A retrospective analysis of peri-implant tissue responses at immediate load/provisionalized microthreaded implants

PURPOSE: The aim of this retrospective study was to examine the peri-implant tissue status at immediately provisionalized anterior maxillary implants 12 to 30 months following tooth replacement. MATERIALS AND METHODS: This is a retrospective study of 43 microthreaded, TiO2 grit-blasted implants placed in healed ridges and immediate extraction sockets to restore maxillary anterior and premolar teeth in 28 patients. The cortical bone position relative to the implant reference point was evaluated at implant placement and 6 to 30 months following restoration. Radiographs were assessed using 7x magnification. The distance from the reference point to the cortical bone was measured to +/- 0.1 mm. The relationship of the peri-implant mucosa to the incisal edge of the definitive prosthesis was recorded. RESULTS: Four implants in 3 individuals failed during the first 6 weeks following placement and provisional loading. Cortical bone adaptation from the time of implant placement up to 30 months following restoration ranged from 0.0 mm to 1.5 mm (average, 0.33 +/- 0.40 mm mesially and 0.28 +/- 0.37 mm distally). The mean radiographic measurements from the interproximal crestal bone to the contact point were 4.53 +/- -0.91 mm (mesial) and 4.06 +/- 0.98. Maintenance and growth of papilla was observed in this group of immediate provisionalized single-tooth implants. Definitive abutment or abutment screw loosening was not observed. DISCUSSION: The linear clinical and radiographic measures of peri-implant tissue responses suggest that proper implant placement is followed by supracrestal biological width formation along the abutment and preservation of toothlike tissue contours. This may influence buccal peri-implant tissue dimensions. CONCLUSIONS: Generalized maintenance of crestal bone and the increased soft tissue dimension with maintenance of peri-implant papilla were identified as expected outcomes for immediate loading/provisionalization of microthreaded, TiO2 grit-blasted implants. Control of peri-implant tissues can be achieved to provide predictable and esthetic treatment for anterior tooth replacement using dental implants.     

前牙种植体即刻种植修复牙龈软组织指标观察

目的　评价种植体即刻种植修复临床效果及美学意义。方法　 18例患者 18枚Camlog种植体在前牙区即刻种植即刻临时冠修复 ,对种植体成功率及周围牙龈附着水平进行观察 ,6个月后永久冠修复。结果　 12个月时所有种植体都发生了骨结合现象 ,牙龈变化平均为 0 .75mm ,在允许范围内。患者对种植即刻修复效果满意。结论　在严格掌握适应证前提下 ,前牙美学区单牙种植体即刻修复与延期修复相比在种植成功率、种植体周围软组织组织学变化上差异无显著性     

Immediate provisionalization on a new implant design for esthetic restoration and preserving crestal bone

PURPOSE: This article describes how the concept of platform switching has been incorporated into a new implant design as a method of reducing crestal bone loss and maintaining the gingival papillae. A 6-month study of the effects of this implant on bone loss is described. MATERIALS: Ten new platform switched implants were placed into fresh anterior maxillary extraction sites in 3 men and 7 women, ranging in age between 29 and 45 years old, and immediately provisionalized. The adjoining bone height was evaluated with digital radiography on the day after implant placement, and at 15 days, 1, 2, 3, and 6 months later. RESULTS: After 6 months, the mean bone loss on the mesial of the central-incisor implants was 0.05 mm. The mean bone loss was 0.07 mm on the distal of the central incisor implants, 0.07 mm on the mesial of the lateral-incisor implants, and 0.06 mm on the distal of the lateral-incisor implants. CONCLUSIONS: An implant design that incorporates the concept of platform switching is a simple and effective way to control circumferential bone loss around dental implants, helping to ensure a predictable esthetic result.     

Immediate loading of hydroxyapatite-coated implants in the maxillary premolar area: three-year results of a pilot study

