Increasing the fracture strength of MOD restorations with Ribbond fibers.

Background: The aim of this study was to compare the fracture strength of two different Ribbond Fiber (Ribbond, Ribbond Inc., Seattle, WA, USA) restoration strategies in 5 mm deep standardized MOD cavities without interaxial dentin. Material and Methods: 34 extracted human molars were randomly divided into two groups and restored as follows: Group 1 restoration with Ribbond Fiber placed at the cavity floor incorporated in Estelite Bulk-Fill Flow Universal composite (Tokuyama Dental Corporation Inc., Tokyo, Japan); Group 2 restoration with RF placed at 3 mm from the occlusal plane over a 2mm layer of Estelite Bulk-Fill Flow. The occlusal plane in both groups was restored with Ceram.x Spectra ST (Dentsply Sirona, Ballantyne Corporate Pl, Charlotte, NC, USA). The restored teeth were subjected to thermal cycling by immersing them for 30 seconds in hot water (55±2°C) followed by 30 seconds in cold water (5±2°C), for 2000 cycles.Their fracture strength was then evaluated using an Instron device. Data were analyzed with Two-sample T Test statistical test to compare fracture strength among groups. Finally, a descriptive analysis of the failure location was performed. Results: A statistically significant difference was found between groups 1 and 2 (P<0.001) in terms of fracture strength. Group 2 exhibited a higher percentage of recoverable fractures compared to group 1. Group 1 had a mean fracture load of 833N and a SD of 248 while group 2 had a mean fracture load of 1286N and SD of 447. Conclusions: RF placed at 3 mm depth from the occlusal plane, on a 2 mm layer Estelite Bulk-Fill Flow Universal composite (Tokuyama Dental Corporation Inc., Tokyo, Japan) contributes to improve fracture resistance in vital teeth without interaxial dentin and reduces the risk of non-recoverable fractures compared to when it is placed at a 5 mm depth. Key words:Ribbond fiber, composite restoration, fracture resistance, Instron machine.

Dental plaque microbiota sequence counts for microbial profiling and resistance genes detection.

Shotgun metagenomics sequencing experiments are finding a wide range of applications. Nonetheless, there are still limited guidelines regarding the number of sequences needed to acquire meaningful information for taxonomic profiling and antimicrobial resistance gene (ARG) identification. In this study, we explored this issue in the context of oral microbiota by sequencing with a very high number of sequences (~ 100 million), four human plaque samples, and one microbial community standard and by evaluating the performance of microbial identification and ARGs detection through a downsampling procedure. When investigating the impact of a decreasing number of sequences on quantitative taxonomic profiling in the microbial community standard datasets, we found some discrepancies in the identified microbial species and their abundances when compared to the expected ones. Such differences were consistent throughout downsampling, suggesting their link to taxonomic profiling methods limitations. Overall, results showed that the number of sequences has a great impact on metagenomic samples at the qualitative (i.e., presence/absence) level in terms of loss of information, especially in experiments having less than 40 million reads, whereas abundance estimation was minimally affected, with only slight variations observed in low-abundance species. The presence of ARGs was also assessed: a total of 133 ARGs were identified. Notably, 23% of them inconsistently resulted as present or absent across downsampling datasets of the same sample. Moreover, over half of ARGs were lost in datasets having less than 20 million reads. This study highlights the importance of carefully considering sequencing aspects and suggests some guidelines for designing shotgun metagenomics experiments with the final goal of maximizing oral microbiome analyses. Our findings suggest varying optimized sequence numbers according to different study aims: 40 million for microbiota profiling, 50 million for low-abundance species detection, and 20 million for ARG identification. KEY POINTS: • Forty million sequences are a cost-efficient solution for microbiota profiling • Fifty million sequences allow low-abundance species detection • Twenty million sequences are recommended for ARG identification.

Analysis of ultra-short implants with different angulations: a retrospective case-control study with 2 to 9 years of follow-up.

