Milena Pisano

Morphine withdrawal-induced morphological changes in the nucleus accumbens

Morphine withdrawal produces a hypofunction of mesencephalic dopamine neurons that impinge upon medium spiny neurons (MSN) of the forebrain. After chronic treatment (from 20 to 140 mg/kg of morphine twice a day over 14 days at escalating doses) rats were withdrawn from chronic morphine spontaneously and pharmacologically. In these two distinct conditions we studied the effects of withdrawal on the morphology of MSN of the core and shell of the nucleus accumbens (Nacc). MSN were stained with the Golgi–Cox procedure and analysed by a confocal laser‐scanning microscope (CLSM). Our analysis shows that, shell and core MSN differed significantly for perikarya size and spine density, and the various morphine treatments did not affect the perikarya morphometry. Both spontaneous and naloxone‐induced withdrawal produced a similar reduction in spine density in MS shell neurons, as compared with MS core neurons. This effect is selectively localized at the level of second order dendritic trunks where afferents converge. By contrast, spine density counts of accumbens MSN from rats chronically treated with morphine, did not reveal any change. Collectively, the results of the present study are twofold: (i) spontaneous and pharmacologically precipitated withdrawal, but not chronic morphine per se, affects spine density of target structures of a reduced mesolimbic dopamine transmission, and (ii) the reduction of spine density in second order dendritic trunks is selectively segregated in the MSN of the shell of the Nacc. In conclusion, morphine withdrawal dramatically alters spine density, selectively in second order dendritic trunks of Nacc shell MSN, thereby further impoverishing the already abated dopamine (DA) transmission. This is in line with recent views suggesting the hypodopaminergic state as a cardinal feature of opioid dependence.

The role of acetaldehyde in the central effects of ethanol.

This article represents the proceedings of a symposium at the 2004 annual meeting of the Research Society on Alcoholism in Vancouver, Canada. The symposium was organized by Etienne Quertemont and chaired by Kathleen A. Grant. The presentations were (1) Behavioral stimulant effects of intracranial injections of ethanol and acetaldehyde in rats, by Mercè Correa, Maria N. Arizzi and John D. Salamone; (2) Behavioral characterization of acetaldehyde in mice, by Etienne Quertemont and Sophie Tambour; (3) Role of brain catalase and central formed acetaldehyde in ethanols behavioral effects, by Carlos M.G. Aragon; (4) Contrasting the reinforcing actions of acetaldehyde and ethanol within the ventral tegmental area (VTA) of alcohol-preferring (P) rats, by William J. McBride, Zachary A. Rodd, Avram Goldstein, Alejandro Zaffaroni and Ting-Kai Li; and (5) Acetaldehyde increases dopaminergic transmission in the limbic system, by Milena Pisano and Marco Diana.

Computed tomography-guided implant surgery for dental rehabilitation in mandible reconstructed with a fibular free flap: description of the technique

The fibular free flap, with or without a cutaneous component, is the gold standard for reconstructing mandibular defects. Dental prosthetic rehabilitation is possible this way, even if the prosthesis-based implant is still a challenge because of the many anatomical and prosthetic problems. We think that complications can be overcome or reduced by adopting the new methods of computed tomography (CT)-assisted implant surgery (NobelGuide, Nobel Biocare AB, Goteborg, Sweden). Here we describe the possibility of using CT-guided implant surgery with a flapless approach and immediate loading in mandibles reconstructed with fibular free flaps.

Computer assisted dental rehabilitation in free flaps reconstructed jaws: one year follow-up of a prospective clinical study

Continuity defects in bone after resection of the jaw may cause problems, and osseo-myocutaneous free flaps are the gold standard for their reconstruction. Implant-supported prosthetic rehabilitation is reliable with these microvascular options, although it is still a serious challenge. The aim of this prospective clinical study was to describe the advantages of implants restored according to a computer-assisted surgical protocol. A group of 10 consecutive patients (both sexes) had already been treated and followed up for at least 1 year after prosthetic loading. The NobelGuide protocol had to be modified to adapt the technique for these patients who had had reconstructions. A total of 56 fixtures were installed and, when possible, immediately loaded (overall survival of implants 95%). Every patient was given correct provisional prosthetic rehabilitation, which was most satisfactory as far as chewing, social functioning, and overall quality of life were concerned. Three-dimensional computed tomographic (CT) examination showed a mean (SD) marginal bone loss of 1.06 (0.5)mm. We used a modified technique of computer-assisted implant surgery in jaws that had been reconstructed with free flaps; from these preliminary findings this approach seems valid when it comes to function, improving prosthetic restoration, and aesthetics.

