MODIFIED INDEXING TECHNIQUE FOR THE IMMEDIATE INTERIM RESTORATION OF A DENTAL IMPLANT

Because of the functional and esthetic requirements of patients, different techniques have been proposed to reduce the time between dental implant placement and interim restoration fabrication. This article describes a modified indexing technique by using a surgical template for open-tray impression and definitive cast development during immediate loading procedures. This technique does not use a complete impression of the oral cavity and, therefore, is more comfortable, less time consuming, and less expensive. It also allows the fabrication of interim restorations with the optimal shape for developing an adequate emergence profile.

Amorphous silicon carbonitride films modified by plasma immersion ion implantation

Amorphous silicon carbonitride (a-SiCN:H) films were deposited from hexamethyldisilazane (HMDSN) organic compounds via radio-frequency (RF) glow discharges. Afterwards the films were bombarded, from 15 to 60 min, with nitrogen ions using Plasma Immersion Ion Implantation (PIII) technique. X-ray photoelectron spectroscopy (XPS) showed that O-containing groups increased, while C-C and/or C-H groups decreased with treatment time. This result indicates chemical alterations of the polymeric films with the introduction of polar groups on the surface, which changes the surface wettability. In fact, the hydrophobic nature of a-SiCN:H films (contact angle of 100 degrees) was changed by nitrogen ion implantation and, and after aging in atmosphere air, all samples preserved the hydrophilic character (contact angle <80 degrees) independently of treatment time. The exposure of the films to oxygen plasma was performed to evaluate the etching rate, which dropped from 24% to 6% while the implantation time increased from 15 to 60 min. This data suggests that Pill increased the film structure strength, probably due to crosslinking enhancement of polymeric chains. Therefore, the treatment with nitrogen ions via Pill process was effective to modify the wettability and oxidation resistance of a-SiCN:H films. (C) 2014 Elsevier Ltd. All rights reserved.

Influence of immediate loading on healing of implants installed with different insertion torques - an experimental study in dogs

Objective: To evaluate the influence of different insertion torques on healing of implants loaded immediately or left unloaded.Material and methods: In six Labrador dogs, all mandibular premolars and molars were extracted. After 4 months of healing, flaps were elevated, and two implant sites were prepared at each side of the mandible. The distal sites were prepared conventionally while the mesial sites were underprepared by 0.3 mm. As a consequence, different final insertion torques of about 30 Ncm at the distal and >70 Ncm at the mesial sites were recorded. Healing abutments were applied to the left and transmucosal abutments to the right side. Flaps were sutured, crown preparation of the upper right second and third premolars was performed, and impressions were taken. Within 24 h, crowns were cemented both to implants and teeth in the right side of the mouth. After 4 months, the animals were sacrificed and ground sections obtained for histological evaluation.Results: A higher buccal bony crestal resorption and a more apical position of the coronal level of osseointegration were found at the loaded compared with the unloaded sites. MBIC% and percentages of peri-implant mineralized tissue (MB%) were higher at the loaded compared with the unloaded sites. Moreover, a higher MBIC% was found at the lower compared with the higher final insertion torque.Conclusions: Immediate loading does not seem to have a negative effect on osseointegration. High torque values for the immediate loading procedures were not necessary. Probably, low torque values, were sufficient to obtain primary stability and hence may provide better osseointegration than high torque value.

Efeito da aPDT na osseointegração de implantes em alvéolos contaminados

Objective: The aim of this study is to evaluate by histometric and immunohistochemistry analysis the effects of antimicrobial photodynamic therapy (aPDT) in alveolar prior to placement of mini-implants in animals with or without induced periodontal disease. Material and method: Thirty-two rats were used. Periodontal disease (PD) was induced by ligature in the lower left first molar. After 7 days of PD evolution, it was performed removal of the ligature and extraction of the left lower first molars in all animals. Thus, animals were divided into 2 groups (n=16) according to the treatments in the dental alveolus before immediate implant installation: MD (control) : mechanical debridement (MD), irrigation with 1 ml of saline solution followed by implant installation; aPDT- MD, irrigation with 1 ml of Toluidine Blue-O and low intensity laser (LLLT) and implant installation. Eight animals from each group were euthanized at 15 and 30 days after the installation of mini-implants. Specimens were processed for histologic, immunohistochemical and histometric analysis. The histometric data were processed for statistical analysis (Kruskall-Wallis and Dunn test; p <0.05). Result: In treatment analysis, results indicated that there was a greater BIC in implants installed in uncontaminated alveolus treated with a PDT ( p<0,05) and greater imuno-reactivity to OPG in bone issue treated with aPDT. Conclusion: The aPDT proved to be effective in bone loss control in no contaminated area and it has increased the bone loss and metabolic activity in alveolus irradiated prior to implant installation.