OBJECTIVES: Does the angulation of ultrashort implants influence the stability of the peri-implant bone? The present study aimed to evaluate the effectiveness of non-axial ultrashort implants after 2 to 9 years of follow-up in resorbed alveolar ridges. MATERIALS AND METHODS: All partially edentulous patients with ultrashort implants (< 6 mm) used in the posterior region of an atrophic mandible or maxilla, to support partial dentures in conjunction with standard implants, were included in this study. Peri-implant bone loss, success and survival rates, crestal bone levels, crown-to-implant ratio and implant angulation were measured for each implant. Implants were divided into two groups: straight implants with angulation < 17° (control group) and tilted implants with angulation > 17° (test group). Statistical analysis was used to find any significant differences between the two study groups and to investigate significant linear correlations among all the variables (p = 0.05). RESULTS: A total of 42 ultrashort implants with a mean of 4 years of follow-up were included: 20 ultrashort axially loaded implants and 22 tilted implants. Mean crestal bone levels from baseline loading to maximum follow-up did not reveal statistical differences in regard to PBL; mean success and survival rates were 100% in all groups. CONCLUSIONS: PBL, success and survival rates of axial ultrashort implants and tilted ultrashort implants are comparable to those of conventional implants. CLINICAL RELEVANCE: This retrospective study revealed that ultrashort implants, even when placed with an angulation > 17°, can safely be used to support partial fixed prostheses. Further prospective clinical studies with larger samples and prospective design are needed to confirm these findings.

Fracture strength and ribbond fibers: In vitro analysis of mod restorations.

Background: Ribbond fibers are supposed to be a reinforcing material in restoration of compromised teeth. This study aims to compare MOD restorations with and without Ribbond Fiber in terms of fracture strength under axial loading; to identify the minimum depth of MOD cavities to use Ribbond Fiber (to improve the fracture strength under axial load. Material and Methods: 20 upper and lower molars extracted intact were used for the experiment. The teeth were prepared with 2 types of cavities and then divided into 4 groups: 1) 5 mm deep MOD cavities with residual interaxial dentin restored without Ribbond; 2) 5 mm deep MOD cavities with residual interaxial dentin restored with Ribbond; 3) 5 mm deep MOD cavities without residual interaxial dentin, restored without Ribbond; 4) 5 mm deep MOD cavities without residual interaxial dentin restored with Ribbond. The restored teeth were then subjected to thermal cycling and their fracture strength was evaluated using an Instron device. The Mann-Whitney statistical test was used to compare fracture strength among groups. Finally, a descriptive analysis of the verified fractures was performed. Results: There was a statistically significant difference between groups 1 and 2 (P = 0.0090) in the loading force required for a fracture. In contrast, there was no statistically significant difference between groups 3 and 4 (P = 0.7540). Groups 1 and 2 had the fewest non-restorable fractures, in contrast to groups 3 and 4. Conclusions: Ribbond fiber application in MOD cavities seems to be more effective in terms of strengthening where cavities have interaxial dentinal tissue. Key words:Ribbond fibers, fracture strenght, direct dental restorations.

Stamp Technique: An Explorative SEM Analysis.

BACKGROUND: Achieving correct tooth anatomy and saving time at the dental chair are some of the goals of modern restorative dentistry. Stamp technique has gained acceptance in clinical practice. The aim of this study was to evaluate the effectiveness of this technique in terms of microleakage, voids, overhangs and marginal adaptation of Class I restorations, and to analyse the operative times in comparison with traditional restorative procedures. METHODS: Twenty extracted teeth were divided into 2 groups. Ten teeth in the study group (SG) were Class I prepared and restored using stamp technique, and ten teeth in the control group (CG) were Class I restored traditionally. SEM analysis was performed to evaluate voids, microleakage, overhangs, and marginal adaptation, and operative times were recorded. A statistical analysis was performed. RESULTS: There were no significant differences in microleakage, marginal adaptation and filling defects between the two groups, however, the stamp technique seems to facilitate the formation of large overflowing margins that require a careful finishing phase. CONCLUSIONS: Stamp technique does not seem to have any critical aspects in terms of restoration durability and it can be performed in a short time.

Insights on dental care management and prevention in children with autism spectrum disorder (ASD). What is new?

