The lipidomic and inflammatory profiles of visceral and subcutaneous adipose tissues are distinctly regulated by the SGLT2 inhibitor empagliflozin in Zucker diabetic fatty rats

The pharmacological inhibition of sodium-glucose cotransporter 2 (SGLT2) has emerged as a treatment for patients with type 2 diabetes mellitus (T2DM), cardiovascular disease and/or other metabolic disturbances, although some of the mechanisms implicated in their beneficial effects are unknown. The SGLT2 inhibitor (SGLT2i) empagliflozin has been suggested as a regulator of adiposity, energy metabolism, and systemic inflammation in adipose tissue. The aim of our study was to evaluate the impact of a 6-week-empagliflozin treatment on the lipidome of visceral (VAT) and subcutaneous adipose tissue (SAT) from diabetic obese Zucker Diabetic Fatty (ZDF) rats using an untargeted metabolomics approach. We found that empagliflozin increases the content of diglycerides and oxidized fatty acids (FA) in VAT, while in SAT, it decreases the levels of several lysophospholipids and increases 2 phosphatidylcholines. Empagliflozin also reduces the expression of the cytokines interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNFα), monocyte-chemotactic protein-1 (MCP-1) and IL-10, and of Cd86 and Cd163 M1 and M2 macrophage markers in VAT, with no changes in SAT, except for a decrease in IL-1β. Empagliflozin treatment also shows an effect on lipolysis increasing the expression of hormone-sensitive lipase (HSL) in SAT and VAT and of adipose triglyceride lipase (ATGL) in VAT, together with a decrease in the adipose content of the FA transporter cluster of differentiation 36 (CD36). In conclusion, our data highlighted differences in the VAT and SAT lipidomes, inflammatory profiles and lipolytic function, which suggest a distinct metabolism of these two white adipose tissue depots after the empagliflozin treatment.

Histological and histomorphometric study of human palatal mucosa: Implications for connective tissue graft harvesting

AIMS

To analyse the histological structure and histomorphometric characteristics of human hard palatal mucosa in order to determine the donor site of choice for connective tissue grafts from a histological point of view.

MATERIALS AND METHODS

Palatal mucosa samples from six cadaver heads were harvested at four sites: incisal, premolar, molar and tuberosity. Histological and immunohistochemical techniques were performed, as was histomorphometric analysis.

RESULTS

In the current study, we found that the density and size of cells were higher in the superficial papillary layer, whereas the thickness of the collagen bundles increased in the reticular layer. Excluding the epithelium, the mean percentage of lamina propria (LP) and submucosa (SM) was 37% and 63%, respectively (p < .001). LP thickness showed similar values in the incisal, premolar and molar regions, and a significantly greater thickness in tuberosity (p < .001). The thickness of SM increased from incisal to premolar and molar, disappearing in the tuberosity (p < .001).

CONCLUSIONS

As dense connective tissue of LP is the tissue of choice for connective tissue grafts, the best donor site from a histological point of view is tuberosity because it is composed only of a thick LP without the presence of a loose submucosal layer.

WISP-2 modulates the induction of inflammatory mediators and cartilage catabolism in chondrocytes

