Effects of Flapless Implant Surgery on Soft Tissue Profiles: A Prospective Clinical Study

Background: Flapless implant surgery has been suggested as a suitable treatment modality for the preservation of soft tissue after implant placement. Purpose: The purpose of this study was to determine the extent of soft tissue profile changes around implants after flapless implant surgery. Materials and Methods: A total of 44 patients received 76 implants using a flapless implant procedure. The marginal level of the peri‐implant soft tissue was evaluated using dental casts 1 week, 1 month, and 4 months after implant placement. Results: The mean soft tissue levels around implants showed 0.7 ± 0.3 mm of coronal growth 1 week after surgery. At 1 month, the levels were 0.2 ± 0.2 mm coronal growth and at 4 months, the values were 0.0 ± 0.3 mm. Soft tissue profiles assessed 4 months after flapless implant placement were similar to profiles assessed immediately before implant placement. Conclusion: Flapless implant surgery is advantageous for preserving mucosal form surrounding dental implants.     

应用不翻瓣技术进行后牙区种植义齿修复的临床体会

目的：总结应用不翻瓣技术进行后牙种植义齿修复的临床体会。方法：后牙缺失需要进行种植义齿修复患者53例,男26例,女27例,平均年龄47.4±12.3岁,90颗缺牙。术前均进行CT扫描,三维重建分析缺牙区可用骨长度、宽度和高度,术中环形切除缺牙区黏骨膜进行不翻瓣种植体植入手术,必要时辅助手术导板引导种植体窝洞预备和种植体植入。记录手术耗时时间,术后即刻CT检查植入位置,观察有无并发症的发生,种植体骨结合后完成上部结构修复并定期随访。结果：53例患者应用不翻瓣种植手术成功植入90枚种植体,种植体植入位置良好,术中耗时平均（17.4±5.8）min,无上颌窦底黏膜穿孔、下颌神经损伤、骨壁侧穿等手术并发症,86枚种植体成功修复义齿并经3～10个月随访正常。结论：绝大多数后牙缺牙患者都适合进行不翻瓣种植手术,选择比种植体直径稍大的黏骨膜环切钻更有利于手术,种植体上方皮质骨需要修整后方能使愈合基台准确就位。     

Bone formation at recombinant human bone morphogenetic protein-2-coated titanium implants in the posterior mandible (Type II bone) in dogs

Background: Conventional oral/maxillofacial implants reach osseointegration over several months during which the titanium fixtures interact with alveolar bone. The objective of this study was to determine if adsorbing recombinant human bone morphogenetic protein‐2 (rhBMP‐2) onto a titanium porous oxide (TPO) implant surface might enhance or accelerate local bone formation and support osseointegration in a large animal oral/maxillofacial orthotopic model. Material and Methods: Endosseous implants with a TPO surface were installed into the edentulated posterior mandible in eight adult Hound Labrador mongrel dogs. The implant surface had been adsorbed with rhBMP‐2 at 0.2 or 4.0 mg/ml. TPO implants without rhBMP‐2 served as control. Treatments were randomized between jaw quadrants. Mucosal flaps were advanced and sutured leaving the implants submerged. Clinical and radiographic evaluations were made immediately post‐surgery, at day 10 (suture removal), and week 4 and 8 post‐surgery. The animals received fluorescent bone markers at week 3, 4, and at week 8 post‐surgery, when they were euthanized for histologic analysis. Results: TPO implants coated with rhBMP‐2 exhibited dose‐dependent bone remodelling including immediate resorption and formation of implant adjacent bone, and early establishment of clinically relevant osseointegration. The resulting bone–implant contact, although clinically respectable, appeared significantly lower for rhBMP‐2‐coated implants compared with the control [rhBMP‐2 (0.2 mg/ml) 43.3±10.8%versus 71.7±7.8%, p<0.02; rhBMP‐2 (4.0 mg/ml) 35.4±10.6%versus 68.2±11.0%, p<0.03]. Conclusions: rhBMP‐2 adsorbed onto TPO implant surfaces initiates dose‐dependent peri‐implant bone re‐modelling resulting in the formation of normal, physiologic bone and clinically relevant osseointegration within 8 weeks.     

