Immediate functional loading of single-tooth TiO2 grit-blasted implant restoration. A controlled prospective study in a porcine model. Part II: Histology and histomorphometry

Background: Evidently, there is a fast‐moving shift from delayed to immediate implant loading. The hypothesis to be tested was that bone reactions adjacent to single TiO₂‐microthreaded implants exposed to immediate masticatory loading for 10 weeks after placement would modulate osseointegration. Materials and Methods: Cylindrical‐ and tapered‐designed implants (Astra Tech AB, Mölndal, Sweden) replaced first and third mandibular premolars respectively in 12 pigs. The animals were allocated into two groups based on soft and hard diet feeding. Each animal received, at random positions, four different masticatory loading conditions: implant with either (1) a cover screw only, (2) a healing abutment, (3) an implant with a crown without occlusal contact, or (4) an implant with a crown in contact with the antagonistic teeth. Results: Histomorphometry showed that there were no statistically significant differences in bone‐implant contact (BIC), bone mass inside/outside of the threads and soft tissue ingrowth ratio for all the implants at 10 weeks after placement irrespective of masticatory loading condition. Bone loss showed a trend of progressive increase for implants with a healing abutment toward implants with occlusal contact. Conclusions: The results of this study rejected the hypothesis and could be explained by the fact that grit‐blasted acid‐etched implants were already placed in dense bone.     

临时种植体即刻负载在半颌即刻种植中的应用

目的：评价临时种植体即刻负载在半颌即刻种植中的应用效果。方法：20例半颌即刻种植患者行136枚即刻种植体植入,采用95枚临时种植体即刻负载恢复患者牙列。3-6月后行固定修复。结果：即刻负载临时种植体和即刻种植体成功率达100%。结论：临时种植体即刻负载半颌即刻种植是很好的临床方法。     

Critical review of immediate implant loading

BACKGROUND: Implant dentistry has become successful with the discovery of the biological properties of titanium. In the original protocol, studies have advocated a 2-stage surgical protocol for load-free and submerged healing to ensure predictable osseointegration. However, the discomfort, inconvenience, and anxiety associated with waiting period remains a challenge to both patients and clinicians. Hence, loading implant right after placement was attempted and has gained popularity among clinicians. Issues/questions related to this approach remain unanswered. Therefore, it is the purpose of this review article to (1). review and analyze critically the current available literature in the field of immediate implant loading and (2). discuss, based on scientific evidence, factors that may influence this treatment modality. MATERIAL AND METHODS: Literature published over the past 20 years was selected and reviewed. Findings from these studies were discussed and summarized in the tables. The advantages and disadvantages associated with immediate implant loading were analyzed. Factors that may influence the success of immediate implant loading, including patient selection, type of bone quality, required implant length, micro- and macrostructure of the implant, surgical skill, need for achieving primary stability/control of occlusal force, and prosthesis guidelines, were thoroughly reviewed and discussed. RESULTS AND CONCLUSION: Various studies have demonstrated the feasibility and predictability of this technique. However, most of these articles are based on retrospective data or uncontrolled cases. Randomized, prospective, parallel-armed longitudinal human trials are primarily based on short-term results and long-term follow-ups are still scarce in this field. Nonetheless, from available literature, it may be concluded that anatomic locations, implant designs, and restricted prosthetic guidelines are key to ensure successful outcomes. Future studies, preferably randomized, prospective longitudinal studies, are certainly needed before this approach can be widely used.     