Wnt-1 inducible signaling pathway protein 2 (WISP-2/CCN5) is a recently identified adipokine that has been described as an important mediator of canonical Wnt activation in adipogenic precursor cells. In osteoarthritis (OA), the most common form of arthritis, chondrocytes exhibit aberrant and increased production of pro-inflammatory mediators and matrix degrading enzymes such as IL-1β and MMP-13. Although recent evidence suggests a role for Wnt signaling in OA physiopathology, little is known about the involvement of WISP-2 in cartilage degradation. In the present study, we determined the expression of WISP-2 in healthy and OA human chondrocytes. WISP-2 expression is modulated along chondrocyte differentiation and downregulated at the onset of hypertrophy by inflammatory mediators. We also investigated the effect of WISP-2 on cartilage catabolism and performed WISP-2 loss-of-function experiments using RNA interference technology in human T/C-28a2 immortalized chondrocytes. We demonstrated that recombinant human WISP-2 protein reduced IL-1β-mediated chondrocyte catabolism, that IL-1β and WNT/b-catenin signaling pathways are involved in rhWISP-2 protein and IL-1β effects in human chondrocytes, and that WISP-2 has a regulatory role in attenuating the catabolic effects of IL-1β in chondrocytes. Gene silencing of WISP-2 increased the induction of the catabolic markers MMP-13 and ADAMTS-5 and the inflammatory mediators IL-6 and IL-8 triggered by IL-1β in human primary OA chondrocytes in a Wnt/β-catenin dependent manner. In conclusion, here we have shown for the first time that WISP-2 may have relevant roles in modulating the turnover of extracellular matrix in the cartilage and that its downregulation may detrimentally alter the inflammatory environment in OA cartilage. We also proved the participation of Wnt/β-catenin signaling pathway in these processes. Thus, targeting WISP-2 might represent a potential therapeutical approach for degenerative and/or inflammatory diseases of musculoskeletal system, such as osteoarthritis.

Immunohistological study of the density and distribution of human penile neural tissue: gradient hypothesis

Immunohistological patterns of density and distribution of neural tissue in the human penis, including the prepuce, are not fully characterized, and effects of circumcision (partial or total removal of the penile prepuce) on penile sexual sensation are controversial. This study analyzed extra- and intracavernosal innervation patterns on the main penile axes using formalin-fixed, paraffin-embedded human adult and fetal penile tissues, single- and double-staining immunohistochemistry and a variety of neural and non-neural markers, with a special emphasis on the prepuce and potential sexual effects of circumcision. Immunohistochemical profiles of neural structures were determined and the most detailed immunohistological characterizations to date of preputial nerve supply are provided. The penile prepuce has a highly organized, dense, afferent innervation pattern that is manifest early in fetal development. Autonomically, it receives noradrenergic sympathetic and nitrergic parasympathetic innervation. Cholinergic nerves are also present. We observed cutaneous and subcutaneous neural density distribution biases across our specimens towards the ventral prepuce, including a region corresponding in the adult anatomical position (penis erect) to the distal third of the ventral penile aspect. We also describe a concept of innervation gradients across the longitudinal and transverse penile axes. Results are discussed in relation to the specialized literature. An argument is made that neuroanatomic substrates underlying unusual permanent penile sensory disturbances post-circumcision are related to heightened neural levels in the distal third of the ventral penile aspect, which could potentially be compromised by deep incisions during circumcision.

Activation of hypothalamic AMPK ameliorates metabolic complications of experimental arthritis

OBJECTIVE

To investigate whether thermogenesis and the hypothalamus may be involved in the physiopathology of experimental arthritis (EA).

METHODS

EA was induced in Lewis male rats by intradermal injection of Freund's complete adjuvant (FCA). Food intake, body weight, plasma cytokines, thermographic analysis, gene and protein expression of thermogenic markers in brown (BAT) and white (WAT) adipose tissue and hypothalamic AMP-activated protein kinase (AMPK) were analyzed. Virogenetic activation of hypothalamic AMPK was performed.

RESULTS

We first demonstrate that EA is associated with increased BAT thermogenesis and browning of subcutaneous WAT (sWAT) leading to elevated energy expenditure. Moreover, rats suffering EA show inhibition of hypothalamic AMPK, a canonical energy sensor modulating energy homeostasis at central level. Notably, specific genetic activation of AMPK in the ventromedial nucleus of the hypothalamus (VMH; a key site modulating energy metabolism) reverses the effect of EA on energy balance, brown fat and browning, as well as promoting an amelioration of the inflammatory status.

CONCLUSION

Overall, these data indicate that EA promotes a central catabolic state that can be targeted and reversed by the activation of hypothalamic AMPK. This might open new therapeutic alternatives to treat rheumatoid arthritis (RA)-associated metabolic comorbidities, improving RA-patients overall prognosis.

