Claudio Mazzotti

Coronally Advanced Flap With and Without Vertical Releasing Incisions for the Treatment of Multiple Gingival Recessions: A Comparative Controlled Randomized Clinical Trial

BACKGROUND Vertical releasing incisions might damage the blood supply to the flap and result in unesthetic visible white scars. The aim of the present study was to compare root coverage and esthetic outcomes of the coronally advanced flap (CAF) with and without vertical releasing incisions in the treatment of multiple gingival recessions. METHODS Thirty-two systemically and periodontally healthy subjects with esthetic complaints due to the exposure of Miller Class I and II multiple (at least two) gingival recession defects (> or =1 mm) affecting adjacent teeth of the same quadrant of the upper jaw were enrolled in the study. Sixteen patients (with 45 gingival recessions) were randomly assigned to the control group, and the other 16 patients (with 47 recession defects) were assigned to the test group. All recessions were treated with a CAF; vertical releasing incisions were performed in the control group, whereas an envelope-type flap was used in the test group. The patients postoperative morbidity was assessed 1 week after the surgery, whereas the esthetic evaluation, made by the patient and independent periodontist, and the clinical evaluation were made 1 year later. RESULTS Surgical time was significantly shorter in the envelope-type CAF group. No statistically significant difference was demonstrated between the two groups in terms of recession reduction and clinical attachment level gain. A statistically greater probability of complete root coverage (adjusted odds ratio, 3.76; 95% confidence interval: 0.92 to 15.33; P <0.05) and a greater increase in buccal keratinized tissue height were observed with the envelope type of CAF. Patient satisfaction with esthetics was very high in both treatment groups, with no statistically significant differences between them. A better postoperative course and better results in the esthetic evaluation made by an independent periodontist were demonstrated in patients treated with the envelope type of CAF. CONCLUSIONS Both CAF techniques were effective in reducing recession depth. The envelope type of CAF was associated with an increased probability of achieving complete root coverage and with a better postoperative course. Keloid formation along the vertical releasing incisions was responsible for the worst esthetic evaluation made by an independent expert periodontist.

Patient morbidity and root coverage outcome after subepithelial connective tissue and de‐epithelialized grafts: a comparative randomized‐controlled clinical trial

AIMS The aim of this randomized-controlled clinical trial was to compare the patient morbidity and root coverage outcomes of a coronally advanced flap (CAF) with connective tissue (CTG) or de-epithelialized gingival (DGG) grafts. METHODS Fifty patients with one recession each were treated. In the control group, the CTG was harvested using the trap-door approach while in the test group the CTG resulted from the de-epithelialization of a free gingival graft. RESULTS No statistically significant differences were demonstrated between groups in patientss pain killer consumption, post-operative discomfort and bleeding. Lower stress and better ability to chew were demonstrated in the CTG group. Analgesic consumption increased with increasing height of the graft and in the case of dehiscence/necrosis of the primary flap. Pain was negatively correlated with the residual thickness of soft tissue covering the palatal bone. A statistically greater increase in buccal soft tissue thickness was observed in the DGG group. CONCLUSIONS No differences were demonstrated in the post-operative pain and root coverage outcome in patients subjected to CAF with CTG or DGG.

An EMG-Controlled Robotic Hand Exoskeleton for Bilateral Rehabilitation

This paper presents a novel electromyography (EMG)-driven hand exoskeleton for bilateral rehabilitation of grasping in stroke. The developed hand exoskeleton was designed with two distinctive features: (a) kinematics with intrinsic adaptability to patients hand size, and (b) free-palm and free-fingertip design, preserving the residual sensory perceptual capability of touch during assistance in grasping of real objects. In the envisaged bilateral training strategy, the patients non paretic hand acted as guidance for the paretic hand in grasping tasks. Grasping force exerted by the non paretic hand was estimated in real-time from EMG signals, and then replicated as robotic assistance for the paretic hand by means of the hand-exoskeleton. Estimation of the grasping force through EMG allowed to perform rehabilitation exercises with any, non sensorized, graspable objects. This paper presents the system design, development, and experimental evaluation. Experiments were performed within a group of six healthy subjects and two chronic stroke patients, executing robotic-assisted grasping tasks. Results related to performance in estimation and modulation of the robotic assistance, and to the outcomes of the pilot rehabilitation sessions with stroke patients, positively support validity of the proposed approach for application in stroke rehabilitation.

