Simone Marconcini

Osteotomy and membrane elevation during the maxillary sinus augmentation procedure. A comparative study: piezoelectric device vs. conventional rotative instruments.

OBJECTIVES The aim of the present study was to investigate in a randomized-controlled clinical trial the performance of rotary instruments compared with a piezoelectric device during maxillary sinus floor elevation. MATERIALS AND METHODS Thirteen patients who required a bilateral maxillary sinus augmentation for implant-prosthetic rehabilitation were included in this study. A within-patient control study was carried out. The osteotomy for sinus access was performed on one side of the maxilla using the piezosurgery (test sites) and on the other side using conventional rotary diamond burs (control sites). The parameters recorded were as follows: bony window length (L), bony window height (H), bone thickness (T) and osteotomy area (A)--calculated by multiplying L and H. In addition, the time necessary for the osteotomy and sinus membrane elevation as well as the number of surgical complications were calculated. RESULTS The mean length and height of the bone window were similar in both groups. The osteotomy area (A) obtained by multiplying L and H was wider in the control group (151.2 +/- 20.4 mm(2)) compared with the test group (137 +/- 24.2 mm(2)). The time necessary for the osteotomy and the sinus membrane elevation with conventional instruments was 10.2 +/- 2.4 min, while with the piezoelectric device it was 11.5 +/- 3.8 min. Moreover, membrane perforation occurred in 30% of the maxillary sinuses in the test group and in 23% of the control group. None of the differences observed between the two groups reached a level of significance. CONCLUSIONS Within the limits of the present study, it may be concluded that piezosurgery and conventional instruments did not show any differences in the clinical parameters investigated for the maxillary sinus floor elevation.

Bacterial plaque colonization around dental implant surfaces

Purpose:To examine the distribution of bacteria into the internal and external surfaces of failed implants using histologic analysis. Materials and Methods:There were 10 failed pure titanium and 5 failed hydroxyapatite-coated titanium implants consecutively removed various years after their placement. Criteria for fixture removal were peri-implant radiolucency and clinical mobility. The mobile fixtures were retrieved with the patients under local anesthesia. Fixtures were removed maintaining the abutments with the aim to observe the bacterial infiltration at the level of abutment/implant interface and on the implant surface. Results:A thin radiolucent space was always present around all the failed implants. The abutments screws were tightly secured in all clinicalcases. The bacterial cells were composed of cocci and filaments, which were adherent to the implant surface with an orientation perpendicular to the long axis of the implant. All the specimens included in this study showed bacteria at the level of implant/abutment interface. Conclusions:Histologic analysis at the level of abutment/implant interface in 2-stage implants identified heavy bacterial colonization. These findings appear to support those studies showing bacteria penetration at the level of the micro-gap, which can legitimate the hypothesis that the micro-gap at the bone level could present a risk for bone loss caused by bacterial colonization.

A Randomized Clinical Evaluation of Ultrasound Bone Surgery Versus Traditional Rotary Instruments in Lower Third Molar Extraction

PURPOSE The purpose of this study was to investigate and compare, in a randomized and controlled clinical trial, the use of ultrasound bone surgery devices and the use of rotary instruments in lower third molar extractions. MATERIALS AND METHODS We selected 26 patients (12 women and 14 men) for this study; the mean age was 31.2 years (range, 24-45 years). A randomized clinical trial was planned. Patients in the control group received treatment with the conventional rotary instruments; patients in the test group received treatment with the ultrasound bone surgery tools. Twenty-six third molars were allocated to the test and control groups according to a computer-generated randomization list. All the surgical procedures were performed by the same surgeon. Pain, trismus, cheek swelling, and number of analgesics taken were evaluated at baseline (before surgery) and at the first-, third-, fifth-, and seventh-day visits. RESULTS Pain levels (evaluated on a visual analog scale) were higher in the control group when compared with the ultrasonic group; however, no statistically significant differences were found. On the contrary, the number of analgesics taken in the test group was significantly lower when compared with the control group. The occurrence of trismus was significantly higher in the control group when compared with the test group. The clinical values of cheek swelling were higher in the rotary group when compared with the ultrasound group at the fifth-day visit. CONCLUSION This study showed that the use of ultrasound bone surgery for third molar extraction significantly reduced the occurrence of postsurgical trismus, the occurrence of swelling, and the number of analgesics taken after surgery.