Immediate and late analysis of dental pulp stem cells viability after indirect exposition to alternative in-office bleaching strategies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immediate human pulp response to ethanol-wet bonding technique

To evaluate the short-term response of human pulps to ethanol-wet bonding technique. Methods Deep class V cavities were prepared on 17 sound premolars and divided into three groups. After acid-etching, the cavities from groups 1 (G1) and 2 (G2) were filled with 100% ethanol or distilled water, respectively, for 60 s before the application of Single Bond 2. In group 3 (G3, control), the cavity floor was lined with calcium hydroxide before etching and bonding. All cavities were restored with resin composite. Two teeth were used as intact control. The teeth were extracted 48 h after the clinical procedures. From each tooth serial sections were obtained and stained with haematoxylin and eosin (H/E) and Masson's trichrome. Bacteria microleakage was assessed using Brown & Brenn. All sections were blindly evaluated for five histological features. Results Mean remaining dentine thickness was 463 ± 65 μm (G1); 425 ± 184 μm (G2); and 348 ± 194 μm (G3). Similar pulp reactions followed ethanol- or water-wet bonding techniques. Slight inflammatory responses and disruption of the odontoblast layer related to the cavity floor were seen in all groups. Stained bacteria were not detected in any cavities. Normal pulp tissue was observed in G3 except for one case. Conclusions After 48 h, ethanol-wet bonding does not increase pulpal damage compared to water-wet bonding technique. Clinical significance Ethanol-wet bonding may increase resin-dentine bond durability. This study reported the in vivo response of human pulp tissue when 100% ethanol was applied previously to an etch-and-rinse simplified adhesive system.

A combined approach for the treatment of resorbed fresh sockets allowing immediate implant restoration: a 2-year follow-up

Introduction: The demand for optimal esthetics has increased with the advance of the implant dentistry and with the desire for easier, safer and faster technique allowing predictable outcomes. Thus, the aim of this case report was to describe a combined approach for the treatment of a periodontally compromised tooth by means of atraumatic tooth extraction, immediate flapless implant placement, autogenous block and particulate bone graft followed by connective tissue graft and immediate provisionalization of the crown in the same operatory time. Case Report: A 27-year-old woman underwent the proposed surgical procedures for the treatment of her compromised maxillary right first premolar. The tooth was removed atraumatically with a periotome without incision. A dental implant was inserted 3 mm apical to the cement-enamel junction of the adjacent teeth enabling the ideal tridimensional implant position. An osteotomy was performed in the maxillary tuber for block bone graft harvesting that allowed the reconstruction of the alveolar buccal plate. Thereafter, an autogenous connective tissue graft was placed to increase both the horizontal and vertical dimensions of the alveolar socket reaching the patient functional and esthetic expectations. Conclusion: This treatment protocol was efficient to create a harmonious gingival architecture with sufficient width and thickness, maintaining the stability of the alveolar bone crest yielding excellent aesthetic results after 2-years of follow-up. We suggest that this approach can be considered a viable alternative for the treatment of periodontally compromised tooth in the maxillary esthetic area enhancing patient comfort and satisfaction.

Rehabilitacion oral sobre implantes instalados por medio de la tecnica sin colgajo (flapless) y carga inmediata

The oral rehabilitation with osseointegrated implants is a well-documented treatment with high rate of success. Nevertheless, demands related to treatment time and surgical technique began to appear. In this context, the procedure of immediate loading in which the dental prosthesis is placed right after implant surgery has become a constant practice. Although immediate loading has been an important advance, minimally invasive procedures, such as implant placement without raising a mucoperiosteal flap (flapless) are increasingly being performed. Association of immediate loading with the flapless technique improves acceptance by patients and professionals, because no suturing is required. Moreover, it reduces swelling, bleeding during and after surgery, postoperative pain, surgery time, discomfort and hematoma, as well as the need for postoperative medication. These characteristics ease the stages of rehabilitation soon after implant placement, cooperating with prosthodontist's work. Thus, the proposal of this study is to present a clinical case of oral rehabilitation with osseointegrated implants and fixed prosthesis in both arches, in which the flapless technique was applied, followed by immediate loading. It will discuss the diagnosis, prosthetic planning, surgical/prosthodontic procedures and follow-up for 20 months.

An alternative technique for fabrication of frameworks in an immediate loading implant fixed mandibular prosthesis

The oral rehabilitation of edentulous patients with immediate loading has become a safe procedure with high predictability. The success is related to immediate fabrication of a passive fit framework to attach the implants. Based on these considerations, this case report shows an alternative technique for mandibular rehabilitation using implants immediately loaded, where the framework was fabricated using cylinders with internal reinforcement and precast pieces, electrowelding, and conventional welding providing esthetics and function to the patient in a short period of time.

