Use of recombinant human bone morphogenetic protein (rhBMP2) in bilateral alveolar ridge augmentation: case report.

In recent years, the delivery of osteoinductive factors such as bone morphogenic proteins (BMPs) has become an alternative approach to traditional bone grafting due to their capacity to produce bone healing and new bone formation. BMP-2 has proved to possess the highest osteoinductive potential among BMPs. The case reported the clinical use of recombinant human BMP-2 for bilateral vertical alveolar ridge augmentation. In a case of 61 year-old patient with a significant bilateral vertical bony deficiency of the mandible, rhBMP-2 administered via an absorbable collagen sponge carrier (ACS) was used for bilateral alveolar ridge bone induction. Augmented sites were covered and fixed with titanium mesh. Augmented sites were reopened 6 months after surgery. Titanium membrane and retaining screws were removed and three dental implants were placed. The tissue samples for the histologic analysis were harvested. Following 3 months healing period, the submerged implants were uncovered and restored with zirconium-ceramic crowns. Cone beam computed tomography (CBCT), panoramix and 3D radiographic evaluation were obtained prior to and after the surgical procedure. Vertical gain of the bone was 5.5 mm on the left and 5 mm on the right side, with 6 mm width of the bone. Histologic analysis revealed formation of mature trabecular bone with signs of osteoblastic proliferation. Implant stability quotient (ISQ) values were in the range between 69 and 75 for all three implants. No suppuration, gingival recession or pain were present 24 months after surgery. Vertical bone augmentation using rhBMP-2 is optional treatment modality to consider when planning dental implant placement in sites where severe vertical insufficiency exists.

The incidence of satellite cysts in keratocystic odontogenic tumors.

Renaming of the Odontogenic Keratocyst as the Keratocystic Odontogenic Tumor by the World Health Organization (WHO) is based on the aggressive nature of this lesion. Satellite cysts founded in the walls of the original cysts may give rise to a new lesion formation. The aim of this retrospecitve study was to identify the existence of specific features according incidence of satellite cysts and the pallisading of the basal layer of the epithelium and to establish their mutual correlation. The histopathologic data of Keratocystic Odontogenic Tumor on the basis of new WHO's classification (2005) were analized. Prominent palisade basal cell layer was found in 415 (94.75%) and partially absent palisade basal cell layer in 23 (5.25%) cases. Satellite cysts were presented in prominent palisade basal cell layer in 85 specimens (20.5%) and in cases with partial absent of the palisade basal layer in 3 spicemens (13%). The higher the frequency of pallisading was the higher the frequency of satellite cysts was (p > 0.05).

Comparison of Er:YAG laser and surgical drill for osteotomy in oral surgery: an experimental study.

PURPOSE: High-energy lasers have been proposed as an alternative to the conventional surgical drill in oral and maxillofacial surgery. The aims of this study were to compare thermal changes of the bone surface, procedure time, and volume of the removed bone after drilling with an erbium (Er):yttrium-aluminum-garnet (YAG) laser versus a low-speed surgical drill. The bone sections were observed under light microscopy and examined histologically. MATERIAL AND METHODS: Thirty bone blocks were prepared from porcine ribs. On each block 2 holes (tunnel preparations) were performed using a low-speed, 1.0-mm-wide, surgical pilot drill and an Er:YAG laser (pulse energy, 1,000 mJ; pulse duration, 300 µs; frequency, 20 Hz). The temperature induced by the preparation techniques was measured using an infrared camera. The removed bone volume was calculated by a modified mathematical algorithm. The time required for the preparation was measured with a digital stopwatch and a time-measurement instrument integrated within the computer program. The cortical and spongiose surfaces of the specimens were examined microscopically and histologically under a light microscope with a high-resolution camera. RESULTS: The Er:YAG laser removed significantly more bone tissue than the drill (P < .01) in a significantly shorter time (P < .01). The temperature was statistically lower during the laser preparation (P < .01). Cavities prepared with the laser were regular with clear sharp edges and knifelike cuts. In the drill group, the preparations exhibited irregular edges full of bone fragments and fiberlike debris. Histologic examination of the laser sides showed a 30-µm-thick altered sublayer. The tissue in the drill group was covered with a smear layer without any alterations. CONCLUSIONS: The Er:YAG laser produced preparations with regular and sharp edges, without bone fragments and debris, in a shorter time, and with less generated heat. Thermal alterations in the treated surface were minimal.

