The clinical application of guided bone regeneration technique in the dental imp

Author：XU Liang-peng（1989―），male，Shandong Province，Medical practitioners， master's degree. E-mail： Corresponding author：JIA Bao-jun，Deputy director of physician， 【Abstract】 Objective To observe the clinical effect of the GBR technique in dental implant of traumatic dentition defect. Methods choose 20 patients who are experiencing dental defect and bone defect as a result of oral and maxillofacial trauma， and implant 45 implants （Ankylos or other type） by using the GBR technique. 3-6 months later， perform the second surgery and repair the upper structure. Observe the stability of implant， the condition of bone combination， the amount of bone mass around the implant and the change of the shape of soft tissue in the later 6-24 months. Results In the following observing period after repairment， the condition of bone combination is good and the success rate is 100%. Further more， the shape of soft tissue is quite normal and patients are all satisfied with the results. The bone mass in the root area of implants is stable within the 6 months after the surgery and the vertical bone absorption in the neck is less than 1mm one year after the operation. Conclusion The GBR technique will get a good effect of bone incremet and the patients will suffer less during the surgery. Therefore， it is well accpeted and can be used to treat a lot of symptoms， which make the GBR technique a better supplementary method in dental implant prosthesis of traumatic dentition defect.

【key words 】 trauma； dentition defect； dental implant； guided bone regeneration

【CLC】R782.1 【Document code】B【Article number】1004-4949（2014）04-0397-02

Guided bone regeneration（GBR） technique， refers to the process where we bulid a biological barrier between soft tissue and the bone defect area by implanting a barrier membrane and therefore it creats a relatively closed environment， preventing gingvial connective tissue and epithelium cells entering into the defect area and reaching the goal of bone regeneration[1]. Trauma caused by missing teeth is often associated with bone tissue damage， and a large number of documents have confirmed that GBR is a mature and stable bone increment method. In recent years， GBR technique has been widely used in implant prosthesis of traumatic dentition defect， greatly improved the success rate of implant and expanded the applicable symptoms[2]. This study focuses on the 20 cases in which we perform GBR technique and regular dental implant technique to evaluate the clinical application effect of GBR.

1 materials and methods

1.1 Clinical materials

2012.1-2014.1 In our hospital， we have patients with oral and maxillofacial trauma.14 of them are male and the other 6 are female cases with age 18 to 65 years old and the average age is 35.5. Among which， we have 15 cases of jaw bone fracture and 5 cases of solely teeth and alveolar bone injury. Continuous teeth lost（3 or more） in 10 cases mainly exists in the front teeth area with different degrees of bone defects-- primarily lip-side bone plate defects and a part of vertical bone defect.

1.2 Equipment and materials

Dental implant machine is produced by 3i company in US； the mainly types of implants used are ITIStraumann（Sweden）， Ankylos（Germany）， DIO（korea）， and OSSTEM. The artificial bone powder we use is produced by Beijing Yihuajianke trade company ltd， while a few patients use Bio-Oss bone powder. Biological barriers are produced by Yantai Zhenghai biological technology company ltd.

1.3 Surgery process

In order to know the condition of bone defect in the implant area， we take pictures of surface layer before surgery. During the surgery， we at first use primacaine to perform the local infiltration anesthesia. When the anesthesia take effect， we cut open the gums， implant the implant and implant artificial bone powder in the defect area in accordance with preoperative design. Then we trim the biological barrier into the same shape as the implant area， make the membrane more than 2-3mm longer than the implant area to cover the whole defect area and tight suture mucosal incision without tension. After surgery， we take rouine pictures of surface layer and use antibiotics for preventive treating.

1.4 Repairment methods

3-6 months later， we check the condition of the implant healing and perform X ray membrane. If bone combination goes well， we need to perform the second surgery. One week after the surgery， we repair the upper side when the shape of gingvia finally fixed. We adopt fixed repairment in all cases except some patients with severe bone defect in which we use gingival porcelain to achieve artistic effect.

2 Results

In this group of 20 patients， we implant 45 implants during the first surgery. 3-6 months later， we can observe that the bone combination goes quite well through X ray membranes and then we conduct repairment for the upper structure. During the 6-24 months of clinical observation after the repairment， we find that the implant is in good stability， the upper side functions well and the soft tissue is in good shape. The patients are all satisfied with the results and the success rate is 100%. After the surgery， the root area of the implant tend to be stablized in 6 months. And one year after the operation， the vertical bone absorption is less than 1mm.

3 Discussion

Guided bone regeneration technique can significantly improve the effect of bone increment in the process of implant. Combined with the application of bone powder， we can improve the result of the bone regeneration surgery， which can lead to a better combination of bone and the implant. This technique expands the scope of implant application and raises the success rate of implant. Traumatic dentition defect is always accompanied by bone defect， we can’t receive a good result by adopting the regular repairment. The emergence of GBR technique has enabled us to achieve the perfect effect of repairment at the minimum cost[3].

