Diagnostic value of VEGF in peri-implantitis and its correlation with titanium particles: A controlled clinical study.

OBJECTIVES: VEGF is prototypic marker of neovascularization, repeatedly proposed as intrinsic characteristic of peri-implantitis. This study aimed to assess pattern of VEGF in peri-implantitis, its correlation with titanium particles (TPs) and capacity as respective biomarker. MATERIAL AND METHODS: Pathological specificity of VEGF was assessed in peri-implant granulations using immunohistochemistry, periodontal granulations represented Ti-free positive controls. VEGF was correlated to TPs, identified using scanning electron microscopy coupled with dispersive x-ray spectrometry. Diagnostic accuracy, sensitivity and specificity of VEGF were estimated in PICF specimens from peri-implantitis, peri-implant mucositis (PIM) and healthy peri-implant tissues (HI) using machine learning algorithms. RESULTS: Peri-implantitis exhibited rich neovascular network with expressed density in contact zones toward neutrophil infiltrates without specific pattern variations around TPs, identified in all peri-implantitis specimens (mean particle size 8.9 ± 24.8 µm2; Ti-mass (%) 0.380 ± 0.163). VEGF was significantly more expressed in peri-implantitis (47,065 ± 24.2) compared to periodontitis (31,14 ± 9.15), and positively correlated with its soluble concentrations in PICF (p = 0.01). VEGF was positively correlated to all clinical endpoints and significantly increased in peri-implantitis compared to both PIM and HI, but despite high specificity (96%), its overall diagnostic capacity was average. Two patient clusters were identified in peri-implantitis, one with 8-fold higher VEGF values compared to HI, and second with lower values comparable to PIM. SIGNIFICANCE: VEGF accurately reflects neovascularization in peri-implantitis that was expressed in contact zones toward implant surface without specific histopathological patter variation around TPs. VEGF answered requests for biomarker of peri-implantitis but further research is necessary to decrypt its exact underlying cause.

Resolution of peri-implant mucositis following standard treatment: A prospective split-mouth study.

BACKGROUND: Peri-implant mucositis (PIM) is a pathological precursor of peri-implantitis, but its pattern of conversion to peri-implantitis is unclear and complicated to diagnose clinically, while none of the available protocols yield complete disease resolution. The aim of this study was the evaluation of PIM responsiveness to standard anti-infective mechanical treatment (AIMT) at clinical and biomarker levels, and estimation of the diagnostic capacity of bone markers as surrogate endpoints and predictors. METHODS: Systemically healthy outpatients presenting one implant exhibiting clinical signs of inflammation confined within the soft tissue (PIM) and one healthy control (HC) implant at a non-adjacent position were included. Clinical parameters and peri-implant crevicular fluid samples were collected baseline and 6 months following mechanical therapy, to assess the levels of RANKL, OPG, and IGFBP2. PIM clustering was performed using machine learning algorithms. RESULTS: Overall, 38 patients met the inclusion criteria. Therapy resulted in the reduction of all clinical and biological indicators, but respective values remained significantly higher compared to HC. Clinical examination noted 30% disease resolution at the 6-month follow-up, while 43% showed no active bone resorption. OPG showed positive prognostic value for treatment outcome, while the clustering based on active bone resorption did not differ in terms of therapeutic effectiveness. CONCLUSION: AIMT is effective in reducing the clinical and biological indicators of PIM, but complete clinical resolution was achieved in only 30% of the cases. Around one third of PIM patients exhibited active bone resorption bellow clinical detectability that was not associated with disease progression and poor treatment responsiveness.

Study on the immunopathological effect of titanium particles in peri-implantitis granulation tissue: A case-control study.

