[Comparison of short-term clinical effect and assessment of influencial factors around single-tooth in the aesthetic area: immediate implant placement versus delayed implant placement].

PURPOSE: To compare the short-term clinical effect and to assess the influencial factors of immediate implant placement and delayed implant placement around single-tooth implant in the aesthetic area. METHODS: A total of 114 patients requiring a single-tooth implant in the aesthetic area were reviewed at Center for Implant Dentistry of Stomatological Hospital of China Medical University. They were divided into immediate implant group and delayed implant group. The patients were followed up for 1 year after upper structure rehabilitation, and the pink esthetic score and the marginal bone absorption around the implants were measured. Statistical analysis was performed using SPSS 17.0 software package. RESULTS: After 1 year of upper structure rehabilitation, 114 implants were stable and the marginal bone absorption around the implants of the immediate implant group was (0.36±0.39) mm,significantly smaller than the delayed implant group [(0.79±0.67)mm, P<0.001]. The difference in PES score between the two groups were not statistically significant on the day of rehabilitation and 1 year after upper structure rehabilitation（P>0.05）. Significant improvement of PES on the day of rehabilitation and 1 year after upper structure rehabilitation and marginal bone absorption was found with flapless surgery. SLA and DAE surface treatment methods had no significant impact on PES and marginal bone absorption (P>0.05). Graft procedure had an unfavorable effect on PES value both on the day of rehabilitation and 1 year after upper structure rehabilitation. CONCLUSIONS: Under appropriate indications, immediate implant placement and immediate repair could reduce the time of missing teeth. The marginal bone absorption of immediate implant group is smaller than delayed implant group. Flapless surgery avoids damage to gingival tissue, reduces postoperative reaction and improves the aesthetic outcomes after repair.

[A clinical retrospective analysis of dental implants replaced in previously failed sites].

PURPOSE: To evaluate the clinical outcomes as well as related factors of dental implants replaced in previously failed sites. METHODS: A total of 12 patients (15 implants) who received replacement in previously failed sites during January 2005 to December 2011 were included. Outcomes of redo-implants were collected and clinical data was recorded and analyzed regarding risk factors related to redo-implants' survival using SPSS13.0 software package. RESULTS: The survival rate of redo-implants was 100% [(33.5±15.4) months]. The mean redo-implant diameter (4.5±0.6) mm was significantly larger than the previous one (4.1±0.7) mm (P<0.05). The mean survival time of implants placed for the first time was (12.9±15.9) months. Implant replacement occurred (6.8±4.4) months after original implant removal. No significant influence was observed on patient and implant-related factors as well as surgery and prosthesis-dependent factors. CONCLUSIONS: Reimplantation in previously failed site is considered as one of feasible prosthesis plans, and surgeons ought to get enough confidence to achieve satisfactory implant survival rates. Supported by Liaoning Provincial Natural Science Foundation (20092093), Liaoning Provincial Science and Technology Foundation (2012225090), and Shenyang Science and Technology Foundation (F11-264-1-25, F12-277-1-18).

Histomorphometrical and clinical study of connective tissue around titanium dental implants with porous surfaces in a canine model.

Connective tissue (CT) reactions and collagen fiber orientation were evaluated on titanium implants with porous surfaces made by a laser method. Three groups in which the diameters of pores were 10 ± 5 µm, 40 ± 5 µm, and 70 ± 5 µm were involved in this test, together with a machined group as control. A total of 24 implants were randomly placed in mandibles after 3 months of premolars and the first molar extraction in beagle dogs. All the implants were firmly anchored in the bone after 3-month insertion. Histological sections showed that the gingival tissue was attached tightly to implant surface and there was no significant difference in inflammatory cell invasion and probing depth among all groups (p > 0.05). Histomorphometric analysis demonstrated that no significant difference in total CT length was observed among four groups (p > 0.05), however, the gingival recession in the 40 ± 5 µm and 70 ± 5 µm porous groups was less than in the 10 ± 5 µm porous group and control group (p < 0.05). Collagen fibers at the inner zone of the CT around the 40 ± 5 µm and 70 ± 5 µm porous implants aligned mostly in an oblique orientation, while there was a mainly parallel fiber direction around the 10 ± 5 µm porous and control implants. It was noted that some fibroblasts and fibers in the 70 ± 5 µm porous group was inserted into the pores of implant surface, indicating that pores of a proper size on the implant surface could induce the insertion of CT and prevent gingival recession.

[An assessment of different crown-to-implant ratio for implant teeth in the posterior region over 5 years].

PURPOSE: To evaluate the influence of crown-to-implant ratio (C/I ratio) on the results of restoration in the posterior region. METHODS: From January 2007 to January 2012,119 patients with 208 ITI implants in the posterior region were followed up for 6-66 months. Implant restorations were divided into three groups according to their respective clinical C/I ratios after noble porcelain-fused-to-mental crown restoration: C/I ≤1,11.5. Cumulative survival rate was calculated by life-table analysis. SPSS 13.0 software package was used for statistical analysis. RESULTS: The mean clinical C/I ratio of 208 implants was 1.07±0.24, with maximum C/I of 1.8 and C/I of 0.6, 9.6 percent; of 208 implants had biomechanical complications. Differences among three groups were not statistically significant in annual crestal bone loss and biomechanical complications. In addition,implant cumulative survival rate in C/I ratio>1 was 97.6 percent;,and 98.8 percent; in C/I≤ 1. CONCLUSIONS: Clinical C/I ratio does not significantly influence peri-implant crestal bone loss and biomechanical complications, implant restorations with C/I ratios>1 is successfully used in the posterior areas in this study.