Autistic subjects represent a severe concern to dentistry due to the considerable difficulty in managing their oral health, maintaining routine toothbrushing, and preventing dental and periodontal problems. The social and economic burden of managing dental care in autism spectrum disorder (ASD) children is particularly cumbersome for families and public and private health expenditure, especially when children reach the dentist following a late diagnosis with evident oral health problems. An early diagnosis of ASD helps dentists better address these children's oral health. Unfortunately, insufficient attention is paid to the training and education of general pediatricians, dentists, and dental hygienists, allowing them to get to approach the different clinical aspects of ASD. Usually, children diagnosed with ASD are scheduled for dental appointments like their neurotypical peers, whereas their needs are typically complex and personalized. Scant attention is also devoted to these patients by commercial manufacturers of dental products and devices for oral hygiene and prevention of caries and periodontal diseases, leaving parents without the support and often failing when they address the oral health of autistic children. The difficulties of oral care do not derive simply from the behavior of ASD patients, as is commonly assumed, and therefore cannot be overcome solely by the patience and attention of parents and dentists. Genetics, dietary habits, sensory impairments, and cognition disorders are other causes contributing in various degrees to the impact on the mood and psychological reactions of autistic children towards dentists. How can we prevent teeth caries, periodontal disorders, and other oral health impairments by properly managing ASD children? This manuscript gives an up-to-date overview of these problems and helps to provide good remarks.

Telediagnosis of dental caries: Possible or impossible? A pilot cross-sectional study.

OBJECTIVES: The aims of this study were to evaluate the effectiveness of teledentistry (based on a home intraoral imaging protocol) in detecting dental caries and to assess the accuracy of this method compared to clinical examination. METHODS: Forty-three patients were recruited for the study. Using a protocol for taking intraoral photographs at home with a smartphone proposed by the Dental School of Verona, a remote diagnosis of dental caries (TD) was performed by an experienced dentist. The same caries sites were also assessed by clinical diagnosis (CD) by a second experienced dentist. Ten photos were taken at home in five different perspectives, with and without flash, and emailed to one of the authors. The best five photos were selected for telediagnosis. The International Caries Detection and Assessment System (ICDAS II) score was used for caries diagnosis. Statistical tests were performed: Sensitivity and specificity of TD, the positive and negative predictive value of TD (PPV-NPV), and Spearman correlation to evaluate the relationship between the scores of TD and CD. RESULTS: A total of 430 photographs were submitted; TD was performed on 215 photographs and 43 patients were visited. A total of 1201 teeth were analyzed. The sensitivity of TD was 74.0, the specificity was 99.1, the PPV of TD was 91.7, and the NPV was 96.4. The Spearman correlation was 0.816, showing a very strong correlation between the values obtained with TD and CD. CONCLUSIONS: The study showed good potential for TD, which proved to be a feasible method to combine with routine caries diagnosis in daily preventive dentistry practice.

Digital Dental Models: Is Photogrammetry an Alternative to Dental Extraoral and Intraoral Scanners?

BACKGROUND: 3D models are nowadays part of daily clinical practice. Photogrammetry is a brand-new method for transforming small objects into 3D models while keeping their original shape and size. The aim of this study was to evaluate the accuracy, in terms of precision and trueness, of a digital dental model acquired with photogrammetry compared with those obtained using extraoral scanners and intraoral scanners, starting from the same plaster model. METHODS: A plaster model was converted into a digital model using photogrammetry, an extraoral scanner and an intraoral scanner. Different references were measured twice at a distance of 30 min for each model, on the digital models using the software Blender and on the plaster model using a calibre. The Interclass Correlation Coefficient was calculated for each pair of measurements. A volumetric analysis was performed by superimposing the digital models. The coefficient of variation was calculated. A two-way ANOVA test was conducted. RESULTS: For each reference, the coefficient of variation was less than 3%, and the two ANOVA tests resulted in a non-significant value in both cases (p > 0.05). The volumetric analysis demonstrated good agreement between the models derived from the different acquisition methods. CONCLUSIONS: Photogrammetry seems to be a good method for acquiring digital models starting from a plaster model, all the methods tested seem to be good for obtaining an accurate three-dimensional digital model. Other studies are needed to evaluate clinical efficacy.