Implant Restoration of Edentulous Jaws with 3D Software Planning, Guided Surgery, Immediate Loading, and CAD-CAM Full Arch Frameworks

Purpose. The aim of this study was to analyze the clinical and radiographic outcomes of 23 edentulous jaws treated with 3D software planning, guided surgery, and immediate loading and restored with CAD-CAM full arch frameworks. Materials and Methods. This work was designed as a prospective case series clinical study. Twenty patients have been consecutively rehabilitated with an immediately loaded implant supported fixed full prosthesis. A total of 120 fixtures supporting 23 bridges were placed. 117 out of 120 implants were immediately loaded. Outcome measures were implants survival, radiographic marginal bone levels and remodeling, soft tissue parameters, and complications. Results. 114 of 117 implants reached a 30 months follow-up, and no patients dropped out from the study. The cumulative survival rate was 97.7%; after 30 months, mean marginal bone level was 1.25 ± 0.31 mm, mean marginal bone remodeling value was 1.08 ± 0.34, mean PPD value was 2.84 ± 0.55 mm, and mean BOP value was 4% ± 2.8%. Only minor prosthetic complications were recorded. Conclusion. Within the limitations of this study, it can be concluded that computer-guided surgery and immediate loading seem to represent a viable option for the immediate rehabilitations of completely edentulous jaws with fixed implant supported restorations. This trial is registered with Clinicaltrials.gov NCT01866696.

Horizontal Ridge Augmentation using GBR with a Native Collagen Membrane and 1:1 Ratio of Particulated Xenograft and Autologous Bone: A 1-Year Prospective Clinical Study.

AIM To clinically and radiographically evaluate bone regeneration of severe horizontal bone defects. MATERIALS AND METHODS This study was designed as a single cohort, prospective clinical trial. Partially or fully edentulous patients, having less then 4 mm of residual horizontal bone width were selected and consecutively treated with resorbable collagen membranes and a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, 7 months before implant placement. Tapered body implants were inserted and loaded 3 to 6 months later with a screw retained crown or bridge. Outcomes were: implant survival rate, any biological and prosthetic complications, horizontal alveolar bone dimensional changes measured on cone beam computed tomography (CBCT) taken at baseline and at implant insertion, peri-implant marginal bone level changes measured on periapical radiographs, plaque index (PI), and bleeding on probing index (BoP). RESULTS Eighteen consecutive patients (11 females, 7 males) with a mean age of 56.8 years (range 24-78) and 22 treated sites received 55 regular platform implants. No patient dropped-out and no implants failed during the entire follow-up, resulting in a cumulative implant survival rate of 100%. No prosthetic or biological complications were recorded. Supraimposition of pre- and 7-month post-operative CBCT scans revealed an average horizontal bone gain of 5.03 ± 2.15 mm (95% CI: 4.13-5.92 mm). One year after final prosthesis delivery, mean marginal bone loss was 1.03 ± 0.21 mm (95% CI 0.83-1.17 mm). PI was 11.1% and BoP was 5.6%. CONCLUSION Within the limitation of the present study, high implant survival rate and high average bone augmentation seem to validate the use of collagen resorbable membranes with a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, for the reconstruction of severe horizontal ridge defects.

Mandibular coronoid process grafting for alveolar ridge defects

OBJECTIVE We describe the clinical results of mandibular augmentation with coronoid process bone grafts for dental implant insertion. STUDY DESIGN Fifteen patients with vertical and transverse defects of the posterior alveolar process of the mandible were treated. All patients underwent mandibular rehabilitation with autogenous coronoid process bone grafts via minimal-access surgery. After 6 months, 40 dental implants were inserted. RESULTS At the time of implant insertion, the grafted alveolar ridges showed mean transverse and vertical augmentations of 3.07 and 2.80 mm, respectively. At 24 months after implant surgery, the cumulative implant survival rate was 95% and mean marginal bone loss was 1.6 ± 0.18 mm. No complete bone graft loss or infection occurred. CONCLUSIONS Coronoid process bone grafts can be used to reconstruct moderate defects in edentulous alveolar processes. The insertion of the graft with minimal access in a tunneled fashion minimizes the risk of infection.

