gingival recession was 2.4 ± 0.8 mm and 2.4 ± 1.0 mm in the CAF + CTG and in the CAF-treated sites, respectively (p = 0.693). The chance to gain and preserve CRC over time is equal to 70% in the CAF + CTG group (Relative Risk [RR] = 1.70, 95% CI [0.84-3.45]; adjusted RR = 1.48, 95% CI [0.61-3.62]). Using the CTG, an increase in KT was recorded 9 years after the surgery (p = 0.019). An OR of 0.12 (p = 0.022) of not achieving CRC was observed in cases with non-carious cervical lesions (NCCL) compared to cases without NCCL. CONCLUSION: Both treatment modalities demonstrated stability over time. Additional use of CTG provided a greater increase in KT. The presence of NCCL negatively affected CRC and REC.

Xenogenic collagen matrix or autologous connective tissue graft as adjunct to coronally advanced flaps for coverage of multiple adjacent gingival recession: Randomized trial assessing non-inferiority in root coverage and superiority in oral health-related quality of life.

AIM: To evaluate the non-inferiority of the adjunct of a xenogeneic collagen matrix (CMX) or connective tissue graft (CTG) to coronally advanced flaps (CAF) for coverage of multiple adjacent recessions and compare superiority in patient-reported outcomes (PROM). MATERIAL AND METHODS: One hundred and eighty-seven subjects (92 CMX) with 485 recessions in 14 centres were randomized and followed up for 6 months. Patients filled daily diaries for 15 days to monitor patient-reported experience. The primary outcome was changed in position of the gingival margin. Multilevel analysis used centre, subject and tooth as levels and baseline parameters as covariates. RESULTS: Average baseline recession was 2.5 ± 1.0 mm. The surgery was 15.7 min shorter (95%CI from 11.9 to 19.6, p < .0001) and perceived lighter (11.9 VAS units, 95%CI from 4.6 to 19.1, p = .0014) in CMX subjects. Time to recovery was 1.8 days shorter in CMX. Six-month root coverage was 1.7 ± 1.1 mm for CMX and 2.1 ± 1.0 mm for CTG (difference of 0.44 mm, 95%CI from 0.25 to 0.63 mm). The upper limit of the confidence interval was over the non-inferiority margin of 0.25 mm. Odds of complete root coverage were significantly higher for CTG (OR = 4.0, 95% CI 1.8-8.8). CONCLUSION: Replacing CTG with CMX shortens time to recovery and decreases morbidity, but the tested generation of devices is probably inferior to autologous CTG in terms of root coverage. Significant variability in PROMs was observed among centres.

Maxillary sinus lift augmentation: A randomized clinical trial with histological data comparing deproteinized bovine bone grafting vs graftless procedure with a 5-12-year follow-up.

INTRODUCTION: Different protocols and procedures for sinus lift and implant placement are available, generally involving the use of grafts to increase the tissue volume and/or prevent the Schneiderian membrane from collapsing. Among xenografts, deproteinised bovine bone graft (DBBP) is frequently used in sinus lift procedures. Leaving an ungrafted space following membrane elevation has proven to have a bony regenerative potential as well. This study aimed to compare the clinical and histological features of sinus lift surgery performed with or without biomaterials. METHODS: Patients with severe maxillary posterior atrophy (residual bone height 2-6 mm and residual crest thickness ≥4 mm), and in need of sinus lift surgery to allow the placement of three implants were enrolled and randomly divided into two groups. They underwent sinus lifts with DBBP (control) or with a graftless technique (test) and immediate placement of two implants (a mesial and distal one). After 6 months, a bone sample was retrieved from the area between the previously inserted fixtures, and a third, central implant was placed. The collected bone samples were analyzed morphologically and histomorphometrically. The patients were provided with prosthetic restorations after 6 months and followed up for 5-12 years. RESULTS: Ten patients were enrolled in the test and nine in the control group. The 6-month follow-up showed in the control group an average augmentation of 10.31 mm (±2.12), while in the test group it was 8.5 mm (±1.41) and a success rate of 96.3% in the control and 86.7% in the test group (p > 0.05). The histological analysis evidenced the presence of new bone tissue surrounded by immature osteoid matrix in the test group, and a variable number of DBBP particles surrounded by an immature woven bone matrix in the control group. CONCLUSION: The results of the present trial indicate that, with residual bone height of 2-6 mm and residual crest thickness ≥4 mm, sinus lift surgery with or without biomaterials followed by implant restoration, produces similar clinical and histological outcomes.

