Distribution of TAS2R38 bitter taste receptor phenotype and haplotypes among COVID-19 patients.

Bitter taste receptor TAS2R38 is expressed in the respiratory tract and can respond to quorum-sensing molecules produced by pathogens, stimulating the release of nitric oxide, with biocidal activity. TAS2R38 presents two main high-frequency haplotypes: the "taster" PAV and the "non-taster" AVI. Individuals carrying the AVI allele could be at greater risk of infections, including SARS-CoV-2. The aim of this study was to assess the frequency of PAV and AVI alleles in COVID-19 patients with severe or non-severe symptoms compared to healthy subjects to further corroborate, or not, the hypothesis that the PAV allele may act as a protecting factor towards SARS-CoV-2 infection while the AVI one may represent a risk factor. After careful selection, 54 individuals were included in the study and underwent genetic analysis and PROP phenotype assessment. Our investigation could not point out at a significant relationship between single nucleotide polymorphisms responsible for PROP bitterness and presence/severity of SARS-CoV-2 infection, as previous studies suggested. Our results uncouple the direct genetic contribution of rs10246939, rs1726866 and rs713598 on COVID-19, calling for caution when proposing a treatment based on TAS2R38 phenotypes.

Iliac crest fresh-frozen allografts and autografts in maxillary and mandibular reconstruction: a histologic and histomorphometric evaluation.

AIM: The aim of this paper was to compare histologically and histomorphometrically the osseointegration of iliac crest fresh-frozen allografts and autografts in human pre-prosthetic maxillary and mandibular onlay bone blocks reconstruction. METHODS: Twelve patients with edentulous atrophic ridges, scheduled for implant-supported prosthetic restorations, underwent reconstruction using iliac crest fresh-frozen allografts (group A, six patients) or autografts (group B, six patients). Four-to-nine months later implants were placed in the augmented areas and bone specimens were simultaneously obtained using trephine burs. The specimens were processed for ground sections and evaluated histologically and histomorphometrically. RESULTS: The postoperative course was uneventful in all patients in group B and in all except one in group A. Late complications occurred in 5 patients of group A. Dental implants could be inserted in all cases. Specimens from group A showed a vascularized bone with osteoprogenitor stem cells and medium-high grade of bone remodeling. Small areas of necrotic bone were observed sporadically. Sections obtained from group B revealed an advanced stage of bone remodeling. The histomorphometric analysis showed in group A a mean proportion of 24.7±14.7% for lamellar bone, 28.4±13.3% for newly formed bone and 46.9±16.9% for bone marrow; in group B the corresponding values were 25.3±15.3%, 22.9±11.0%, 51.7±15.7%. No statistically significant difference was found (Wilcoxon Test; P>0.05). CONCLUSION: There were no significant histological differences between group A and B. Larger studies with long term follow-up are needed to confirm that fresh-frozen allografts are a reliable alternative to autografts.

Screening for the undiagnosed diabetes at dental chair-side of an Italian university clinic. A pilot prospective study.

AIM: In Italy there is about one undiagnosed case of diabetes for each known case. The dental office might represent an important setting for screening the glycemic status of patients. The aim of the present study was to evaluate the effectiveness of dental chair-side capillary blood sampling for the identification of undiagnosed hyperglycemia in a group of Italian patients. METHODS: Five hundred fifteen patients >45 years old consecutively visiting a public university dental clinic, where admission is regulated by medical or income criteria, were considered for the study. Demographic data, medical history, time of the last caloric intake and waist width were recorded for each participant. All participants underwent an oral examination. Glycemic values were obtained by capillary blood glucose testing. RESULTS: Of the 400 subjects who took part in the study, a low percentage of unaware diabetic individuals (1.7%) was identified. Inclusion criteria restriction to subjects between 50 and 75 years of age and a waist circumference >92 cm would have resulted in a proportion of diabetic patients of 4.3%. CONCLUSION: Dental chair-side in a public university clinic in Italy failed to disclose the expected number of unaware diabetic patients.

A survey on the experience with dental tourism in a sample of Italian patients.

AIM: Dentistry in Italy is mainly private and therefore perceived as forcedly expensive. Dental tourism is becoming popular in order to get cheap dental care. The aim of this study was to carry out a survey aimed at investigating the perception of dental tourism by Italian patients who have recently received such dental care abroad. METHODS: A questionnaire was posted on the web site of an Italian consumers association (Altroconsumo) and members were invited to fill in the questionnaire in case they had experienced dental treatment abroad. RESULTS: Eighty-one complete forms were included in the study. The main motivation for turning to dental tourism was saving money. Another frequent reason for choosing dental tourism was that full rehabilitation was offered in a short time span, usually one week. Patients have often underlined that they appreciated different aspects of the foreign dentists, like speed, kindness, humanity, interest in the course of the treatment, the feeling of ease conveyed by the environment and the personnel. Past negative experiences with Italian dentists were in some cases advocated as reasons for searching dental care abroad. Such negative experiences resulted in a lack of trust in Italian dentists. Some patients reported that while the overall treatment abroad was carried out in a short time, single prosthetic sessions were very long, up to 6 hours. CONCLUSIONS: Most patients were satisfied with dental tourism.