OBJECTIVES: To identify titanium particles (TPs) in biopsy specimens harvested from peri-implantitis lesions and secondarily to study the histopathological characteristics in peri-implantitis compared to periodontitis, in order to evaluate whether the presence of TPs could alter respective inflammatory patterns. MATERIAL AND METHODS: Biopsies containing granulation tissue were harvested during routine surgical treatment in 39 peri-implantitis cases and 35 periodontitis controls. Serial sections were obtained using titanium-free microtome blades. The first and last sections of the peri-implantitis specimens were used for identification of TPs by scanning electron microscopy coupled with dispersive X-ray spectrometry. Intermediate sections and periodontitis specimens were processed for descriptive histological study using haematoxylin-eosin staining and for immunohistochemical analysis using CD68, IL-6, Nf-kB and VEGF markers. RESULTS: TPs were identified in all peri-implantitis specimens as free metal bodies interspersed within granulation tissue. However, presence of macrophages or multinucleated giant cells engulfing the TPs were not identified in any specimen. Peri-implantitis granulations were characterized by a chronic inflammatory infiltrate rich in neutrophils. About half of peri-implantitis patients exhibited a subacute infiltrate characterized with lymphocytes interweaved with neutrophils and eosinophils. When compared to periodontitis, peri-implantitis tissues showed higher proportions of macrophages and a more intense neovascularization, based on significantly higher expression of CD68 and VEGF respectively. CONCLUSION: TPs were identified in all peri-implantitis specimens, but without evidencing any foreign body reaction suggestive for direct pathological effects of TPs. The peri-implantitis granulation tissue was characterized by intense neovascularization and presence of a chronic inflammatory infiltrate dominated by plasma cells, neutrophils and macrophages.

Underdiagnosis in Background of Emerging Public Health Challenges Related to Peri-Implant Diseases: An Interventional Split-Mouth Study.

Peri-implant diseases are an emerging public health problem, and it's considered that limitations of standard diagnostics play the role herein. The study objective was the estimation of pathological bone resorption at clinical and biological level in patients with peri-implant mucositis (PIM) and peri-implantitis (PI) before and 6 months after standard treatment and to compare them with healthy controls (HC). The split-mouth interventional study included 60 patients affected with PIM or PI. Patients that also presented at least one more HC were enrolled in the study and underwent standard non-surgical and surgical treatment, respectively. Standard clinical parameters and soluble levels of RANKL were measured in peri-implant crevicular fluid baseline and 6 months following treatment. Clinical parameters and RANKL significantly decreased following treatment in PIM and PI. However, bleeding on probing and probing depth remained significantly increased when compared to HC. RANKL answered requests for biomarker of peri-implant diseases, its baseline levels were significantly increased in PIM and PI, they decreased following treatment and reached HC in peri-implantitis, while in PIM RANKL remained significantly increased. Presence of pathological bone resorption in patients lacked its clinical signs, and respective persistence following treatment suggest the need for biomarker-supported diagnosis for timely diagnosis of peri-implantitis and appropriate orientation of respective management strategies.

Treatment of Early Developed Peri-Implantitis in Fibula Graft Site.

The fibula microvascular free flap technique and placement of dental endosseous implants seem to be viable options for reconstructing the mandible, following a resective jaw surgery. The causes of early failures of implants include bone overheating, latent infection by surgical trauma, the factors related with the implant, and overcompression. This case report reviews the mechanisms of early post-implantation bone loss, and suggests the course of treatment for early peri-implantitis for implants that show no mobility. Radiographs and clinical data presented have shown that the surgical treatment of early developed peri-implantitis using GBR methods in free fibula graft sites offers promising and stabile results.

Application of Semipermanent Cements and Conventional Cement with Modified Cementing Technique in Dental Implantology.

OBJECTIVES: The aim of this study was to evaluate the influence of artificial ageing on the retention force of original semipermanent cements, as well as the possibility of using conventional cements for semipermanent cementation with adequate modification of the cementing protocol. MATERIALS AND METHODS: Forty CoCrMo alloy crowns were divided in four groups (each group n=10) and fixed with two semipermanent cements (resin-based and glass ionomer-based cements) and one conventional (zinc phosphate), using conventional and modified cementation techniques on titanium abutments. The samples were stored in humid conditions for 24 hours at 37°C and subjected to thermocycling (500 cycles) and mechanical cyclic loading (7 days, 3, 6, 9 and 12 months function simulation). The cast crowns were removed and the retention force was recorded. RESULTS: The highest initial retention force measured was for zinc-phosphate cement - conventional cementing (198,00±61,90 N), followed in descending order by zinc-phosphate cement - modified cementing technique (152,00±45,42 N), long term temporary cement - GC Fuji Temp LT (57,70±20,40 N), and semipermanent cement - Telio CS Cem Implant (56,10±18,68 N). After 12 months, the highest retention force measured was for zinc-phosphate cement - conventional cementing (88, 90±14, 45 N), followed by zinc-phosphate cement - modified cementing (48, 15±14,41N), semipermanent cement GC Fuji Temp LT (16,55±3,88 N) and Telio CS Cem Implant (15,55±5,52 N). CONCLUSIONS: Zinc-phosphate cement - modified cementing technique and original semipermanent cements can be recommended for conditional permanent cementing of implant supported crowns. CLINICAL RELEVANCE: The use of semipermanenet cements and zinc-phosphate cement - modified cementing technique provides a predictable retrievability of implant-supported crowns.