Xenograft Combined with a Mixture of Polynucleotides and Hyaluronic Acid (PNs-HA) for Horizontal Alveolar Bone Regeneration: Clinical and Histologic Assessments in a Case Series.

The present case series aims to investigate the use of polynucleotides mixed with hyaluronic acid (PNs-HA) in the form of gel to promote bone regeneration in horizontal alveolar defects. Overall, 6 adult patients underwent localized horizontal guided bone regeneration by means of xenogeneic bone substitute and a resorbable barrier with a staged approach. The graft consisted in a mixture of deproteinized bovine bone mineral (DBBM) particles and PNs-HA gel in a 3:1 ratio, respectively. The material was covered by a resorbable collagen membrane fixed with pins to the underlying bone. Implant placement was performed after 5 months. Healing proceeded uneventfully, and, upon re-entry, the graft appeared well vascularized and firmly attached to the recipient bone. Histologically, the regenerated bone appeared highly mineralized, well-organized in lamellae and totally embedding the residual granules of the biomaterial. Histomorphometric evaluations revealed that newly formed bone occupied on average 41.2% ± 12.4% of the analysed samples. Linear measurements performed on CBCT scans yielded an overall linear horizontal bone gain of 4.91 ± 0.88 mm. These data suggest that a mixture of DBBM and PNs-HA can be safely used to promote bone regeneration in case of horizontal alveolar defects.

Molecular Analysis of Peri-implant Soft Tissue Response to Different Abutment Materials in Humans. A Pilot Study.

PURPOSE: To evaluate the response of human peri-implant soft tissue (PIST) on different healing abutment materials 24 hours after positioning, by assessing the expression of genes related to the early connective tissue wound healing response. MATERIALS AND METHODS: Experimental abutments of 4 different materials (A): grade 4 titanium, (B) grade 5 titanium, (C) zirconia and (D) PEEK, were mounted on installed implants in 5 patients, four different abutments each. Before implant placement, a gingival biopsy (control-CT) was obtained using a 2 mm diameter punch (T0). After 24 hours (T24), PIST biopsies were collected using a specifically designed custom-made cutting device. Real-time PCR was performed to analyze the expression of the following genes: COL-I, COL-III, MMP-1, TIMP-1,TGF-b1, FN, ITGA4, ITGA5, ITGB1, RAC-1, COL-IV, aSMA, IL-6 and CXCL-1. RESULTS: Gene expression analysis showed some differences between CT and abutment of different materials, although no significant differences were detected comparing the experimental groups. COL-I was significantly down-regulated in groups A and C compared to CT. MMP-1 and TIMP-1 increased in all the experimental groups, although at a lower extent in group A. FN, RAC-1, COL-IV and aSMA were down-regulated, especially in group A, in which CXCL-1 and IL-6 showed the lowest expression. CONCLUSIONS: The results of grade 4 titanium and zirconia abutments seem to be promising, since a lower expression of genes related with inflammation, myofibroblasts activation and ECM remodeling was observed when compared with grade 5 titanium and PEEK, without triggering a pro-fibrotic response in the early phases of PIST repair.

COVID-19 monitoring of school personnel through molecular salivary test and dried blood spot analysis.