Case report of segmental odontomaxillary dysplasia with cutaneous manifestations

BACKGROUND

Segmental odontomaxillary dysplasia is an uncommon nonhereditary growth disorder that affects the maxilla, gums and ipsilateral dentition. The disorder is diagnosed mainly based on dental (over-retention of primary teeth, dental agenesis and diastemas) and bone findings (bone sclerosis, irregular trabeculation of immature bone and reduced maxillary sinus). This paper provides a case report.

CASE REPORT

A 5-year-old child with skin manifestations including hypertrichosis, facial erythema and pigmented nevus was diagnosed with type II segmental odontomaxillary dysplasia based on clinical, radiographic and histopathological analysis.

CONCLUSION

The skin findings can help with the suspicion of segmental odontomaxillary dysplasia, although the definitive diagnosis is typically established by a paediatric dentist based on clinical and radiological findings.

Correlation between HER2 amplification level and response to neoadjuvant treatment with trastuzumab and chemotherapy in HER2 positive breast cancer

e12641

Background: HER2 targeted therapy in combination with chemotherapy have changed the aggressive natural history of HER2-positive tumors. To select patients to be treated with this type of agents, determination of HER2 status is usually carried out by immunohistochemistry, followed by in situ hybridization in equivocal cases (2+). There are contradictory data in literature regarding correlation between level of HER2 amplification determined by FISH and early and long-term treatment benefits. Objectives: The aim of this study was to correlate quantitative results of FISH (ratio HER2/CEN17 and number of HER2 signals/nucleus) with the grade of response to neoadjuvant treatment with trastuzumab and chemotherapy. Methods: We analyzed 100 consecutive cases of stage I-III breast carcinomas treated with trastuzumab and chemotherapy in the neoadjuvant setting at A Coruña University Hospital between 2005 and 2016. At Santiago University Hospital, 4 tissue microarrays were prepared and the IQFISH (Dako-Agilent) technique was performed using pretreatment biopsies. Results: HER2 amplification was found in 92 of 100 cases studied. Pathological Complete Response (pCR) (Miller-Payne grading system) was obtained in 58% of the patients whose tumors showed amplification. No pCR was obtained in the 8 patients whose tumors were negative by FISH (not amplified). Analysis of the quantitative results demonstrated a statistical significant direct correlation between pCR and both HER2/CEN17 ratios and HER2 gene copies/nucleus (p = 0.002 and p= 0.004, respectively). We also demonstrated an association between the HER2 amplification level (both ratios and numbers of HER2 signals) and a trend toward improved disease free survival (DFS) (p = 0.451 and p= 0.619, respectively). Conclusions: HER2 amplification level determined by FISH it is a good and available predictive factor of response and must be included in pathologic reports because it can provide valuable information to oncologists on the possibilities of achieving pCR after neoadjuvant treatment in HER2-positive breast cancer. Key words: Breast cancer, FISH, HER2 amplification, trastuzumab, neoadjuvant therapy, pathological complete response.

Merkel cells of human oral mucosa express the pluripotent stem cell transcription factor Sox2

Merkel cells are neuroendocrine cells associated to a neural sensitive ending and localized primarily in the epidermis, although they are also found in oral mucosa. Sox2 or SRY-box2 is a key transcription factor important in the maintenance of embryonic neural crest stem cell pluripotency. Sox2 has been described in Merkel cells of skin and in Merkel cell carcinomas, but not specifically in oral Merkel cells. The aims of the present study were to analyze the density of Merkel cells in human oral mucosa and to study the expression of Sox2 in these cells. For these purposes, immunohistochemical analyses for Sox2 and CK20 (the best marker for Merkel cells) were automatically performed on sections of normal human oral mucosa. Double immunofluorescence for Sox2 and CK20 was also performed. To analyze the density of Merkel cells, CK20 positive cells were counted in each sample and the length of the epithelial apical edge was measured (cells/mm). Merkel cells, demonstrated by CK20 immunoreactivity, were found in 95% of oral mucosa specimens studied (n=21). Mean density of Merkel cells in oral mucosa was 1.71±2.34 cells/mm. Sox2 immunoreactivity was found in the nuclei of scattered cells located at the basal layer. Serial sections immunostained for Sox2 and CK20 showed that Sox2-positive cells of oral mucosa coexpressed CK20, confirming that they were Merkel cells. Immunofluorescence for Sox2 and CK20 showed colocalization of both markers, demonstrating that virtually all oral Merkel cells expressed Sox2. This transcription factor could play a role in Merkel cell maturation and maintenance.