Immediate functional loading of implants in single tooth replacement: a prospective clinical multicenter study

Objectives: The aim of the present study was to evaluate the outcome of immediate functional loading of implants in single-tooth replacement using two different installation procedures.
Material and Methods: One hundred and fifty-one subjects, who required single-tooth rehabilitation in the area of 15–25 and 35–45, were enrolled in eight private clinics in Italy. The implant sites were randomly allocated to one of the following treatment groups. In the control group, in which a standard preparation procedure for implant placement and submerged healing of the implant was used, abutment connection and loading of the implants were performed 3 months after installation. In the test group 1, a standard preparation procedure for the implant placement and immediate functional loading of implant was carried out. In the test 2 group, however, a modified implant installation procedure (osteotome technique) was used followed by immediate functional loading of the implant. Clinical and radiographic examinations were performed at 3 and 12 months of follow-up at all sites.
Results: Three implants (5.5%) from the test 2 group (osteotome preparation) and one (2%) from the test 1 group (conventional drill preparation) failed to integrate and were removed one and three months after implant installation. The mean marginal bone loss assessed at 12 months was 0.31 mm (test 1), 0.25 mm (test 2) and 0.38 mm (control) (no statistically significant differences were found between the three treatment groups.)
Conclusion: It is suggested that immediate functional loading of implants that are placed with a conventional installation technique and with sufficient primary stability may be considered as a valid treatment alternative in a single-tooth replacement.     

Immediate loading of single-tooth implants in the anterior maxilla. Preliminary results after one year

According to the standard protocol, a load-free healing period is one of the most emphasized requirements for implant integration. Recent studies have encouraged a progressive shortening of the healing period for single-tooth implants and immediate loading has been proposed for the aesthetic zone in the maxilla. The present study evaluated clinical outcomes of immediately loaded FRIALIT-2 Synchro implants 12 months after placement in the maxillary incisal region. In the course of our investigation, nine patients have been treated following an immediate loading protocol. The stepped-screw type implants were inserted with an increasing torque up to 45 Ncm, thus measuring the primary stability of the implants. All implants were immediately restored with unsplinted acrylic resin provisional crowns and the patients provided with occlusal splints. Regular controls were performed at monthly intervals, intraoral radiographs were taken directly after implant placement, 6 and 12 months post insertion. The survival rate, clinical stability (Periotest) and radiographic coronal bone defects (CBD) were evaluated at delivery of the definitive superstructures (CBD 6) and 6 months later (CBD 12). Twelve FRIALIT-2 Synchro stepped screws of 3.8, 4.5 and 5.5 mm diameter and 13 and 15 mm length were placed in the incisal maxillary region. The median Periotest value 6 months post insertion was -2 with a minimum of -5 and a maximum of +2. The mean coronal bone level changes (CBD) at 6 and 12 months were 0.45 and 0.75 mm. No implant failed up to 12 months after insertion, resulting in a 100% survival rate. The presented results showed promising data for immediately loaded single-tooth implants in the anterior maxilla. Periotest values were within the range published for submerged implants. The radiographic coronal bone resorption after 6 and 12 months was even less than evaluated for implants placed in a standard two-stage procedure. It is evident that successful immediate loading protocols require a careful and strict patient selection aimed at achieving the best primary stability and avoiding any excessive functional or non-functional loading. Additional research needs to be done to provide data in situations where problems of poor bone quality, multiple implants or augmentation procedures must be overcome.     

Immediate loading of two implants supporting a ball attachment-retained mandibular overdenture: a prospective clinical study

Background: A prospective clinical study was conducted to evaluate clinically and radiographically the performance of two implants immediately loaded supporting a ball attachment‐retained mandibular overdenture. Materials and Methods: Seventeen completely edentulous patients were included in the study. Each patient received two implants inserted after a minimal flap reflection and no vestibular extension in order to reduce the postoperative swelling and facilitate immediate prosthesis connection. After implant placement, a mandibular complete denture was connected to the implants using ball attachments of appropriate height according to the depth of the peri‐implant tissue. Patients were asked not to remove the denture for 1 week. No limitations to chewing function were given. At implant placement, the maximum value of insertion torque was recorded. Patients were examined at 1, 2, 4, 12, and 52 weeks postsurgery. At postoperative visit, occlusion was checked and the need for any prosthesis maintenance was recorded. The radiographic bone level (RBL) change was measured on periapical radiographs at baseline and 12 months after loading. Results: After 12 months of loading, no implant failure was reported and the survival rate was 100%. Average RBL change was 0.7 mm ± 0.5 mm. Of the 17 cases, two had major prosthetic complications and five patients required minor extra maintenance appointments. Conclusions: The immediate loading of two implants by means of ball attachment‐retained mandibular complete denture may be a predictable treatment option. This clinical approach offers increased stability and comfort, while keeping a high implant success rate.     

