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The objective of this study was to investigate the clinical course of shortened dental arches (‘SDA group’) compared to SDAs plus removable denture prosthesis (‘SDA plus RDP group’) and complete dental arches (‘CDA group’, controls). Data (numbers of direct and indirect restorations, endodontic treatments, tooth loss and tooth replacements) were extracted from patient records of subjects attending the Nijmegen Dental School who previously participated in a cohort study on shortened dental arches with three to four posterior occluding pairs (POPs). Records of 35 % of the original cohort were retrievable. At the end of the follow-up (27.4 ± 7.1 years), 20 out of 23 SDA subjects still had SDA with 3–4 POPs compared to 6 out of 13 for SDA plus RDP subjects (follow-up 32.6 ± 7.3 years). Sixteen out of 23 CDA subjects still had CDA; none of them lost more than one POP (follow-up 35.0 ± 5.6 years). SDA group lost 67 teeth: 16 were not replaced, 16 were replaced by FDP and 35 teeth (lost in three subjects) replaced by RDP. Mean number of treatments per year in SDA subjects differed not significantly compared to CDA subjects except for indirect restorations in the upper jaw. Shortened dental arches can last for 27 years and over. Clinical course in SDA plus RDP is unfavourable, especially when RDP-related interventions are taken into account. The shortened dental arch concept seems to be a relevant approach from a cost-effective point of view. Replacement of absent posterior teeth by free-end RDP cannot be recommended.

The purpose of this in vitro study was to compare the precision of fit of frameworks milled from semi-sintered regular zirconia and high-translucent (HT) zirconia blanks, fabricated with two different CAD/CAM systems. Three-unit, posterior fixed dental prostheses (FDP) frameworks were fabricated for standardized dies (n = 11) with two different laboratory computer-aided design (CAD)/computer-aided manufacturing (CAM) systems (Cercon/Ceramill). The replica technique was used to evaluate the marginal and internal fit under an optical microscope. Evaluation of the data was performed according to prior studies at a level of significance of 5%. The systems showed a statistically significant influence on the internal fit of the frameworks (p ≤ 0.001) and on the marginal fit (p < 0.001). The type of material showed no influence on the marginal fit for the Cercon system (p = 0.636) and on the marginal fit (p = 0.064) and the internal fit (p = 0.316) for the Ceramill system, while regular zirconia from Cercon showed higher internal values than HT zirconia (p = 0.016). Both investigated systems showed clinically acceptable values within the limitations of this in vitro study. However, one showed less internal accuracy when regular zirconia was used.

The aim of this study was to evaluate the effect of different irrigation protocols on the root dentin structure using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thirty-nine lower bovine incisors were hemisected longitudinally and randomly divided into 13 groups (n = 3). After the root halves were reassembled, it was applied a specific irrigation protocol for each group, as following: G1, distilled water (control); G2, 0.9% saline; G3, saline + 17% EDTA; G4, saline + PUI; G5, saline + PUI + EDTA; G6 to G9 received the same protocol as above replacing 0.9% saline by 2.5% NaOCl; and G10 to G13 by 2% CHX. One-half of each sample was prepared and evaluated using SEM and the other one by TEM observations. TEM descriptive analysis showed modifications in dentin organic ultrastructure, characterized by the thinning of dentin collagen fibrils, caused by NaOCl, enhanced by EDTA and/or PUI. SEM analysis showed that NaOCl with PUI caused significantly larger erosion of the peritubular dentin than in all the other groups (P < 0.05), followed by NaOCl + EDTA and NaOCl + EDTA + PUI. NaOCl caused ultrastructural alterations in the dentin collagen, and enhanced by EDTA and/or PUI, promoted peritubular and intertubular erosion. The effect of irrigating solutions on dentin ultrastructure was still unclear. The acknowledgment about the kind of solution, concentrations, application time, and sequence of use was important to achieve the right sanitization without jeopardizing the dentin ultrastructure quality.

Cold atmospheric plasma (CAP), a room temperate ionized gas, seems to be a possible way to enhance tissue recovery. An in vitro study was conducted to investigate the influence of medical CAP on the regenerative capacity of human periodontal ligament (PDL) cells. Human PDL cells were subjected to CAP at various intensities, distances, and durations. The effects of CAP on a number of specific markers were studied at transcriptional level using real-time PCR. Additionally, an in vitro wound healing assay was applied to PDL cell monolayers either in the presence or absence of CAP by using JuLI™ Br Live Cell Analyzer and software. Finally, cell viability of CAP-treated cells was analyzed by an XTT assay. CAP treatment enhanced significantly the expression of the cytokines tumor necrosis factor (TNF)α, cyclooxygenase (COX)2, interleukin (IL)-1β, IL-6, IL-8, collagen (COL)1α, and matrix metalloproteinase (MMP)1, as well as the proliferation markers Ki67 and proliferating cell nuclear antigen (PCNA), but downregulated apoptotic markers Apaf1 and p53. Additionally, the in vitro wound healing rate was significantly enhanced after CAP application. Moreover, CAP treatment resulted in a significantly increased cell viability in the XTT assay. This in vitro study shows that CAP has regulatable effects on markers of periodontal wound healing thereby underlining the potential use of CAP as a benefit treatment strategy. Our study demonstrates the application of CAP in the treatment of oral pathologies suggesting a promising future treatment approach.

