Differences in Mechanical and Physicochemical Properties of Several PTFE Membranes Used in Guided Bone Regeneration.

Non-resorbable PTFE membranes are frequently used in dental-guided bone regeneration (GBR). However, there is a lack of detailed comparative studies that define variations among commonly used PTFE membranes in daily dental clinical practice. The aim of this study was to examine differences in physicochemical and mechanical properties of several recent commercial PTFE membranes for dental GBR (CytoplastTM TXT-200, permamem®, NeoGen®, Surgitime, OsseoGuard®-TXT, OsseoGuard®-NTXT). Such differences have been rarely recorded so far, which might be a reason for the varied clinical results. For that reason, we analyzed their surface architecture, chemical composition, tensile strength, Young's modulus, wettability, roughness, density, thickness and porosity. SEM revealed different microarchitectures among the non-textured membranes; the textured ones had hexagonal indentations and XPS indicated an identical spectral portfolio in all membranes. NeoGen® was determined to be the strongest and OsseoGuard®-TXT was the most elastic. Wettability and roughness were highest for Surgitime but lowest for OsseoGuard®-NTXT. Furthermore, permamem® was the thinnest and NeoGen® was identified as the thickest investigated GBR membrane. The defect volumes and defect volume ratio (%) varied significantly, indicating that permamem® had the least imperfect structure, followed by NeoGen® and then Cytoplast TM TXT-200. These differences may potentially affect the clinical outcomes of dental GBR procedures.

Comparative analysis of paediatric and adult surgically drained dental infections at a university teaching hospital.

In the United Kingdom (UK) the estimated prevalence of dental infection involving the supporting bone is 2%, and from 2014-2015 there were 2281 admissions in England alone due to dental abscess. We undertook an analysis of 184 dental abscesses that required surgical drainage, as there is surprisingly little in the literature on the subject. This was a retrospective study of 184 consecutive patients with dental abscesses who were admitted between January 2016 and September 2019. On admission, all patients had orthopantomograms (OPG) and baseline blood tests. Surgical drainage was performed under a general or local anaesthetic and a pus swab sent for culture and sensitivity. The submandibular space was the most commonly involved site and paediatric patients most often presented with buccal space abscesses. A lower molar tooth was the cause in 132 patients. White blood cells (WBC) and C-reactive protein (CRP) were both raised in 63.6% (n=117), but were normal in 4.9% (n=9). The remaining patients had either raised WBC (2.7%) or CRP (28.8%). Streptococcus milleri was the most common organism isolated in 66.6% (n=42). There was no association between CRP or WBC values and duration of hospital stay. Paediatric patients had a shorter duration of admission (1.96 days vs 2.81 days) and significantly lower CRP values (120.9 vs 45.7; p=0.001). The submandibular space was the commonest site involved and mandibular molars the most frequent source of infection. An elevated CRP value appeared to be a more sensitive indicator of infection in this study population. Adult and paediatric patients present in a different manner.

Evaluation of lower facial heights as related to different anthropometric measurements in dentate and completely edentulous subjects.

OBJECTIVE: The aim was to compare two measurements of lower facial height (base of chin-subnasale and base of chin- tip of the nose) as related to different anthropometric measurements in dentate and completely edentulous subjects. METHOD AND MATERIALS: This cross-sectional study was conducted on 132 male subjects (group 1 [G1], 120 dentate subjects; and group 2 [G2], 12 completely edentulous subjects). Base of chin-subnasale measurement (FM1), base of chin-tip of the nose measurement (FM2), Willis' measurement (FM3), glabella-subnasale measurement (FM4), length of the index finger measurement (AM1), and tip of thumb-tip of index finger measurement (AM2) of subjects of G1 and G2 were measured by using a modified caliper while the subjects in G1 closed in centric occlusion, and the subjects of G2 were asked to close the maxillary and mandibular complete dentures in centric relation. Statistical analysis was carried out by using paired t test, Pearson's correlation (PC), and regression analysis. RESULTS: There were no significant differences between G1FM1 and G1FM3, G1FM1 and G1FM4, G1FM1 and G1AM2 (P > .05), and PCs were R = 0.74, R = -0.35, and R = -0.32 respectively. However, there were significant differences between G1FM2 and G1FM3, G1FM2 and G1FM4, G1FM2 and G1AM2 (P ≤ .05), and there were significant differences between G2FM2 and different measurements of G2 (P ≤ .05). CONCLUSION: The use of the linear equation to predict the possible base of chin-subnasale measurement through the Willis' measurement was recommended and could be used as a guide during restoration of the vertical dimension of occlusion when it has been lost.