Milan Jurisic

Guided bone regeneration with a synthetic biodegradable membrane: a comparative study in dogs

OBJECTIVES The aim of the present study was to compare a newly developed biodegradable polylactide/polyglycolide/N-methyl-2-pyrrolidone (PLGA/NMP) membrane with a standard resorbable collagen membrane (RCM) in combination with and without the use of a bone substitute material (deproteinized bovine bone mineral [DBBM]) looking at the proposed tenting effect and bone regeneration. MATERIALS AND METHODS In five adult German sheepdogs, the mandibular premolars P2, P3, P4, and the molar M1 were bilaterally extracted creating two bony defects on each site. A total of 20 dental implants were inserted and allocated to four different treatment modalities within each dog: PLGA/NMP membrane only (Test 1), PLGA/NMP membrane with DBBM (Test 2), RCM only (negative control), and RCM with DBBM (positive control). A histomorphometric analysis was performed 12 weeks after implantation. For statistical analysis, a Friedman test and subsequently a Wilcoxon signed ranks test were applied. RESULTS In four out of five PLGA/NMP membrane-treated defects, the membranes had broken into pieces without the support of DBBM. This led to a worse outcome than in the RCM group. In combination with DBBM, both membranes revealed similar amounts of area of bone regeneration and bone-to-implant contact without significant differences. On the level of the third implant thread, the PLGA/NMP membrane induced more horizontal bone formation beyond the graft than the RCM. CONCLUSION The newly developed PLGA/NMP membrane performs equally well as the RCM when applied in combination with DBBM. Without bone substitute material, the PLGA/NMP membrane performed worse than the RCM in challenging defects, and therefore, a combination with a bone substitute material is recommended.

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.

Immediate vs. early loading of SLA implants in the posterior mandible: 5‐year results of randomized controlled clinical trial

OBJECTIVES The aim of this study was to compare clinical results of immediate and early loading (EL) self-tapping implants placed in posterior mandibles. MATERIAL AND METHODS Twelve patients with bilateral edentulous posterior mandibular were randomly assigned to treatment either with immediate (test) or early loaded implants (control). Seventy-two self-tapping implants with SLA surface (Ø 4, 1/4, 8 mm; length 8 and 10 mm) were analyzed in this study. Test implants (36) were loaded on the day of surgery and control implants 6 weeks later. The measuring of implant stability quotient (ISQ) was performed on 0, 6th, 12th, and 52nd week after implant insertion. The bone resorption, modified plaque, and bleeding index were notified at 1 and 5 years later. RESULTS After 5 years, survival in the both groups was 100%. The mean value of primary implant stability was 76.92 ± 0.79 ISQ. In the first 6 weeks, ISQ values significantly increased in the test group (77.92 ± 1.16 vs. 79.61 ± 0.90) as well as in the control group (7.92 ± 1.05 vs. 77.55 ± 0.99). A significant longitudinal increase in ISQ value was recorded in test and control group. The differences between immediate and early loaded implants were statistically insignificant (P > 0.05). At the 5 years, no statistically significant differences were found between immediate and early loaded implants with respect to mean crestal bone loss measurements (0.4 ± 0.24 vs. 0.8 ± 0.15 mm), mean bleeding index (0.22 ± 0.11 vs. 0.25 ± 0.11), and mean plaque index (0.17 ± 0.15 vs. 0.19 ± 0.20). CONCLUSION Based on these results, the self-tapping implants inserted in posterior mandible can provide adequate primary stability value as the main factor for immediate and EL protocol.

Correlation of bone vascularity in the posterior mandible and subsequent implant stability: a preliminary study.

