A novel technique to preserve the alveolar ridge width following tooth extraction in the maxillary frontal area / 北京大学学报(医学版)

Objective:To introduce a novel ridge preservation technique with micro-titanium plate avoiding the use of bone grafting materials,and evaluate the potential horizontal bone preservation effect of this new technique,applied on single maxillary central incisors after tooth extraction for future implant restoration.Methods:Nine patients (six women and three men),mean age (26.0 ±5.7)years(from 1 8 to 34 years)referred to the Department of Oral Implantology,Peking University School and Hospital of Stomotology,were selected and diagnosed with unsalvageable single middle incisor with fine general con-ditions,no signs of acute local inflammation,no ongoing or previous periodontitis,healthy neighboring teeth and intact buccal bone walls.Tooth extraction,delayed implant placement and implant-supported single crown restoration were selected as treatment plan.The teeth were extracted atraumatically with lo-cal anesthesia,followed by a reflection of a minor flap to exposed 2-3 mm of the buccal bone plate.Af-ter that,a micro-titanium plate was trimmed and bended to fit the convexity of the labial bone and fixed by two mini pins with intent to support the labial soft tissue.The flap was then repositioned over the micro titanium plate and secured with two single sutures.No bone grafting materials or releasing incisions were needed.The sockets were left to heal without any intention of primary wound closure.Cone-beam compu-ted tomographic (CBCT)scans were obtained before and four months after tooth extraction.Horizontal ridge widths were measured with CBCT software,and the preservation effects were calculated and recor-ded by the percentage of horizontal ridge alteration.Results:The nine extraction sockets were healed un-eventfully.The average socket width before extraction was (7.51 ±0.48)mm (6.92-7.82 mm).The average alveolar ridge labial-palatal width at the control point of the edentulous area was (6.81 ±0.44) mm (6.04-7.38 mm)4 months after tooth extraction,the mean percentage of ridge width preserved was 90.87%±2.91%(87.28%-95.60%).Conclusion:This novel ridge preservation method by the usage of a micro-titanium plate did not interfere with the natural socket healing process,and at the same time,largely preserved the width of alveolar ridge without any bone grafting procedures.Long term results remain to be seen.

Maxillary sinus augmentation and implant placement following removal of a maxillary antral cyst: a preliminary clinical study / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical outcome of maxillary sinus augmentation and implant placement following removal of a maxillary antral cyst.</p><p><b>METHODS</b>In this study 32 patients with 33 maxillary antral cysts were enrolled. The partial wall of cyst was removed through a small lateral sinus approach and cyst spontaneous shrink was expected when wall of cyst was destroyed for open drainage. Three to six months later the secondary sinus approach 1.5 mm circling the first approach for augmentation was undertaken. Dental implants were placed simultaneously or later. All patients finished prosthetic rehabilitation in the study and were followed up for (30.9 ± 11.5) months. The intraoperative and postoperative complications were recorded. The survival rate of the implants was calculated.</p><p><b>RESULTS</b>In this study, 33 maxillary antral cysts of 32 patients were removed. Maxillary sinus augmentation was performed after a mean of (4.5 ± 1.5) months (range, 2-8 months). Sixty-two implants were inserted and all patients finished prosthetic rehabilitation after a mean of (10.8 ± 2.7) months (range, 5-17 months). The survival rate of implants was 95% (59/62). Three implants failed before their prosthesis delivered due to failure of osseointegration and were reinserted later. No recurrence of cyst was observed until the last recall. In this study, 24 specimens were mucosal cysts. Five specimens were mucoceles and 4 specimens were not certain in pathology.</p><p><b>CONCLUSIONS</b>Maxillary sinus cysts have a negative effect on maxillary sinus augumentation if not removed. The present preliminary data of the study suggests that the clinical result of maxillary sinus augmentation and implant placement following removal of a maxillary antral cyst is predictable.</p>

Application of xenograft for alveolar ridge preservation in posterior sites: a randomized controlled clinical trial / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of ridge preservation with Bio-Oss Collagen and Bio-Gide in posterior sites.</p><p><b>METHODS</b>From May 2010 to July 2013, 16 patients with bilateral posterior teeth planned to be extracted and replaced by implants were enrolled. One of the sockets was randomly selected and presserved with Bio-Oss Collagen and Bio-Gide (intervention group). The contralateral socket was left to heal spontaneously (control group). Cone-beam (CBCT) scans were performed immediately after the extraction and 6 month later. The bone cores were collected during the implant placement surgery and analyzed by micro-computed tomography.</p><p><b>RESULTS</b>After 6 month healing, the vertical and horizontal dimensional alteration of the treatment group were (0.55 ± 1.05) mm and (-0.99 ± 0.94) mm respectively, while the vertical and horizontal change of control group were (-0.71 ± 1.41) mm and (-2.26 ± 1.29) mm respectively. The micro-computed tomography results showed that there was no significant difference in new bone volume between control and intervention groups.</p><p><b>CONCLUSIONS</b>Applying Bio-Oss Collagen and Bio-Gide for ridge preservation in posterior sites resulted in less vertical and horizontal bone resorption of sockets following extraction.</p>

A 10-year retrospective analysis of clinical results of implant-retained/ supported prostheses in full edentulous patients / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the 10-year clinical results of implant prostheses in edentulous patients.</p><p><b>METHODS</b>Between August 1994 and November 2009, 762 implants were placed in 127 patients (162 jaws) with the mean age of (56.0 ± 10.9) years in Peking University, School and Hospital of Stomatology. Sinus lift, guide bone regeneration (GBR) and onlay graft were used according to the indications of bone defect types. Overdentures and fixed bridges were delivered.Overdentures were retained/supported by ball, magnet, telescopic crown or milled bar. Clinical evaluation included peri-implant soft tissue health status, prostheses functional status and complications.Radiographic evaluations were conducted at operation day, 3 months post-operatively, right after prostheses delivery, and annually afterwards. Clinical data were collected and analyzed.</p><p><b>RESULTS</b>Of the 127 patients, 116 were edentulous mandible and 46 edentulous maxilla, with a mean follow-up period 109.2 months(45-228 months). Thirteen implants were lost and the 10-year implant cumulative survival rate was 97.8% and the prostheses success rate was 100.0%. The prevalence of peri-implantitis was 3.8% (29/762). Sixty-seven point nine percent of the patients underwent implant placement without bone graft.Sinus lift technique and guided bone regeneration technique were the most often used with 84.8% (39/46) in the upper jaws and 6.2% (10/162) in the total jaws respectively. Seventy-one percent of the cases(115/162) was overdentures. Telescopic, milled-bar, and magnetic retained/supported overdentures were the most commonly used with 34.8% (40/115) , 27.0% (31/115) , and 20.0% (23/115) respectively. The implant-supported fixed prostheses included adhesive retained fixed bridges and screw retained fixed bridges with the ratio of 19.1% and 80.9% respectively. The prevalence of 10-year post-prosthodontic complications was 53.5% (68 cases). The most common complications were prosthetic and uperstructure complications.</p><p><b>CONCLUSIONS</b>The 10-year implant-retained/supported prostheses was a successful modality in edentulous cases.Sinus lift technique and guided bone regeneration technique are the most commonly used techniques with predictable clinical results. Telescopic crowns milled bar and magnet with 4-6 implants retained/supported overdenture were the most often used retention systems and telescopic crown overdenture had more advantages in terms of long-term maintenance and satisfaction.</p>