Table of contents
Prof. Dr. Vo Van Nhan
External sinus lift and bone graft is the technique that increases the maxilla bone thickness in dental implant technique. There are 2 methods; the 1st technique: lift the sinus and place implants at the same time. The 2nd technique: sinus lift, and bone graft, and then place the implant, 3 months later.
From 2007 to 2013, we were operating external sinus lift operation for 62 patients: 39 male and 22 female, age 18-61. These patients had 8mm in their residual bone height. Including, 67sinuses were lifted in the one-stage procedure, and 19 sinuses were lifted in the two-stage procedure. Follow-up time is over 2 year. Result: Of 120 implant were placed, 117 implants were survival (97.5%), 3 implants were failed (2.5%). No membrane perforation. Infection (1.16 %), dehiscence flap (1.16 %) were also recorded.
The Dental implant is a technique that results in chewing, aesthetics and good pronunciation. Therefore, this technique is growing. However, the bone at the implanted place should be sufficiently thick (> 10 mm). There are many methods increase the bone thickness, but external sinus lift is the most effective and controllable method.
Now, thanks to the improvement of the dental implant design creating the compression between the crest of the bone and the abutment to achieve the initial stability that allows placing the implant as the same time as the sinus lift even when the residual bone height from the crest of the bone to the sinus floor is1-2mm. However, currently, there are not many kinds of research in this field. So we make the one-stage and two-stage external sinus lift research with the purpose:
Estimating the successful rate when placing the dental implants with the different groups of initial maxilla bone height: 1-2mm; 3-5mm, and 5-8mm.
- Assess complications: membrane perforation, infection, and dehiscence flap.
I. OBJECTIVES AND RESEARCH METHODS
1. Research objects
The study was performed on 61 patients including 39 men and 22 women, aged 18 to 61 years old.
a. Criteria for selecting patients</strong
- Residual bone height: 1-8mm.
- Periodontal condition: No acute periodontal inflection.
- Good general health, well-controlled medical conditions, stable mental stage.
b. Exclusion criteria
- The malformation in the maxillary sinus. The sinus mucosa reduces its function or scarring due to trauma, surgery.
- Having sinusitis (chronic or acute sinusitis, cysts, lumps).
- After radiotherapy dose over 45 Gy. Immunotherapy. Smoke over 20 cigarettes a day
2. Research methodology
2.1. The study, description of the cross section
2.2. Technical description
2.2.1 Equipment, materials:
- Dental car seat machine, ultrasonic bone cutting machine, external sinus lift toolkit.
- Bone (pelvic bone or bones in the mouth) combined with the fellow bone and synthetic material HA & β tricalcium phosphate.
- Self-absorbing collagen membrane Salvin oralmem®absorbable collagen membrane.
- Implant: Implant of Korean DIO (RBM surface). Length: 10-14mm, diameter 3.5-4mm
Open an oval sinusoidal window on the side of the sinus in case of needing to lift the sinus including 4 teeth from the first small molar to the 7th molar, opening two windows, one small first molar and one large first molar, keeping the bone between the two sinus windows to increase the rigidity of the lateral wall and the maturity of the grafted bone.
Using a Tungsten round drill bit and a slow-speed drill, combined with an ultrasonic bone cutter to open the sinus window to speed up work and reduce the risk of perforation, then use a hand-held instrument to lift the sinus membrane( the tool always contact with sinus wall when lifting the sinus membrane). Open the window so that the wall is 3mm deep at the bottom of the sinus cavity for easy viewing in the sinus cavity and to retain bone grafts. The sinusoidal bone filling according to technical requirements.
The implant placement is smaller than the implant diameter and uses a threaded implant, manny infinitesimal threads in the abundant, roughen the implant surface to increase the pressure to the abutment to create the initial stable sense. Implant placement is marked by surgical gut. Get collagen membrane. Retrofitting the flap.
2.3 Criteria for evaluation
- Measure the height of the jaw bone: X-ray Cone Beam
- Determination of firmness between Implant and jaw bone: Force tool.
II. RESEARCH RESULTS
From December 2007 to June 2013, 61 patients (39 males and 22 females) were implanted with sinus implants.
