Bozidar Brkovic

Maxillary sinus floor augmentation: comparing osteotome with lateral window immediate and delayed implant placements. An interim report

OBJECTIVE A retrospective study was performed to observe clinical outcomes of dental implants placed in augmented maxillary sinuses using an osteotome or a lateral approach technique with synchronous or delayed implant placement. STUDY DESIGN A total of 61 patients were enrolled in the study. The distribution and frequency of sinus augmentation techniques and implant placements were evaluated according to the implant site and Cawood-Howell classifications. The implant survival rates were assessed clinically and radiographically over a minimum of 3 years of follow-up. RESULTS The number of implants placed was fewer in the molar region compared with the premolar region and was independent of the surgical techniques used. Significantly fewer implants were placed in implant site class D and Cawood-Howell class V. Optimal survival rates were evident in all groups, with no significant changes. CONCLUSION The most predictable region for sinus augmentation with simultaneous implant placement was the maxillary premolar area. All 80 implants were successful using either osteotome or lateral approaches to augment the maxillary sinus floor.

Bone healing with an in situ-formed bioresorbable polyethylene glycol hydrogel membrane in rabbit calvarial defects.

OBJECTIVES The aims of this study were to test whether or not the application of an in situ-formed synthetic polyethylene glycol hydrogel (PEG) used as a biodegradable membrane for guided bone regeneration with a variety of graft materials and ambient oxygen or hyperbaric oxygen (HBO) environments would result in enhanced bone regeneration, and to observe the histologic and histomorphometric aspects of bone healing of the calvarial defects with and without a PEG membrane. STUDY DESIGN Thirty adult, skeletally mature, male New Zealand white rabbits were randomly divided into 3 groups of 10 animals each. Bilateral 15-mm-diameter critical-size defects were created in the parietal bones of each animal. Group 1 served as a control with unfilled bilateral calvarial defects, group 2 had bilateral calvarial defects filled with morcelized autogenous calvarial bone, and group 3 had bilateral calvarial defects filled with a biphasic calcium phosphate ceramic. One of the calvarial defects was randomly protected with a PEG resorbable liquid membrane in each animal. Five animals from each group underwent a course of HBO treatment (2.4 ATA 100% oxygen for 90 minutes 5 days a week for 4 weeks) and the other 5 served as control and did not receive any supplemental oxygen (normobaric). The animals were killed 6 weeks after their surgery, and their parietal bones were harvested. The specimens were analyzed with microscopic computerized tomography (microCT) scans and histomorphometrics. RESULTS The unfilled normobaric control bony defects did not heal, proving the critical-size nature of these defects. The presence of autogenous bone or bone ceramic in the defects increased the bone volume fraction and bone mineral density of the defects (P < .001). The presence of a membrane in the ungrafted and autogenous bone grafted defects resulted in a decrease in the corrected bone volume fraction (P = .002) but not in the bone ceramic grafted defects (P = .580). Bony healing of defects where the membrane was unsupported was compromised; the membrane did not maintain the desired bone regeneration volume with the unfilled and autogenous bone grafted groups. The PEG resorbable liquid membrane worked best with the bone ceramic material. HBO did not ameliorate the healing of the autogenous bone graft or ceramic filled defects in the 6-week time period of this study. CONCLUSIONS Although the PEG resorbable liquid membrane is easy to use and forms an occlusive layer, caution is recommended when using the membrane over an unsupported defect. HBO did not ameliorate bony healing with the membrane at the early 6-week time point. The authors recommend future assessment with HBO at the 12-week time point.

Functional endoscopic sinus surgery as an adjunctive treatment for closure of oroantral fistulae: a retrospective analysis.

OBJECTIVE The objective of this study was to report results of functional endoscopic sinus surgery (FESS) for treatment of chronic maxillary sinusitis of dental origin in a series of patients with oroantral fistulae (OAF). STUDY DESIGN Fourteen patients were treated by FESS and OAF closure by local flap. Data on severity of symptoms, diagnostic endoscopy, and coronal CT scan findings, as well as intraoperative course and complications, were recorded. The follow-up period lasted up to 2 years, comprising clinical examinations and control CT scans. RESULTS All OAF healed uneventfully. All patients reported improvement in severity of sinusitis symptoms, which was confirmed through results of clinical examinations and control CT scans. No significant complications were recorded. No revision surgery was needed in any case. CONCLUSION These results indicate that FESS, combined with OAF closure by buccal flap, might be an effective and safe option for treatment of selected cases of chronic odontogenic sinusitis with OAF.