Radiographic evaluation of marginal bone levels during healing period,adjacent to parallel‐screw cylinder implants inserted in the posterior zone of the jaws,placed with flapless surgery

Objective: The purpose of this study was to compare changes at the marginal bone level adjacent to implants placed with flapless surgery and flap surgery during a stress‐free healing period. Material and methods: Seven hundred and eighty‐five implants were placed in 417 patients with a flapless approach and 459 implants were placed in 227 patients using flap techniques. The marginal bone level was determined radiographically, using digitized panoramic radiographs, at two time points: at implant placement (baseline) and after the healing period. Results: The median follow‐up time was 0.5 years (SD, 1.2; range: 0.3–0.7). Implants placed with flapless surgery had a mean crestal bone loss of 0.5 mm (SD, 0.5; range: ?0.7–2.4) and implants placed with flap surgery had a mean bone loss of 0.5 mm (SD, 0.7; range: ?2.0–3.0) after healing. Differences in bone level changes between smokers and non‐smokers were statistically significant for the flapless group (P<0.01). Conclusions: A radiographic evaluation of marginal bone levels adjacent to implants showed comparable results for implants placed with flapless surgery and flap surgery. Appropriate case selection after virtual planning of the implant position and a sound surgical protocol is necessary for flapless surgery. Smoking habits may compromise the efficacy of flapless implant procedures. To cite this article:
Nickenig H‐J, Wichmann M, Schlegel KA, Nkenke E, Eitner S. Radiographic evaluation of marginal bone levels during healing period, adjacent to parallel‐screw cylinder implants inserted in the posterior zone of the jaws, placed with flapless surgery.
Clin. Oral Impl. Res. 21 , 2010; 1386–1393.
doi: 10.1111/j.1600‐0501.2009.01961.x     

Flapless implant surgery in the esthetic region: advantages and precautions

Because osseointegration is now considered highly predictable, the current trend is to develop techniques that can provide function, esthetics, and comfort with a minimally invasive surgical approach. To achieve those goals, flapless implant surgery using a tissue punch technique has been suggested. This paper presents two clinical cases of single-tooth implants placed in the esthetic region (anterior maxilla), which illustrate systematic approaches to flapless implant surgery for immediate and delayed loading protocol. For both cases, a tissue punch technique using a surgical guide fabricated with the aid of a radiographic stent was performed to provide access for implant site preparation and placement. The implants were loaded either immediately or 4 months after implant placement. With the planned flapless surgical technique, reduced operative time, accelerated postsurgical healing, and increased patient comfort and satisfaction were achieved. This paper also describes precautions of the flapless implant surgery in case selection, surgical techniques, and prosthodontic protocol. In conclusion, appropriate case selection and well-tailored surgical guides with sound surgical and prosthodontic protocols are considered to be the key elements in the success of flapless implant surgery.     

Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-2: histologic observations

Background: Studies using ectopic rodent, orthotopic canine, and non‐human primate models show that bone morphogenetic proteins (BMPs) coated onto titanium surfaces induce local bone formation. The objective of this study was to examine the ability of recombinant human BMP‐2 (rhBMP‐2) coated onto a titanium porous oxide implant surface to stimulate local bone formation including osseointegration and vertical augmentation of the alveolar ridge. Material and Methods: Bilateral, critical‐size, 5 mm, supra‐alveolar, peri‐implant defects were created in 12 young adult Hound Labrador mongrel dogs. Six animals received implants coated with rhBMP‐2 at 0.75 or 1.5 mg/ml, and six animals received implants coated with rhBMP‐2 at 3.0 mg/ml or uncoated control. Treatments were randomized between jaw quadrants. The mucoperiosteal flaps were advanced, adapted and sutured to submerge the implants for primary intention healing. The animals received fluorescent bone markers at weeks 3, 4, 7 and 8 post‐surgery when they were euthanized for histologic evaluation. Results: Jaw quadrants receiving implants coated with rhBMP‐2 exhibited gradually regressing swelling that became hard to palpate disguising the contours of the implants. The histologic evaluation showed robust bone formation reaching or exceeding the implant platform. The newly formed bone exhibited characteristics of the adjoining resident Type II bone including cortex formation for sites receiving implants coated with rhBMP‐2 at 0.75 or 1.5 mg/ml. Sites receiving implants coated with rhBMP‐2 at 3.0 mg/ml exhibited more immature trabecular bone formation, seroma formation and peri‐implant bone remodelling resulting in undesirable implant displacement. Control implants exhibited minimal, if any, bone formation. Thus, implants coated with rhBMP‐2 at 0.75, 1.5 and 3.0 mg/ml exhibited significant bone formation (height and area) compared with the sham‐surgery control averaging (±SD) 4.4±0.4, 4.2±0.7 and 4.2±1.2 versus 0.8±0.3 mm; and 5.0±2.2, 5.6±2.2 and 7.4±3.5 versus 0.7±0.3 mm², respectively (p<0.01). All the treatment groups exhibited clinically relevant osseointegration. Conclusions: rhBMP‐2 coated onto titanium porous oxide implant surfaces induced clinically relevant local bone formation including vertical augmentation of the alveolar ridge and osseointegration. Higher concentrations/doses were associated with untoward effects.     