Background: When the coronavirus disease 2019 (COVID-19) pandemic broke out, most countries enforced school closures as a precautionary measure. Although COVID-19 is still present three years later, schools have been reopened. We aimed to test the association of molecular salivary testing (MST) and dried blood spot (DBS) analysis for community surveillance by investigating the immunological profile of a group of school staff during and following COVID-19 vaccination. Methods: We conducted the study in a school in Milan from April 2021, when school staff were administered the first dose of vaccine against SARS-CoV-2, until the school year ended in June 2022. Each participant provided samples for MST and DBS one month (T1, W1) after receiving their first dose of vaccine. Subsequently, they collected weekly MST samples for five weeks (W2-W6), plus a DBS sample in the last week (T2). Both samples were collected one (T3), four (T4), and seven months (T5) after the administration of the second vaccine dose in May 2021. A final DBS sample was collected one year (T6) after T3. Results: Sixty participants provided 327 MSTs and 251 DBSs. None of the MST samples tested positive for SARS-CoV-2 RNA during the study period. A total of 201 DBS samples tested positive for the IgG semiquantitative analysis. Negative samples were found only at T1 (20.45%) and T2 (7.32%). We observed borderline results at T1 (4.55%), T2 (7.32%), and T4 (2.70%). The anti-SARS-CoV-2 average antibody ratio increased after the second dose between T2 and T3, and the trend peaked after the third dose between T4 and T6. We performed an immunoenzymatic assay of antibodies against nucleocapsid protein on samples collected at T1 from five participants who reported having been infected before the study and from four subjects with an abnormal increase in the antibody values at T4. Two samples tested positive in the first group and two in the second one. Conclusions: Our findings show that MST and DBS could be effective tools in the active surveillance of school personnel and that schools could be considered safe settings in view of SARS-CoV-2 infection. Vaccines might have contributed to case and/or symptom reduction.

Myofunctional Speech Therapy for Facial Rejuvenation and Orofacial Function Improvement: A Systematic Review.

This review aims to reveal the effectiveness of myofunctional speech therapy on facial rejuvenation and/or improvement of orofacial function. A systematic review of four medical electronic databases (Medline, Google Scholar, SciELO, and LILACS) was conducted between January and March 2023. The research question was defined using the PICO model: Population (P): adult subjects with signs of physiological aging of facial skin. Intervention (I): aesthetic speech therapy (facial exercises and/or myofunctional therapy). Control (C): absence of treatment. Outcome (O): facial rejuvenation. Through the search process, a total of 472 potentially relevant articles were identified. A total of 21 studies were included in the review. Most of the studies required the participants to perform exercises learned during the weekly session on a daily basis. The subjects underwent an integrated treatment with facial exercises and worked on the stomatognathic functions for different durations. Many differences were found in the evaluation tools used to investigate the starting situation and the effects obtained following the treatment. At the diagnostic level, there was no concordance in the choice of the most appropriate scales and assessment tools, but great heterogeneity was observed. Indeed, forty-eight percent of the studies collected objective data through the use of various instruments (oral devices, electromyographs, cutometers, muscle ultrasound scans, and laser scans of the face). The observed improvements included not only a reduction in wrinkles and frown lines but also decreased muscle tension and slackness, enhanced facial symmetry and lip competence, improved skin elasticity, and restored stomatognathic function. These changes led to myofunctional restoration and facial rejuvenation, resulting in increased satisfaction with self-image and proprioception.

Soft tissue surrounding switched platform implants: an immunohistochemical evaluation.

OBJECTIVES: This clinical and immunohistochemical study was designed to characterize the cellular and molecular patterns for bone loss of soft tissues surrounding implants restored with different implant platform configurations. MATERIAL AND METHODS: A total of 32 implants were restored using abutments with the following mismatches: 0 mm (control group), 0.25 mm (test group(1)), 0.5 mm (test group(2)) and 0.85 mm (test group(3)). Four years after, loading all sites were clinically healthy, and soft tissue samples were harvested and processed for immunohistochemical analysis. Amounts of lymphocytes T (LyT) -B (LyB), IL-17 and RANKL were assessed. RESULTS: No significant difference was found between groups (P > 0.05) in terms of infiltrated T and B cell counts, IL-17 and RANKL expressions. When pooled data were analysed, lymphocytes T counts and IL-17 were higher than lymphocytes B counts and RANKL. LyT and LyB counts were highly negatively correlated (Pearson's r > 0.7) and IL-17 was correlated (Pearson's r > 0.4, <0.7) to LyT and LyB. CONCLUSIONS: After prolonged exposure of abutments in the oral cavity, the configuration of the implant abutment interface does not seem to affect the inflammatory cellular and molecular pattern responsible for bone loss.

Personal Protection Equipment and Infection Control Procedures among Health Workers during the COVID-19 Pandemic.

