Impact of Cut-out-rescan and Data Exchange by Over-scanning Techniques on Marginal Fit of CAD/CAM Lithium Disilicate Crowns.

OBJECTIVE: Evaluate the impact of adjustment procedures - cut-out-rescan (COR) and data exchange by over-scanning (DEOS) techniques - through CAD/CAM software on the marginal fit outcome of ceramic crowns. METHODS AND MATERIALS: Twenty-eight de-identified teeth were adapted in a mandibular typodont set. Tooth #19 was prepared for a lithium disilicate crown and seven groups, G0 to G6 (n=10), were created based on the rescanned areas (mesial and/or buccal) on the typodont using an intraoral scanner through COR or DEOS techniques. A digital workflow was used to design and mill 70 crowns according to the groups. Each crown was temporarily cemented on tooth #19 and scanned with micro-computed tomography to measure the marginal fit. The data were analyzed statistically by the Kruskal-Wallis test followed by the Mann-Whitney test to compare the groups pairwise as a post-hoc (α=0.05). RESULTS: Statistically significant differences were found for vertical misfit (µm) between the groups for Marginal Gap Buccal (MGB) and Marginal Gap Mesial (MGM) (p=0.003 and p=0.029, respectively). No significant difference was found for Finish Line Buccal (FLB) and Finish Line Mesial (FLM) (p=0.062 and p=0.092, respectively). G3 (COR buccal and mesial) had the highest MGB (57.75 µm), statistically different from all other groups. G4 (DEOS buccal) (41.60 µm) was different from G6 (DEOS buccal and mesial) (44.21 µm) (p=0.023). For MGM, G0 (control) (53.96 µm) was different from G5 (DEOS mesial) (45.76 µm) and G6 (DEOS buccal and mesial) (48.56 vm) (p=0.013 and p=0.041, respectively) and G2 (COR mesial) (58.43 µm) was different from G5 (DEOS mesial) (45.76 µm) (p=0.016). CONCLUSIONS: Despite a statistically significant difference in certain groups for both techniques, COR and DEOS techniques are viable options for image editing during acquisition. Lithium disilicate crowns can be produced with satisfactory marginal gap values utilizing a chairside CAD/CAM system.

Control of tissue homeostasis by the extracellular matrix: Synthetic heparan sulfate as a promising therapeutic for periodontal health and bone regeneration.

Proteoglycans are core proteins associated with carbohydrate/sugar moieties that are highly variable in disaccharide composition, which dictates their function. These carbohydrates are named glycosaminoglycans, and they can be attached to proteoglycans or found free in tissues or on cell surfaces. Glycosaminoglycans such as hyaluronan, chondroitin sulfate, dermatan sulfate, keratan sulfate, and heparin/heparan sulfate have multiple functions including involvement in inflammation, immunity and connective tissue structure, and integrity. Heparan sulfate is a highly sulfated polysaccharide that is abundant in the periodontium including alveolar bone. Recent evidence supports the contention that heparan sulfate is an important player in modulating interactions between damage associated molecular patterns and inflammatory receptors expressed by various cell types. The structure of heparan sulfate is reported to dictate its function, thus, the utilization of a homogenous and structurally defined heparan sulfate polysaccharide for modulation of cell function offers therapeutic potential. Recently, a chemoenzymatic approach was developed to allow production of many structurally defined heparan sulfate carbohydrates. These oligosaccharides have been studied in various pathological inflammatory conditions to better understand their function and their potential application in promoting tissue homeostasis. We have observed that specific size and sulfation patterns can modulate inflammation and promote tissue maintenance including an anabolic effect in alveolar bone. Thus, new evidence provides a strong impetus to explore heparan sulfate as a potential novel therapeutic agent to treat periodontitis, support alveolar bone maintenance, and promote bone formation.

Periodontal Status as Mediator of the Association between Socioeconomic Status and Oral Health-Related Quality of Life in Pregnant Women.

OBJECTIVE: To test periodontal status as a mediator between socioeconomic status (SES) and oral health-related quality of life (OHRQoL) in pregnant women. BASIC RESEARCH DESIGN: Secondary cross-sectional analysis of baseline data from a randomised clinical trial with 303 pregnant women. MAIN OUTCOME MEASURES: Demographic variables, SES, smoking, interproximal hygiene, and self-reported gingival bleeding were collected as independent variables. The Oral Health Impact Profile-14 was used to assess OHRQoL. The relationship between SES, periodontal status and OHRQoL was investigated in structural equation modelling. RESULTS: There was a moderate association of SES with periodontal status (standardised coefficient SC = -0.26, p⟨0.01) and number of teeth (SC = 0.24, p⟨0.01). Periodontal status and the number of teeth were also associated with OHRQoL (respectively, SC = 0.25, p⟨0.01 and SC = -0.31, p⟨0.01), but SES was only indirectly related to OHRQoL (SC = -0.17, p⟨0.01). Socioeconomic inequalities in quality of life were mainly explained by the remaining number of teeth, contributing to about 47%, and periodontal status, contributing to about 41%. CONCLUSIONS: There was no direct effect of SES on OHRQoL in pregnant women. Periodontal status and missing teeth each explained almost half of the total indirect association.

Quality assessment of randomised controlled trials in oral and maxillofacial surgery.

Randomised controlled trials are the best way to study the evaluation of treatments. We have evaluated the quantity and quality of clinical trials in three of the main journals in the specialty of oral and maxillofacial surgery between January 2010 and December 2016, using a scientometric analysis, and evaluation by the Jadad scale. In this period, 303 randomised controlled trials (5% of the total) were identified; the largest number of studies were from Asia (45%) followed by Europe (32%). The subgroup that concerned most studies was oral surgery. The mean score on the Jadad scale was 3.06 points, which means that 32% of the total studies had a low risk of bias. Studies that declared funding and adherence to Consolidated Standards of Reporting Trials (CONSORT) were given significantly higher scores (p<0.001) than studies that did not. We conclude that randomised controlled trials in oral maxillofacial surgery have evolved in both quality and quantity since previous surveys were published. The quality of trials was related to the presence of funding and adherence to CONSORT.