Ridge alterations following immediate implant placement and the treatment of bone defects with Bio-Oss in an animal model

Background: Conflicting data exist on the outcome of placing Bio‐Oss® (Geitslich Pharm AG, Wolhausen, Switzerland) into extraction sockets. It is therefore relevant to study whether the incorporation of Bio‐Oss into extraction sockets would influence bone healing outcome at the extraction sites. Purpose: The aim of this study was to assess peri‐implant bone changes when implants were placed in fresh extraction sockets and the remaining defects were filled with Bio‐Oss particles in a canine mandible model. Materials and Methods: Six mongrel dogs were used in the study. In one jaw quadrant of each animal, the fourth mandibular premolars were extracted with an elevation of the mucoperiosteal flap; implants were then placed in the fresh extraction sockets and the remaining defects were filled with Bio‐Oss particles. After 4 months of healing, micro‐computed tomography at the implant sites was performed. Osseointegration was calculated as the percent of implant surface in contact with bone. Additionally, bone height was measured in the peri‐implant bone. Results: Average osseointegration was 28.5% (ranged between 14.8 and 34.2%). The mean crestal bone loss was 4.7 ± 2.1 mm on the buccal aspect, 0.4 ± 0.5 mm on the mesial aspect, 0.4 ± 0.3 mm on the distal aspect, and 0.3 ± 0.4 mm on the lingual aspect. Conclusion: The findings from this study demonstrated that the placement of implants and Bio‐Oss® particles into fresh extraction sockets resulted in significant buccal bone loss with low osseointegration.     

Effects of implant design on marginal bone changes around early loaded, chemically modified, sandblasted Acid-etched-surfaced implants: a histologic analysis in dogs

Background: A minimal marginal bone loss around implants during early healing has been considered acceptable. However, the preservation of the marginal bone is related to soft tissue stability and esthetics. Implant designs and surfaces were evaluated to determine their impact on the behavior of the crestal bone. The purpose of this study is to evaluate histologic marginal bone level changes around early loaded, chemically modified, sandblasted acid‐etched–surfaced implants with a machined collar (MC) or no MC (NMC). Methods: Three months after a tooth extraction, 72 sandblasted acid‐etched chemically modified implants were placed in six dogs. Thirty‐six implants had NMC, and 36 implants had a 2.8‐mm MC. All implants were loaded 21 days after placement. For histologic analyses, specimens were obtained at 3 and 12 months. Assessments of the percentage of the total bone‐to‐implant contact and linear measurements of the distance from the shoulder of the implant to the first bone‐to‐implant contact (fBIC) were performed. Based on fBIC measurements, estimates of bone loss were obtained for each implant. A mixed‐model analysis of variance was used to assess the effects of implant type and sacrifice time. Results: All implants achieved osseointegration. The mean bone gain observed around NMC early loaded implants (at 3 months: 0.13 ± 0.37 mm; at 12 months: 0.13 ± 0.44 mm) was significantly different from the mean bone loss for MC early loaded implants (at 3 months: ?0.32 ± 0.70 mm; at 12 months: ?0.79 ± 0.35 mm) at 3 months (P = 0.003) and 12 months (P <0.001). No infrabony component was present at the marginal fBIC around NMC implants in most cases. There were no statistically significant differences among the means of total bone contact for implant types. Conclusions: Chemically modified, sandblasted acid‐etched–surfaced implants with NMC presented crestal bone gain after 3 and 12 months under loading conditions in the canine mandible. The implant design and surface were determinants in the marginal bone level preservation.     