Microleakage of Direct Restorations-Comparisonbetween Bulk-Fill and Traditional Composite Resins:Systematic Review and Meta-Analysis.

Since the bulk-fill composites were produced, there was a progressive diffusion of their use for direct conservative treatment in posterior teeth. Their chemical structure increases the depth of cure and decreases the polymerization contraction; in this manner, bulk-fill composites can be placed in 4 mm single layers and the treatment times are considerably reduced. However, aesthetic and mechanical properties and impact on microleakage of bulk-fill resins are still unclear.This systematic review and meta-analysis aimed to assess the risk of microleakage of direct posterior restorations made of bulk-fill versus conventional composite resins.Researches were performed on PubMed and Scopus databases. Eligible in vivo studies, published since 2006, were reviewed. Outcomes of marginal discoloration, marginal adaptation, and recurrent caries were considered to conduct the systematic review and meta-analysis. Secondary data were examined to implement additional analysis and assess the risk of bias.Eight randomized clinical trials were analyzed, involving 778 direct restorations. The summary of RCTs led to significant but inconsistent results; the marginal discoloration and recurrent caries were found to be improved respectively by 5.1 and 1.4%, whereas the marginal adaptation was reduced of 6.5%. Secondary analyses revealed that follow-up periods, the adhesive system used and the class of carious lesions evaluated are confounding factors, and they result in a risk of bias across studies.Bulk-fill composites are innovative materials for conservative dentistry and they can be used to reduce treatment steps and duration of operative times. There are insufficient data to explore the relationship between bulk-fill composites and microleakage and further investigations are needed.

Oral Lichen Planus: risk factors of malignant transformation and follow up. Ten years retrospective study.

BACKGROUND: Oral Lichen Planus (OLP) is an inflammatory chronic disease. Modified World Health Organization (WHO) diagnostic criteria (2003) suggest diagnosing OLP both clinically and histologically. Furthermore, it is known the potential of malignant transformation of OLP, especially those affecting mucosa. Aims of this retrospective study on 100 patients were i) to estimate the timing of transformation of OLP lesions in OSCC in a cohort of patients observed between 2008 and 2018; ii) to assess risk factors of OLP patients diagnosed with OSCC; iii) to analyse forms of OLP evolved in cancer. MATERIAL AND METHODS: A database of 100 patients diagnosed with OLP was evaluated and clinical, histological features of lesions, habits of patients and systemic diseases were analysed in a follow up ranged between 5 and 10 years. RESULTS: Mean time of malignant transformation was 31,62± 18,26 months; however, 4 malignant transformations out of 8 occurred about after 4 years of observation. Furthermore, Odds ratios for risk factors showed an association between malignant transformation and location. CONCLUSIONS: More focused attention on follow-up scheduling and designing could be a valuable resource in early diagnosis and cancer prevention in OLP patients. Key words:Oral Lichen Planus, Oral Cancer, Malignant transformation, risk factors.

How to deal with coronavirus disease 2019: A comprehensive narrative review about oral involvement of the disease.

OBJECTIVES: The aim of this narrative review was to collect all findings from literature about oral signs and symptoms of COVID-19, in order to draw a picture of oral involvement of this challenging viral infection, to help oral professionals in a better triage and early diagnosis. MATERIAL AND METHODS: The search for international literature was made including articles written in English and reporting about oral manifestations in patients with a diagnosis of COVID-19. The publication time was limited to 2019 and 2020, up to May 20, 2020. A narrative review was performed. RESULTS: Twenty-three articles were included in this review. Three different oral manifestations were found: taste alteration, oral blister and ulcers, and oral lesions associated with Kawasaki-like diseases (erythema, bleeding of lips, "strawberry tongue"). The higher expression of Angiotensin-converting enzyme 2 in the oral cavity and in endothelial cells might be responsible for oral manifestation and the major report of signs and symptoms in the occidental countries. CONCLUSIONS: Detecting oral signs and symptoms of COVID-19 could be useful to perform a better preliminary triage in dental setting, and in recognizing possible early manifestations of the disease. However, considering the outbreak of COVID-19 and the consequent difficulty of undergoing oral examinations, the oral manifestations might be misdiagnosed; then, we would encourage oral professionals to perform other studies about this topic.

