Dense Polytetrafluoroethylene Membrane versus Titanium Mesh in Vertical Ridge Augmentation: Clinical and Histological Results of a Split-mouth Prospective Study.

AIM AND OBJECTIVE: The aim of the present split-mouth prospective study was to evaluate clinically and histologically the bone regeneration obtained following preprosthetic vertical bone augmentation performed with titanium-reinforced dense polytetrafluoroethylene membrane (d-PM) compared to titanium mesh (TM). MATERIALS AND METHODS: Healthy adult patients presenting with bilateral partial edentulism in the posterior mandible requiring vertical ridge augmentation for implant placement purposes were consecutively included. One side of the mandible was randomly assigned to the use of d-PM, the other to TM. The graft consisted in a mixture of autogenous bone harvested nearby the surgical site and deproteinized bovine bone mineral particles in a 1:1 ratio. On each side during bone augmentation surgery, a 2-mm diameter mini-implant was inserted for clinical and histological analyses. After a healing period of 8 months, the second surgical phase was carried out to remove the nonresorbable barriers, to evaluate clinically the vertical bone gain, and to collect a bone biopsy that included the mini-implant. During the same surgical session, dental implants were inserted in a prosthetically guided position. RESULTS: A total of five patients were enrolled. Eight out of 10 sites healed uneventfully. In the remaining two sites, premature exposure of the TM was observed. Mean vertical bone gain of 4.2 and 1.5 mm was achieved in d-PM and TM groups, respectively (p = 0.06). A mean mineralized tissue of 48.28 and 35.54% was observed in d-PM and TM groups, respectively (p = 0.51). CONCLUSION: The vertical bone gain, although not significantly, was higher in the d-PM group. Similar histological outcomes were noticed if exposure did not occur. In case of wound dehiscence, major resorption was observed. CLINICAL SIGNIFICANCE: Both d-PM and TM can be used to augment atrophic localized ridges vertically. The outcome of bone regeneration seems to be impaired by exposure of the device. How to cite this article: Maiorana C, Fontana F, Rasia dal Polo M, et al. Dense Polytetrafluoroethylene Membrane versus Titanium Mesh in Vertical Ridge Augmentation: Clinical and Histological Results of a Split-mouth Prospective Study. J Contemp Dent Pract 2021;22(5):465-472.

MCQ-Balance: a method to monitor patients with balance disorders and improve clinical interpretation of posturography.

BACKGROUND: An estimated 20% to 30% of the global population has suffered a vertiginous episode. Among them, 20% do not receive a clear diagnosis. Improved methods, indicators and metrics are necessary to assess the sensory systems related to balance, especially when patients are undergoing treatment for vertiginous episodes. Patients with balance disorders should be monitored for changes at the individual level to gather objective information. In this study, we evaluate the use of the MCQ-Balance (Measure, Classify and Qualify) assessment for examining a patient's balance progression using tests to measure static balance control and dynamic postural balance with a stabilometric platform. MATERIALS AND METHODS: The MCQ-Balance assessment comprises three stages: (i) measuring the progression of each variable between two separate and consecutive days (called sessions) using the Magnitude-Based Decision analysis; (ii) classifying the progression of the patient's balance with a score; and (iii) qualifying the progression of the patient's balance from the resulting scores using a set of rules. This method was applied to 42 patients with balance disorders of peripheral or central origin characterised by vertigo as the cardinal symptom. Balance progression was measured using the MCQ-Balance assessment over the course of three months, and these results were compared with the assessment of a clinical expert. RESULTS: The MCQ-Balance assessment showed an accuracy of 83.4% and a Cohen's Kappa coefficient of 0.752 compared to the assessment of a clinical expert. CONCLUSION: The MCQ-Balance assessment facilitates the monitoring of patient balance and provides objective information that has the potential to improve medical decision making and the adjustment of individual treatment.

Applying the Minimal Detectable Change of a Static and Dynamic Balance Test Using a Portable Stabilometric Platform to Individually Assess Patients with Balance Disorders.