Health workers have been particularly affected by the COVID-19 pandemic, but it is unclear which healthcare professions are more exposed. We search for information that can help identify health workers who are employed in exposure-prone professions and who, therefore, routinely wear and adopt strict infection control equipment and measures from other colleagues. Our purpose is to test the hypothesis that health professionals historically considered less exposure-prone are affected more severely by COVID-19. Taking dentists as an example of exposure-prone healthcare professionals, this study aims to analyze data on COVID-19-related deaths reported by the Italian board of doctors and dentists' database to evaluate the number of COVID-19-related deaths of doctors and dentists in Italy from the beginning of the pandemic to 31 December 2022. As of 31 December 2021, out of 364 deaths, 38 were dentists, and of the remaining 326 doctors, 140 were general practitioners (GPs). The percentage of deaths among dentists, total doctors and GPs results in 0.06%, 0.09% and 0.33%, respectively, for the whole sample. Excluding subjects over 70 years of age, the corresponding values are 0.05%, 0.06% and 0.25%. Most of the deaths occurred in Lombardia, and the geographical distribution overlaps the trend of the corresponding general Italian population. Considering the outcome of "death", dentists, despite being at high risk, are not particularly affected by COVID-19.

Comparison of Different Chemical and Mechanical Modalities for Implant Surface Decontamination: Activity against Biofilm and Influence on Cellular Regrowth-An In Vitro Study.

Objectives: The aim of this in vitro study was to compare the efficacy of chemical and mechanical methods for decontamination of titanium dental implant surfaces previously infected with polymicrobial biofilms in a model simulating a peri-implant defect. Furthermore, the effect of each decontamination protocol on MG-63 osteoblast-like cells morphology and adhesion to the treated implants was assessed. Background: Peri-implantitis is a growing issue in dentistry, and evidence about implant surface decontamination procedures is lacking and inconclusive. Methods: A total of 40 previously biofilm-contaminated implants were placed into a custom-made model simulating a peri-implant defect and randomly assigned to five treatment groups: (C) control (no treatment); (AW) air abrasion without any powder; (ESC) air abrasion with powder of erythritol, amorphous silica, and 0.3% chlorhexidine; (HBX) decontamination with a sulfonic/sulfuric acid solution in gel; and (HBX + ESC) a combination of HBX and ESC. Microbiological analysis was performed on five implants per treatment group, and the residual viable bacterial load measured in log 10 CFU/mL was counted for each bacterial strain and for the total number of colonies. The remaining three implants per group and three noncontaminated (NC) implants were used to assess surface biocompatibility using a scanning electron microscope and a backscattered electron microscope after seeding with MG-63 cells. Results: A significant decontaminant effect was achieved using HBX or HBX + ESC, while no differences were observed among other groups. The percentage of implant surface covered by adherent MG-63 cells was influenced by the treatment method. Progressive increases in covered surfaces were observed in groups C, AW, ESC, HBX, HBX + ESC, and NC. Conclusions: A combination of mechanical and chemical decontamination may provide more predictable results than mechanical cleaning alone.

Morphological and Immunopathological Aspects of Lingual Tissues in COVID-19.

COVID-19, a recently emerged disease caused by SARS-CoV-2 infection, can present with different degrees of severity and a large variety of signs and symptoms. The oral manifestations of COVID-19 often involve the tongue, with loss of taste being one of the most common symptoms of the disease. This study aimed to detect SARS-CoV-2 RNA and assess possible morphological and immunopathological alterations in the lingual tissue of patients who died with a history of SARS-CoV-2 infection. Sixteen cadavers from 8 SARS-CoV-2 positive (COVID-19+) and 8 negative (COVID-19-) subjects provided 16 tongues, that were biopsied. Samples underwent molecular analysis through Real-Time RT-PCR for the detection of SARS-CoV-2 RNA. Lingual papillae were harvested and processed for histological analysis and for immunohistochemical evaluation for ACE2, IFN-γ and factor VIII. Real-Time RT-PCR revealed the presence of SARS-CoV-2 RNA in filiform, foliate, and circumvallate papillae in 6 out of 8 COVID-19+ subjects while all COVID-19- samples resulted negative. Histology showed a severe inflammation of COVID-19+ papillae with destruction of the taste buds. ACE2 and IFN-γ resulted downregulated in COVID-19+ and no differences were evidenced for factor VIII between the two groups. The virus was detectable in most COVID-19+ tongues. An inflammatory damage to the lingual papillae, putatively mediated by ACE2 and IFN-γ in tongues from COVID-19+ cadavers, was observed. Further investigations are needed to confirm these findings and deepen the association between taste disorders and inflammation in SARS-CoV-2 infection.

