Bone formation over a TiAl6V4(IMZ) implant placed into an extraction socket in association with membrane therapy (Gengiflex)

Complete restoration of an osseous defect around a TiAl₆V₄(IMZ) implant is accomplished by the combined use of an implant placed in the alveolus of a fractured lower bicuspid and the principles of guided tissue regeneration. Gengiflex (Gengiflex ‐ BioFill ‐ Productos Biotecnologices, Curitiba, PR, Brazil), a new membrane, was used to cover the implant and porous hydroxyapatite was used as grafting material. The filling of the osseous defect that also covered the implant was verified clinically at re‐entry 6 months later. Histological analysis of the mineralized tissue collected during exposure of the implant confirmed bone formation.     

Complications of computer-aided-design/computer-aided-machining-guided (NobelGuide) surgical implant placement: an evaluation of early clinical results

Purpose: The aim of this study was to evaluate early clinical results of computer-aided design (CAD)/computer-aided machining (CAM)-guided surgical implant placement (NobelGuide™, Nobel Biocare, Yorba Linda, CA, USA) with focus on surgical and/or prosthetic complications, management, and prevention.
Materials and Methods: Thirteen patients rehabilitated between March 2003 and October 2006 with CAD/CAM-guided dental implants and immediate loading (NobelGuide, Nobel Biocare) were evaluated. The treatment planning and procedures were carried out in accordance to the system protocol. The complications encountered in this case series were classified and assessed according to early (planning and procedural – surgical; prosthetic) and late complications (surgical; prosthetic).
Results: The prosthetic complications outnumbered surgical complications both in the early and late treatment phases. The main early surgical complication was bony interference that prevented complete seating of the prostheses. Most of the late surgical complications were implant failures with an overall failure rate of 9%. Fracture of the carbon fiber framework prosthesis was the main late prosthetic complication.
Conclusions: The NobelGuide system is a reliable treatment modality, but not without its complications. Strict adherence to the system protocol is the key prevention of complications.     

浓缩生长因子在口腔种植中的临床应用

目的总结骨量不足种植患者中,浓缩生长因子(concentrate growth factors,CGF)促进骨组织再生和修复的临床效果。方法我科自2012年7月—2014年10月期间,在骨量不足患者中,例如前牙唇侧凹陷、即刻种植、上颌后牙区垂直高度不足患者行上颌窦外提升、上颌窦内提升(包括嵌入式上颌窦内提升术),采用CGF技术共76例,年龄在17~63岁,男45例,女31例。本研究将需增加骨量采用引导骨组织再生术(guided bone regeneration,GBR)患者分为单独使用CGF组、CGF与自体骨或骨代材料混合组。对患者术后1周、1个月、3个月、6个月、1年定期复查,术后第2年后每隔半年复查一次。重点检查创口愈合情况、牙龈牙周情况、种植体松动度及患者对美观、咀嚼功能的评价,并使用数字化化牙片、口腔锥形束CT(CBCT)观察骨组织再生和修复情况。术后随访平均时间22个月(6~34个月)。结果 76例应用CGF技术引导骨组织再生病例术后反应轻,除混合组1例创口裂开、6周种植体脱落外,其他患者均创口愈合良好,CBCT复查显示种植区骨整合良好。成功率98.68%。结论 CGF能促进创口愈合、新骨形成和种植体骨结合的能力,并缩短了这一过程所需的时间。临床使用安全简单且费用低廉,值得推荐。     

Treatment of an early implant failure according to the principles of guided tissue regeneration (GTR)

The present case report demonstrates the application of guided tissue regeneration (GTR) in combination with antimicrobial therapy for the treatment of an early implant failure. This treatment approach both prevented further loss of bone as well as led to the regeneration of lost bone. By means of color-converted digital subtraction images, remodelling of the tissues adjacent to the defect was documented as early as one month postsurgically. The images demonstrated "bone-fill" in the apical portion of the defect and resorptive changes at the bone crest. This case report demonstrates that combined regenerative and antimicrobial therapy may be a successful treatment approach restoring osseointegration of dental implants following loss of bone due to infection. Continuously increasing bone-fill inside the defect was documented when comparing the radiograph obtained immediately before the GTR procedure and at months 1, 2, 4, 5 and 6 of the healing period, respectively. Clinical measurement obtained at the time of the surgery and at the time of the membrane removal confirmed the radiographic evidence of bone-fill by demonstrating new tissue resistant to probing in close contact to the implant surface at the site of the previous defect. Antimicrobial therapy included an antibiotic regimen during the 1st month of healing as well as topical rinses with an antiseptic (chlorhexidine) over the entire healing period of 6 months. As a result of this treatment approach, the implant was saved and could be used as an abutment for a bridge reconstruction.     