The clinical and radiographic outcome of implants placed in the posterior maxilla with a guided flapless approach and immediately restored with a provisional rehabilitation: a randomized clinical trial

Objectives: To evaluate and compare the outcome of dental implants placed using a flapless protocol and immediate loading with a conventional protocol and loading after 6 weeks. Materials and methods: Fourteen patients with bilateral maxillary edentulous areas were treated using Straumann SLA‐implants. Using a randomized split‐mouth design, implants were placed in one side of the maxilla using a stereolithographic surgical guide for flapless surgery and immediately loaded on temporary abutments with a bridge (test). Implants in the other side were placed using the conventional protocol and loaded after 6 weeks of healing (control). Clinical and radiographic evaluation of peri‐implant tissues was performed at time of implant surgery, and after 1 week, 6 weeks, 3, 6, 12 and 18 months. Results: A total of 70 implants were placed (36 test and 34 control). One implant (test) was lost after 3 months, resulting in a survival rate of 97.3% for the test implants and 100% for the control implants. Marginal bone levels were not statistically significantly different between the test and control implants but at baseline the marginal bone level was significantly lower compared to the other evaluation periods (P < 0.05). The mean bone level for test and control implants was 1.95 mm ± 0.70 and 1.93 mm ±0.42 after 18 months, respectively. There was a significant change in height of the attached mucosa at implants placed with a conventional flap between post‐operative and 1 week and between 1 week and 6 weeks. Statistically significant differences were found between the test side and the control side for opinion about speech, function, aesthetics, self‐confidence and overall appreciation the first 6 weeks. Conclusion: Implants can successfully integrate in the posterior maxilla using a flapless approach with immediate loading similar to a conventional protocol. The mucosal tissues around implants placed with a conventional flap changed significantly compared with flapless placed implants. To cite this article:
Van de Velde T, Sennerby L, De Bruyn H. The clinical and radiographic outcome of implants placed in the posterior maxilla with a guided flapless approach and immediately restored with a provisional rehabilitation: a randomized clinical trial.
Clin. Oral Impl. Res. 21 , 2010; 1223–1233.
doi: 10.1111/j.1600‐0501.2009.01924.x     

Peri-implant bone organization under immediate loading conditions: collagen fiber orientation and mineral density analyses in the minipig model

Background: Mechanical properties of bones are greatly influenced by percentages of organic and mineral constituents. Nevertheless, information about mineralization level on a microscopic scale and collagen fiber organization in peri‐implant bone after immediate loading is scarce. Purpose: The aim of this work was to analyze and compare the degree of mineralization and collagen fiber orientation in alveolar bone (AB) and peri‐implant bone of immediately loaded (IL) and unloaded (NL) implants. Materials and Methods: A total of 25 dental implants of 3.8 mm in diameter and 11 mm in length were used in the present study. In five minipigs, three premolars and the first molar were removed from the left side of the mandible. Three months later, five implants for each animal were inserted. Four implants were loaded immediately with a fixed restoration, while one implant was left unloaded. After a 4‐month healing period, all implants were retrieved. Circularly polarized light and scanning electron microscope with backscattered electron imaging were used to analyze both peri‐implant and AB retrieved 5 mm from the implant. Results: The bone/implant contact ratio (BIC %) was 77.8 ± 5.9% for the IL implants and 78.0 ± 5.8% for the NL implants; the difference was not statistically significant (p = 0.554). In the peri‐implant bone, the area related to transverse collagen fibers was 112,453 ± 4,605 pixels for IL implants and 87,256 ± 2,428 pixels for NL implants. In the AB, the area related to transverse collagen fibers was 172,340 ± 3,892 pixels. The difference between groups was statistically significant (p < .001). The degree of mineralization of peri‐implant bone was 137 ± 19 gray level for IL implants and 115 ± 24 gray level for NL implants, while in the AB, the degree of mineralization was 125 ± 26 gray level. This difference was statistically significant (p < .001). Conclusion: In this study, it was found that IL and NL implants showed the same degree of osseointegration. The bone matrix around IL implants had a higher quantity of transverse collagen fibers and presented a higher level of mineralization.     