Balance disorders have a high prevalence among elderly people in developed countries, and falls resulting from balance disorders involve high healthcare costs. Therefore, tools and indicators are necessary to assess the response to treatments. Therefore, the aim of this study is to detect relevant changes through minimal detectable change (MDC) values in patients with balance disorders, specifically with vertigo. A test-retest of a static and dynamic balance test was conducted on 34 healthy young volunteer subjects using a portable stabilometric platform. Afterwards, in order to show the MDC applicability, eight patients diagnosed with balance disorders characterized by vertigo of vestibular origin performed the balance test before and after a treatment, contrasting the results with the assessment by a specialist physician. The balance test consisted of four tasks from the Romberg test for static balance control, assessing dynamic postural balance through the limits of stability (LOS). The results obtained in the test-retest show the reproducibility of the system as being similar to or better than those found in the literature. Regarding the static balance variables with the lowest MDC value, we highlight the average velocity of the center of pressure (COP) in all tasks and the root mean square (RMS), the area, and the mediolateral displacement in soft surface, with eyes closed. In LOS, all COP limits and the average speed of the COP and RMS were highlighted. Of the eight patients assessed, an agreement between the specialist physician and the balance test results exists in six of them, and for two of the patients, the specialist physician reported no progression, whereas the balance test showed worsening. Patients showed changes that exceeded the MDC values, and these changes were correlated with the results reported by the specialist physician. We conclude that (at least for these eight patients) certain variables were sufficiently sensitive to detect changes linked to balance progression. This is intended to improve decision making and individualized patient monitoring.

The use of a collagenated porcine cortical lamina in the reconstruction of alveolar ridge defects. A clinical and histological study.

BACKGROUND: Alveolar ridge reconstruction by means of resorbable and non-resorbable membranes has been proposed to increase the hard tissue volume in deficient sites. The purpose of this study was therefore to clinically and histologically evaluate the use of collagenated porcine bone lamina in case of horizontal and vertical bone augmentation procedures in conjunction with particulate porcine xenograft. METHODS: Overall, 8 partially edentulous patients (6 females and 2 males) with a mean age of 45 years requiring bone regeneration procedures to achieve a prosthetically driven implant placement were enrolled. All ridge defects were augmented using a xenogeneic cortical bone barrier in combination with particulate heterologous bone. Bone biopsies were collected during the re-entry procedure. RESULTS: A total of 15 implants were placed both simultaneously or in a staged approach in the augmented sites. No complications occurred during the rehabilitation. Histologically, the bone lamina was widely vascularized and integrated with the surrounding soft tissues and the native bone. The presence of osteoclastic lacunae suggested an active remodeling of the particulate graft and a gradual substitution with the newly formed bone. CONCLUSIONS: Alveolar reconstruction by means of the collagenated cortical lamina gave promising clinical and histological results. The rigidity and the slow resorption pattern allowed for the blood clot protection even in case of vertical defects, avoiding at the same time the re-entry surgery for its removal.

The use of a collagenated porcine cortical lamina in the reconstruction of alveolar ridge defects. A clinical and histological study.

BACKGROUND: Alveolar ridge reconstruction by means of resorbable and non-resorbable membranes has been proposed to increase the hard tissue volume in deficient sites. The purpose of this study was therefore to clinically and histologically evaluate the use of collagenated porcine bone lamina in case of horizontal and vertical bone augmentation procedures in conjunction with particulated porcine xenograft. METHODS: Overall, 8 partially edentulous patients (6 females and 2 males) with a mean age of 45 years requiring bone regeneration procedures to achieve a prosthetically driven implant placement were enrolled. All ridge defects were augmented using a xenogeneic cortical bone barrier in combination with particulated heterologous bone. Bone biopsies were collected during the re-entry procedure. RESULTS: A total of 15 implants were placed both simultaneously or in a staged approach in the augmented sites. No complications occurred during the rehabilitation. Histologically, the bone lamina was widely vascularized and integrated with the surrounding soft tissues and the native bone. The presence of osteoclastic lacunae suggested an active remodelling of the particulated graft and a gradual substitution with the newly formed bone. CONCLUSION: Alveolar reconstruction by means of the collagenated cortical lamina gave promising clinical and histological results. The rigidity and the slow resorption pattern allowed for the blood clot protection even in case of vertical defects, avoiding at the same time the re-entry surgery for its removal.