120 DIO implants have been placed. Implants have initial stabilization depending on the initial bone height but they reach 20N /cm or more. Successful implantation of 117 implants accounted for 97.5%, 3 failed implants, 2.5%. (Table 1)
At the residual bone height 1-2 mm, 39 implants were placed, 37 implants were successful (94.9%), 2 implants failed (5.1%). When the residual bone height is 3-5mm, 56 implants were placed, 55 implants were successful (98.2%), 1 implants failed (1.8%). When the residual bone height is over 5mm, 25 implants were placed. 100% success, no failure cases (Table 1). Fisher's test showed that the success rate for bone height was statistically significant. (p < 0.05).
There were 67 cases of one-stage sinus lift, 94 implants were placed, 92 implants were successful (97.9%), 2 implants failed (2.1%). 19 cases of two-stage sinus lift, 26 implants were placed, 25 implants were successful (96.1%), 1 failed (3.9%) (Table 2). The Fisher test showed no significant difference millet between 2 techniques. (p < 0.05).
Table 2: the success rate of implant and failure according to the type of sinus lift
Average follow-up time: 24.7 months (the longest: 75 months, the shortest: 4 months).
There were 3 cases of failure, including 3 implants used:
- 1 case of failure before restoration with the remaining bone 4 mm, failure of 8 months after the implanted sinus lift.
- 2 cases after the complete restoration. There was one case with the remaining bone height of 3mm, failure after 27 months of restorative load, the remaining case with the remaining 1.3mm bone failure after 8 months of the restorative load.
- Infection: 1 case accounted for 1.16%, infection 10 days after surgery and lead to implant failure. Opened 1 case accounted for 1.16%.
Sinus implants have become a good prognosis for the placement of the dental implant in the posterior region of the jaw on the bone. At the consensus meeting on the issue of sinus elevation held in Germany in 1996, when bone height remained 1-3m, two-stage lifted sinus, when the remaining bone height from 4-6mm indicated to lift the one-stage sinus. This is to ensure that the implant is stabilized initially when the bone height remains from 7 mm to the closed sinus.
However, 10 years later, in 2006, Peleg and his colleagues published a study of 9-year follow-up sinus surgery for 731 patients with 2,132 implants successfully placed on 97.9% of implants. here were 3 groups: group 1 had 1-2mm bone height with success rate of 95.9% (failure 4.1%); Group 2 from 3-5mm had a success rate of 98.5% (failure of 1.5%) and group 3 had a bone height of more than 5mm with a success rate of 98.4% (failure of 1.6%).  Compared to the study by Peleg et al., This study achieved a success rate of 97.5% (equivalent to Peleg's results). In the group of 1-2mm, the success rate reached 94.4%, implant failure of 5.1%; In the group of 3-5mm, the success rate was 98.2%, the implant failure was 1.8%, the group over 5mm to less than 8mm achieved the success rate of 100%, no implant failure. The study found that the success rate of implantation in group 3 (100%) was higher in Peleg's study but the follow-up time was shorter. Different failure rates for 3 different bone heights were 5.1%, 1.8% and 0% for the implant placed in the 1- 2mm, 3-5mm, and 5mm region. <0.05). Although the rate of failure was higher in the 1- 2mm bone group than in the other two groups, the incidence was very low for this very complex clinical condition.
When the bone is 1-2mm, it is a challenge to place the implant at the same time as the sinus lift and sinus transplant. In this case, almost one-stage sinus surgery technique can only be performed when the remained bone is of good quality. Indeed, in our study, when the residual bone height is 1-2 mm, 13 cases were treated by the one-stage external sinus lift and the left 14 cases hade to be done by the two-stage method.