Relationship Between Human Periodontitis and Type 2 Diabetes at a Genomic Level: A Data-Mining Study

BACKGROUND The leader gene approach is a data-mining method based on the systematic search for the genes involved in a specific process and their ranking according to the interconnections with the other genes identified. The application of this algorithm to human periodontitis gave promising results. The present study used this algorithm to formulate new hypotheses about the association between periodontitis and type 2 diabetes. METHODS The genes involved in a given process were identified via interrelated queries of several databases. The interactions among such genes were mapped and given a significance score. The weighted number of links (sum of weighted scores for every interaction in which a gene is involved) was calculated for each gene. Genes were clustered according to this parameter; those in the highest cluster were termed leader genes. This algorithm was applied to diabetes and sinusitis. Sinusitis was chosen as a control because it is an inflammatory infectious disease like periodontitis. The results were compared to those previously calculated for periodontitis. RESULTS Periodontitis and diabetes share four leader genes; all leader genes are linked in a complex map of interactions. Periodontitis and sinusitis share no leader genes; no interactions were identified. CONCLUSIONS Even with the limitations of ab initio analyses, these theoretical results might suggest the existence of some common genomic pathways between periodontitis and type 2 diabetes, despite the different pathogenesis of these diseases. In particular, the shared leader genes could have an important role in this relationship, which may be investigated further with targeted experimentation.

Immediate Implant Placement in Infected Sites: A Case Series

BACKGROUND Immediate implant placement has several advantages, such as reduction in the number of surgical treatments and reduction of the time between tooth extraction and the placement of the definitive prosthesis. However, there are still some situations that could jeopardize the success of the aforesaid therapy, such as the presence of an infection caused by periodontal disease or periapical lesions. The aim of this case series is to evaluate the clinical success of implants placed in fresh extraction sockets that showed clinical signs of periodontal disease. METHODS Thirteen patients (six males and seven females, 24 to 65 years old) are included in this case series. After initial examination and treatment planning, all patients underwent the periodontal treatment deemed necessary to facilitate wound healing. Twenty teeth were extracted as a result of an infection. Second-stage surgery was performed 4 months after the initial procedure. The following clinical parameters were evaluated for each patient at the time of implant placement and at the end of the 12-month follow-up period: 1) clinical attachment level (CAL); 2) presence or absence of mobility; 3) presence or absence of pain; and 4) presence or absence of suppuration. The bone level was measured as the distance from the implant shoulder to the first bone-implant contact (distance bone-implant [DIB]) by periapical radiographs. The stability and health of the soft tissue were clinically evaluated by means of the plaque score. RESULTS The healing period was uneventful for all the patients. All the implants were osseointegrated. At the end of the 12-month follow-up period, patients were asymptomatic and showed no signs of infection or bleeding when probed. The mean CAL at the mid-buccal location per implant was 0.8 mm at baseline and 0.9 mm at the end of the follow-up. The mean width of keratinized mucosa measured at the mid-buccal location per implant at baseline and 1-year visits was 3.2 ± 0.4 mm and 3.3 ± 0.5 mm, respectively. The periapical radiographs, obtained in a standardized manner, revealed a mean increase of 0.5 mm in the DIB value. At the 12-month follow-up, the presence of plaque was observed in 44 of the 80 sites analyzed. CONCLUSION Based on the results of this case series, placement of implants in fresh extraction sockets affected by infection may be a valid operative technique that leads to predictable results if adequate preoperative and postoperative care is taken.