MCH Regulates SIRT1/FoxO1 and Reduces POMC Neuronal Activity to Induce Hyperphagia, Adiposity, and Glucose Intolerance

Melanin-concentrating hormone (MCH) is an important regulator of food intake, glucose metabolism, and adiposity. However, the mechanisms mediating these actions remain largely unknown. We used pharmacological and genetic approaches to show that the sirtuin 1 (SIRT1)/FoxO1 signaling pathway in the hypothalamic arcuate nucleus (ARC) mediates MCH-induced feeding, adiposity, and glucose intolerance. MCH reduces proopiomelanocortin (POMC) neuronal activity, and the SIRT1/FoxO1 pathway regulates the inhibitory effect of MCH on POMC expression. Remarkably, the metabolic actions of MCH are compromised in mice lacking SIRT1 specifically in POMC neurons. Of note, the actions of MCH are independent of agouti-related peptide (AgRP) neurons because inhibition of γ-aminobutyric acid receptor in the ARC did not prevent the orexigenic action of MCH, and the hypophagic effect of MCH silencing was maintained after chemogenetic stimulation of AgRP neurons. Central SIRT1 is required for MCH-induced weight gain through its actions on the sympathetic nervous system. The central MCH knockdown causes hypophagia and weight loss in diet-induced obese wild-type mice; however, these effects were abolished in mice overexpressing SIRT1 fed a high-fat diet. These data reveal the neuronal basis for the effects of MCH on food intake, body weight, and glucose metabolism and highlight the relevance of SIRT1/FoxO1 pathway in obesity.

Association between hospital interval and survival in patients with oral cancer: A waiting time paradox

BACKGROUND

In early diagnosis studies on symptomatic cancer, survival was the most recommended outcome. The magnitude and impact of the patient interval and primary care interval is well-known in oral cancer; however, the hospital interval and its influence on surviving this neoplasia are not well known.

AIMS

To quantify the interval between the first contact with the specialist and the start of treatment for patients with oral cancer and to evaluate whether there was a link between this interval and disease survival.

METHODS

We designed a hospital-based study that included 228 patients diagnosed with oral/oropharyngeal squamous cell carcinoma between 1998 and 2008 at A Coruña University Hospital (Spain) who were followed up until 2016. The data were extracted retrospectively from hospital medical charts. The study interval was defined in the context of the "pathways to treatment" model as the interval from the first specialist visit (start point) to the start of treatment (end point). We calculated the total interval (from first symptom to treatment) to evaluate the relative length of the hospital interval, and we considered the variables age, sex, location, comorbidity and tumour classification stage. Survival time was defined as the interval from the first treatment to death or censoring.

RESULTS

The median hospital interval was 20 days, with an interquartile range of 15-29.1 days. The most relevant prognostic variable was the tumour stage (III-IV: Exp. ß = 2.8, p = 0.001). The hospital interval was part of the multivariate model, and its association with mortality showed a V-shaped association, where patients with short hospital intervals (3-18 days) and those with long hospital intervals (26-55 days) had significantly higher mortality than those with medium hospital intervals (19-25 days).

CONCLUSION

The hospital interval represents a relevant interval for the patient's path towards treatment, has prognostic implications and is subject to a severity bias (waiting time paradox) that should be avoided.

Oral mucosal peeling related to dentifrices and mouthwashes: A systematic review

Background

The aim of this systematic review was to summarise the clinical information available about oral mucosal peeling (OMP) and to explore its aetiopathogenic association with dentifrices and mouthwashes.

Material and Methods

PICOS outline: Population: subjects diagnosed clinically and/or pathologically. Intervention: exposition to oral hygiene products. Comparisons: patients using products at different concentrations. Outcomes: clinicopathological outcomes (primary) and oral epithelial desquamation (secondary) after use. Study design: any. Exclusion criteria: reports on secondary or unpublished data, in vitro studies. Data were independently extracted by two reviewers.