Alveolar ridge reconstruction with titanium meshes: A systematic review of the literature

Alveolar bone regeneration by means of titanium meshes is a widespread procedure, however to date, only few relevant studies were reported in literature concerning this technique. Consequently, the aim of the present systematic review was to analyze the reliability of the titanium mesh as a barrier, in conjunction with horizontal and vertical ridge reconstruction for implant placement purposes. A total of 17 articles complying with the inclusion and exclusion criteria were reviewed. Three outcome variables were defined: a) horizontal and vertical bone regeneration obtained, b) complication rate, defined as the percentage of membrane exposures and c) evaluation of implant survival, success and failure rate. In regards to the vertical regeneration the mean was 4.91 mm (range: 2.56 - 8.6), while a mean of 4.36 mm (range: 3.75 - 5.65) was calculated for horizontal reconstruction. Considering the exposure rate, a mean of 16.1% was found, nevertheless, implant placement were placed in almost all of the sites. A mean success rate of 89,9%, a mean survival rate of 100% and a failure rate of 0% emerged from the data evaluation. A meta-analysis could not be performed due to the heterogeneity of the data, however the final results were comparable with those reported in case of bone regeneration obtained through other types of non-resorbable membranes. An advantage in favour of the titanium mesh was found in terms of bone loss after exposure, as implant placement was not jeopardized in almost all of the cases. It could be deduced that titanium meshes represented a reliable solution for alveolar ridge reconstruction. The clinical studies currently available in literature have shown the predictability of this technique in both lateral and vertical bone regeneration

Alveolar ridge reconstruction with titanium meshes: a systematic review of the literature.

Alveolar bone regeneration by means of titanium meshes is a widespread procedure, however to date, only few relevant studies were reported in literature concerning this technique. Consequently, the aim of the present systematic review was to analyze the reliability of the titanium mesh as a barrier, in conjunction with horizontal and vertical ridge reconstruction for implant placement purposes. A total of 17 articles complying with the inclusion and exclusion criteria were reviewed. Three outcome variables were defined: a) horizontal and vertical bone regeneration obtained, b) complication rate, defined as the percentage of membrane exposures and c) evaluation of implant survival, success and failure rate.In regards to the vertical regeneration the mean was 4.91 mm (range: 2.56 - 8.6), while a mean of 4.36 mm (range: 3.75 - 5.65) was calculated for horizontal reconstruction.Considering the exposure rate, a mean of 16.1% was found, nevertheless, implant placement were placed in almost all of the sites. A mean success rate of 89,9%, a mean survival rate of 100% and a failure rate of 0% emerged from the data evaluation. A meta-analysis could not be performed due to the heterogeneity of the data, however the final results were comparable with those reported in case of bone regeneration obtained through other types of non-resorbable membranes. An advantage in favour of the titanium mesh was found in terms of bone loss after exposure, as implant placement was not jeopardized in almost all of the cases. It could be deduced that titanium meshes represented a reliable solution for alveolar ridge reconstruction. The clinical studies currently available in literature have shown the predictability of this technique in both lateral and vertical bone regeneration.

Two-photon continuous flow lithography.

A new approach for microfluidics-based production of polymeric particles, namely two-photon continuous flow lithography, is reported. This technique takes advantage of two-photon lithography to create objects with sub-micrometer and 3D features, and overcomes the traditional process limitations of two-photon lithography by using multiple beam production under continuous flow. Polymeric fibers, helical and bow-tie particles with sub-diffraction resolution and surface roughness as low as 10 nm are demonstrated.

Polarized absorption, spontaneous and stimulated blue light emission of J-type tetraphenylbutadiene monocrystals.

Blue amplified spontaneous emission at room temperature is demonstrated from the exposed face of the strongly emitting organic semiconductor 1,1,4,4-tetraphenyl-1,3-butadiene in single crystal form. The symmetry of the crystal and calculation of lattice sums indicate the J-type organization of the molecular transition moments. The minimum in the lowest exciton dispersion branch, from which emission takes place, is found at the edge of the Brillouin zone leading to a dominant vibronic emission since the zero-phonon line is forbidden. The observed gain narrowed line is attributed to the vibronic replica which becomes amplified with increased pumping. The reported emission is along the normal to the exposed crystal face, important for the development of vertical cavity geometry lasers based on organic single crystals. The threshold excitation fluence of 400 microJ cm(-2) is comparable to other organic crystalline systems, even if the amplification path is much reduced as a consequence of the vertical geometry. Considering these relevant aspects, the optical characterization of this material is provided. The polarized absorption spectra are reported and the properties of the lowest-energy excitonic state investigated. Calculation of the electronic transitions for the isolated molecule, lattice sums for the transition at lowest energy, and the symmetry of the crystal allow attributing the largest face of the samples and the observed optical bands in the spectra. Polarized time-resolved spectra are also reported allowing to identify the intrinsic excitonic emission.