Non-carious cervical lesions associated with gingival recessions: a decision-making process.

BACKGROUND A method to predetermine the maximum root coverage level (MRC) was recently demonstrated to be reliable in predicting the position of the soft tissue margin after root coverage surgery. The aim of the present study is to suggest a decision-making process for treating non-carious cervical lesions (NCCLs) associated with gingival recessions based upon the topographic relationship between the MRC and NCCL and to assess patient and independent-periodontist esthetic evaluations. METHODS Five treatments were performed in 94 patients with NCCLs associated with a single gingival recession: 1) coronally advanced flap (CAF); 2) bilaminar procedure; 3) coronal odontoplasty plus restoration plus root odontoplasty plus CAF; 4) restoration plus CAF; and 5) restorative therapy. Clinical and esthetic evaluations made by the patient and an independent periodontist were done 1 year after treatments. RESULTS The satisfaction of the patient and periodontist with esthetics was very high in all NCCL treatments and Miller Class gingival recessions. The patient satisfaction and evaluation of root coverage and the periodontist evaluation of root coverage were statistically correlated with color-match evaluations and not with the amount of root coverage clinically achieved in each patient. CONCLUSION The proposed approaches provided good esthetic appearance and correct emergence profile for the great majority of NCCLs associated with gingival recessions.

Coronally advanced flap with and without connective tissue graft for the treatment of multiple gingival recessions: a comparative short- and long-term controlled randomized clinical trial.

AIM The aim of this study was to compare short- and long-term root coverage and aesthetic outcomes of the coronally advanced flap (CAF) alone or in combination with a connective tissue graft (CTG) for the treatment of multiple gingival recessions. METHODS Fifty patients with multiple (≥2) adjacent gingival recessions (≥2 mm) in the upper jaw were enrolled. Twenty-five patients were randomly assigned to the control group (CAF), and the other 25 patients to the test group (CAF + CTG). Clinical outcomes were evaluated at 6 months, 1 and 5 years. The aesthetic evaluations were made 1 and 5 years after the surgery. RESULTS No statistically significant difference was demonstrated between the two groups in terms of Rec Red and complete root coverage (CRC) at 6 months and 1 year. At 5 years, statistically greater recession reduction and probability of CRC, greater increase in buccal KTH and better contour evaluation made by an independent periodontist were observed in the CAF + CTG group. Better post-operative course and better colour match were demonstrated in CAF-treated patients both at 1 and 5 years. CONCLUSIONS CAF + CTG provided better CRC at 5 years; keloid formation due to graft exposure was responsible for the worse colour match evaluation.

Predetermination of Root Coverage

BACKGROUND A method to predetermine the maximum root coverage level (MRC) achievable with surgery was recently presented. The present study evaluates the predictability of such a method by comparing the predetermined MRC with that effectively achieved by means of root coverage surgical procedures. METHODS A total of 50 patients with single and multiple recession defects were enrolled. MRC was predetermined by an independent periodontist by assessing the ideal height of the interdental papilla. The distance from the apical reference point of a stent (StRP) and the MRC was measured 7 days before root coverage surgery. A total of 135 Miller Class I, II, and III gingival recessions were treated with the coronally advanced flap (CAF) or with the subepithelial connective tissue graft (SCTG). The distance from StRP and the gingival margin (GM) was measured by another independent periodontist 15, 30, and 90 days after surgery. RESULTS In 97 (71.8%) of 135 treated gingival recessions, the StRP-MRC distance coincided exactly with the StRP-GM distance. No statistically significant difference was demonstrated in the cases with exact predetermination between gingival recessions belonging to the maxilla or mandible and between gingival defects treated with CAF or SCTG. The StRP-MRC distance measured before surgery was greater in 24 recession defects (17.7%) and lower in 14 gingival recessions (10.3%) than the StRP-GM distance measured 90 days after surgery. More cases of underestimation and fewer cases with overestimation of the level of root coverage were found in the SCTG group compared to the CAF group. The difference was statistically significant (P <0.01). CONCLUSIONS The adopted method was effective in predetermining the position of the soft tissue margin 90 days after root coverage surgery. The cases with underestimation of the level of root coverage should be considered clinically and esthetically successful.