Immediate Implant Placement After Removal of a Failed Implant: A Clinical and Histological Case Report

The purpose of this study was to evaluate the clinical success of an implant placed immediately after the explantation of a fractured blade implant. A healthy 58-year-old male nonsmoker presented with a fractured blade implant that had been subjected to biomechanical overload. A new blade implant was placed immediately after the removal of the fractured one. The new implant was placed with a composite graft of collagen gel and corticocancellous porcine bone and covered with a bioabsorbable membrane. Radiographic evaluation at 6 months postoperation showed complete bone healing. No residual bone defect was observed or probed during the uncovering phase; moreover, no mobility, pain, suppuration, or presence of peri-implant radiolucency were observed at the second-stage surgery.

Esthetic Outcome of Implants Placed in Fresh Extraction Sockets by Clinicians with or without Experience: A Medium-Term Retrospective Evaluation.

PURPOSE This study discussed a 3-year retrospective survey of clinical and esthetic outcomes of immediate implants placed by experienced senior surgeons and residents in implant dentistry. MATERIALS AND METHODS The retrospective chart review included patients who received single-tooth extraction and immediate implant placement at the Tuscan Stomatology Institute between 2009 and 2011. Treated independent postextraction areas were divided into two groups according to the operators experience: expert versus nonexpert group. Patient satisfaction with the esthetic aspect, chewing, speaking, comfort, self-esteem, and ease of cleaning were assessed by visual analog scales. Changes in the marginal bone level and parameters describing the changes of the facial soft tissue and in papilla index were assessed. Proper pairwise comparison tests were applied with a significant level α = .05. RESULTS Of the 60 selected patients, 31 were in the expert group and 29 in the nonexpert group. At the 3-year follow-up, findings attested to a significantly higher bone loss in the nonexpert group (1.74 ± 0.59 mm) than those registered in the expert group (1.34 ± 0.45 mm), with a P value of .0044. The papilla index (PI) appeared very stable in the group of experts, whereas it showed a significant loss throughout the study in patients in the nonexpert group (PI = 2 at 1 year and PI = 1.5 at 3 years). Moreover, significant recessions at the buccal soft tissue were registered for all groups at both check-ups; however, in the expert group, slight soft tissue recession was evident 3 years later (0.58 ± 0.72 mm), whereas the nonexpert group showed greater recession (1.52 ± 0.74 mm). Patients reported higher overall satisfaction when treated by the group of experts (85.2%) than when treated by the nonexperts (81.1%) with P < .0001. CONCLUSION The findings from this study suggested that immediate implant procedures could be considered a successful and satisfying treatment strategy when strict selection criteria together with a high level of surgical expertise are applied.

Sub-micrometric liposomes as drug delivery systems in the treatment of periodontitis.

Periodontitis is a complex disease and bacterial infection is one of the most common factors involved in this disease. Current strategies for the local delivery of antibiotics do not allow a complete clearance of bacteria filling dentinal tubules and this limits their therapeutic efficacy. Therefore, there is a strong need for the development of new delivery strategies aimed at improving the efficacy of antibiotic therapy for periodontitis with special reference to their ability to penetrate into the tubules. The aim of the present study is to develop liposome-based delivery systems of sub-micron dimension, able to diffuse into the dentinal tubules. A further aim of the research is to develop a protocol for enhanced diffusion based on the use of magnetic liposomes and magnetic fields. Liposomes were produced by hydration of a pre-liposomal formulation. The vesicles were stabilised with PEG and their re-sizing was achieved by extrusion. Magnetite nanoparticles were synthesized inside the vesicles, i.e., the chemical reaction involving FeCl2, FeCl3 and NH3 occurred within the core of the newly formed liposomes. Dynamic Light Scattering analysis was performed for size characterization. A mathematical model was implemented to predict the diffusion of the liposomes in dentinal tubules. Ex-vivo validation was performed on extracted human teeth. We produced PEG-ylated liposomes (average size 204.3 nm) and PEG-ylated magnetic liposomes (average size 286 nm) and an iron content of 4.2μg/ml. Through mathematical modelling, we deduced that sub-micrometer vesicles are able to penetrate into dentinal tubules. This penetration is considerably more effective when the vesicles are magnetized and subjected to an external magnetic field which accelerates their movement within the tubules. The liposome-based delivery systems developed by the present study are able to penetrate deeply into the tubules, sometimes reaching their terminal ends.