Immediate loading of single-tooth ITI implants in the anterior maxilla: a prospective 5-year pilot study

The aim of the present study was to evaluate the success rate of immediately loaded single-tooth ITI solid plasma-sprayed (TPS) implants in the maxilla. Eight implants were loaded immediately after placement in eight different patients, and were followed for five years. Temporary acrylic resin restorations, which were fabricated from impressions that were taken immediately after implant placement, were connected one week later. These temporary restorations were adjusted in order to avoid any direct occlusive contacts. After six months, the provisional crowns were replaced by definitive ceramic crowns. Regular follow-ups were performed during the investigation period. No implants were lost, and the mean marginal bone level for the eight implants increased by 0.53 mm (range - 0.83 to + 1.54 mm) from placement to the final examination. Only minor complications were noted, and overall patient satisfaction was high.     

Immediate loading of mandibular overdentures supported by unsplinted direct laser metal-forming implants: results from a 1-year prospective study

Background: At present, only some studies have dealt with immediate loading of unsplinted implants supporting mandibular overdentures. The aim of this prospective study is to evaluate treatment outcomes of mandibular overdentures supported by four one‐piece, unsplinted, immediately loaded, direct laser metal‐forming (DLMF) implants by assessing implant survival rate, implant success, marginal bone loss, and prosthetic complications. Methods: A total of 96 one‐piece DLMF implants were inserted in the edentulous mandible of 24 patients. Four implants were placed in each edentulous mandible. Immediately after implant placement, a mandibular overdenture was connected to the implants. At 1‐year follow‐up, clinical, radiographic, and prosthetic parameters were assessed. Success criteria included absence of pain, suppuration, and implant mobility; absence of continuous peri‐implant radiolucency; and distance between the implant shoulder and the first visible bone contact <1.5 mm. Results: After a 1‐year loading time, the overall implant survival rate was 98.9%, with only one implant lost. Among the surviving 95 implants, two did not fulfill the success criteria; therefore, the implant success rate was 97.8%. The mean distance between the implant shoulder and the first visible bone contact was 0.28 ± 0.30 mm (95% confidence interval, 0.24 to 0.32). Some prosthetic complications were reported. Conclusion: Based on the present results and within the limits of this study, the immediate loading of four unsplinted DLMF implants by means of ball attachment–supported mandibular overdentures seems to represent a safe and successful procedure.     

全口即刻负重种植固定义齿2例

对2例全口多数牙缺失、残留少量重度牙周炎患牙的患者拔除全口余牙,即刻于上下颌分别植入10颗和8颗Straumann种植体,36颗种植体经共振频率分析,种植体稳定指数（ISQ）值大于60的34颗种植体即刻接入临时基台行复合树脂临时固定桥修复,3个月左右种植体形成骨整合后完成永久性修复。修复后追踪18～26个月,无1颗种植体失败,平均累积骨丧失为0.41 mm。     

Immediate functional loading of TiOblast dental implants in full-arch edentulous mandibles: a 3-year prospective study