3.1 The features of traumatic dentition defect

Oral and maxillofacial trauma is a common surgical injury， which is usually accompanied by injury of teeth and alveolar bone， especially in the front teeth area[4]. Injury of teeth and alveolar process is commonly seen in our clinical practice and this kind of injury is usually a result of fall over， firearm injury， traffic accident， fight and so on. These accidents can easily lead to lip-side bone defect， even vertical bone defect in some servere cases. To deal with this kind of teeth defect through implant restoration， the most important step is to recover the bone mass in the implant area. However， the method of bone graft and the Onlay bone graft can not be accepted by patients easily becasue it will cause greater trauma， therefore a second surgery is often required. Thus the application of GBR technique resolves this problem successfully. In this group of cases， most of them have lip-side bone defect. By applying GBR technique to dental implant， we resolve the problem of teeth defect for patients with little trauma.

3.2 The application of GBR technique in traumatic dentition defect

The bone defect caused by traumatic dentition defect is different from regular bone defect. The regular bone defect is more often a result of periodontitis with relatively small amount of bone defect. Besides， the defect area is in regular shape， which make it relatively easier to perform implant prosthesis. While the bone defect caused by trauma is always accompanied by a bigger loss of bone mass. So the regular way of dental implant can not obtain an ideal effect. Therefore， chosing an appropriate supplementary means is the key to the success of dental implant. Since the GBR technique has a better effect of bone increment and can be used to treat a wide scope of symptoms， it becomes the most common supplementary means in dental implant of traumatic dentition defect.

In normal cases， to apply the GBR technique， we usually use biological barries and other kind of bone implant material jointly. The clinical application research indicates that this method of bone increment will receive a good effect， which generally takes 3-6months to get a stable bone combination. Compared with bone split technique， the Onlay bone graft method and any other means of bone increment， the application of GBR can significantly reduces the suffering of patients and shorten the implant prosthesis treatment. We apply the GBR technique to this group of cases and obtain a good clinical effect.

3.3 The noteworthy problems in the application of GBR technique

3.3.1 To build and maintain a space for bone regeneration

How to build a space and maintain this space for the bone regeneration and how to effectively stop the soft tissue from getting into this space， which two are the most important factors influencing the success ful application of GBR[5]. A larger number of animal study and clinical research has indicated that， the size and shape of bone regeneration space decide the amout of bone regeneration and its shape. In clinical practice， to build and maintain the space for bone regeneration， we usually use specific nails for membrane fix and tent screw， or by covering titanium mesh to prevent the membrane from moving. Additionally， lots of scholars advocate the method of bone implant material filling under the membrane， which prevents the membrane collapse and increases the bone mass.

3.3.2 the size of membrane

The size of the barrier membrane must be appropriate. If the membrane is too small， the soft tissue will grow along the edge of the membrane and get into the space， therefore harms the bone regeneration. However， it will cause trouble in wounds closure and easliy lead to wound dehisscene[6]. Thus， we need to use the membrane to cover the whole implant area and make sure it exceeds the membrane by 2-3mm， which is beneficial for the bone regeneration and reduces the chances of getting infected.

3.3.3 The split of soft tissue， membrane exposure and infection

A large amount of study has showed that ， the GBR technique can restrain the soft tissue from growing， supplying the blood to the implant area and protecting this area. Therefore， it is always accompanied by the risk of wound dehisscene if we use the barrier membrane[7]. We need to use the method of tension-reduced suture or even palatal side mucosal flap suture if necessary. In this way， we can prevent the wound from split. According to some scholars[8]， we can address the problem of membrane infection by rinsing， applying medicine partly， resuture and strengthening the oral health education after the membrane exposure.

In conclusion， this study testifies that， with the application of GBR technique， we can obtain a better effect in dental implant prosthesis of traumatic dentition defect. It improves the success rate significantly and has a great prospect.

References

[1] SU Yu-cheng. Contemporary oral implantology[M]. Beijing：People’s Medical Publishing House Press， 2004： p207

[2] FEI Wei， YANG Xiao-min， LI Zheng et al. Experimental study of the bioresorbable collagen membrane used for guided bone regeneration around dental implants [J]. West China Journal of Stomatology Press，2008，26（5）：494-498.

[3] RUI Yu-xin，Wang Yi. Clinical application of guided bone regeneration in the bone defects in anterior implants [J].Journal of Clinical Stomatology Press， 2011，27（7）：418-420.

[4] JIA Bao-jun， Huang Zheng-nan， Lei Ming et al. Dental Implant in the Restoration of Traumatic Dentition Defect[J]. Journal of Oral and Maxillofacial Surgery Press， 2011，21（4）：265-268.

[5] Cheng Bo， Qiu Li-xin， Hua Ye et al. Esthetic outcome of guided bone regeneration w ith titanium membrane in single anter iormax illary implant site[J]. Journal of odern Stomatology Press， 2011，25（3）：165-170.

[6] Thorwarth M， Schlegel KA， Wehrhan F， et al. Acceleration of de novo bone formation following application of autogenous bone to particulated anorganic bovinematerialin vivo[J]. Oral Surg Oral Med Oral Pathol Oral Radiol Endod， 2006， 101（3）： 309-316.

[7] Zhou Lei， Xu Shu-lan，Huang， Jian-sheng， et al. Clinical application of guided bone regeneration with resorbable or non- resorbable membrane in dental implants[J]. Journal of Moder Stomatology Press， 2006， 101（3）：309-316.

[8] Shanaman R H. A retrospective study of 237 sites treated consecutively with guided tissue regeneration [J] . Int J Periodentics Restorative Dent，1994，14（4）：293-301.