Hyaluronic acid treatment outcome on the post-extraction wound healing in patients with poorly controlled type 2 diabetes: A randomized controlled split-mouth study

BACKGROUND: Hyaluronic acid is widely used in the medical field. However, there is a lack of research about its effect on patients with certain risks, such as compromised wound healing commonly found in patients with poorly controlled type 2 diabetes. The aim of this study is to investigate the efficacy of hyaluronic acid on the post-extraction wound healing and pain in patients with poorly controlled type 2 diabetes. MATERIAL AND METHODS: The randomized controlled split-mouth study was designed, which included 30 patients with poorly controlled type 2 diabetes with a bilaterally same teeth in the lower jaw for extraction. The sockets treated with 0.8% hyaluronic acid represented the study group, while the sockets where hyaluronic acid was not applied represented the control group. Wound closure rate (WCR), clinical scores in wound healing scale (WHS) and pain intensity in Visual analogue scale (VAS) were recorded. Patients were followed up on 5th, 10th, 15th, 20th, 25th day after tooth extraction. RESULTS: The results showed a higher WCR at the extraction site where hyaluronic acid was applied. Also, statistically significant difference was found (p < 0.001). In regards to WHS, the sockets treated with hyaluronic acid showed better healing, especially on day 10 (p = 0.006) and day 15 (p = 0.021). However, there were no statistically significant differences in VAS scores between groups. CONCLUSIONS: Hyaluronic acid placed in post-extraction socket in patients with poorly controlled diabetes may improve wound healing, especially in the first days after application

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Is the personalized approach the key to improve clinical diagnosis of peri-implant conditions? The role of bone markers.

BACKGROUND: Study objectives were 1) to estimate diagnostic capacity of clinical parameters, receptor activator of nuclear factor kappa-B (RANKL) and osteoprotegerin (OPG) to diagnose healthy peri-implant condition (HI), peri-implant mucositis (PIM) and peri-implantitis (PIMP) by assessing respective diagnostic accuracy, sensitivity, specificity and diagnostic ranges 2) to develop personalized diagnostic model (PDM) for implant monitoring. METHODS: Split-mouth study included 126 patients and 252 implants (HI = 126, PIM = 57, and PIMP = 69). RANKL and OPG concentrations were estimated in peri-implant crevicular fluid using enzyme-linked immunosorbent assay method and assessed with clinical parameters using routine statistics, while the diagnostic capacity of individual parameters and overall clinical diagnosis were estimated using classifying algorithms. PDM was developed using decision trees. RESULTS: Bleeding on probing (BOP), plaque index, and probing depth (PD) were confirmed reliable discriminants between peri-implant health and disease, while increase in PD (PD > 4 mm) and suppuration were good discriminants amongst PIM/PIMP. Bone turnover markers (BTMs) demonstrated presence of bone resorption in PIM; between comparable diagnostic ranges PIM/PIMP, PIMP was clinically distinguished from PIM in about 60% of patients while 40% remained diagnosed as false negatives. PDM demonstrated highest diagnostic capacity (accuracy: 96.27%, sensitivity: 95.00%, specificity: 100%) and defined HI: BOP ≤0.25%; PIM: BOP >0.25%, PD ≤4.5 mm; PIMP: BOP >0.25%, PD >4.5 mm and RANKL ≤19.9 pg/site; PIM: BOP >0.25%, PD >4.5 mm, and RANKL >19.9 pg/site. CONCLUSIONS: BTMs demonstrated capacity to substantially improve clinical diagnosis of peri-implant conditions. Considering lack of difference in BTMs between PIM/PIMP and cluster of PIM with exceeding BTMs, a more refined definition of peri-implant conditions according to biological characteristics is required for further BTMs validation and appropriate PIMP management.