Introduction: Implant-prosthetic rehabilitation of the completely edentulous mandible has evolved to a simplified procedure with shorter treatment time and survival rates of 95–100% depending on the implant system used.
Purpose: The aim was to evaluate the 3-year clinical success of Astra Tech TiOblast implants, functionally loaded on the day of surgery with a fixed full-arch bridge in the mandible.
Materials and methods: One hundred and twenty-five implants of 3.5–4 mm width and 11–17 mm length were installed in 25 edentulous mandibles of 15 female and 10 male patients. Implants were functionally loaded on the day of surgery with a provisional, acrylic, glassfibre reinforced, 10 unit bridge. After 3–4 months, the final 12-unit bridge was constructed. Radiographical bone loss was measured on peri-apical radiographs after 3, 12, 24 and 36 months.
Results: All implants were functional during the whole study period yielding a survival rate of 100%. None of the fixtures showed pain or mobility after manual torque with 20 N cm at the 3-month control. Mean radiographical bone loss after 3 months and 1, 2 and 3 years was 0.6 mm (SD 0.7), 0.8 mm (SD 0.8), 1 mm (SD 0.8) and 1.3 (SD 1) respectively, which was statistically significantly increasing up to 1 year.
Conclusion: Immediate loading of full-arch mandibular bridgework on five TiOblast implants offers a long-lasting clinical result with 100% fixture survival and stable bone-to-implant contact up to 3 years.     

Immediate loading after implant placement following tooth extraction up-regulates cellular activity in the dog mandible

Objectives: The aim of this study was to investigate cellular activity of the cervical portion of peri‐implant tissue due to immediate loading after implant placement following tooth extraction from the dog mandible, in terms of morphological, immunohistochemical and molecular characteristics. Material and methods: A sand‐blasted implant was inserted into the root septum bone of each extraction socket and was connected to a superstructure made from resin and then covered with an expanded polytetrafluoroethylene membrane. Implants without the superstructure were used as the non‐loading control group. Animals were sacrificed 1–3 weeks later and specimens were observed using light microscopy and mRNA levels were analyzed by real‐time polymerase chain reaction. Results: The new bone formation ratio in the loading group at 3 weeks was significantly higher than in the non‐loading group. Alkaline phosphatase (ALP)‐positive cells were observed in tissues around the implant surface in both groups at each of the time periods. More osteocalcin (OCN)‐positive cells were observed in the non‐loading group than in the loading group at 2 weeks. The expression of ALP mRNA in the loading group was significantly up‐regulated compared with the non‐loading group (P<0.05). The expression of OCN mRNA in the loading group was significantly up‐regulated compared with the non‐loading group at 2 weeks (P<0.05). Conclusion: These results suggest that immediate loading after implant placement following tooth extraction osteogenic affects cellular activity of cervical portion of peri‐implant tissue. To cite this article:
Sato R, Matsuzaka K, Kokubu E, Inoue T. Immediate loading after implant placement following tooth extraction up‐regulates cellular activity in the dog mandible.
Clin. Oral Impl. Res. xx , 2011; 000–000.
doi: 10.1111/j.1600‐0501.2010.02118.x     

Indications for immediate loading of implants and implant success

Abstract: It was the aim of this review to compare the survival and success rates of immediately loaded dental implants with those of conventionally loaded dental implants, based on prospective controlled studies and prospective studies without controls. Studies on immediate loading were identified in the current literature by electronic and hand searches. Only clinical data on root-form or cylindrical threaded oral implants were included. For immediate loading of oral implants in the edentulous and partially dentate, mandible and maxilla controlled studies could be found. All of these studies were based on limited patient numbers. Therefore, definitive conclusions could not be drawn concerning survival and success rates of immediately loaded implants compared with conventionally loaded implants. The compilation of the current literature shows that prospective controlled studies as well as prospective studies without controls using several different approaches to immediate loading have demonstrated high implant survival and success rates. However, more high-level evidence-based studies are needed to demonstrate the relative merits of immediate loading compared with conventional loading in all potential applications.     

Evaluation of single-tooth restorations on ITI dental implants. A prospective study of 29 patients

From January 1992 to March 1997, a total of 30 ITI hollow cylinder implants were installed to replace lost single maxillary incisor teeth. Conical abutments with cemented all-ceramic crowns were used in 10 cases and the Octa-abutment with screw-retained metallo-ceramic crowns in 19 cases. One implant failed due to postoperative infection, and was extracted a month after installation. After a mean observation time of 3.4 years, the cumulative success rate is 96.7%. Only minor bone loss has occurred around the implants, and there have been no other complications to date. The implant system fulfills the requirements for good function and esthetics.     