Long‐Term Results of Endosteal Implants Following Radical Oral Cancer Surgery with and without Adjuvant Radiation Therapy

Purpose: The aim of this study was to analyze the long‐term survival of implants and implant‐retained prostheses in patients after ablative surgery of oral cancer with or without adjunctive radiation therapy. Materials and Methods: Between 1997 and 2008, 66 patients who had undergone ablative tumor surgery in the oral cavity were treated with dental implants (n = 262). Thirty‐four patients received radiation therapy in daily fractions of 2 Gy administered on 18 to 30 days. Implants were inserted in the maxilla (49; 18.7%) or mandible (213; 81.3%), in non‐irradiated residual (65; 24.8%) or grafted bone (44; 16.8%) and in irradiated residual (15.6%) or grafted bone (39; 14.9%). Seventeen fixed protheses and 53 removable dentures (34 bar attachments, 9 telescopic and 10 ball retained dentures) were inserted. Results: Mean follow‐up after implant insertion was 47.99 (±34.31) months (range 12–140 months). The overall 1‐, 5‐, and 10‐year survival rates of all implants were 96.6%, 96.6%, and 86.9%, respectively. Fourteen implants were lost in nine patients (5.3% of all implants); eight implants were primary losses, and five secondary losses because of an operation of tumor recurrence. There was no significantly lower implant survival for implants inserted into irradiated bone (p = .302), bone and/or soft‐tissue grafts (p = .436), and maxilla or mandible (p = .563). All prosthetic restorations in patients without tumor recurrence could be maintained during the observation period. Conclusions: Implant survival is not significantly influenced by radiation therapy, grafts (bone and/or soft tissue), or location (maxilla or mandible). However, implants placed in irradiated bone exhibit a higher failure rate during the healing period than those placed in non‐irradiated bone. No superstructure was particularly favorable. Osseointegrated implants can be used successfully in patients with prior history of ablative surgery with and without additional radiation therapy.     

Transmucosal healing around peri‐implant defects: crestal and subcrestal implant placement in dogs

Objective: This study was designed to evaluate the transmucosal healing response of implants placed with the junction of the smooth surfaces, either crestal or subcrestal, into simulated extraction defects after healing periods of 1 and 3 months. Materials and methods: A total of 23 Straumann SP ?3.3 mm NN, SLA^® 10 mm implants were placed in the mandibular premolar regions of three greyhound dogs 3 months after the teeth were removed. Five control implants were placed at the crestal bone level, and test implants with surgically created peri‐implant defects of 1.25 mm wide × 5 mm depth were placed either at the crestal (nine implants) or at the 2 mm subcrestal (nine implants) bone level. Implants on the right side were placed 1 month before the dogs were sacrificed, and implants on the left side were placed 3 months before sacrifice. All dogs had daily plaque control following surgery and were sacrificed 3 months after implant placement for histological and histometric analyses. Results: Mesial–distal ground sections of the control and test implant specimens showed a greater %BIC in the coronal defect region after 3 months of healing. This healing response was incomplete for the test implants compared with the control implants after a 1‐month healing period. The histometric measurements for test implants placed at the crestal bone level or 2 mm subcrestal with surgically created peri‐implant defects were more coronal or closer to the implant margin compared with the control implants. Additionally, the degree of osseointegration between the newly formed bone and the implant surface was similar between the test implants. Conclusion: Peri‐implant defects of 1.25 mm width healed with spontaneous bone regeneration around implants placed transmucosally at crestal or 2 mm subcrestal with a high degree of osseointegration after a 3‐month healing period. To cite this article:
Tran BLT, Chen ST, Caiafa A, Davies HMS, Darby IB. Transmucosal healing around peri‐implant defects: crestal and subcrestal implant placement in dogs.
Clin. Oral Impl. Res. 21 , 2010; 794–803.
doi: 10.1111/j.1600‐0501.2010.01911.x     

Effect of Flapless Surgery on Single‐Tooth Implants in the Esthetic Zone: A Randomized Clinical Trial