Association of Cytokine Gene Polymorphism with Peri-implantitis Risk.

PURPOSE: To investigate whether polymorphisms of cluster of differentiation 14 (CD14), tumor necrosis factor alpha (TNFα), interleukin (IL)6, IL10, and IL1ra genes are associated with the risk of peri-implantitis susceptibility in patients with dental implants in the Serbian population. MATERIALS AND METHODS: Isolated DNA from the blood was used for IL10-1082, TNFα-308, IL6-174, CD14-159, and interleukin 1 receptor antagonist (IL1ra) genotyping using polymerase chain reaction (PCR)-based methodology. Clinical parameters included: peri-implant pocket depth (PPD), Plaque Index (PI), Gingival Index (GI), bleeding on probing (BOP), and radiologic bone loss. RESULTS: The study included 98 patients with dental implants in function for at least 1 year, divided into peri-implantitis (34) and healthy peri-implant tissue (64) groups. The percentage distribution of smokers was significantly different between patients who developed peri-implantitis and patients with healthy peri-implant tissue (71% vs 42%, respectively) and associated with increased peri-implantitis risk (OR: 3.289, 95% CI: 1.352 to 8.001; P = .007). A positive history of periodontitis was more frequent in the peri-implantitis group (62%) than in the healthy peri-implant tissue (20%) group and associated with increased peri-implantitis risk (OR: 6.337, 95% CI: 2.522 to 15.927; P = .0001). Frequencies of CD14-159, TNFα-308, IL10-1082, and IL6-174 genotypes were significantly different between patients with and without peri-implantitis. However, logistic regression revealed only TNFα-308 polymorphic GA/AA genotypes (OR: 8.890, 95% CI: 2.15 to 36.7; P = .003) and smoking (OR: 6.2, 95% CI: 1.44 to 26.7; P = .014) as independent factors associated with increased peri-implantitis risk, while CD14-159 polymorphic CT/TT genotypes were associated with decreased risk for peri-implantitis (OR: 0.059, 95% CI: 0.009 to 0.355; P = .002). CONCLUSION: The findings suggest that smoking and the presence of TNFα-308 GA/AA genotypes may increase the risk for peri-implantitis, while CD14-159 polymorphic CT/TT genotypes decrease the risk. The results also indicate significant association of CD14-159, TNFα-308, and IL6-174 genotypes and clinical parameters in the Serbian population. However, future studies in larger patient groups are necessary to confirm these observations.

Radiographic cephalometry analysis of condylar position after bimaxillary osteotomy in patients with mandibular prognathism.

Background/Aim: Postoperative condylar position is a substantial concern in surgical correction of mandibular prognathism. Orthognathic surgery may change condylar position and this is considered a contributing factor for early skeletal relapse and the induction of temporomandibular disorders. The purpose of this study was to evaluate changes in condylar position, and to correlate angular skeletal measurements following bimaxillary surgery. Methods: On profile teleradiographs of 21 patients with mandibular angular and linear parametres, the changes in condylar position, were measured during preoperative orthodontic treatment and 6 months after the surgical treatment. Results: A statistically significant difference in values between the groups was found. The most distal point on the head of condyle point (DI) moved backward for 1.38 mm (p = 0.02), and the point of center of collum mandibulae point (DC) moved backward for 1.52 mm (p = 0.007). The amount of upward movement of the point DI was 1.62 mm (p = 0.04). Conclusion: In the patients with mandibular prognathism, the condyles tend to migrate upward and forward six months after bimaxillary surgery.

Decompression as an effective primary approach to large radicular cyst in the maxillary sinus--A case report.

INTRODUCTION: Therapeutic approach to jaw cysts may depend on their dimensions and localization. Enucleation of cystic lesion is not always preferable in the first act, especially if large cysts are in close proximity to important anatomical structures. The aim of this paper was to present the outcome of the treatment protocol comprising preoperative decompression and subsequent enucleation of a large maxillary cyst. CASE REPORT: A 21-year-old male patient with large asymptomatic radicular cyst in the right maxillary sinus was presented to our clinic. Cone-beam computed tomography (CBCT) showed a large cyst, which perforated the right anterior maxillary wall by 1.5 cm, and was in the intimate contact with the orbital floor. Surgical treatment of the cystic lesion comprised: preoperative decompression with biopsy in the first act and enucleation, performed under general anesthesia, 6 months after the observation period. CONCLUSION: Decompression with subsequent enucleation proved to be effective treatment of large radicular cyst in maxillary sinus with low-morbidity.