Real-Time Quantitative Polymerase Chain Reaction Analysis of Patients With Refractory Chronic Periodontitis

BACKGROUND Periodontitis is a complex multifactorial disease and is typically polygenic in origin. Genes play a fundamental part in each biologic process forming complex networks of interactions. However, only some genes have a high number of interactions with other genes in the network and may, therefore, be considered to play an important role. In a preliminary bioinformatic analysis, five genes that showed a higher number of interactions were identified and termed leader genes. In the present study, we use real-time quantitative polymerase chain reaction (PCR) technology to evaluate the expression levels of leader genes in the leukocytes of 10 patients with refractory chronic periodontitis and compare the expression levels with those of the same genes in 24 healthy patients. METHODS Blood was collected from 24 healthy human subjects and 10 patients with refractory chronic periodontitis and placed into heparinized blood collection tubes by personnel trained in phlebotomy using a sterile technique. Blood leukocyte cells were immediately lysed by using a kit for total RNA purification from human whole blood. Complementary DNA (cDNA) synthesis was obtained from total RNA and then real-time quantitative PCR was performed. PCR efficiencies were calculated with a relative standard curve derived from a five cDNA dilution series in triplicate that gave regression coefficients >0.98 and efficiencies >96%. The standard curves were obtained using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and growth factor receptor binding protein 2 (GRB2), casitas B-lineage lymphoma (CBL), nuclear factor-KB1 (NFKB1), and REL-A (gene for transcription factor p65) gene primers and amplified with 1.6, 8, 40, 200, and 1,000 ng/μL total cDNA. Curves obtained for each sample showed a linear relationship between RNA concentrations and the cycle threshold value of real-time quantitative PCR for all genes. Data were expressed as mean ± SE (SEM). The groups were compared to the analysis of variance. A probability value <0.01 was considered statistically significant. RESULTS The present study agrees with the preliminary bioinformatics analysis. In our experiments, the association of pathology with the genes was statistically significant for GRB2 and CBL (P <0.01), and it was not statistically significant for REL-A and NFKB1. CONCLUSION This article lends support to our preliminary hypothesis that assigned an important role in refractory aggressive periodontitis to leader genes.

Odontogenic Orofacial Infections

Abstract Acute dental abscess is a frequent and sometimes underestimated disease of the oral cavity. The acute dental abscess usually occurs secondary to caries, trauma, or failed endodontic treatment. After the intact pulp chamber is opened, colonization of the root canals takes place with a variable set of anaerobic bacteria, which colonize the walls of the necrotic root canals forming a specialized mixed anaerobic biofilm. Asymptomatic necrosis is common. However, abscess formation occurs when these bacteria and their toxic products breach into the periapical tissues through the apical foramen and induce acute inflammation and pus formation. The main signs and symptoms of the acute dental abscess (often referred to as a periapical abscess or infection) are pain, swelling, erythema, and suppuration usually localized to the affected tooth, even if the abscess can eventually spread causing a severe odontogenic infection which is characterized by local and systemic involvement culminating in sepsis syndrome. The vast majority of dental abscesses respond to antibiotic treatment, however, in some patients surgical management of the infection may be indicated. In the present work, a retrospective analysis of the patients with dental orofacial infections referred to the Unit of Dentistry and Maxillofacial Surgery of the University of Verona from 1991 to 2011 has been performed.