STATEMENT OF THE PROBLEM: Although immediate loading of implants in the edentulous mandible has been described in the literature, there is limited information regarding immediate loading of single implants. PURPOSE: This prospective clinical study evaluated the clinical parameters of immediately loaded single-threaded hydroxyapatite-coated (HA) root form implants. MATERIAL AND METHODS: Ten human subjects were included in this report. In all situations, a screw-retained provisional acrylic resin crown was placed in the maxillary premolar area immediately after implant surgery. Definitive screw-retained metal-ceramic prostheses were placed 6 months after surgery. Standardized periapical radiographs were made before implant surgery, immediately after surgery, and 1, 3, 6, 12, and 36 months after implant surgery. Mobility (measured with the Perio-Test), distance from implant platform to the gingival crevice, distance from the implant platform to the depth of the sulcus, peri-implant probing depth, and bleeding on probing index were recorded at 3, 6, 12, and 36 months after implant placement. For clinical measurements, a 5-mm healing abutment was placed. RESULTS: All implants appeared clinically osseointegrated. Standardized radiographs demonstrated mean marginal bone loss of 0.6, 0.7, 0.8, 0.9, and 1.0 mm at 1, 3, 6, 12, and 36 months after implant surgery, respectively. Mean implant mobility was -3.3 at the day of surgery and -3.8, -3.4, -3.6, and -4.2 at 3, 6, 12, and 36 months, respectively. The distance from implant platform to the gingival crevice was 2.8, 2.4, 2.4, and 3.1 mm at 3, 6, 12, and 36 months, respectively. The distance from the implant platform to the depth of the sulcus was 0.8, 0.9, 0.9, and 1.1 mm at 3, 6, 12, and 36 months, respectively. The peri-implant probing depth was 3.6, 3.3, 3.2, and 4.3 mm at 3, 6, 12, and 36 months, respectively. The bleeding on probing index was 0.4, 0.4, 0.4, and 0.1 at 3, 6, 12, and 36 months, respectively. CONCLUSION: The results of this prospective pilot study provide initial evidence that single root form implants may be immediately loaded when placed at the maxillary premolar area.     

Three-year evaluation of single-tooth implants restored 3 weeks after 1-stage surgery

PURPOSE: The possibility of expediting dental implant therapy by early or immediate loading protocols requires long-term clinical investigation. The aim of this prospective cohort trial was to determine the 3-year implant success rate and prosthesis complications associated with functional loading 3 weeks after 1-stage placement of Astra Tech single-tooth implants replacing maxillary anterior teeth. A secondary objective was to determine peri-implant tissue responses at these implants. MATERIALS AND METHODS: The peri-implant bone and mucosal conditions of 43 implants in 39 subjects were radiographically and clinically measured 3 years after implant placement. RESULTS: Of the 48 patients originally treated, 39 patients and 43 implants were examined at the 3-year time point. Three of 54 implants failed within the first year. No additional failures were recorded since the 12-month reporting period. Peri-implant bone levels were stable for the 3-year period following implant placement. The change in marginal bone levels after 3 years was 0.42 +/- 0.59 mm. Papilla growth was measured at 1 and 3 years (0.61 +/- 0.95 mm and 0.74 +/- 0.79 mm, respectively). The buccal peri-implant tissue dimensions at the gingival zenith also increased at 1 and 3 years (0.34 +/- 0.94 mm and 0.51 +/- 1.42 mm, respectively). No abutment screw loosening or fracture occurred. DISCUSSION AND CONCLUSIONS: Early loading of endosseous dental implants placed in healed ridges offers select benefits to clinicians and their patients.     

Effects of immediate loading with threaded hydroxyapatite-coated root-form implants on single premolar replacements: a preliminary report

PURPOSE: This prospective study evaluated the immediate loading of single, threaded, root-form implants placed in the maxillary premolar area. MATERIALS AND METHODS: Ten human subjects were included in this preliminary report. In all cases, a screw-retained temporary acrylic resin crown was placed immediately after implant surgery. The definitive screw-retained metal-ceramic crown was placed 6 months later. RESULTS: Standardized radiographs demonstrated 0.58, 0.73, 0.84, and 0.90 mm mean marginal bone loss at 1, 3, 6, and 12 months after implant surgery, respectively. Implant mobility was evaluated with the Periotest device. At the day of surgery, mean mobility was -3.3, while minor changes were observed thereafter: mean values of -3.77, -3.47, and -3.63 were recorded at 3, 6, and 12 months after implant surgery, respectively. Sulcus depth appeared relatively stable after the 3rd month when the implant platform was used as a reference. Recession of 0.43 mm was recorded between the 3rd and 12th month; when the depth of the peri-implant sulcus was measured from the implant platform, 0.1 mm of change was seen between the 3rd and 12th month. Probing depth measurements revealed that 3 months after implant placement, average probing depth was 3.60 mm, while at 12 months it was 3.20 mm. DISCUSSION: The peri-implant soft tissue parameters (bleeding on probing, probing depth, peri-implant soft tissue level), mobility, and marginal bone level appeared to be similar to findings of previous studies regarding the conventional 2-stage loading protocol. CONCLUSION: Results of the current study provided evidence that, under the condition of this investigation, single root-form implants can be immediately loaded when placed in the maxillary premolar area.     