Impact of dental implant insertion method on the peri-implant bone tissue--an experimental study.

BACKGROUND/AIM: The function of dental implants depends on their stability in bone tissue over extended period of time, i.e. on osseointegration. The process through which osseointegration is achieved depends on several factors, surgical insertion method being one of them. The aim of this study was to histopathologically compare the impact of the surgical method of implant insertion on the peri-implant bone tissue. METHODS: The experiment was performed on 9 dogs. Eight weeks following the extraction of lower premolars implants were inserted using the one-stage method on the right mandibular side and two-stage method on the left side. Three months after implantation the animals were sacrificed. Three distinct regions of bone tissue were histopathologically analyzed, the results were scored and compared. RESULTS: In the specimens of one-stage implants increased amount of collagen fibers was found in 5 specimens where tissue necrosis was also observed. Only moderate osteoblastic activity was found in 3 sections. The analysis of bone-to-implant contact region revealed statistically significantly better results regarding the amount of collagen tissue fibers for the implants inserted in the two-stage method (Wa = 59 < 66.5, alpha = 0.05), but necrosis was found in all specimens, and no osteoblastic activity. Histopathological analysis of bone-implant interface of one-stage implants revealed increased amount of collagen fibers in all specimens, moderate osteoblastic activity and neovascularization in 2 specimens. No inflammation was observed. The analysis of two-stage implants revealed a marked increase of collagen fibers in 5 specimens, inflammation and bone necrosis were found in only one specimen. There were no statistically significant differences between the two methods regarding bone-implant interface region. Histopathological analysis of bone tissue adjacent to the one-stage implant revealed moderate increase of collagen tissue in only 1 specimen, moderate increase of osteoblasts and osteocytes in 3 specimens. No necrotic tissue was found. The analyzed specimens of bone adjacent to two-stage implants revealed a moderate increase in the number of osteocytes in 3 and a marked increase in 6 specimens respectively. This difference was statistically significant (Wb = 106.5 > 105, alpha = 0.05). No necrosis and osteoblastic activity were observed. CONCLUSION: Better results were achieved by the two-stage method in bone-to-implant contact region regarding the amount of collagen tissue, while the results were identical regarding the osteoblastic activity and bone tissue necrosis. There was no difference between the methods in the bone-implant interface region. In the bone tissue adjacent to the implant the results were identical regarding the amount of collagen tissue, osteoblastic reaction and bone tissue necrosis, while better results were achieved by the two-stage method regarding the number of osteocytes.

The impact of thickness of resorbable membrane of human origin on the ossification of bone defects: a pathohistologic study.

BACKGROUND/AIM: A wide range of resorbable and non-resorbable membranes have been investigated over the last two decades. The barrier membrane protects the defect from ingrowth of soft tissue cells and allows bone progenitor cells to develop bone within a blood clot that is formed beneath the barrier membrane. The membranes are applied to reconstruct small bony defect prior to implantation, to cover dehiscences and fenestrations around dental implants. The aim of this study was to evaluate the influence of human resorbable demineralized membrane (RHDM) thickness on bone regeneration. METHODS: The experiment, approved by Ethical Committee, was performed on 6 dogs and conducted into three phases. Bone defects were created in all the 6 dogs on the left side of the mandible, 8 weeks after extraction of second, third and fourth premolars. One defect was covered with RHDM 100 micro thick, one with RHDM 200 micro thick, and the third defect left empty (control defect). The histopathological analysis was done 2, 4 and 6 months after the surgery. In the third phase samples of bone tissue were taken and subjected to histopathological analysis. RESULTS: In all the 6 dogs the defects treated with RHDM 200 micro thick showed higher level of bone regeneration in comparison with the defect treated with RHDM 100 micro thick and especially with empty defect. CONCLUSION: Our results demonstrated that the thicker membrane showed the least soft tissue ingrowths and promoted better bone formation at 6 months compared with a thinner one.

[Histopathological evaluation of bone regeneration using human resorbable demineralized membrane].