Objectives:Bone vascularity is an important factor in process of osseointegration. The aim of this study was to find whether or not blood perfusion of the bone around the prepared implant sites influences subsequent implant stability. Methods:Patients with bilaterally edentulous mandible were treated with dental implants. Bone vascularity in implant sites was previously noted using Laser Doppler Flowmetry (LDF). Implant stability quotient (ISQ) was measured during follow-up period of 26th week. Statistical distribution and correlation between LDF and ISQ values were presented. Other variables (type of implant loading; sex and distance from the apical part of implant sites to the roof of the mandibular canal) were collected and correlated with LDF values. Results:The mean recorded LDF value was 53.05 perfusion unit. Eighteen implants were immediately loaded, and the other 18 were early loaded. In the group of early loaded implants, a statistically significant correlation between mean value of LDF and changing value of resonance frequency analysis (P < 0.05) was noted at 5th, 6th, 12th, and 26th weeks. Using Pearson coefficient of correlation, there was no statistically significant relationship between other variables and LDF values. Conclusion:LDF values of implant sites might determine future implant stability.

Keratocystic Odontogenic Tumors – Clinical and Molecular Features

Keratocystic odontogenic tumors (KCOTs) are certainly among the most studied lesions in oral pathology, which is not a surprise considering their perplexing clinical behavior and complicated mechanism of pathogenesis. In fact, the specific KCOT features are the reason for numerous discussions regarding the true nature and classification of these lesions, which are still debated in the scientific community.Until recently these lesions were known as odontogenic keratocysts (OKCs), a term first used by Philipsen in 1956. In the beginning, the term was used to describe any jaw cyst in which keratin was formed. However, it became obvious that some other types of jaw cysts, such as radicular and residual cysts, may exhibit keratinization as well, leading to the conclusion that specific histological features of OKCs and not solely the presence of keratin, should be used to distinguish these lesions from other cysts of the jaws [1]. Researchers soon realized that OKCs show aggressive clinical behavior and high recurrence rates, features which are not typical for other odontogenic cysts [2]. Be‐ sides that, it has been noted that OKCs are among the most prominent feature of Nevoid Basal Cell Carcinoma Syndrome (NBCCS), also known as Gorlin-Goltz syndrome. Finally, numerous studies have shown that genetic factors are predominant in etiology of these le‐ sions and that some mechanisms of pathogenesis, typical for neoplastic lesions, are also in‐ volved in formation of OKCs [3]. Therefore, in 2005 these lesions were reclassified as Keratocystic Odontogenic Tumors (KCOTs) and defined as benign, odontogenic, unior multicystic intraosseous tumors, with characteristic parakeratinized squamous epithelium lining, having a potential for aggressive and infiltrative growth [4]. However, since KCOTs also exhibit some cysts-like features, including response to decompression [5], the tumoral

C-reactive protein as an inflammatory marker in monitoring therapy effectiveness of acute odontogenic infections

INTRODUCTION Clinical presentation of acute odontogenic infections may vary, while adequate evaluation of its severity is of great importance for determination of appropriate and effective therapy. OBJECTIVE The aim of the present study was to monitor changes of C-reactive protein (CRP) levels, to correlate its values with symptoms of different acute odontogenic infections (AOI), and to monitor the effectiveness of the applied therapy. METHODS Fifty-four patients with AOI were included in the study. Eighteen patients with good drainage and normal body temperature were treated only by surgical incision without using antibiotics. Twenty-two patients with poor drainage after incision and normal body temperature were treated by surgical incision and antibiotics. Fourteen patients with elevated body temperature were treated by incision and antibiotics, irrespective of the quality of the drainage. CRP levels were measured on admission, on the 3rd and 7th day after therapy initiation. RESULTS On admission CRP levels were higher in AOI with elevated body temperature compared to poorly and well-drained AOI. There were no differences in CRP levels between well and poorly drained AOI on admission. On the 3rd day, a decline in the CRP levels was evident in all three groups of patients, and there was no difference among the groups. On the 7th day, the CRP levels normalized in all groups. CONCLUSION CRP levels correlate well with the severity and resolution of AOI and could be used as a reliable parameter in monitoring the effectiveness of AOI therapy.