Biofunctionalization of titanium implants with a biomimetic active peptide (P‐15) promotes early osseointegration

Objectives: The early stages of peri‐implant bone formation play an essential role in the osseointegration and long‐term success of dental implants. By incorporating bioactive coatings, this biofunctionalization of implant surfaces may enhance the attachment of the implant to the surrounding bone and stimulate bone regeneration. Material and methods: To demonstrate faster osseointegration, the surfaces of dental implants were grit‐blasted and acid‐etched. They were then coated with hydroxyapatite (HA) and experimental implants were further coated with a biomimetic active peptide (P‐15) in one of two concentrations. These biofunctionalized samples and controls with no peptide were placed in the forehead region of 12 adult pigs. Six animals were evaluated for a period of 14 or 30 days. Results: Histomorphometric analysis demonstrated that the implants with the high concentration of P‐15 had significantly higher percentage of bone‐to‐implant contact (BIC) at 14 (P=0.018) and 30 (P=0.015) days compared with the other groups. Both concentrations of P‐15 showed increased peri‐implant bone density compared to the control group at 30 days. Conclusion: Biofunctionalization of the implant surface with a biomimetic active peptide leads to significantly increased BIC rates at 14 and 30 days and higher peri‐implant bone density at 30 days. To cite this article:
Lutz R, Srour S, Nonhoff J, Weisel T, Damien CJ, Schlegel KA. Biofunctionalization of titanium implants with a biomimetic active peptide (P‐15) promotes early osseointegration.
Clin. Oral Impl. Res. 21 , 2010; 726–734.
doi: 10.1111/j.1600‐0501.2009.01904.x     

Dental implants as risk factors for patients with medication-related osteonecrosis of the jaws (MRONJ)

An increasing number of patients with medication-related osteonecrosis of the jaws (MRONJ) has recently been reported. It is still being debated whether the presence or placement of dental implants can lead to MRONJ, so the aim of this study was to find out whether dental implants are a risk factor for MRONJ. From January 2003-January 2019 180 patients with MRONJ were seen at the Leiden University Medical Center. Luxating moments for the onset of MRONJ were calculated retrospectively. We collected clinical data and details of antiresorptive medication and found 22 patients with both dental implants and MRONJ. In 18 patients the implants were in the region of the MRONJ and they were included in this study, 14 who had had implants before using antiresorptive drugs and four who had had antiresorptive drugs before or at the time that the implants were placed. The median times between the placement of implants and the diagnosis of MRONJ in these two groups were 24 months and 6 months, respectively. Among the 47 implants, 30 were located in the necrotic region, and all 30 were either lost spontaneously or had to be removed during treatment of MRONJ. Our results show an increased risk for developing MRONJ in patients with dental implants. Both peri-implantitis around previously placed implants, and insertion of dental implants, are risk factors. Prevention of peri-implantitis and caution when inserting dental implants in patients who take antiresorptive medication are therefore important.     

Sinus floor augmentation using large (1-2 mm) or small (0.25-1 mm) bovine bone mineral particles: a prospective, intra-individual controlled clinical, micro-computerized tomography and histomorphometric study

Objectives: To compare the amount of newly formed bone after sinus floor augmentation with two different particle sizes of bovine bone mineral (BBM) using clinical, micro‐computerized tomography (CT) and histological techniques. Methods: Bilateral sinus floor augmentations were performed in 10 patients. Six to 9 months later, bone samples were retrieved and analyzed. Results: Results: Both groups were not different in vertical bone height achieved after augmentation, post‐operative complications and maximal torque for the insertion of implants. Micro‐CT measurements could not detect a statistically significant difference in bone volume between the groups (with a tendency for new more bone in the small granules group). Histomorphometric analysis revealed that both granule sizes produced the same pattern of bone formation, surrounding the graft granules, and producing a shape of a network, “bridging” between the BBM particles. Multi‐nucleated giant cells, probably osteoclasts, were observed directly on the BBM particle surface in both groups. The osteoclast‐like cells preferred the small‐size BBM particles and not the large particles both in the small‐size and the large‐size granules group. Conclusion: Both sizes of BBM granules preformed equally and achieved the aim of the sinus floor augmentation procedure clinically and histologically. To cite this article:
Chackartchi T, Iezzi G, Goldstein M, Klinger A, Soskolne A, Piattelli A, Shapira L. Sinus floor augmentation using large (1–2 mm) or small (0.25–1 mm) bovine bone mineral particles: a prospective, intra‐individual controlled clinical, micro‐computerized tomography and histomorphometric study.
Clin. Oral Impl. Res 22 , 2011; 473–480
doi: 10.1111/j.1600‐0501.2010.02032.x     

The effect of splinting on tooth mobility (2) After osseous surgery

The purpose of this study was to determine if fixed splinting of teeth with intraoral wire and acrylic splints had advantages with respect to tooth mobility, bone level and attachment level over unsplinted teeth following osseous surgery. Ten patients were chosen who exhibited bilaterally similar chronic destructive periodontitis and mobile teeth. One maxillary sextant was splinted, while the other was unsplinted. Both sextants functioned against an unsplinted mandibular arch. Following initial therapy, osseous surgery was performed in both maxillary sextants on the same day. Tooth mobility data was collected 1 week before and at 3, 6, 12, and 24 weeks following surgery. Levels of gingival attachment and bone were recorded before and 24 weeks after surgery. Splints were removed before measurements, then replaced, and the occlusion refined. Prophylaxes and oral hygiene instruction were repeated every 3 weeks throughout the study. For all categories of teeth and mobility examined, tooth mobility increased initially after surgery and subsequently decreased by 24 weeks to about presurgical values. The splinted and unsplinted segments reacted similarly throughout the study; splinting did not significantly reduce the mobility of individual teeth. Pre- and postsurgical bone and gingival attachment levels were also similar for the splinted and unsplinted segments.     