BACKGROUND/AIM: Filling a bone defect with bone substitution materials is a therapy of choice, but the infiltration of connective tissue from the mucoperiostal flap may compromise a healing of bone substitutions with bony wall defects. Application of membrane as a barrier is indicated as a solution to this problem. The aim of this study was to show a pathohistological view of bone regeneration and the significance of human resorbable demineralized membrane (HRDM), 200 microns thick in bone regeneration regarding mandibular defects in an experiment on dogs. METHODS: The experiment was performed on six dogs. Bone defects were created in all six dogs on the right side of the mandible after the elevation of the mucoperiostal flap. One defect was filled with human deproteinised bone (HDB), and in between HDB and soft tissue RHDM of 200 microns thick was placed. In the second defect, used as a control one, only HDB without RHDM was placed. Two dogs were sacrificed two months after the surgery, another two dogs four months after the surgery and the last two dogs six months after the surgery. After that, samples of bone tissue were taken for histopathological analysis. RESULTS: In all the six dogs with defects treated with HDB and RHDM the level of bone regeneration was much higher in comparison with the control defects without RHDM. CONCLUSION: Membrane, as a cover of bony defect, is useful and benefits bone regeneration. Bony de fects covered with RHDM show better bony healing despite the fact that bone regeneration was not fully complete for as long as six months after the RHDM implantation.

Clinical parameters of the local anesthetic effects of bupivacaine applied with and without a vasoconstrictor in oral implantology.

BACKGROUND/AIM: Bupivacaine (Marcaine), homologue of mepivacaine, chemically related to lidocaine, is used as a local anesthetic for local infiltration, peripheral nerve block, retrobulbar block, symphathetic block, and caudal and epidural anesthesia. The aim of this investigation was to determine and to compare clinical parameters of the local anesthetic effects of bupivacaine applied with and without a vasoconstrictor. METHODS: This investigation included a total of 30 randomly selected patients, who ranged in age from 30-60 years, with partial or total anodontia in the molar region of the mandible. These patients with total or partial edentulous molar part of the mandible, scheduled for dental implantation placement, were asked to participate in the study. In the first phase of the investigation, the patients were subjected to local anesthesia with 3.5 cm3 of 0.5% bupivacaine with a vasoconstrictor (adrenalin, 1: 200,000) in the right side of the mandible. After administering local anesthesia, the placement of blade, cylindrical, transdental (B.C.T.) implants was performed. In the second stage of the investigation, in 7-10 days period after the first oral surgery, the patients were subjected to local anesthesia with 3.5 cm3 of 0.5% bupivacaine, but without a vasoconstrictor, in the left side of the mandible. After administering local anesthesia, the placement of B.C.T. implants was performed. During the performance of both oral surgery procedures, the following clinical parameters of the local anesthetic effects were monitored: latent period, duration and the potency of anesthesia, and the evaluation of the postoperative pain level. RESULTS: The latent period under local anesthesia with 3.5 cm3 of 0.5% bupivacaine and vasoconstrictor was statistically significantly shorter than without vasoconstrictor. The duration of local anesthesia was longer without vasoconstrictor. There was no difference in the potency of anesthesia with or without a vasoconstrictor, while the lowest level of postoperative pain was found after administering bupivacaine without a vasoconstrictor use. CONCLUSION: The results of this investigation show that bupivacaine without a vasoconstrictor is efficient when used for local anesthesia in placing dental implants since it provides better blood circulation required for good dental implant osseointegration.

[Mobility of B.C.T. dental implants inserted by one- and two-phase surgical method--an experimental study].