Periodontal disease and preterm birth relationship: a review of the literature.

Despite medical care improves consistently, the rate of preterm birth has risen in recent years. In Italy the rate of preterm birth between the XXXIII and the XXXVI week is 13.5%, while it amounts to 1.3% for preterm birth between XXIV and the XXXII week. Consequently, the identification of risk factors for preterm birth that might be modified would have far-reaching and long-lasting effects. A significant number of preterm birth may be attributed to infections of the urogenital tract, such as bacterial vaginosis. In the last decade, great interest has been generated to support the hypothesis that sub-clinical infection at sites that are also distant from the genito-urinary tract may be an important cause of preterm labour, probably through the activation of abnormal inflammatory responses within the uterus and intrauterine tissues. There is emerging evidence of a possible relationship between maternal periodontal diseases as a potential risk factor of adverse pregnancy outcomes, like preterm low birth weight even though not all of the actual data support such hypothesis. Further studies are clearly required to clarify the causes and/or relationships linking pathologic oral conditions and adverse pregnancy outcomes. So far, from a clinical standpoint, it would appear that the assessment of the periodontal status of pregnant women during an early pregnancy might be useful in providing an important indicator of risk for future obstetric complications.

Peri-implant diseases. A systematic review of the literature.

Peri-implantitis surrounding oral implants is an inflammatory process affecting the soft and hard tissues resulting in rapid loss of supporting bone associated with bleeding and suppuration. The etiopathogenesis of early and late peri-implantitis is less well understood and seems to be related to the peri-implant environment and to the soft tissues/implant interface, to patient-related factors (smoke, systemic diseases, plaque control) and to host-parasite equilibrium. However, there is wide scientific evidence that demonstrates the direct correlation between oral microbiota and peri-implant mucositis or peri-implantitis. In particular, adherence and colonization of microbiota on plaque-exposed biomaterials, like c.p. titanium, are discriminant factors for the development of infection. Regenerative or resective surgical approaches are proposed for the treatment of peri-implantitis depending on the morphology and the shape of bone defects. The therapeutical approach of peri-implantitis surrounding dental implants comprises several aspects such as the removal of supra-gingival bacterial plaque, an appropriate surgical approach, the removal of granulation tissue and detoxification of the exposed implant surface, the elimination of the anaerobic ecosystem by the removal of peri-implant pocket (gingivectomy or apically repositioned flap) or by the regeneration of the peri-implant hard tissues and, finally, the establishment of an efficient plaque control regimen.

Orthodontic movement in bone defects augmented with Bio-Oss. An experimental study in dogs.

OBJECTIVE: To study if it was possible to move, by orthodontic means, a tooth into an area of the jaw that had been augmented with Bio-Oss. MATERIAL AND METHODS: 5 beagle dogs were used. The 1st, 2nd, and 4th mandibular premolars on each side were removed. The defect at the left 4th premolar site was filled with a biomaterial (Bio-Oss) while the corresponding defect in the right side was left for spontaneous healing. 3 months later, an orthodontic device was inserted in each side of the mandible. The device was designed to allow distal, bodily movement of the 3rd premolars. When the experimental teeth had been moved into the extraction sites of the 4th premolars, the animals were sacrificed and biopsies of the premolar-molar regions of the mandible sampled. The tissues were prepared for histological analysis using standard procedures. In the sections, 3 zones were identified: zone A=the bone tissue within the distal portion of the previous extraction site (4th premolar), zone B=the pressure side of the 3rd premolar, zone C=the tension side of the 3rd premolar. The area occupied by mineralized bone, Bio-Oss particles and bone marrow was determined by a point counting procedure. The width of the periodontal ligament as well as the percentage of the root surface (in zone B) that exhibited resorption was determined. RESULTS: The findings demonstrated that it was possible to move a tooth into an area of an alveolar ridge that 3 months previously had been augmented with a biomaterial. It was also demonstrated that 12 months after grafting, Bio-Oss particles remained as inactive filler material in the not utilized part of zone A. The biomaterial was not present in zone C but present in small amounts in zone B. CONCLUSION: During the orthodontic tooth movement the graft material (Bio-Oss) was degraded and eliminated from the part of the alveolar ridge that was utilized for the experiment. In the non-utilized part of the ridge the biomaterial, however, remained as a seemingly inactive filler material.