Aesthetic Dentistry, How You Say and How You See: A 500-People Survey on Digital Preview and Color Perception.

PURPOSE: Digital technologies have improved ways to perform aesthetic dentistry in the last few years. The aims of this survey were to investigate the most preferred way to preview the result of an aesthetic dental rehabilitation among a population of dental professionals and laypeople and to compare aesthetic standards of the general population and dentists in terms of the color of teeth for aesthetic dental rehabilitations. PATIENTS AND METHODS: A questionnaire was sent to the subjects (dentists and laypeople) during a 1-year period and, together with their demographic data, different ways to preview the result of an aesthetic rehabilitation were submitted, such as digital smile design, dental wax-up and oral explanation. Furthermore, an additional section of the questionnaire investigated the most suitable color for an aesthetic rehabilitation based on the colors of the VITA Scale. Results were statistically analyzed (with Chi-square of independence and Mann-Whitney U-test) highlighting differences of answers based on age groups, educational attainment, gender, and belonging or not to the dental field. RESULTS: Findings showed that digital smile design (digital preview) is a high-appreciated method for previewing and communicating with patients both by dental professionals and laypeople. Furthermore, lighter colors were found to be more valued by laypeople and significant differences were highlighted between the two populations assessed. CONCLUSION: It seems to be viable to use digital preview for dentists and laypeople to improve previewing and communicating ways. It might be advisable to better motivate patients in recognizing aesthetical features and to raise their awareness in preferring more mimetic aesthetic results. Great opportunities are opened up by digital smile design in teaching, learning, and routine practice.

A Snapshot of Knowledge about Oral Cancer in Italy: A 505 Person Survey.

Objectives: Patients' knowledge about oral squamous cell carcinoma (OSCC) plays an important role in primary prevention, early diagnosis, and prognosis and survival rate. The aim of this study was to assess OSCC awareness attitudes among general population in order to provide information for educational interventions. Methods: A survey delivered as a web-based questionnaire was submitted to 505 subjects (aged from 18 to 76 years) in Italy, and the answers collected were statistically analyzed. Information was collected about existence, incidence, features of lesions, risk factors of oral cancer, and self-inspection habits, together with details about professional reference figures and preventive behaviors. Results: Chi-square tests of independence with adjusted standardized residuals highlighted correlations between population features (age, gender, educational attainment, provenance, medical relationship, or previous diagnoses of oral cancer in family) and knowledge about oral cancer. Conclusions: Knowledge about OSCC among the Italian population is limited, and it might be advisable to implement nudging and sensitive customized campaigns in order to promote awareness and therefore improve the prognosis of this disease.

Conservative non-surgical management in medication related osteonecrosis of the jaw: A retrospective study.

OBJECTIVES: To date, the best treatment for Medication Related Osteonecrosis of the jaw (MRONJ) is controversial. Recent studies suggest different therapies, considering the stage of MRONJ; however, sometimes patients, although with remarkable extension of disease, cannot undergo surgery. The purpose of present preliminary study was to evaluate the efficacy of conservative non-surgical treatment of MRONJ lesions in a cohort of patients ineligible for surgery or refusing any surgical treatment for stage II and III of MRONJ. MATERIALS AND METHODS: Patients with MRONJ (staging II or III) ineligible for surgical treatment were selected for a retrospective study. A conservative non-surgical therapy (antibiotics and antiseptic) was administered for 1 year. Five scheduled checks were performed to assess changes in signs and symptoms during the observational period. RESULTS: Our observation was carried out on 12 patients. Improvement of signs and symptoms of disease were observed in population. CONCLUSION: This study suggests that non-surgical treatment may be a valid therapeutic option in patients ineligible for surgery. The sample size is small, further studies should be carried out to satisfy the aim of a conservative non-surgical treatment protocol establishment.

Malignant transformation evidences of Oral Lichen Planus: When the time is of the essence.