Analysis of the association of IL1B (C+3954T) and IL1RN (intron 2) polymorphisms with dental implant loss in a Brazilian population

Background: Although dental implants have a high success rate, failures occur, in spite of adequate clinical conditions. Together with the observation that multiple implant losses occur in certain groups of individuals (clusterization phenomenon), this suggests that host response may influence implant failure. Little is known about the influence of genetic susceptibility on implant loss. Interleukin (IL)-1β and IL-1ra are believed to play a key role in the immune-inflammatory response, and polymorphisms IL1B (C+3954T) and IL1RN (intron 2) are shown to alter the coding proteins expression.
Objectives: The aim of this study was to investigate the association between dental implant loss and polymorphisms IL1B (+3954) and IL1RN (intron 2).
Material and methods: The study population ( n =266) was divided into Test group (T) – 90 subjects with implant loss, and Control group (C) – 176 subjects without any implant failure. Genotyping was performed by PCR-RFLP.
Results: The number of present teeth was observed to influence implant loss. No differences in genotype and allele frequencies between C and T were found for IL1B (+3954) and IL1RN (intron 2) polymorphisms. However, the analysis of the whole study population (control and test groups) showed that genotype 2/2 was significantly more frequent in individuals with multiple implant losses ( n =35) than in individuals that lost up to a single implant ( n =231) (OR: 3.07, IC: 1.13–8.34, P =0.027).
Conclusion: It was observed that number of teeth and edentulism were associated with implant loss. Genotype 2/2 of IL1RN polymorphism was significantly more frequent in patients who presented multiple losses, which suggests that the clusterization phenomenon has a genetic basis.     

Controlled local application of basic fibroblast growth factor (FGF-2) accelerates the healing of GBR. An experimental study in beagle dogs

This animal study was performed to ascertain whether the regeneration of membrane-protected bone defects can be accelerated by the controlled application of basic fibroblast growth factor (FGF-2) using a new drug delivery system. Standardized alveolar bone defects were made surgically in 9 beagle dogs, and FGF-2 was administered using specially made collagen minipellets. A minipellet containing either 0.15 microgram FGF-2 (FGF) or 0 microgram FGF-2 (placebo) was placed in the defect or no minipellet was used (control), and bone regeneration was evaluated radiologically, histologically, and histometrically 8 weeks after the operation. Radiographs showed a surprisingly large radiopaque region in FGF sites compared with placebo or control sites. Histologically, mature bone filled the majority of the inner space of the membrane-protected defect in FGF sites. New bone formation was also seen in the control and the placebo sites, however, it filled less than half the area of the defect. Histometrically, the area of regenerated bone in FGF sites was significantly higher than in the other sites (P < 0.01). These results demonstrate that the controlled application of FGF-2 accelerates bone regeneration in membrane-protected bone defects in the canine model.     

Enhanced osteoconductivity of micro-structured titanium implants (XiVE S CELLplus™) by addition of surface calcium chemistry: a histomorphometric study in the rabbit femur

Objectives: This study evaluated the osseointegration in rabbit cancellous bone of titanium (Ti) implants with a micro-topographically complex surface structure produced by grit-blasting/acid-etching with or without the addition of surface calcium ion (Ca) chemistry.
Material and methods: Micro-structured Ti implants (XiVE S CELLplus^™ screw implant, Dentsply Friadent GmbH) were hydrothermally treated in an alkaline Ca-containing solution to produce a nano-structured Ca-incorporated oxide surface layer. The surface characteristics were evaluated by scanning electron microscopy and stylus profilometry before and after Ca surface treatment. Twenty implants (10 control and 10 experimental) were placed in the femoral condyles of 10 New Zealand White rabbits. Histomorphometric analysis was performed 6 weeks after implantation.
Results: Ca-incorporated and untreated control implants showed similar surface morphologies and surface roughness values at the micron scale. Untreated micro-structured Ti implants achieved a high degree of bone-to-implant contact (BIC), and Ca incorporation further increased BIC% ( P <0.05). Active new bone apposition was found on surfaces of Ca-incorporated implants in areas of loose trabeculae.
Conclusion: The nano-structured Ca-incorporated oxide surface significantly enhanced osteoconductivity of micro-structured Ti implants in rabbit cancellous bone. Results indicate that this surface produced by simple hydrothermal treatment may be effective in improving the osseointegration of implants with micro-topographically complex surface structures in areas of loose cancellous bone.