The success rate of this study (97.5%) was achieved by creating a sinusoidal sinus cavity, the lower wall of the sinus at the base of the 3 mm sinusoidal cavity, which allows for retention of the grafted material, easy to observe when lifting the membrane, and put the material into the sinus. Combination of rotary instruments and ultrasound instruments to shorten the opening time of the window, and open the oval window should ensure the safety of perforation of the sinus membrane, combined with the opening of two windows when need to lift the sinus Large and wide, this ensures the stability of the lateral wall of the sinus, retaining many of the true bone walls that heal rapidly following the bone-building mechanism. The bone graft includes the cancellous bone placed in contact with the implant surface, the cancellous bone is considered as the golden standard for grafting materials, compress the bone carefully, long implant placement, choose the tapered multiple implant placement in the neck region ( easy to reach the initial stability). The RBM surface implant is an abrasive surface treated by hydroxy apatic coating for better results than the smooth surface. The coating of the grafted material prevents competition. The soft tissues should create a favorable environment for bone growth.
The process of lifting the sinus, bone grafting can introduce new bacteria into the sinus and noise, so antibiotic prophylaxis is required to prevent infection. High doses of antibiotics prior to surgery and good oral hygiene are not limited postoperative infection but also a significant reduction in surgical implant failure rates of two-stage. Especially for smoked patients.[3,6,7]
There is one case of implant failure prior to loading force, one case in which patients with postmenopausal women have severe osteoporosis, thus affecting the integration of the bone.There are two cases of failure after the restoration of the restorative force, one case using implants on the implant stand alone in the rear teeth can be overloaded.One case of infection 10 days after surgery in patients who eat betel and smoked, but this patient is treated by opening the pump flush part of the material and using the antibiotics then the implant is well healed.Only one case of hypertrophy accounts for 1.16%. There is no case of perforation. This is a very low rate probably due to the use of proper sinus surgery.Compared to the rate of perforation of other studies from 0-58%. 
The successful implantation results when the remaining bone size is 5-8mm to 100% when bone height remains 3-5mm is 98.2% and the remaining bone height from 1-2mm is 94.9%.The difference between the three groups was a significant statistic(p < 0.05).
The incidence of complications, infections, and dehiscenced flapwas low (1.16%), with no perforation.
The male patient was 54 years old, lost teeth, some teeth loose and painful when eating or chewing.Patient demand for fixed dentures including implant treatment.General condition: Patients with good general health do not have diabetes.Habits: Smoking over 20 years.Less than 10 cigarettes a day but stopped smoking five years ago.
Oral examination: Patients have a medium laugh, face and lip contour.
Visits in the mouth and x-rays:
Teeth on tooth loss 18, 17, 25, 26, 28;17 teeth gutter slit close to the tooth root, teeth 14.15: deep pockets 7mm, shaking degree 3; Teeth 12, 11, 21, 22 Gingival recession.Lower teeth 36, 47,48 teeth 37 swing level 3, pocket side near 6mm deep.
Image on CT Cone Beam:
Teeth 17, the outer surface of the bone, the inside and the tongue, the tip of the teeth, the sinus cavity.
Teeth 14, 15 bone around the root of the tooth, the tip of the tooth to the floor of the sinus.
Tooth decay 24 around the root of the tooth and the outside, the tip of the tooth to the floor of the sinus cavity).
27 teeth of the outer surface of the teeth, the inside, the tip of the tooth to the floor of the sinus.
Diagnosis: Tooth loss and periodontitis
- Tooth extraction 17,14,15,24,27,38 clean up inflammatory granule tissue.
- Treatment of periodontal inflammation: tartar scraping, periodontal, antibiotic, anti-inflammatory and mouthwash chlohexidine 0.12% in 7 days.Wait 6 weeks later, lift the sinus, bone graft and implant a transplant at the positions R 16,15,14;R 24,26,27;It also implanted in R37.
CT scan 6 weeks after extraction
Challenge: bone height remaining from 1 to 3mm sinus screen, it is difficult to put the implant to stabilize initially.
Solution: Choose transplant implant, with surface treatment, multiple threads of the neck implant.Boreholes are smaller than the diameter of the implant, placing the implant on or resting on the rest of the bone, using the hand-held implant to ease the direction and sense of initial stability.
Technique: Open two oval windows using a rotary device and a window ultrasound, a sinus lift, an implant, a graft and a membrane.
The CT Cone beam survey over 9 months post-surgery
Soft tissue healing after 9 months
Surgical imaging revealed 2 months after surgery with good bone integration.
Image of surgical removal of snail 9 months after surgery
Image 18 months after last restoration
Panorama image 18 months after last restoration
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