Results

Fifteen reports were selected from 410 identified. Descriptive studies mainly showed low bias risk, experimental studies mostly an “unclear risk”. Dentifrices or mouthwashes were linked to OMP, with an unknown origin in 5 subjects. Sodium lauryl-sulphate (SLS) was behind this disorder in 21 subjects, tartar-control dentifrices in 2, and flavouring agents in 1 case. Desquamation extension was linked to SLS concentration. Most cases were painless, leaving normal mucosa after desquamation. Tartar-control dentifrices caused ulcerations more frequently.

Conclusions

OMP management should consider differential diagnosis with oral desquamative lesions, particularly desquamative gingivitis, with a guided clinical interview together with pathological confirmation while discouraging the use of the product responsible for OMP.

Key words:Systematic review, oral mucosal peeling, dentifrices, sodium lauryl-sulphate, oral hygiene products.

The effect of dentist experience on the treatment of individuals with disability under general anesthesia

AIMS

The aim of the present work was to assess in patients with severe disability operated under general anesthesia whether the progressive acquisition of experience by the dental team affects the type of procedure performed and the duration of operations.

METHODS AND RESULTS

A study group of 911 patients who underwent dental treatment under general anesthesia between 1997 and 2014 was conformed. Information was collected from every patient including: dental diagnosis, dental procedures and duration of the operating times. To analyze the impact of the operators' experience, the study period was divided into three 6-year periods. The most prevalent systemic diagnosis was "mental disease and behavior disorders" (42.9%). The most common dental procedures were extractions and fillings. Fewer extractions were performed during the third 6-year period (p = .000). Compared with the other two periods, during the first period fewer composite fillings (p = .000 and p = .000, respectively) and more fissure sealants (p = .001 and p = .023, respectively) were performed. The number of amalgam fillings decreased progressively (p = .000). There was a statistically significant reduction in the mean duration of the operations between the first and third period (p = .002).

CONCLUSION

The dental team's experience entailed a significant reduction in the duration of operations.

Effect of chewing an apple on dental plaque removal and on salivary bacterial viability

OBJECTIVES

Studies on dental plaque removal by chewing an apple are scarce and dated, with conflicting findings. This study aimed to determine whether chewing an apple produced mechanical removal of dental plaque or had any effect on salivary bacterial viability.

METHODS

The study group consisted of 20 healthy adults with good oral health status who were randomly assigned to brush their teeth or eat an apple. After 2 weeks, the experiment was repeated with the order reversed. Plaque index (PI) and the bacterial viability (BV) in a sample of whole saliva (spit) were determined before brushing or apple eating (baseline, B), immediately afterward (A) and 24 hours afterward (24).

RESULTS

After chewing an apple, PI-A was significantly higher than both PI-B (P < .001) and PI-24 (P < .001). BV-A was significantly lower than BV-B (P < .001), with a return to baseline values at the BV-24 measurement.

CONCLUSIONS

Chewing an apple does not remove dental plaque, and may favor plaque regrowth during the first 24 hours, but it does produce an immediate reduction in salivary bacterial viability similar to that after tooth brushing.

A Dramatic Case of Odynophagia

We report the case of a 77-year-old male with a history of aortic stenosis and interstitial lung disease, who debuted 3 years ago with an outbreak of necrotic and very painful canker sores. The severity of the lesions and their refractory response to treatment led to several hospital admissions and multiple consultations to different specialists (ENT, rheumatology, dermatology, ophthalmology, cardiology, and internal medicine). During this time, the patient received central parenteral nutrition with an episode of catheter-related septicemia, and he came to require psychiatric assistance for autolytic ideation. Numerous diagnostic tests were performed with inconclusive results, including biopsy of the lesion (histological study, immunohistochemistry for CD68 + , CD4 + , CD8 + , CD20 + , MCT +, and cytomegalovirus, PAS, Grocott-Gomori and Zielh-Neelsen staining, and in situ hybridization for Epstein Barr virus). Numerous treatments were unsuccessfully tested until thalidomide was administered, thus completely remitting lesions but leaving retractable scarring sequelae. Since then, the patient has had two recurrences, coinciding with the reduction of thalidomide dosages, which were controlled by increasing the dose of the immunomodulator. Recurrent necrotizing major aphthous stomatitis (Sutton's disease) is a clinical variant of recurrent aphthous stomatitis that may have a dramatic course. Unfortunately, the lack of etiopathogenetic uniformity precludes any specific treatment. In severe cases, immunomodulators, including thalidomide, may represent a valid therapeutic option.

