Vertical preparation: a new technique for analogical and digital impressions

The BOPT technique (Biologically Oriented Preparation Technique) was proposed by Loi et al. (1) and has become a popular form of vertical preparation for complete crowns with promising results. In this procedure, the clinician can operate on the gingival tissue during preparation and modify its structure in thickness and height by adding modifications on the provisional restoration. However, one of the main challenges in this technique is the transference of information about the gingival tissue to the laboratory technician, who will place the margin of the restoration randomly in a space determined by two marks on the working cast.The technique proposed enables the accurate transmission of the exact point where the margin of the restoration needs to be placed. Furthermore, it facilitates the recording of conventional impression materials and intraoral scanners due to the compression of polytetrafluoroethylene (PTFE) tape into the sulcus, which allows to arrest bleeding or intracrevicular liquid and is easily registered irrespective of the method of impression used

In Vitro Biocompatibility of Several Children's Toothpastes on Human Gingival Fibroblasts

The European Academy of Paediatric Dentistry has recommended fluoride toothpastes from the eruption of the first teeth in children. Toothpastes stay in the mouth in contact with human gingival fibroblasts (hGFs) for a long time. Thus, the objective of this study was to compare the cytotoxicity of five different commonly used children's toothpastes: Oral B Kids +3 (Procter & Gamble, Alicante, Spain), Fluor Kin Calcium (Kin, Madrid, Spain), PHB Junior (PHB, Barcelona, Spain), Colgate +3 (Colgate Palmolive, Madrid, Spain) and Vitis Kids (Dentaid, Valencia, Spain) on hGFs. The children's toothpastes were exposed to hGFs at different concentrations (1:1, 1:2, 1:4). Afterwards, several tests were performed: MTT assays, cell cycle analyses, cell cytoskeleton staining assays, apoptosis/necrosis assays, and ICP-MS and ion chromatography. Oral B displayed the lowest cytotoxicity and was the toothpaste with the highest fluoride ion release; meanwhile, the other toothpastes were cytotoxic (*** p < 0.0001); Fluor Kin being the one with the lowest fluoride ion release. Among all the toothpastes analyzed, Oral B exhibited the best results in vitro in terms of biocompatibility. Future evaluations, both in vitro and in vivo, are required to confirm the biocompatibility of sodium lauryl sarcosinate and sodium lauryl sulfate containing toothpastes

Assessment of time intervals in the pathway to oral cancer diagnosis in north-westerm Spain. Relative contribution of patient interval

Despite continuous advances in diagnosis and therapy, oral cancers are mostly diagnosed at advanced stages with minor survival improvements in the last two decades. Both phenomena have been attributed to delays in the diagnosis. This study aims at quantifying the time elapsed until definitive diagnosis in these patients and the patient interval?s contribution. A hospital-based, ambispective, observational study was undertaken on incident cases with a pathological diagnosis of oral squamous cell carcinoma recruited during 2015 at the Oral and Maxillofacial Surgery services of CHUAC (A Coruña) and POVISA (Vigo) hospitals. 74 consecutive oral cancer patients (59.5% males; median age: 65.0 years (IQ:57-74)) were studied. Most cases (52.7%; n=39) were at advanced stages (TNM III-IV) at diagnosis. The period since first sign/symptom until the patient seeks health care was the longest interval in the pathway to diagnosis and treatment (median: 31.5 days; IQR= 7.0 ? 61.0) and represents >60% of the interval since symptom onset until referral to specialised care (pre-referral interval). The average interval assigned to the patient resulted to be relatively larger than the time elapsed since the patient is seen at primary care until a definitive diagnosis is reached (diagnostic interval). Median of the referral interval for primary care professionals: 6.5 days (IQR= 0.0 ? 49.2) and accounts for 35% (19% - 51%) of the diagnostic interval. The patient interval is the main component of the pathway to treatment since the detection of a bodily change until the definitive diagnosis. Therefore, strategies focused on risk groups to shorten this interval should be implemented in order to ease an early diagnosis of symptomatic oral cancer

Laser‐guided corrosion control: a new approach to tailor the degradation of Mg‐alloys

Despite corrosion being commonly seen as a problem to be avoided, applications such as batteries or biodegradable implants do benefit from corrosion‐like phenomena. However, current strategies address corrosion control from a global perspective for a whole component, without considering local adaptations to functionality specifications or inhomogeneous environments. Here, a novel concept is presented: the local control and guidance of corrosion through a laser surface treatment. Immersion tests in saline solution of AZ31 magnesium alloy samples show degradation rates reduced up to 15 times with the treatment, owing to a fast passivation after the induced microstructural modifications. By controlling the treatment conditions, the degradation can be restricted to delimited regions and driven towards specific directions. The applicability of the method for the design of tailored degradation biomedical implants is demonstrated and uses for cathodic protection systems and batteries can also be anticipated.Xunta de Galicia | Ref. ED431C 2019/23Xunta de Galicia | Ref. ED481D 2017/010Xunta de Galicia | Ref. ED481B 2016/047‐0Xunta de Galicia | Ref. ED431B2017/65‐GPCAgencia Estatal de Investigación | Ref. RTI2018-095490-J-I00Agencia Estatal de Investigación | Ref. PID2019-111285RB-I0

Nanosecond, picosecond and femtosecond laser surface treatment of magnesium alloy: role of pulse length

Despite having a whole range of applications as in weight-saving structures, biodegradable implants and rechargeable batteries, the usage of magnesium is still hindered by its high tendency to corrosion. Pulsed laser treatments are an interesting approach to modify the surface of magnesium aiming the improvement of the corrosion properties as well as the generation a controlled roughness, which is useful for improving coatings adhesion or tailoring the interactions with living cells at the surface of an implant. In this work, a novel study on the role of the pulse length on topography and corrosion properties of AZ31 magnesium alloy laser-treated surfaces is presented. Three different laser sources with pulse lengths of 20 ns, 800 ps and 266 fs were employed with a similar experimental setup. Surface topography analysis revealed a reduction of the amount of melt generated and an increase in the aspect ratio (depth/width) of the ablated features as the pulse length is reduced. All three treatments significantly improved the corrosion performance of the untreated base material. Thicker and more homogenously distributed recast material for the longer pulses of the nanosecond treatment resulted in a longer-lasting protection (11–12 fold reduction in mass loss rate vs base material) compared to the pico- and femtosecond treatments (4–5 fold reduction)European Union | Ref. EAPA_151 / 2016Ministerio de Ciencia e Innovación | Ref. PID2020-117900RB-I00Ministerio de Ciencia, Innovación y Universidades | Ref. EQC2018-004315-PXunta de Galicia | Ref. ED431C 2019/23Ministerio de Universidades | Ref. FPU16/0549