[Is hypertriglyceridaemia a risk factor for coronary heart disease?]. / Je li hipertrigliceridemija cimbenik rizika od koronarne bolesti srca?

Although it is still not clear whether elevated serum triglycerides are directly atherogenic or not, the results of many studies indicate that they are undoubtedly an important risk factor/biomarker for coronary heart disease (CHD). Therefore, targeting hypertriglyceridaemia should be beneficial for subjects at high risk for CHD. Elevated triglycerides are often accompanied with low HDL cholesterol, particularly in high risk patients with diabetes type 2 and/or metabolic syndrome. Such a disturbance is called atherogenic dyslipidaemia and has an increasing prevalence. The treatment of hypertriglyceridaemia has to be focused primarily on intensive lifestyle changes (weight reduction in obesity, reduction of alcohol consumption as well as reduction of added sugars, fructose and trans-fatty acids, regular aerobic physical activity) by which reduction of up to 50% in triglycerides can be achieved. Subjects with high CHD risk who cannot lower hypertriglyceridaemia by lifestyle measures should be treated with pharmacological therapy. The available medications include fibrates, niacin and prescription omega-3 polyunsaturated fatty acids. If LDL cholesterol is elevated too, combination therapy is needed. Based upon recent studies in such patients a combination of a statin with fenofibrate and/or omega-3 fatty acids can be recommended.

Immediate implantation in infected tooth sockets.

Although immediate implantation has not been previously recommended in infected sites, it is now becoming a procedure of choice in modern implant dentistry. We report a case of a 65-year-old male patient, who required multiple tooth extractions in the lower jaw and fabrication of a new overdenture in the lower jaw and a complete denture in the upper jaw. Immediate implantation in infected tooth sockets followed extraction. Two NobelReplace Tapered implants (Nobel BioCare, Zürich, Switzerland), one 13 mm long and 4.3 mm wide and the other 13 mm long and 5.0 mm wide, were placed in the position 33 and 43. The site was sutured and a temporary denture was fabricated by adjusting the old denture. After a period of three months the implant site was reopened and healing abutments were placed. Impressions were made using the Impregum Penta Soft (3M ESPE, St. Paul, Minn, USA) polyether material. Ball Abutment Titanium" was used as a patrix attachment and a matrix was inserted into the denture. Clinical examination and x-ray analysis after six months showed no significant changes of the implants. Bone resorption was within standard values. Although it is still a controversial subject, immediate implantation in infected sites can be a safe and predictable procedure if surgical protocols are followed. However, further research is needed to draw firm conclusions.

Spontaneous perforation of the small intestine, a novel manifestation of classical homocystinuria in an adult with new cystathionine beta-synthetase gene mutations.

The clinical picture of classical homocystinuria is diverse. This is the first report of an adult homocystinuric patient with non-traumatic spontaneous small bowel perforation. A 47-year old man presented with abdominal rebound tenderness, hypotension and tachycardia, anemia, and elevated markers of inflammation. Other routine laboratory tests were normal. Abdominal x-ray showed no free air. An emergency laparotomy revealed jejunal perforation in the left upper quadrant. Histologic specimen showed full-thickness nonspecific inflammation of the intestinal wall with granulocytic infiltration, hemorrhage and necrosis. Tuberculosis, actinomycosis and typhus were histologically and clinically excluded. After excluding all known possible causes of perforation, we presumed a causative relationship between homocystinuria and small bowel perforation. It could be hypothesized that connective tissue weakness in homocystinuria is a result of homocysteine interference with recombinant human fibrillin-1 fragments or cross-linking of collagen through permanent degradation of disulfide bridges and lysine amino acid residues in proteins. DNA analysis showed three detectable mutations in the cystathionine beta-synthetase gene, 1278T:c.833T>C, and two new mutations, V372G:c.1133T > G, and D520G:c.1558A > G in the aternatively spliced exon 15.

[Low HDL-cholesterol--an important risk factor for cardiovascular diseases]. / Snizeni HDL-kolesterol--vazan cimbenik rizika od kardiovaskularnih bolesti.