Dental implants placed into alveolar clefts reconstructed with tongue flaps and bone grafts

OBJECTIVE The aim of this study was to describe a case series using surgical and prosthodontic modifications of tongue flaps necessary to adapt them for use in the reconstruction of large cleft deformities refractory to customary measures using dental implants and to study their outcomes in patients with complex cleft lip and palate deformities. STUDY DESIGN Five patients were treated with iliac crest bone grafts and covered by anteriorly based tongue flaps divided at either 3 or 4 weeks after surgery. The patients were followed clinically and radiographically for 3-12 years after placement of their dental implants to monitor implant survival and success. RESULTS One of the 5 patients suffered a partial tongue flap detachment, graft dehiscence, and recurrence of an oronasal fistula, which was successfully treated by shifting the tongue flap tissue from its new location in the palate. A total of 18 dental implants were placed into bone-grafted tissue covered by the tongue flaps. There was 1 implant failure. There were no cases of periimplantitis or bone loss in the 17 surviving implants. CONCLUSIONS Tongue flaps are rarely used clinical entities with a very narrow range of indications. Tongue flaps are useful in the preprosthetic reconstruction of select cases with large residual oronasal fistulae with soft tissue deficits due to scarring from previously failed surgery. Tongue flaps are extremely stressful procedures for patients to endure. Patient selection is of the utmost importance.

Dental Pulp Blood Flow and Its Oscillations in Women with Different Estrogen Status

INTRODUCTION The skin microcirculation is significantly affected by serum estrogen levels. The objective of this study was to investigate the effects of estrogen serum level changes associated with the menstrual cycle and postmenopause on dental pulp blood flow (PBF) as well as its dynamics. METHODS Young women at the menstrual phase (low serum estrogen levels) and in the mid-cycle phase of the menstrual cycle (high serum estrogen levels) and postmenopausal women were enrolled in the study. PBF and its oscillations were measured by laser Doppler flowmetry and analyzed by using wavelet transform. Serum levels of estradiol-17β were measured by immunoassay. RESULTS PBFs of young women in the menstrual phase and postmenopausal women were mutually similar and significantly lower than those of young women in the mid-cycle period. With respect to the mid-cycle phase, relative amplitude and power were significantly increased in the interval 0.0095-0.02 Hz and decreased in the intervals 0.02-0.06 and 0.06-0.2 Hz in the menstrual phase. A significant decrease in 0.0095-0.02 Hz and increase in 0.02-0.06, 0.06-0.2, 0.2-0.6, and 0.6-1.6 Hz intervals were observed in postmenopause. CONCLUSIONS The study has shown that the menstrual phase of the menstrual cycle and postmenopause have similar PBF decrease, but PBF oscillations are differently affected in the mid-cycle phase.

Does Oxidative Stress Play a Role in Altered Characteristics of Diabetic Bone? A Systematic Review

Diabetes mellitus (DM) has been associated with increased bone fracture rates, impaired bone regeneration, delayed bone healing, and depressed osteogenesis. However, the plausible pathogenic mechanisms remain incompletely understood. The aim of the present systematic review was to investigate whether oxidative stress (OS) plays a role in altered characteristics of diabetic bone under in vivo conditions. An electronic search of the MEDLINE (via PubMed) and Embase databases was performed. In vivo animal studies involving DM and providing information regarding assessment of OS markers combined with analyses of bone histology/histomorphometry parameters were selected. A descriptive analysis of selected articles was performed. Ten studies were included in the present review. Both bone formation and bone resorption parameters were significantly decreased in the diabetic groups of animals compared to the healthy groups. This finding was consistent regardless of different animal/bone models employed or different evaluation periods. A statistically significant increase in systemic and/or local OS status was also emphasised in the diabetic groups in comparison to the healthy ones. Markers of OS were associated with histological and/or histomorphometric parameters, including decreased trabecular bone and osteoid volumes, suppressed bone formation, defective bone mineralisation, and reduced osteoclastic activity, in diabetic animals. Additionally, insulin and antioxidative treatment proved to be efficient in reversing the deleterious effects of high glucose and associated OS. The present findings support the hypotheses that OS in the diabetic condition contributes at least partially to defective bone features, and that antioxidative supplementation can be a valuable adjunctive strategy in treating diabetic bone disease, accelerating bone healing, and improving osteointegration.