Mechanical characteristics of the maxillary sinus Schneiderian membrane ex vivo

OBJECTIVES

It has been speculated that certain Schneiderian membrane thickness (SMT) might be more prone to perforation. This investigation was aimed at studying the mechanical characteristics of the Schneiderian membrane under one- and two-dimensional tests and their correlation to the histological SMT in human samples.

MATERIAL AND METHODS

Sixteen Schneiderian membranes were collected from 11 cadaver heads treated with Thiel's embalming method. The samples were processed and analyzed clinically and histologically. One-dimensional maximum elongation until perforation and two-dimensional resistance to ball penetration were performed after the biopsy. Data was analyzed by using the Wilcoxon rank test and the Spearman's rank correlation.

RESULTS

The histological SMT was 1.36 ± 0.42 mm, whereas the clinical thickness was 0.27 ± 0.21 mm, yielding statistical significance (p = 0.000). The resistance under ball penetration was 0.59 ± 0.43 N and the mean maximum elongation in the one-dimension test 11.19 ± 7.14 mm. Expressed in percentage, the mean stretch was 241.36 ± 227.97% (range 31.5 up to 947%). A weak positive correlation was found between the ball penetration test and the SMT (r = 0.10, p = 0.711), while a weak negative correlation was found between stretching test and the SMT (r = -0.021, p = 0.94).

CONCLUSIONS

Mechanical tests seem to indicate that SMT might not significantly predispose to Schneiderian membrane perforation. Hence, other anatomical and operator's factors should be considered of surpassing importance.

CLINICAL RELEVANCE

Thinner SM might be more prone to perforation when detaching it from the maxillary sinus antrum; however, a thick membrane is not prevented to tear, as their resistance under elastic forces is not higher than thinner ones.

Pseudoepitheliomatous hyperplasia after diode laser oral surgery. An experimental study

Background

To examine the process of epithelial reparation in a surgical wound caused by diode laser.

Material and Methods

An experimental study with 27 Sprage-Dawley rats was undertaken. The animals were randomly allocated to two experimental groups, whose individuals underwent glossectomy by means of a diode laser at different wattages, and a control group treated using a number 15 scalpel blade. The animals were slaughtered at the 2nd, 7th, and 14th day after glossectomy. The specimens were independently studied by two pathologists (blinded for the specimens’ group).

Results

At the 7th day, re-epithelisation was slightly faster for the control group (conventional scalpel) (p=0.011). At the 14th day, complete re-epithelization was observed for all groups. The experimental groups displayed a pseudoepitheliomatous hyperplasia.

Conclusions

It is concluded that, considering the limitations of this kind of experimental studies, early re-epithelisation occurs slightly faster when a conventional scalpel is used for incision, although re-epithelisation is completed in two weeks no matter the instrument used. In addition, pseudoepitheliomatous hyperplasia is a potential event after oral mucosa surgery with diode laser. Knowledge about this phenomenon (not previously described) may prevent diagnostic mistakes and inadequate treatment approaches, particularly when dealing with potentially malignant oral lesions.

Key words:Diode laser, animal model, oral biopsy, oral cancer, oral precancer, pseudoepitheliomatous hyperplasia.