Background: Implant therapy is a highly predictable treatment option; however, insufficient data exist to show whether flapless implant surgery provides better esthetic outcomes and less bone loss than implant surgery with a flap approach. Methods: In this randomized, controlled study comparing the flapless and traditional flap protocol for implant placement, 24 patients received a single implant in the anterior maxillary region. A cone beam computed tomography–aided surgical guide was used for implant placement surgery for both groups. Implants were restored using a one‐piece, screw‐retained ceramic crown at 3 months. Radiographic and clinical measurements were assessed at baseline (implant placement) and at 3 (crown placement), 6, 9, and 15 months. Clinical parameters evaluated were plaque index, gingival index, papillary index (PPI) (0 = no papilla, 1 = less than half, 2 = more than half but not complete, 3 = complete fill, and 4 = overfill), marginal tissue levels, biotype, width of keratinized tissue, and soft tissue thickness. Results: Implant success rate was 92% in both groups. Mean PPI values for the flap control group and flapless test group were 2.38 ± 0.51 versus 2.31 ± 0.48 at crown placement (P = 0.68) and 2.52 ± 0.52 versus 2.64 ± 0.54 at 15 months (P = 0.42), respectively. PPI increased over time in both groups, although the flapless group had a significantly larger change in PPI from crown placement to 6 and 9 months (P <0.01). Crestal bone levels in the flap group were more apical in relation to the implant platform than those in the flapless group for the duration of the study. No differences among groups were noted for all other measurements. Conclusions: Both flapless and flap implant placement protocols resulted in high success rates. A flapless protocol may provide a better short‐term esthetic result, although there appears to be no long‐term advantage.     

Stability, marginal bone loss and survival of standard and modified sand-blasted, acid-etched implants in bilateral edentulous spaces: a prospective 15-month evaluation

Objectives: Chemical modification of the already proven sand‐blasted and acid‐etched (SLA) implant had increased its surface wettability and consequent early‐term osseointegration characteristics. The aim of this clinical trial was to compare the stability changes, success, survival, peri‐implant parameters and marginal bone loss (MBL) of the early‐loaded standard (SLA) and modified sand‐blasted, acid‐etched (modSLA) implants. Material and methods: A total of 96 SLA and modSLA implants were placed in a bi‐lateral, cross‐arch position to the jaws of 22 patients. Resonance frequency analysis (RFA) was used to measure the implant stability in the surgery and following healing after 1, 3 and 6 weeks. At the stage of loading, a panoramic X‐ray was obtained and RFA measurement was repeated for all implants. Implants were restored by metal–ceramic crowns and followed for 1 year to determine the success, survival rate, peri‐implant parameters and MBL. Results were compared by one‐ and two‐way ANOVA, log‐rank test and generalized linear mixed models (P<0.05). Results: One modSLA implant was lost after 3 weeks following the surgery yielding to a 100 and 97.91% success rate for SLA and modSLA implants, respectively (P=0.323). At the loading stage, modSLA implants showed significantly lower MBL (0.18 ± 0.05 mm) than SLA implants (0.22 ± 0.06 mm; P=0.002). In the loading stage, RFA value of the modSLA implants (60.42 ± 6.82) was significantly higher than the both implant types in the surgical stage (55.46 ± 8.29 and 56.68 ± 8.19), and following 1 (56.08 ± 7.01 and 55.60 ± 9.07) and 3 weeks of healing (55.94 ± 5.95 and 55.40 ± 6.50 for SLA and modSLA implants, respectively). Conclusions: modSLA implants demonstrated a better stability and a reduced MBL at the loading stage. Both SLA and modSLA implants demonstrated a favorable success and survival at the end of 15‐month follow‐up. To cite this article :
Karabuda ZC, Abdel‐Haq J. Arιsan V. Stability, marginal bone loss and survival of standard and modified sand‐blasted, acid‐etched implants in bilateral edentulous spaces: a prospective 15‐month evaluation.
Clin. Oral Impl. Res. 22 , 2011; 840–849
doi: 10.1111/j.1600‐0501.2010.02065.x     

Comparison of implant stability by means of resonance frequency analysis for flapless and conventionally inserted implants

Background: Resonance frequency analysis (RFA) is a noninvasive technique for the quantitative assessment of implant stability. Information on the implant stability quotient (ISQ) of transmucosally inserted implants is limited. Purpose: The aim of this investigation was to compare the ISQ of conventionally inserted implants by raising a muco‐periostal flap with implants inserted using a flapless procedure. Materials and Methods: Forty elderly patients with complete edentulous maxilla were consecutively admitted for treatment with implant‐supported prostheses. A computer tomography was obtained for the computer‐assisted implant planning. One hundred ten implants were placed conventionally in 23 patients (flap‐group) and 85 implants in 17 patients by means of the flapless method (flapless‐group) using a stereolithographic template. RFA measurements were performed after implant placement (baseline) and after a healing time of 12 weeks (reentry). Results: All implants exhibited clinically and radiographically successful osseointegration. Bone level did not change significantly neither for genders nor type of surgical protocol. Mean ISQ values of the flapless‐group were significantly higher at baseline (p < .001) and at reentry (p < .001) compared with the flap‐group. The ISQ values were significantly lower at reentry compared with baseline for the flap‐group (p = .028) but not for the flapless‐group. This group showed a moderate, but insignificant increase. RFA measurements of males resulted in ISQ values that were thoroughly higher as compared with females at both time‐points in both groups. Correlation between RFA and bone level was not found. Conclusions: The flapless procedure showed favorable conditions with regard to implant stability and crestal bone level. Some changes of the ISQ values that represent primary (mechanical) and secondary (bone remodeling) implant stability were observed in slight favor of the flapless method and male patients. In properly planned and well‐selected cases, the minimal invasive transmucosal technique using a drill‐guide is a safe procedure.     