It has been known for quite a long time that the concentration of HDL-cholesterol correlates inversely with cardiovascular disease (CVD) risk and that low HDL-cholesterol is an independent CVD risk factor. This review aims to highlight evidence on several topics concerning the role of HDL particles and the importance of HDL-cholesterol. The main antiatherogenic functions of HDL particles are presented in details--reverse cholesterol transport, but also their anti-oxidant, anti-inflammatory, anti-thrombotic and anti-apoptotic properties as well as endothelial stabilizing and repair properties. Lifestyle management of low HDL-cholesterol is explained, particularly physical activity and aerobic exercise, smoking cessation, weight reduction in the overweight individuals and composition of the diet but also moderate alcohol consumption stressing the fact that HDL particles from alcoholics are dysfunctional. This is important since it has been shown that it is not only the quantity of HDL particles, and thus HDL-cholesterol level in plasma, that matters, but their quality and impaired functionality as well. HDL from diabetic subjects also lose some of their antiatherogenic properties but a common feature of patients with diabetes type 2 is atherogenic dyslipidemia which is characterized exactly by low HDL-cholesterol and high triglycerides. Diabetic patients with such dyslipidemia are at particularly high CVD risk and the results of recent studies such as ACCORD-Lipid suggest that in them treatment of these lipid abnormalities may be beneficial. Treatment options with fibrates, particularly fenofibrate, and niacin are discussed based upon published trials, as well as combination therapy with these medicines and other lipid-lowering drugs.

A three-dimensional evaluation of microleakage of class V cavities prepared by the very short pulse mode of the erbium:yttrium-aluminium-garnet laser.

The aim of this study was to evaluate microleakage along resin restoration in cavities prepared with an erbium:yttrium-aluminium-garnet (Er:YAG) laser, with and without acid etching, and to compare it with that in diamond-drilled cavities. Thirty intact molars were divided into three equal groups. In the teeth in group I, class V cavities were prepared with a diamond drill. Cavities in groups II and III were prepared with an Er:YAG laser (400 mJ/15 Hz for enamel and 250 mJ/10 Hz for dentine). The cavities in groups I and II were acid-etched and adhesive and flowable composite were applied to all cavities. The specimens were first immersed in dye for 24 h and then in 5% nitric acid for 72 h for softening. The fillings were extracted and photographed through a dissecting microscope. The leakage area was measured with specially designed software. The Kruskal-Wallis test showed that the best ranking was group II [mean range (m.r.) = 27.46], followed by group I (m.r. = 33.48) and, lastly, group III (m.r. = 45.15). The differences between groups I and III (P = 0.023) and between groups II and III were statistically significant (P = 0.080). The least microleakage was found in those cavities prepared by Er:YAG laser and subsequently acid-etched, whereas the most leakage was in the lased cavities that had not been etched; the traditional diamond-drilled acid-etched cavities produced medium leakage.

A study of the surface topography and roughness of glazed and unglazed feldspathic ceramics.

The aim of this study was to obtain the 3-D qualitative and quantitative nanoscale data of the surface topography and surface roughness of glazed and unglazed feldspathic ceramics. Twelve samples composed of Ni-Cr alloy (Wiron 99, Bego Germany) and feldspathic ceramics (IPS Classic, Ivoclar-Vivadent, Schaan, Liechtenstein) were prepared, and divided into two groups, dependent of the surface final finishing; 6 unglazed and 6 glazed samples. The surface of the samples was recorded and analysed by atomic force microscopy (AFM, Veeco Instruments, Santa Barbara, CA, U.S.A.). According to the results of this study, unglazed ceramic surface is significantly rougher than the glazed one, showing significantly higher root mean square (RMS), mean roughness (Ra) and maximum height (Z range values) (p < 0.01), higher crystallites with sharper peaks and deeper pores. The roughness parameters of the unglazed samples were almost twice or even more higher than of the glazed samples. Exposed unglazed ceramic surfaces can therefore promote antagonistic tooth wear.

Comparative study of condylar inclination settings in two types of semiadjustable articulators.

The purpose of this study was to research the possible influence of difference in construction of mechanical joint in arcon and nonarcon articulators, upon the adjustment of condylar inclination by intraoral protrusive record. The determination of condylar inclination by protrusive record in two types of articulators was performed on 30 examinees, and the adjustment of condylar inclination in each articulator was done for left and right joint. In arcon articulator the measured values for condylar inclination were higher and the mean difference for right joint was 7.4 degrees, and for the left joint 7.2 degrees The found differences are statistically significant for both, left and right joint, at the level of P < 0.001. There is possible influence of difference in construction of mechanical joint upon the adjustment of condylar inclination by intraoral protrusive record. The arcon articulator, due to constant relation between occlusal plane and mechanical fossa, reproduces the movements more accurately.

Assessing health-related quality of life outcomes after the surgical removal of a mandibular third molar.