Efficacy and safety of 4% articaine with epinephrine for anterior middle superior alveolar nerve block comparing computer-controlled and conventional anesthetic delivery: Prospective, randomized, cross-over clinical study

Bacground/Aim. The efficient dental anesthesia, which is related to the clinically adequate depth, duration and the width of anesthetic field, is an important prerequisite for successful dental treatment. The aim of this study was to investigate and compare the pulpal anesthesia and cardiovascular parameters after the anterior middle superior alveolar (AMSA) nerve block with 4% articaine with epinephrine administered by conventional cartridge-syringe and computer- controlled local anesthetic delivery system (CCLADS). Methods. This controlled double-blind cross-over randomized clinical study included 38 healthy volunteers. Efficacy of pulpal anesthesia after the AMSA nerve block was evaluated by measuring a success rate, onset and duration of pulpal anesthesia, using an electrical pulp tester. The parameters of cardiovascular function (systolic and diastolic blood pressure, heart rate) were monitored noninvasively. Results. Successful pulpal anesthesia of all tested teeth was obtained in 57.9% participants with CCLADS and in 44.7% participants with conventional syringe. The onset time was not significantly different between two investigated groups. The pulpal anesthesia duration was not significantly different neither within nor between investigated groups. The systolic and diastolic blood pressures were significantly decreased in both investigated groups, in comparison with the baseline values. Heart rate significantly decreased within CCLADS from 10th to 30th minute when compared to baseline. Conclusion. The efficacy of pulpal anesthesia and safety of cardiovascular profile of 0.6 mL of articaine with epinephrine (1:100.000) delivered with CCLADS were improved in comparison to the conventional syringe delivery. Significant changes of cardiovascular function were not observed. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 175021]

The effect of piezosurgery on the oxidative stress and immediate post extraction discomfort following complex teeth extractions prior to implant placement

1 ITI Scholar, Department for Craniofacial Science, University of Connecticut, United States ; 2 Department for Reconstructive Science, University of Connecticut, United States ; 3 Department for Oral Surgery, University of Belgrade, Serbia ; 4 Department of Pharmacology in Dentistry, School of Dental Medicine, University of Belgrade, Serbia ; 5 Department of Oral Surgery, School of Dental Medicine, University of Belgrade, Serbia

Histomorphometric evaluation of bone regeneration using autogenous bone and beta-tricalcium phosphate in diabetic rabbits

Background/Aim The mechanism of impaired bone healing in diabetes mellitus includes different tissue and cellular level activities due to micro- and macrovascular changes. As a chronic metabolic disease with vascular complications, diabetes affects a process of bone regeneration as well. The therapeutic approach in bone regeneration is based on the use of osteoinductive autogenous grafts as well as osteoconductive synthetic material, like a β-tricalcium phosphate. The aim of the study was to determine the quality and quantity of new bone formation after the use of autogenous bone and β-tricalcium phosphate in the model of calvarial critical-sized defect in rabbits with induced diabetes mellitus type I. Methods The study included eight 4-month-old Chincilla rabbits with alloxan-induced diabetes mellitus type I. In all animals, there were surgically created two calvarial bilateral defects (diameter 12 mm), which were grafted with autogenous bone and β-tricalcium phosphate (n = 4) or served as unfilled controls (n = 4). After 4 weeks of healing, animals were sacrificed and calvarial bone blocks were taken for histologic and histomorphometric analysis. Beside descriptive histologic evaluation, the percentage of new bone formation, connective tissue and residual graft were calculated. All parameters were statistically evaluated by Friedman Test and post hock Wilcoxon Singed Ranks Test with a significance of p < 0.05. Results Histology revealed active new bone formation peripherally with centrally located connective tissue, newly formed woven bone and well incorporated residual grafts in all treated defects. Control samples showed no bone bridging of defects. There was a significantly more new bone in autogeonous graft (53%) compared with β-tricalcium phosphate (30%), (p < 0.030) and control (7%), (p < 0.000) groups. A significant difference was also recorded between β-tricalcium phosphate and control groups (p < 0.008). Conclusion In the present study on the rabbit grafting model with induced diabetes mellitus type I, the effective bone regeneration of critical bone defects was obtained using autogenous bone graft. [Projekat Ministarstva nauke Republike Srbije, br. 175021].