To establish a three-dimensional finite element model of the upper palate, pharyngeal cavity, and levator veli palatini muscle in patients with unilateral complete cleft palate, simulate two surgical procedures that the two-flap method and Furlow reverse double Z method, observe the stress distribution of the upper palate soft tissue and changes in pharyngeal cavity area after different surgical methods, and verify the accuracy of the model by reconstructing and measuring the levator veli palatini muscle. Mimics, Geomagic, Ansys, and Hypermesh were applied to establish three-dimensional finite element models of the pharyngeal cavity, upper palate, and levator veli palatini muscle in patients with unilateral complete cleft palate. The parameters including length, angle, and cross-sectional area of the levator veli palatini muscle etc. were measured in Mimics, and two surgical procedures that two-flap method and Furlow reverse double Z method were simulated in Ansys, and the area of pharyngeal cavity was measured by hypermesh. A three-dimensional finite element model of the upper palate, pharyngeal cavity, and bilateral levator veli palatini muscle was established in patients with unilateral complete cleft palate ; The concept of horizontal projection characteristics of the palatal dome was applied to the finite element simulation of cleft palate surgery, vividly simulating the displacement and elastic stretching of the two flap method and Furlow reverse double Z method during the surgical process; The areas with the highest stress in the two-flap method and Furlow reverse double Z method both occur in the hard soft palate junction area; In resting state, as measured, the two flap method can narrow the pharyngeal cavity area by 50.9%, while the Furlow reverse double Z method can narrow the pharyngeal cavity area by 65.4%; The measurement results of the levator veli palatini muscle showed no significant difference compared to previous studies, confirming the accuracy of the model. The finite element method was used to establish a model to simulate the surgical procedure, which is effective and reliable. The area with the highest postoperative stress for both methods is the hard soft palate junction area, and the stress of the Furlow reverse double Z method is lower than that of the two-flap method. The anatomical conditions of pharyngeal cavity of Furlow reverse double Z method are better than that of two-flap method in the resting state. This article uses three-dimensional finite element method to simulate the commonly used two-flap method and Furlow reverse double Z method in clinical cleft palate surgery, and analyzes the stress distribution characteristics and changes in pharyngeal cavity area of the two surgical methods, in order to provide a theoretical basis for the surgeon to choose the surgical method and reduce the occurrence of complications.

To assess in persons aged 70 years or older the microbiological alterations occurring around implants and natural teeth during and after 3 weeks of undisturbed plaque accumulation. Furthermore, to test the predictive value of several markers at baseline for the extent of inflammation around implants and teeth after this period. Twenty partially edentulous participants with titanium implants refrained from oral hygiene practices while being clinically monitored in weekly intervals for 21 days. Teeth and implants were then cleaned, oral hygiene resumed, and the participants were further monitored. Levels of six subgingival plaque microorganisms, the plaque index (PI), and the gingival index (GI) were assessed before (baseline), during (days 0, 7, 14, 21), and after plaque accumulation (days 28, 42). Six microorganisms; demographic and clinical variables at day 0 were further evaluated as potential predictors for presence of GI > 1 at days 21 and 28. The detection frequency of the selected bacteria did not differ between implants and teeth at any time point. Bacteria counts decreased in the preparatory phase and increased in the plaque accumulation phase. Patterns observed at implants and teeth were similar. Only Parvimonas micra at day 21 reached significantly higher counts at implants than teeth. For the prediction of clinical outcome at day 21, in the multivariable model, only implant vs. tooth was significant indicator for the primary outcome (p = 0.01). Overall, the analysis of subgingival/submucosal samples revealed only minor differences between implants and teeth during the development and resolution of inflammation. Within the limitations of our study, with plaque accumulation, elders develop more inflammation around implants than around teeth, in spite of similar bacterial profiles.

Fusobacterium nucleatum is an important oral pathogen involved in endodontic infections. This study aimed to assess the frequency of Fusobacterium nucleatum in primary and secondary endodontic infections and its associations with the clinical features in a Brazilian population by using both culture and nested PCR methods. A total of 100 microbial samples from patients with primary (n=50) and secondary endodontic infections (n=50) were analyzed by using culture and nested PCR methods. Strict anaerobic techniques were used for culture and identification of F. nucleatum. The DNA extracted from the samples was analyzed for the presence of target species by using species-specific primers. Culture and nested PCR methods detected F. nucleatum, respectively, in 11/100 and 82/100 root canals. F. nucleatum was isolated by culture from 10/50 (20%) root canals with primary infections and from 1/50 (2%) root canal with secondary/persistent infections. Nested PCR detected F. nucleatum in 42/50 (84%) root canals with primary infections and in 40/50 (80%) root canals with secondary/persistent endodontic infections. F. nucleatum was associated with spontaneous pain, tenderness to percussion, pain on palpation, swelling, tooth mobility, wet root canals, hemorrhagic exudate, tooth decay, inadequate restoration, and poor endodontic filling. F. nucleatum was found in more cases of primary endodontic infections than in cases of secondary/persistent ones. A higher prevalence of F. nucleatum was detected by using the nested PCR method than by using culture. The presence of F. nucleatum in the root canals was associated with several clinical features. The high prevalence of F. nucleatum in the root canals detected by molecular methods, and its association with several clinical features reveals the importance of these species in the development of apical pathologies and reinforces the need of an endodontic treatment directed to bacterial elimination.