Immediate and delayed loading of fixed dental prostheses supported by single or two splinted implants: A histomorphometric study in dogs

To evaluate presumptive differences in osseointegration at implants supporting crowns that are physiologically loaded either immediately or 3 months after installation. All premolars and first molars were extracted bilaterally in six dogs. After 3 months of healing, three implants were installed on the premolar region and two in the molar region in one side of the mandible. Likewise, after another 3 months, five implants were installed in the contralateral side, and impressions were taken bilaterally. Within 48 hours, two single crowns were screwed bilaterally onto two implants in the premolar region, and two splinted crowns reproducing the shape of the first molar were screwed bilaterally onto the implants in the molar region. The mesial implants were used as no‐loaded controls. Sacrifices were performed after 3 months, and histological analyses were performed. At the premolar sites, mineralised bone‐to‐implant contact (MBIC%) was 78.0 ± 4.0% and 70.9 ± 7.9% at the delayed and immediately loaded sites, respectively. This difference was statistically significant. At the control implants, MBIC% was 61.4 ± 14.7% and 63.1 ± 13.1% at the delayed and the immediately loaded sites, respectively. At the molar sites, MBIC% was 79.2 ± 10.9% and 61.1 ± 10.3% at the delayed and immediately loaded sites, respectively. Applying a delayed loading to fixed dental prostheses supported by single or two splinted implants yielded higher proportions of bone‐to‐implant contact (osseointegration) compared to immediately loaded implants. Moreover, both types of loading protocols yielded a higher rate of osseointegration compared to unloaded implant sites after 3 months following implant installation.     

Immediate loading of implants in the edentulous maxilla: use of an interim fixed prosthesis followed by a permanent fixed prosthesis: a 32-month prospective radiological and clinical study

Purpose: The aim of this study was to prospectively evaluate the survival rate of splinted and immediately loaded Straumann sandblasted, large-grit, acid-etched, solid-screw dental implants in the edentulous maxilla after 32 months of loading.
Materials and Methods: Twenty-eight patients (mean age 63 years) with edentulous maxillae received 168 implants (six each) and an implant-supported fixed interim prosthesis within 24 hours after surgery. After a mean healing time of 15 weeks, the patients received permanent screw-retained prostheses. Clinical and radiological examinations were made at implant placement and after 8, 20, and 32 months of loading. All permanent prostheses were removed at the 32-month follow-up; implant stability was checked with a torque device, and the implant stability quotient was determined with resonance frequency analysis.
Results: Mean marginal bone loss from baseline to 8 months after loading was 1.6 mm (SD 1.16; p  = .094), from 8 to 20 months 0.41 mm (SD 0.63; p  = .094), and from 20 to 32 months 0.08 mm (SD 0.49; p  = .039). The 32-month cumulative survival rate was 98.2%.
Conclusions: The 32-month survival of solid-screw implants – immediately loaded within 24 hours after placement – was similar to survival rates reported for solid-screw implants with conventional loading. Immediate loading and splinting of implants in the edentulous maxilla is a viable treatment alternative.     

牙周炎患者种植修复即刻负荷的临床应用及体会

目的:探讨牙周炎患者种植修复时采取即刻负荷的临床效果。方法:牙周炎患者6例,完善的牙周治疗后在下颌颏孔间植入四枚种植体,于术后48小时内用SynCone基台即刻负荷过渡义齿,并定期复诊检查。结果:术后随访12～40个月,植体无松动,无明显骨吸收,义齿使用良好,患者满意。结论:牙周炎患者经完善治疗后接受种植即刻负荷的修复方法,近期效果满意,远期效果需进一步观察。