Grafting after sinus lift with anorganic bovine bone alone compared with 50:50 anorganic bovine bone and autologous bone: results of a pilot randomised trial at one year

Our aim was to compare the outcome of implants inserted in maxillary sinuses augmented with anorganic bovine bone grafts compared with those augmented with mixed 50:50 bovine and autologous bone grafts. Twenty sinuses with 1-4mm of residual crestal height below the maxillary sinuses were randomised into two groups according to a parallel group design (n=10 in each). Sinuses were grafted using a lateral approach. In one group the grafts were 50:50 anorganic bovine bone and autologous bone and in the other anorganic bovine bone alone. After 7 months, 32 implants had been inserted. Outcome measures were survival of implants, complications, marginal changes in the height of the bone, and soft tissue variables (pocket probing depth and bleeding on probing). Probabilities of less than 0.05 were accepted as significant. No patient failed to complete the trial and no implant had failed at 1 year. There were some minor complications. After 12 months, the mean (SD) marginal bone loss (mm) was 1.06 (0.61) in the 50:50 group and 1.19 (0.53) in the anorganic bovine group. The mean (SD) values for pocket probing depth (mm) and bleeding on probing (score) were 2.49 (0.38) and 1.59 (0.82) in the 50:50 group and 2.31 (0.64) and 1.36 (0.87) in the anorganic bovine group (neither difference was significant). The present data are consistent with the hypothesis that the outcome of implants inserted in sinuses grafted with either material is comparable.

Arthrocentesis and temporomandibular joint disorders: clinical and radiological results of a prospective study

Purpose. We evaluated the efficacy of arthrocentesis in the treatment of temporomandibular joint (TMJ) disorders. Material and Methods. In this prospective clinical case series, 30 consecutive patients with TMJ disorders underwent arthrocentesis using saline and sodium hyaluronate injections. Outcome measures were TMJ pain, maximum mouth opening (MMO), joint noises, and anatomical changes in the TMJ architecture. Patients were evaluated using cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) at the beginning of treatment and 60 days after the last arthrocentesis. Pretreatment and posttreatment clinical parameters were compared using paired and unpaired t-tests, and McNemars test was used to evaluate CBCT and MRI changes (P < 0.05). Results. At 1-year follow-up examinations, visual analogue scale scores indicated that pain was reduced significantly and mean postoperative MMO was increased significantly. CBCT findings showed no significant change, and MRI showed only slight reductions in inflammatory signs. Conclusions. Within the limitations of this study, we can conclude that arthrocentesis is a simple, minimally invasive procedure with a relatively low risk of complications and significant clinical benefits in patients with TMJ disorders. This trial is registered with NCT01903512.

An up to 7-Year Retrospective Analysis of Biologic and Technical Complication With the All-on-4 Concept

The aim of this study was to evaluate retrospectively biologic and technical complications as well as clinical and radiographic outcomes of patients treated with 4 implants according to the All-on-4 protocol and followed up to 7 years of function. Data from 56 consecutive patients presenting complete edentulous jaw, aged 18 years or older, treated between January 2008 and December 2013, were evaluated. The outcomes were implant and prosthetic survival and success rates, any complications, and marginal bone loss (MBL). Two-hundred twenty-four implants were placed in 56 patients. During the entire follow-up, 1 maxillary implant but no prosthesis failed during the healing process. Fourteen patients experienced 1 complication each (10 technical, 4 biologic). The overall implant and prosthetic success rate was 98.2% and 82.1%, respectively. All complications were considered as minor and successfully resolved chairside. A mean MBL of 1.30 ± 0.63 mm was observed at the last follow-up. Statistically significant difference was found for postextractive implants (0.79 ± 0.26) vs implants placed in healed sites (1.03 ± 0.46; P = 0.024). Within the limits of the present study, the All-on-4 concept may be a valuable surgical and prosthetic option for the treatment of complete edentulous jaws. However, minor technical and biologic complications can occur. Further long-term prospective data with primary outcomes focused on success rates are needed.