Oral Lichen Planus (OLP) is an inflammatory chronic disease, its potential of malignant transformation is widely known, especially for lesions affecting mucosa. This letter aims to highlight, thanks to results obtained from a long-term observation of one hundred patient suffering from OLP, the importance to set proper and sufficiently long follow-ups. An important evidence observed is the malignant developing after 4 years of observation in 4 cases of 8. This leads to conclude that follow-up for OLP lesions is required to be as long as possible in order to timeously intercept malignant transformations of these lesions and to perform a realistic early diagnosis. Final suggestion is to design more prospective studies based of long observation period.

Oral MALT Lymphoma: Something to remember.

Oral MALT Lymphoma is rare condition and its pathogenesis are related to persistent immune stimulation caused by chronic infection or inflammation. We report a case of MALT lymphoma of the palatal minor salivary glands in a 73-year-old white woman with clinical history of osteoporosis and systemic lupus erythematosus associated with Sjögren's syndrome. This letter aims to call the attention on large number of factors to take into account in evaluating patients with an history of auto-immune diseases. This idea results from our difficulty in identifying this pathology in first diagnosis, due to rarity of this condition and severe comorbidity associated.

Resin Infiltration in Dental Fluorosis Treatment-1-Year Follow-Up.

Background and objective: Dental fluorosis is a disease affecting dental hard tissues featured with white or yellowish lesions. Several treatments are proposed in the literature, some even invasive. This clinical study aimed to evaluate the effectiveness of resin infiltration in terms of lesions resolution, trend of sensitive teeth and satisfaction of patients over time. Methods and material: 200 fluorosis lesions were treated using ICON infiltrating resin (DMG, Hamburg, Germany). Parameters related to patients were collected by a questionnaire and analyzed aesthetic dissatisfaction about lesions, Shiff Air Index Sensitive Scale, sensitive teeth after treatment, the satisfaction of duration of treatment. The same operator measured dimensions of lesions Tooth Surface Index of Fluorosis (TSIF) and numbers of etching cycles needed for treating lesions. Statistical analysis was performed. The follow-up was of 1-year a measurement were performed at baseline (t0), immediately after the treatment (t1) and every three months during the observation period. Results: All lesions disappeared after one treatment. Pain or sensitive teeth were reported inside the 72 h and they disappeared after. Statistical analysis showed highly statistically correlation between etching cycles and the dimension of lesions and TSIF at the time-points evaluated as well as for pain during treatment, whereas a statistical significance was not noticed where etching cycles were correlated to sensitive teeth after 72 h. Overall, the treatment was found to be statistically significantly associated with differences in answers of aesthetic dissatisfaction between t0 and t1 and those collected between t1 and t2. Between t2 and t3 and between t3 and t4 no statistical differences were found in answers of patients about dissatisfaction, indicating the stability of the results. Conclusions: The ICON resin infiltration technique was found to be effective in lesions resolution with steady results.

Fresh-frozen homologous bone in sinus lifting: histological and radiological analysis.

BACKGROUND: The aim of this study was to evaluate radiological and histological characteristics of fresh-frozen homologous bone as grafting material for maxillary sinus floor augmentation. Radiological, histological and clinical evaluations were made. METHODS: Twenty-three patients with a 2 mm to 6 mm alveolar ridge height in the posterior maxilla have been enrolled. Unilateral or bilateral sinus floor augmentations were performed with fresh frozen morcelized homologous bone. Together with implant placement, 7 months after surgery, a bone core was harvested for histological analysis. Radiological measurements were obtained by superimposition of CT scans carried out at the surgery time and six months later. A total of 93 implants were positioned. RESULTS: A mean (±SD) increase in mineralized tissue height of 10.74±2.82 mm was noticed by comparing the CT scans. Histological analysis revealed the presence of newly formed bone in the grafted sites. The follow up period after the prosthetic load ranged from 8 to 31 months. One implant failure occurred. CONCLUSIONS: Fresh frozen homologous bone seems to have a good healing pattern and to be a successful and steady grafting material for the treatment of maxillary ridge atrophy. It might be considered a valid alternative to autologous bone in sinus floor augmentation procedures.