This study was designed to assess the impact of the surgical removal of a mandibular third molar on health-related quality of life (HRQoL) in the postoperative period. Data was obtained from 101 patients who had undergone 105 surgical procedures. Only one mandibular third molar was removed per visit. The inclusion criterion for surgical procedures was creating a mucoperiosteal flap either with or without osteotomy. Surgical details were noted in a pre-made questionnaire. A self-administered health-related quality of life questionnaire, designed for assessment of the patient's perception of recovery for pain, lifestyle and oral function, was given to all patients. Patients evaluated postoperative pain and other sequelae on a scale ranging from 0 (none) to 3 (severe). Follow-up visits were scheduled on the third and the seventh postoperative day, when wound healing was clinically evaluated and noted. At the review appointment, one week later, patients had their sutures removed and returned a completed follow-up questionnaire. Patients were contacted 14 days after surgery for the purpose of gathering additional data pertaining to their recovery. The mean score for pain had a peak value on day one (1.8), and showed an exponential decrease (1.2 on day three, 0.5 on day seven, 0.1 on day 14). All the other postoperative sequelae showed the same tendency to decrease exponentially. The type of operative procedure and tooth position showed significant impact on postoperative recovery. The surgical removal of a mandibular third molar causes severe deterioration in a patient's quality of life during the first 3 days postoperatively. The quality of life can be expected to return to a preoperative level by the end of the first postoperative week.

The prevalence of proximal fractures of dental crowns with amalgam fillings.

The purpose of this paper was to determine the prevalence and impact of various etiological factors on marginal ridge fractures of teeth with amalgam fillings. 50 subjects participated in this research, 172 teeth restored with amalgam were examined out of which 28 premolars and 144 molars of both jaws. Data used in the research was obtained by nonaggressive exploration of oral cavity and by checking dental charts and radiographic charts of patients. Patients were divided in three gendered age groups. Etiological factors used in the research were: the position of teeth in jaws, classification of amalgam fillings according to Black, the duration of fillings, the presence of caries on proximal surfaces not included in restoration and tooth vitality. Also, Angle Class, habits and presence of fixed prosthetic appliances in opposite jaw were taken into consideration. Results for each patient were separately written in the questionnaire. Statistical analysis was carried out by Pearson's chi2-test. According to obtained results 51% of teeth with amalgam fillings have a fracture of marginal ridge. Statistically significant factors that influenced the occurrence of fractures of proximal surfaces in this research were classification of amalgam fillings according to Black, the patient's age and the existence of caries on proximal surface.

Densitometric analysis of dental implant placement between flapless technique and the two-stage technique--a pilot study.

Flapless technique is a surgical approach of implant placement without raising a mucoperiosteal flap. Such approach has many advantages: shorter surgical treatment, minimal bleeding, postoperative discomfort for the patient is reduced; possibility of immediate loading of the inserted implant, faster procedure of implant placement and by that less time is needed for the complete implant-prosthetic restoration. Purpose of this pilot study was radiographic assessment of flapless technique and determination of its clinical values in comparison with two-stage dental implant technique through computerized densitometric analysis. The sample consisted of 10 patients with missing teeth in the premolar region in the upper jaw. An implant was placed in that position. In the first group of 5 patients the implants were inserted with the flapless technique, and in the other group of 5 patients implant insertion was done with a two-stage technique. All inserted implants were loaded with metal-ceramic crowns 3 months after placement. The patients were followed for 18 months through clinical follow-ups and radiovisiographical (RVG) images made after 3, 12 and 18 months. After comparing the average densities, the results showed similar decrease of density in both groups, conventional two-stage technique showed 3.24 and flapless technique 1.23. It can be concluded that flapless technique in everyday clinical usage has the same result as the two-stage dental implant technique.

Implant stability comparison of immediate and delayed maxillary implant placement by use of resonance frequency analysis--a clinical study.

The purpose of this study was to objectively evaluate the stability of dental implants by use of resonance frequency analysis (RFA). In this study, 60 Nobel Replace Tapered Groovy implants were placed in the premolar region of the maxilla in 60 patients. Thirty implants were placed immediately after tooth extraction and 30 implants were placed in healed bone sites. Implant stability quotient (ISQ) was obtained by use of the Osstell Mentor device and was recorded at the time of implant placement (T1) and 20 weeks after placement, at the time of implant loading (T2). All implants were not functionally loaded during the follow up period. Data were analyzed using simple linear regression. No implant failures were reported in the 6-month follow up period. The mean ISQvalue for immediate implant placement was 61.43 at T1 and 66.23 at T2. The implants placed in healed bone showed higher ISQvalues compared to the immediately placed implants (mean ISQvalue was 64.17 at T1 and 68.83 at T2). Differences in the mean ISQ values were statistically significant (p < 0.001). After the completed period of osseointegration, the mean ISQ value was 4.8 for immediately placed implants compared to 4.67 for implants placed in delayed sites.