Unifocal orofacial granulomatosis in retromolar mucosa: surgical treatment with Er,Cr:YSGG laser

Orofacial granulomatosis is defined by permanent or recurrent swelling of orofacial tissues with different multiform and multifocal clinical patterns. An 11-year old boy presented with a 2-month history of mucosa enlargement. Intraoral examination revealed an erythematous, polylobulated, exophytic lesion with a smooth surface located in retromolar mucosa, non-tender and non-infiltratated to palpation. The diagnosis was inflammatory lesion compatible with pyogenic granuloma and laser excision was decided. Haematological parameters were within normal range, as well as chest Xrays. These findings lead to a diagnosis of non-symptomatic orofacial granulomatosis, whose early diagnosis can minimize the impact of systemic-related disorders, like Chron’s disease.

Key words:Laser, orofacial granulomatosis, childhood, oral lesions, diagnosis.

In vivo antiplaque effect of three edible toothpastes

OBJECTIVES

The objective of this study was to analyse the antibacterial and antiplaque activity of three edible toothpastes with the widest worldwide distribution: KidScents™, which contains essential oils; Browning B& B™, with medicinal plants; and Wysong Probiodent™, which contains probiotics.

STUDY DESIGN

The study group was formed of twenty healthy volunteers (dental students) with a good oral health status. Using a balanced randomisation system, all volunteers performed toothbrushing with four products (the three edible toothpastes and water) at intervals of one week. Bacterial vitality in the saliva was analysed by epifluorescence microscopy and plaque regrowth was evaluated using the Turesky-Quigley-Hein plaque index.

RESULTS

Bacterial vitality in the saliva was significantly higher after toothbrushing with water (positive control) than with the three toothpastes (P=0.002, P=0.003 and P<0.001, respectively). The plaque index was significantly higher after using these three toothpastes than after toothbrushing with water (P=0.047, P=0.032 and P<0.001, respectively).

CONCLUSIONS

The three edible toothpastes analysed have some antimicrobial activity but favour plaque regrowth.

Membrane perforation in sinus floor elevation - piezoelectric device versus conventional rotary instruments for osteotomy: an experimental study

PURPOSE

Sinus membrane perforation is the most common intraoperative complication of maxillary sinus floor elevation (MSFE) procedures and frequently causes postoperative problems. Piezoelectric devices have been claimed to reduce the frequency of membrane perforations although no clear evidence supports this view.

MATERIALS AND METHODS

Ten surgeons with different expertise levels performed 80 MSFEs in selected lamb heads, with rotary and piezoelectric instruments following standard protocols. After the procedures, specimens were coded and perforations or tears determined through a microscope.

RESULTS

No significant differences in terms of thickness either of the sinus lateral wall (xi -xj  = 73.2; 95% confidence interval [CI] = 45.3-191.8) or the membrane (xi -xj  = 24.2; 95% CI = -29.4 to 77.9) were identified between the specimens allocated to each group. Nine membrane perforations (11.2%) occurred during the study, all within the lower expertise group. Membrane elevation by hand instruments caused five perforations (40%) in the rotary instrument group and one in the piezoelectric group. Expert surgeons produced no membrane perforations, the size of the antrostomy that was smaller in the piezoelectric group being the only significant difference between the rotary and piezoelectric groups.

CONCLUSIONS

The use of piezoelectric material for MSFE reduces the frequency of membrane perforation among surgeons with a limited experience.

Er,CR:YSGG lasers induce fewer dysplastic-like epithelial artefacts than CO2 lasers: an in vivo experimental study on oral mucosa

Our aim was to assess wounds made by lasers (CO(2) and Er,Cr:YSGG) for their epithelial architectural changes and width of damage. We allocated 60 Sprague-Dawley(®) rats into groups: glossectomy by CO(2) laser at 3 different wattages (n=10 in each); glossectomy by Er,Cr:YSGG laser at two different emissions (n=10 in each), and a control group (n=10). Histological examination assessed both prevalence and site of thermal artefacts for each group. Both lasers (CO(2) and Er,Cr:YSGG) caused the same type of cytological artefacts. The 3W Er,Cr:YSGG laser produced the fewest cytological artefacts/specimen, and was significantly different from the other experimental groups: 3W CO(2) laser (95% CI=0.8 to 1.0); the 6W CO(2) laser (95% CI=0.1 to 2.0) and the 10W CO(2) laser (95% CI=1.1 to 3.0). CO(2) lasers (3-10W) generate epithelial damage that can simulate dysplastic changes with cytological atypia that affects mainly the basal and suprabasal layers. Irradiation with Er,CR:YSGG laser (2-4W) produces significantly fewer cellular artefacts and less epithelial damage, which may be potentially useful for biopsy of oral mucosa.