[Implant-supported overdenture after pectoralis major myocutaneous flap reconstruction of tongue/floor of the mouth cancer:a case report].

Patients with oral cancer, undergoing ablative surgery, were left with severe deformities and dysfunction. Although the defect can be repaired by flap transplantation, there were still difficulties to restore normal oral structure and function of the oral cavity. In these instances, rehabilitation of mastication and occlusion is of the utmost importance. This article described the procedure that implants were inserted and bar/clips retained overdenture was applied to a patient who underwent reconstruction with pectoralis major myocutaneous flap after cancer ablation surgery. The patient's oral structure and functions was recovered, and the quality of life was greatly improved.

[Effect of HA/TiO2 coating titanium surface on the growth of MG63].

PURPOSE: To evaluate the bioactivity of titanium surface treated by micro-arc oxidation (MAO) combined with ion beam assisted deposition (IBAD). METHODS: Titanium surfaces were treated by machined(S0), micro-arc oxidation(S1) and micro-arc oxidation combined with IBAD(S2), respectively. The topography and roughness of surfaces were determined by profilometer, and the bioactivity of the surface was evaluated by CLSM, MTT assay and ALP activity of cells. The data was analyzed by one-way ANOVA using SPSS11.0 software. RESULTS: The surfaces of S2 group were smoother than those of S1 group. On day 5, the OD value of S2 group was the highest among the three groups.10 days later, ALP activity on S1 and S2 groups were higher than that of S0 group. CONCLUSIONS: It is concluded that IBAD technique which provides HA coating on MAO surface could reinforce the bioactivity of micro-arc oxidation and could have a rapid osseointegration.

[Restoration of deformities caused by complex fracture of the orbit region and adjacent cranio-maxillofacial fracture].

OBJECTIVE: In order to improve the diagnosis and treatment of the complex fracture of the orbit region and adjacent cranio-maxillofacial fracture. METHODS: 73 cases with blowout fracture of the orbit and adjacent cranio-maxillofacial fracture in recent years were retrospectively analyzed and comparied with different methods of treatment. All cases had undertaken CT examinations. RESULTS: The positive rate of the CT examinations with blowout fracture of the orbit and adjacent cranio-maxillofacial region were 100%. Operating repositioning, rigid fixation and artificial material placement were used to treat this kind of deformities. CONCLUSIONS: With the progress of modern photographic methods, blowout fracture of the orbit and adjacent cranio-maxillofacial fracture can be diagnosed clearly and help the operation procedure. Operations with reduction, rigid fixation and filling materials can be used to restore this kind of fracture and appearance.

[The development and collagen ingredients analysis of submandibular gland acellular matrix].

PURPOSE: To develop submandibular gland acellular matrix and observe its structure and analyze its histological ingredients. METHODS: The fresh submandibular glands of SD mice were cell-extracted by chemical detergent and histological ingredients were analyzed by immunohistochemistry. RESULTS: Submandibular gland cells disappeared, matrix ingredients appeared network structure under microscopy. I, II and III type collagen proteins of submandibular gland before and after cell-extracted were positive under immunohistochemistry. CONCLUSIONS: The main ingredients of submandibular gland acellular matrix were I, II and III type collagen proteins.

[The development and ultrastructure study of acellular submandibular gland scaffold].

PURPOSE: To develop nature acellular submandibular gland scaffold materials and observe its ultrastructures. METHODS: The fresh submandibular glands of SD rats were cell-extracted by chemical detergent and observed with transmission and scanning electron microscope. RESULTS: Submandibular gland cells were dissolved and destroyed under transmission electron microscope. Normal submandibular gland cells were ball, but the shape of cells disappeared after cell-extraction under scanning electron microscope. Collagen fibers were arranged as net structure. CONCLUSIONS: Submandibular gland cells disappeared and the arrangement of collagen fibres were normal by Triton X-100 cell-extraction.

[Effects of epidermal growth factor on calciumion and cAMP in the ductal cells of submandibular glands].

PURPOSE: To study the effects of EGF on Ca(2+) and cAMP in the ductal cells of rat SMG. METHODS: Fluorometric technique and radioimmunological technique were used to investigate the dynamic changes of Ca(2+) and cAMP in the ductal cells. The data were analysed statistically by t test. RESULTS: After an momently latent period, intercellular calcium increased rapidly, then began to decline. This period could last 5 minutes. After 3 minutes, cAMP showed a rapid decrease, and then increased slowly. Its concentration could restore 90 minutes later. CONCLUSION: EGF may regulate intercellular calcium and cAMP, which results in the proliferation of the ductal cells.