Maxillary Implants Loaded at 3 Months after Insertion: Results with Astra Tech Implants after up to 5 Years

Background: To date, clinical studies have mainly focused on early loading of mandibular implants. Recently, there has also been considerable interest in early loading of maxillary implants. Purpose: The purpose of this article is to report the outcome of maxillary implants loaded after a 3‐month healing period and followed up to 5 years. Materials and Methods: Seventeen patients (11 males and 6 females) received 44 Astra Tech implants (Molndal, Sweden) for treatment of single‐tooth (13 cases) and partial edentulism (9 cases). The patients were followed up to 5 years after implant placement:50% of the implants were followed for 3 years and 16% have been followed throughout the observation period. Preoperatively, bone height and width were assessed on radiographs. Marginal bone loss was recorded on intraoral radiographs annually. Results: No implant was lost during the observation period. The average marginal bone loss was 0.5 ± 0.7 mm after 1 year, 0.6 ± 0.7 mm after 3 years, and 0.9 ± 1.6 mm after 5 years. There were no soft‐tissue or prosthetic failures recorded during the observation period. Conclusion: Early loading of Astra Tech implants was highly successful in maxillary partial and single‐tooth cases followed up to 5 years in function.     

Stability and marginal bone level measurements of unsplinted implants used for mandibular overdentures: a 1-year randomized prospective clinical study comparing early and conventional loading protocols

Objectives: The aim of this study was to compare the performance of two non‐splinted implants used as retention for a mandibular overdenture when applying conventional or early loading protocols. Material and methods: Twenty edentulous patients were treated with two unsplinted and non‐submerged implants (15 mm long, TiUnite RP, Brånemark System) in the anterior mandible. The patients were randomly allotted into two groups: (i) test group (Group A), in which the overdenture was connected 1 week after surgery, and (ii) control group (Group B), in which the overdenture was connected after 12 weeks of healing. Resonance frequency analyses (RFA) for implant stability measurements were performed at implant surgery and after 1, 3, 6, 9 and 12 months. Marginal bone levels were evaluated at implant surgery and after 6 and 12 months. Results: No implant from either group was lost and all implants showed less than 1 mm of marginal bone resorption during the first year. The mean implant stability quotient (ISQ) values at implant surgery were 76.2±2.8 for Group A and 75.6±4.5 for Group B. The 12‐month measurements showed 76.4±2.5 ISQ and 76.4±2.8 ISQ for Groups A and B, respectively. There were no statistically significant changes between or within the groups with time. There were no differences in marginal bone loss, which was on average 0.3 mm for both groups after 1 year. Conclusion: Although a limited number of patients were followed for 1 year only, the results of the present study indicate that early loading of two unsplinted 15 mm long implants with an overdenture does not negatively affect implant stability or marginal bone conditions when compared with implants subjected to 12 weeks of healing before loading.     

Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects

Objective: This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite® with that around Nanotite^? implants. Materials and methods: The premolars on both sides of the mandible in four beagle dogs were extracted. Following 4 months healing, two Nanotite^? implants and two Osseotite® implants were partially inserted in the left side of each mandible. Some threads protruded from the tissues into the oral cavity. Following a 5 week healing period, the implants were removed and the contaminated part of each implant was cleaned. They were then installed to the full implant length on the contra lateral side of the mandibles. The coronal 5 mm of each implant was surrounded by 1 mm circumferential bone defect. Following 12 weeks of healing period, the dogs were sacrificed and biopsies were obtained. Ground sections were prepared for histomorphometric analysis. Results: All implants were associated with direct bone‐to‐implant contact on the portion of the implant surface contaminated previously and surrounded by bone defect. Nanotite^? implants performed better than Osseotite® implants. Conclusions: The results demonstrated that implant surfaces, which were contaminated previously and were surrounded by bone defects, can osseointegrate. To cite this article:
Mohamed S, Polyzois I, Renvert S, Claffey N. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects. Clin. Oral Impl. Res. 21 , 2010; 513–519.
doi: 10.1111/j.1600‐0501.2010.01913.x     