Nonlinear Creep, Poisson’s Ratio, and Creep-Damage Interaction of Concrete in Compression

This paper presents results of a set of experimental short-term creep tests on concrete specimens under uniaxial compression at different stress levels. Creep Poissons ratio evolution with time, nonlinear creep strain amplification, damage growth, and creep-damage interaction of concrete in compression were studied. The electronic speckle pattern interferometry technique was used to measure transverse strain when, at high stress levels, cracks grow and propagate in concrete specimens. Under high stresses, creep Poissons ratio shows variation in time, associated with damage evolution. In addition, tests showed that for medium to high stress levels, nonlinear creep strain amplification occurs, even if not accompanied by significant concrete damage.

Confinement of masonry columns with PBO FRCM composites

The overarching goal of this work is to provide a fundamental understanding of the behavior of solid brick masonry columns confined with fiber reinforced cementitious matrix (FRCM) composites. FRCM is a newly-developed type of composite material comprised of a cementitious inorganic matrix (binder) and embedded fibers that are usually bundled to improve the bond between the matrix and the fibers. Compression tests were carried out to investigate the influence of the FRCM confinement and the brick patterns on the load-carrying capacity of the confined columns. Compression tests were conducted on brick masonry columns with different brick configurations. Digital image correlation measurements on the surface of the composite and on the surface of the brick for the control specimens were attempted in order to understand the role of the mortar joints and the arch effect across the section of the columns due to the confinement. The experimental results indicate that FRCM composites can effectively increase the load-carrying capacity of brick masonry columns and the failure mode could be different from the one observed for masonry columns confined with fiber-reinforced polymer (FRP) composites.

An emg-based robotic hand exoskeleton for bilateral training of grasp

This work presents the development and the preliminary experimental assessment of a novel EMG-driven robotic hand exoskeleton for bilateral active training of grasp motion in stroke. The system allows to control the grasping force required to lift a real object with an impaired hand, through the active guidance provided by a hand active exoskeleton, whose force is modulated by the EMG readings acquired on the opposite unimpaired arm. To estimate the grasping force, the system makes use of surface EMG recordings during grasping, developed on the opposite unimpaired arm, and of a neural network to classify the information. The design, integration and experimental characterization of the system during the grasp of two cylindrical objects is presented. The experimental results show that an optimal force tracking of the interaction force with the object can be achieved.

Strengthening of Masonry Elements by FRP: Influence of Brick Mechanical and Microstructural Properties

In this paper, the effect of several brick and mortar mechanical and microstructural parameters on the maximum debonding force of the same glass fiber reinforced polymer (GFRP), applied on different bricks and on corresponding masonry panels, was investigated. GFRP sheets were bonded by epoxy resin to four different types of solid fired-clay brick and four types of masonry panels, manufactured using the same bricks and a natural hydraulic lime mortar. The reinforced specimens were subjected to bond tests to evaluate the maximum debonding force. Bricks and mortar were characterized in terms of compressive strength (in the case of bricks, along two different orthogonal directions), surface roughness and pore size distribution. Based on the results of the study, alongside brick mechanical properties in different directions, also brick microstructural parameters seem to play a very important role, which should be taken into account for fully explaining the experimental results.