Neuromuscular Stability of Dental Occlusion in Patients Treated with Aligners and Fixed Orthodontic Appliance: A Preliminary Electromyographical Longitudinal Case-Control Study.

The aim of the present study was to evaluate if, after treatment with aligners (ALIGN) and fixed orthodontic appliance (FOA), alterations of the neuromuscular activity may occur and if differences in these changes can be detected between the two treatments. Sixteen healthy patients (7 FOA, 9 ALIGN) with class I or class II molar relation were recruited. Standardized surface electromyography (ssEMG) was used to evaluate the activity of the masticatory muscles (masseters-MM and temporalis-TM) before the beginning of the orthodontic treatment (T1), at the end (T2), and 3 months (T3) after the end of the treatment. Intragroup (within timepoints) and intergroup differences were statistically analyzed. At T1, the mean values of each ssEMG index were within the normal range in both groups. At T2, the FOA group showed larger differential recruitment of the MM than TA muscles with a value slightly over the normal range. All the indexes were normalized at T3, and no differences emerged between groups. In the FOA group, the index of MM symmetrical contraction increased significantly at T3 compared to T1 and T2. In the ALIGN group, no significant changes were observed between each timepoint. In FOA subjects, a slight alteration of the muscular activity appeared immediately after bracket removal and this alteration normalized after 3 months of rescue. In subjects treated with aligners, no significant alteration of the muscular activity was assessed.

Soft tissues around long-term platform switching implant restorations: a histological human evaluation. Preliminary results.

BACKGROUND: Switching platform restorations seems to reduce the peri-implant bone resorption and to preserve the peri-implant soft tissues. AIM: The aim of the present human study was to compare histologically the peri-implant soft tissue in switching and traditional platform implants 4 years after restoration. MATERIALS AND METHODS: Forty-eight months after implant restoration, 37 peri-implant soft tissue samples from 14 patients were harvested from traditionally restored implants (control group) and from three different platforms mismatching 0.25-0.85 mm (test groups). At the harvesting time, all sites were clinically healthy. Samples were processed to evaluate the inflammatory infiltrate area [inflamed connective tissue (ICT)], the microvascular density (MVD) and the collagen content (AA%). RESULTS: At the analyses, no significant differences were found between groups in terms of ICT, MVD and AA% (p>0.05). In all groups, most samples with a well-preserved junctional epithelium showed a small and localized inflammatory infiltrated associated with not-well-oriented collagen fibres and an increased MVD. CONCLUSIONS: Forty-eight months after restoration, switching and traditional platform implants had similar histological peri-implant soft tissue features, despite different bone level changes detected radiographically and published in a previous parent study. The present study seems to confirm platform switching as a safe prosthetic concept leading to better maintenance of peri-implant bone levels. However, further histological studies are required to longitudinally confirm the present data.

Histological assessment of mandibular bone tissue after guided bone regeneration with customized computer-aided design/computer-assisted manufacture titanium mesh in humans: A cohort study.

BACKGROUND: Innovative customized computer-aided design/computer-assisted manufacture (CAD-CAM) titanium meshes have been proposed for guided alveolar bone regeneration. Histological confirmation on the quality of the regenerated bone is needed. Purpose of the study is to assess the integration capabilities of these innovative meshes and to evaluate the histological features of the regenerated alveolar bone. MATERIALS AND METHODS: Twenty partially edentulous patients, with severe posterior mandibular atrophy, underwent a guided bone regeneration technique by means of customized CAD-CAM titanium mesh in association with a mixture of autologous bone in chips and deproteinized bovine bone (1:1). At 9 months of healing, titanium meshes and bone samples were collected and histomorphometrically analyzed. RESULTS: In all patients, implants were placed according to the original plan. At histologic analysis, mesh appeared well osseointegrated, except that in sites where membrane exposure occurred. In all sites, newly formed tissue resulted highly mineralized, well-organized, and formed by 35.88% of new lamellar bone, 16.42% of woven bone, 10.88% of osteoid matrix, 14.10% of grafted remnants, and 22.72% of medullary spaces. Blood vessels were the 4% of the tissue. CONCLUSIONS: Data from this study support the use of customized CAD/CAM titanium mesh for regeneration of vital, well-structured, and vascularized alveolar bone.