Oral health profile in an institutionalized population of Italian adults with mental retardation.

The oral health of 219 residents with mental retardation living in a long-term-care institution near Milan was assessed. The dental and periodontal status, daily habits, oral hygiene, and oral mucosal status were evaluated. Of the sample, 179 (81.7%) were males. The mean age of the residents was 61.3 years, and the degree of cooperation was evaluated as good for 131 subjects (59.8%), fair for 79 (36.1%), and poor for nine (4.1%). The percentage of residents who were edentulous was 21.5% (47 subjects), of whom 28 subjects (59.6%) were without dentures. Evaluation showed an overall DMFT of 23.1, and the average number of missing teeth was 20.5. All subjects had periodontal disease: Forty-five subjects had calculus and/or shallow pockets (4-5 mm); 61 had deep pockets (> or = 6 mm). The most common mucosal lesion was oral stomatitis (49.3%). These findings underline the need for special programs aimed at institutionalized subjects with mental retardation.

Bone healing around implants placed in a jaw defect augmented with Bio-Oss. An experimental study in dogs.

The present experiment was carried out to study some tissue reactions around implants that were placed in an edentulous ridge which had been augmented with deproteinized natural bovine cancellous bone mineral. In 4 male beagle dogs, the premolars in the right side of the mandible were extracted and a large buccal ridge defect was created by mechanical means. The bone plate at the lingual aspect of the defect was left intact. 5 months later, the distal 2/3 of the defect area was augmented with Bio-Oss (Geistlich Sons Ltd, Wolhusen, Switzerland) mixed with a fibrin sealer (Tisseel, Immuno AG, Vienna, Austria). After 3 months of healing, 3 fixtures (Astra Tech AB, Mölndal, Sweden; TiO-blast; 8x3.5 mm) were installed in the mandible; 2 were placed in the augmented portion and I was placed in the non-augmented portion of the defect. After a healing period of 3 months, abutment connection was performed and a plaque control period initiated. 4 months later, the dogs were sacrificed and each implant region was dissected. The tissue samples were dehydrated, embedded in plastic, sectioned in the bucco-lingual plane and examined in the light microscope. It was observed that osseointegration failed to occur to implant surfaces within an alveolar ridge portion previously augmented with Bio-Oss. In the augmented portion of the crest, the graft particles were separated from the host tissue as well as from the implant by a well-defined connective tissue capsule. Although the lingual aspect of all fixtures (test and control) was in contact with hard tissue at the time of installation, after 4 months of function, a deep vertical bone defect frequently had formed at the lingual surface of the implants. It was concluded that in this model (i) Bio-Oss failed to integrate with the host bone tissue and (ii) no osseo-integration occurred to the implants within the augmented portion of the crest.

Bone tissue reaction around implants placed in a compromised jaw.

The present experiment was carried out to examine bone tissue alterations that occurred around implants at which the marginal level of bone support at fixture installation was different at buccal and lingual surfaces. 8 beagle dogs were randomly divided into one test group and one control group. The mandibular premolars in the left side of the mandible (P1, P2, P3, P4) were extracted. In the 4 dogs of the test group, the buccal bone plate in the mandibular premolar region was removed to establish a bone defect that was about 25 mm long, about 5-6 mm high, and about 4 mm wide. In the 4 dogs of the control group, no bone resection was performed. 8 months after tooth extraction, 3 fixtures (Astra Tech AB, Mölndal, Sweden:TiO-blast: 8x3.5 mm) were installed in each dog. In the 4 dogs of the test group, the implants were positioned in the defect sites in such a way that (i) mechanical stability was achieved and (ii) their lingual surfaces were entirely invested in bone. At the buccal and approximal surfaces of the fixtures, however, the unthreaded portion (2 mm) and the 3 marginal threads remained exposed. In the control group, all implants were following installation entirely surrounded by bone tissue. After a healing period of 3 months, abutment connection was performed and a plaque control program initiated. 4 months later, the dogs were sacrificed. The mandibles were removed and placed in a fixative. Each implant region was dissected, the tissue samples were dehydrated, embedded, sectioned in a bucco-lingual plane and used for light microscopic examination. The findings demonstrated that osseointegration occurred at implants, placed in a chronic defect with large discrepancies between the buccal and lingual bone. During the process of healing and function, however, marked modeling and remodeling of the bone tissue took place. Thus, at the buccal surface, some bone regrowth and osseointegration occurred while at the lingual wall, there was a substantial resorption of the marginal bone and an enhanced number of bone multicellular units. Concomitant with the bone tissue alterations described, there was some recession of the peri-implant mucosa.