Comparative study of the osseointegration of dental implants after different bone augmentation techniques: vascularized femur flap, non-vascularized femur graft and mandibular bone graft

Objectives: The purpose of this study was to evaluate the osseointegration of the dental implants placed into the mandible augmented with different techniques in pigs. Material and methods: Four adult domestic pigs were used. Horizontal augmentation of the mandible was performed in animals by using vascularized femur flap (VFF), non‐vascularized femur graft (NVFG) and monocortical mandibular block graft (MG). After 5 months of healing 10 dental implants were placed into each augmented site. The pigs were sacrificed after 3 months of healing. Undecalcified sections were prepared for histomorphometric analysis. Results: Mean bone–implant contact (BIC) values for implants placed into MG, NVFG and VFF were 57.38 ± 11.97%, 76.5 ± 7.88%, 76.53 ± 8.15%, respectively. The BIC values of NVFG and VFF group were significantly greater than MG group (P<0.001). On the other hand, there was not statistically significant difference between NVFG group and VFF group (P=0.999). Conclusion: NVFG as well as VFF can be considered as a promising method for augmentation of alveolar defects and the placement of the implants. The selection of non‐vascularized graft or vascularized flap depends on the condition of the recipient site. To cite this article:
Benlidayi ME, Gaggl A, Bürger H, Brandner C, Kurkcu M, Ünlügenç H. Comparative study of the osseointegration of dental implants after different bone augmentation techniques: vascularized femur flap, non‐vascularized femur graft and mandibular bone graft.
Clin. Oral Impl. Res. 22 , 2011; 594–599
doi: 10.1111/j.1600‐0501.2010.02013.x     

Dimensional profile of oral mucosa around combined tooth-implant-supported bridgework in macaque mandible

Purpose: A stable oral mucosa is crucial for long‐term survival and biofunctionality of implants. Most of this evidence is derived from clinical and animal studies based solely on implant‐supported prosthesis. Much less is known about the dimensions and relationships of this soft tissue complex investing tooth‐implant‐supported bridgework (TISB). The aim here was to obtain experimental evidence on the dimensional characteristics of oral mucosa around TISB with two different abutment designs. Methods: Sixteen 3‐unit TISB were constructed bilaterally in the mandible of eight adult Macaca fascicularis. An implant system with a standard progressive thread design was the bone‐anchoring implant in the second mandibular molar region while the second mandibular premolar served as the natural tooth abutment. Eight implants were connected with the tapered abutment, the remaining with butt‐joint abutment, in a split‐mouth design. These were allowed to functional load for 6 months before sacrification for histomorphometry. Six soft tissue indices were scored: coronal gingival mucosa‐to‐implant top distance (DIM); sulcus depth (SD); junctional epithelium (JE); connective tissue contact (CTC); implant top to first bone‐to‐implant contact distance (DIB); and biologic width (BW=SD+JE+CTC); corresponding parameters in the natural tooth abutment were also measured. Results: Mucosal dimensions in tapered implants (^*BW=3.33±0.43; SD=1.03±0.24; JE=1.08±0.13; CTC=1.22±0.23 mm) were comparable with those of natural tooth abutments (BW=3.04±0.18; SD=0.93±0.1; JE=0.78±0.1; Attachment=1.33±0.09 mm), but differed from butt‐joint implants (^*BW=4.88±1.24; SD=1.47±0.38; JE=1.49±0.4; CTC=1.92±0.93 mm) (^*P<0.05). Conclusions: Results suggested that soft tissue dimensions around TISB are influenced by the implant–abutment interface and abutment material used. Mucosa investing tapered abutment tends to recapitulate soft tissue physiologic dimensions of natural tooth. To cite this article:
Siar CH, Toh CG, Ali TBT, Seiz D, Ong ST. Dimensional profile of oral mucosa around combined tooth‐implant‐supported bridgework in macaque mandible.
Clin. Oral Impl. Res. 23 , 2012 438–446.
doi: 10.1111/j.1600‐0501.2010.02145.x