Lamb ex vivo model for training in maxillary sinus floor elevation surgery: a comparative study with human standards

BACKGROUND

Many models have been suggested for surgical training in sinus floor elevation (SFE), but information on key features that provide feedback to the trainee is scarce. The aim of this study is to compare the thickness of the lateral wall of the maxillary sinus (TLWMS) and the thickness of the Schneiderian membrane (TSM) between an animal model and the human standard.

METHODS

The observational study used 20 fresh lamb heads. Cone-beam computed tomography (CT) was performed for recording the following: TLWMS, sinus lateral floor width, distance from the lateral border of the anteroposterior bone crest to the sinus wall, and height of lateral maxillary sinus. Thirty human radiologic exploration cone-beam CTs were used for comparisons. The sinus membrane thickness was measured at three points per section and compared to those of 10 formalin-preserved human membranes.

RESULTS

TLWMS in the animal model scored 2.25 ± 0.3 mm and was thicker than that of humans with subsinusal edentulism (Xi - Xj = 0.3; 95% confidence interval = 0.1 to 0.4), although this difference was not considered clinically relevant. The average thickness of the sinus membrane was 485.5 ± 137.1 μm with no significant differences between sides (P = 0.12) or between the thickness of human and lamb Schneiderian membranes.

CONCLUSIONS

The model based on lambs is potentially useful for training in SFE techniques because of the similarities in the TLWMS and particularly the TSM. Additional studies are needed to validate this model within a teaching environment.

Evaluation of chlorhexidine substantivity on salivary flora by epifluorescence microscopy

OBJECTIVE

To evaluate the in vivo antimicrobial activity of chlorhexidine (CHX) in saliva 7 h after its application using an epifluorescence microscopy technique.

SUBJECTS AND METHODS

Fifteen volunteers performed a single mouthrinse with sterile water (SM-water) and with 0.2% CHX (SM-0.2% CHX). Saliva samples were taken at 30 s and 1, 3, 5 and 7 h after each application. The bacterial suspension was mixed with the SYTO 9/propidium iodide staining and observed using an Olympus BX51 microscope. The mean percentage of viable bacteria was calculated for each sample.

RESULTS

In comparison with baseline values, the frequency of viable bacteria decreased significantly at 30 s after the SM-0.2% CHX (P < 0.001) and presented significant antibacterial activity up to 7 h after the mouthrinse (P < 0.001). In comparison with SM-water, the prevalence of viable bacteria was significantly lower at 30 s after the SM-0.2% CHX (P < 0.001) and showed a significant antibacterial effect up to 7 h after the mouthrinse (P < 0.001).

CONCLUSIONS

Epifluorescence microscopy permits evaluating the antimicrobial activity of CHX on the salivary flora in real-time. Fluorescence assays could be particularly useful to analyse simultaneously the effect of antimicrobials that alter the cytoplasmic membrane integrity on different oral ecosystems.

Unsuspected foreign body aspiration

Aspiration of foreign bodies is a serious complication that may occur during the course of dental treatment. A case report of a 60-year-old man with recurrent pneumonia is presented. One year after the onset of his initial symptoms, a hard substance that made a complete mold of the bronchial tree at the inferior right lobe was extracted with a rigid bronchoscopy. This green material of elastic consistency was dental impression material (polyvinylsiloxane). On careful questioning, the patient indicated that he had dental impressions taken 2 months before the onset of the symptoms. Surgery was indicated and lobectomy of the inferior right lobe was performed without incident. To avoid this complication, some preventive precautions such as identifying high-risk patients; using rubber dam; tethering any small instrument with a ligature; placing a gauze screen to protect the oropharynx in sedated patients; and using custom impression trays to minimize the amount of impression material required have been suggested. In case of a suspected aspiration, the patient must be referred to appropriate medical care.