Immediate and long-term effects of psychological stress during adolescence in cardiovascular function: comparison of homotypic vs heterotypic stress regimens

Adolescence has been proposed as an ontogenic period of vulnerability to stress. Nevertheless, the impact of stressful events during adolescence in cardiovascular activity is poorly understood. Therefore, the purpose of this study was to investigate the immediate and long-lasting effects of exposure to stressful events during adolescence in cardiovascular function of rats. To this end, we compared the impact of 10-days exposure to two chronic stress protocols: the repeated restraint stress (RRS, homotypic) and chronic variable stress (CVS, heterotypic). Independent groups of animals were tested 24 h (immediate) or three weeks (long-lasting) following completion of stress period. Exposure to CVS, but not RRS, during adolescence increased basal HR values without affecting arterial pressure, which was followed by augmented power of oscillatory component at low frequency (sympathetic-related) of the pulse interval (PI). RRS enhanced variance of the PI with an increase in the power of both low and high (parasympathetic-related) frequency components. RRS also increased the baroreflex gain. Neither RRS nor CVS affected systolic arterial pressure variability. The RRS-evoked changes in PI variability were long-lasting and persisted into adulthood while all alterations evoked by the CVS were reversed in adulthood. These findings indicate a stress type-specific influence in immediate and long-term effects of stress during adolescence in cardiovascular function. While immediate changes in cardiovascular function were mainly observed following CVS, long-lasting autonomic consequences in adulthood were observed only in animals exposed to RRS during adolescence.

Efeito da ovariectomia e da reposição hormonal no reimplante dentário imediato: análise histomorfométrica e imunoistoquímica em ratas

Pós-graduação em Odontologia - FOA

Impact of patient training patterns on peritonitis rates in a large national cohort study

Background. Ideal training methods that could ensure best peritoneal dialysis (PD) outcome have not been defined in previous reports. The aim of the present study was to evaluate the impact of training characteristics on peritonitis rates in a large Brazilian cohort.Methods. Incident patients with valid data on training recruited in the Brazilian Peritoneal Dialysis Multicenter Study (BRAZPD II) from January 2008 to January 2011 were included. Peritonitis was diagnosed according to International Society for Peritoneal Dialysis guidelines; incidence rate of peritonitis (episodes/patient-months) and time to the first peritonitis were used as end points.Results. Two thousand two hundred and forty-three adult patients were included in the analysis: 59 +/- 16 years old, 51.8% female, 64.7% with <= 4 years of education. The median training time was 15 h (IQI 10-20 h). Patients were followed for a median of 11.2 months (range 3-36.5). The overall peritonitis rate was 0.29 per year at risk (1 episode/41 patient-months). The mean number of hours of training per day was 1.8 +/- 2.4. Less than 1 h of training/day was associated with higher incidence rate when compared with the intervals of 1-2 h/day (P = 0.03) and > 2 h/day (P = 0.02). Patients who received a cumulative training of > 15 h had significantly lower incidence of peritonitis compared with < 15 h (0.26 per year at risk versus 0.32 per year at risk, P = 0.01). The presence of a caregiver and the number of people trained were not significantly associated with peritonitis incidence rate. Training in the immediate 10 days after implantation of the catheter was associated with the highest peritonitis rate (0.32 per year), compared with training prior to catheter implantation (0.28 per year) or > 10 days after implantation (0.23 per year). More experienced centers had a lower risk for the first peritonitis (P = 0.003).Conclusions. This is the first study to analyze the association between training characteristics and outcomes in a large cohort of PD patients. Low training time (particularly < 15 h), smaller center size and the timing of training in relation to catheter implantation were associated with a higher incidence of peritonitis. These results support the recommendation of a minimum amount of training hours to reduce peritonitis incidence regardless of the number of hours trained per day.

Oxidative dtress status and placental implications in diabetic rats undergoing swimming exercise after embryonic implantation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Behaviour of the buccal crestal bone levels after immediate placement of implants subjected to immediate loading

The aim of this study was to measure changes in buccal alveolar crestal bone levels after immediate placement and loading of dental implants with Morse taper prosthetic abutments after tooth extraction. This study followed the STROBE guidelines regarding prospective cohort studies. The sample comprised 12 patients with a mean age of 45 years, in whom a central or upper lateral incisor was indicated for extraction. Prior to extraction, computed tomography (CT) analysis was carried out to assess the presence of the buccal bone crest. CT scans were performed at 24 h and at 6 months after immediate implant placement and immediate loading. The distance from the most apical point of the implant platform to the buccal bone crest was assessed at the two time points. The buccal bone crest height was evaluated at three points in the mesio-distal direction: (1) the centre point of the alveolus, (2) 1 mm mesial to the centre point, and (3) 1 mm distal to the centre point. The values obtained were subjected to statistical analysis, comparing the distances from the bone crest to the implant platform for the two time points. After 6 months there was a statistically significant, non-uniform reduction in height at the level of the crest of the buccal bone in the cervical direction. It is concluded that the buccal bone crest of the immediate implants that replaced the maxillary incisors underwent apical resorption when subjected to immediate loading.