BACKGROUND/AIM: Achievement of the osseointegration of dental implants is of crucial importance for their long-term survival. One of the factors that influence the osseointegration is a surgical method of implantation. The outcome of osseointegration can be evaluated on the basis of implant mobility in bone. The aim of this study was to investigate and compare the mobility of B.C.T. dental titanium implants inserted to experimental animals using an one- and two-phase method. METHODS: The investigation was performed using a split-mouth design on nine dogs, male german shephards, average age of 3.5 years and average weight of 32 kg. Extractions of the third and fourth lower premolars were performed under intravenous (i.v.) anaesthesia with 5% ketamine chloride. Eight weeks after the extractions, the implants, diameter of 4.5 mm each, with four threads 13.7 mm long, were inserted. Eighteen implants were inserted one side of the jaw using a one-phase method, and another 18 implants were inserted contralaterally using a two-phase method. Three months after the implantation, the implant mobility was evaluated. Three measurements were performed with a Periotest device, and average values were calculated. The implant mobility was classified according to the Periotest scale in four groups of Periotest values (PTV) and compared. A total of 36 implants were inserted in 9 experimental dogs. The PTV ranged from -7.666 to + 50. RESULTS: According to the Periotest scale, 14 one-phase implants (78%) were classified into the 0 group of PTV, and 4 one-phase implants (22%) in the 3rd group. Thirteen two-phase implants (72%) were classified in the 0 group, and 5 implants in the 3rd group of Periotest scale. The difference in the average values of PTV between the two methods was 0.879 which was not statistically significant. CONCLUSION: This study showed that the method of implant insertion had no influence on the implant mobility, i.e. satisfactory osseointegration could be achieved by both methods. Further clinical parameters, as well as pathohistological and histomorphometric ones, have to be evaluated in order to assess better outcome of a particular method.

[Possibilty of the lower third molar eruption--radiographic analysis].

BACKGROUND/AIM: To assess the possibility of the eruption of the lower third molar on the basis of the measured parameters: retromolar space, mesiodistal crown width of a molar and the third molar angulation. METHODS: The investigation included 104 patients both sexes (43 boys, and 61 girls), 16 to 25 years old (mean age, 18 years). It was performed using the orthopanthomographic radiographs analysis of those patients. Each radiograph was covered by tracing paper, and the contoures of the following anatomic details were drawn: a) the crown and root contours of third molars, upper and lower central incisors, distal molars in occlusion, anterior edge of ramus mandible, b) lines: 1. the occlusal plane, 2. the line of retromolar space, 3. the mesiodistal crown width of third molar, 4. the axial shaft of the third molar and the distal angle between occlusal plane and the axial shaft of the third molar. The values were measured with an orthodontic caliper: the diameter of retromolar space, diameter of mesiodistal width, the value of distal angle between occlusal plane and axial shaft of molar. RESULTS: A favourable angulation of the lower third molar (more than 60 degrees) was found in, boys (left 27.90%, right 32.55%), girls (left 39.34%, right 37.77%). A favourable relationship between the diameters of mesiodistal width of the third molar and retromolar space was found in, boys, (left 13.59%, right 16.27%), girls, (left 8.19%, right 14.75%). A favourable relationship between the diameters of mesiodistal width of the third molar and the retromolar space and the angulation was found in boys, (left 9.30%, right 11.62%), girls, (left 6.56%, right 9.83%). CONCLUSION: There was not any statistically significant difference found between the relation of the retromolar value, third molar mesiodistal diameter, or of the third molar angulation to the left and the right side nor of their mutual relations in comparing boys and girls. A favourable prognosis was found in 9.33% of the patients.

[Possibility of the use of serological method for the determination of immunoglobuline A antibody against early antigene of Epstein-Barr virus as a marker in the diagnosis of nasopharyngeal tumors].

BACKGROUND/AIM: According to the data from immunological, biological and molecular researches, there is a close association between the undifferentiated carcinoma of nasopharyngeal type (UCNT) and Epstein-Barr virus (EBV). To use IgA EA antibody as a serological marker in our patients with nasopharyngeal carcinoma from a clinical viewpoint. METHODS: 91 patients were followed in the period from 1989-1998. In 11 of the patients the antibody titre serum for the early antigen of EBV virus were determinated before the treatement, and in 24 of the patients 3 years after the treatement. There were three control groups of patients: 20 voluntary blood donors, 26 patients with squamocellular laryngeal carcinoma, and 10 patients with squamocellular nasopharyngeal carcinoma. RESULTS: In the group of 11 patients with UCNT before the treatment, the value of anti-EA IgA titre was 31.09, and in the patients after the treatement anti-EA IgA antiody titre was 14.56. In the control groups of patients the results were: in the blood donors 5.00; in the group with the diagnosis of squamocellular laryngeal carcinoma, the titre was 5.00; in the patients with squamocellular nosopharyngeal carcinoma, the titre anti-EA IgA was 5.36. CONCLUSION: These results were statisticly highly significant (p < 0.01). Our research clearly showed that anti-EA IgA EBV marker could be useful in diagnosing, differential diagnosing and prognosing as well.