Efficiency of polylactide/polyglycolide copolymers bone replacements in bone defects healing measured by densitometry.

Healing of bone defects is the most frequent cause of failure in surgical treatments of an odontogenic ostitic processes. The aim of this study was to determine successfulness in healing of bone defects after implantation of alloplastic co-polymer-polyglycol bone implant. A group of 45 cases with periradicular ostitic processes were examined. The densitometric measurements were taken from radiovisiographic dental x-ray images. Patients were observed throughout a period of one year. The results obtained were analyzed and presented graphically. Thirty-eight patients (84%) were treated successfully, and seven patients (16%) showed unsuccessful healing of the bone defects. The results obtained indicate that polyglycol copolymer bone implants can be successfully used in a treatment of odontogenically caused bone defects. Their fundamental advantage is a slow biodegradation, which ensures a more suitable area for the apposition of a new bone in the defect, simple application in clinical work and the possibility of a mutual combination of all three available forms.

The effects of bluephase LED light on fibroblasts.

OBJECTIVE: The aim of this study was to evaluate the effect of Bluephase light emitting diode (LED) light on cell viability, colony-forming ability and proliferation in V79 cell culture and to determine how much the temperature of the nutrient medium rose. METHODS: The investigation included a low (L), soft start (S) and high (H) illumination mode for 20, 40 and 80 seconds. The viability was determined by the trypan blue exclusion test, colony-forming ability by counting colonies 7 days after exposure and cell proliferation by the cell counts on 5 post-exposure days. The temperature change during illumination was recorded (0.1°C sensitivity). RESULTS: In each experimental condition, 90-95% of the cells were viable, which was in the same range as the controls. Colony-forming ability was not found to be significantly lower (P<.05). A significant decrease in proliferation was recorded on the 4th post-exposure day with S and H irrespective of time, on the 3(rd) day with S for 80 s and H for 40 and 80 s, and with S and H for 80 s on the 2(nd) day (P<.05).The temperature rise was significant with S (P<.05) and H (P<.05), irrespective of exposure duration. CONCLUSION: Dependent on total energy density, LED blue light affects the mitotic activity of cells in its path to a certain extent. Altered mitotic activity was not noted with illumination at the low power mode (intensity of 421.7 ±1.1 mW/cm(2)). The greatest temperature rise was 8.3 °C and occurred at the highest intensity and exposure duration.

Clinical study on the effect of simvastatin on paraoxonase activity.

Human paraoxonase (PON1) is a serum high-density lipoprotein-associated phosphotriesterase. High-density lipoprotein (HDL) plays the role of a carrier and the site of action of this enzyme. According to a majority of authors, PON1 acts as an antioxidant, preventing low-density lipoprotein (LDL) peroxidation. However, due to the fact that in vivo serum PON1 is predominantly associated with HDL, its major physiological role might be to protect HDL, rather than LDL, from oxidation. Nevertheless, the physiological substrate of PON1 still remains to be discovered. The objective of this study was to determine changes in PON1 activity during treatment with simvastatin (CAS 79902-63-9, Lipex) in patients with type IIa and/or IIb hyperlipoproteinemia. PON1 activity was assessed in 32 patients with hyperlipoproteinemia type IIa or IIb with an LDL cholesterol concentration higher than 4.2 mmol/l. Patients received simvastatin in a daily dose of 20 mg. The lipid status and PON1 activity were assessed at baseline, as well as 3 and 6 months after the beginning of treatment. The study demonstrated a statistically significant lipid lowering effect of simvastatin on total and LDL cholesterol, and an increase in PON1 activity in patients with both types of hyperlipoproteinemia. No statistically significant correlation was observed either between changes in PON1 activity and HDL, HDL2, HDL3 and LDL cholesterol and triglyceride levels, or between their first differences in patients with both type IIa and IIb hyperlipoproteinemia. The obtained results suggest that the antioxidant properties of simvastatin might be caused by a mechanism independent of apoAI-containing lipoprotein concentration. The antioxidant properties of simvastatin, which play an important role in HDL protection from oxidation, could be the mechanism inducing the increase in PON1 activity.