Single-blind randomized clinical trial to evaluate clinical and radiological outcomes after one year of immediate versus delayed implant placement supporting full-arch prostheses

Purpose: To evaluate and compare peri-implant health, marginal bone loss and success of immediate and delayed implant placement for rehabilitation with full-arch fixed prostheses. Material and Methods: The present study was a prospective, randomized, single-blind, clinical preliminary trial. Patients were randomized into two treatment groups. In Group A implants were placed immediately post-extraction and in Group B six months after extraction. The following control time-points were established: one week, six months and twelve months after loading. Measurements were taken of peri-implant crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis. Implant success rates were evaluated for the two groups. The study sample included fifteen patients (nine women and six men) with a mean average age of 63.7 years. One hundred and forty-four implants were placed: 76 placed in healed sites and 68 placed immediately. Results: At the moment of prosthetic loading, keratinized mucosa width and probing depth were higher in immediate implants than delayed implants, with statistically significant differences. However, after six and twelve months, differences between groups had disappeared. Bone loss was 0.54 ± 0.39 mm for immediate implants and 0.66 ± 0.25 mm for delayed implants (p=0.201). No implants failed in either group. Conclusions: The present study with a short follow-up and a small sample yielded no statistically significant differences in implant success and peri-implant marginal bone loss between immediate and delayed implants with fixed full-arch prostheses. Peri-implant health showed no statistically significant differences for any of the studied parameters (crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis) at the twelve-month follow-up. Key words:Immediate implants, delayed implants, peri-implant health, success rate.     

即刻种植和早期种植对前牙美学区种植体周软组织影响的对比研究

目的 对比研究种植体即刻种植和早期种植对前牙美学区种植体周软组织的影响.方法 22例单颗前牙缺失病例,A组12例,拔牙后即刻植入Zimmer TSV种植体;B组10例,拔牙后早期植入Zimmer TSV种植体.A、B两组在种植体植入6个月后氧化锆全冠永久修复.修复后6~12个月复查,测定红色美学评分(pink esthetic score,PES).对数据进行统计学分析.结果 修复后6~12个月,PES总分整体均数为9.27(美学效果可接受).即刻种植组与早期种植组之间,PES总分、单个PES评分点之间的差异无统计学意义(P>0.05).在各个PES评分点中,近、远中龈乳头高度与缺牙原因,远中龈乳头、牙槽骨缺损与牙龈生物型,唇侧牙龈高度与缺失牙位具有显著相关性.结论 即刻种植和早期种植对前牙美学区软组织美学效果的影响无显著差异.前牙美学区种植修复时,软组织美学效果受缺牙原因、牙龈生物型、缺失牙位的影响.     

Survival of immediately provisionalized dental implants placed immediately into fresh extraction sockets

BACKGROUND: The aim of this study was to evaluate the survival rate of immediately provisionalized dental implants immediately placed into fresh extraction sockets. METHODS: The study consisted of 87 consecutive patients, ranging in age from 21 to 76 years (average: 53.30 +/- 13.34 years), who received 210 immediately provisionalized, immediately placed dental implants between the years 2000 and 2005. Data were recorded regarding the survival rate of these implants and the incidence of complications. RESULTS: Follow-up ranged from 6 to 52 months (mean: 15.60 +/- 12.60 months). Smoking, past and present, was reported by 28.7% and 20.7% of patients, respectively. The maxillary incisors were replaced most frequently, followed by the mandibular lateral incisors. Most of the implants were >13 mm in length and > or = 3.75 mm in diameter. There were 47 (22.4%) single restored implants and 163 (77.6%) splinted implants. Overall, the implant survival rate was 97.6% (five implants failed). Complications, such as swelling, inflammation, and pain, were observed in 24 (11.4%) of the implants. No relation was found between complications and failure. The present study failed to reveal a relationship between implant survival rate and smoking, implant dimensions, and area of implantation. CONCLUSION: Immediately provisionalized immediate implants can serve as a predictable procedure with high survival rates.     

Immediate loading of single-tooth implants in the posterior region

PURPOSE: The aim of this study was to evaluate the clinical response and safety of immediately loaded single-tooth implants placed in the posterior region of the maxilla and mandible. MATERIALS AND METHODS: Single-tooth implants were placed in healed extraction sites in 20 adult patients. Temporary pre-fabricated acrylic resin crowns were prepared and adjusted. The crown occlusion was adjusted to obtain minimal contacts in maximum intercuspation. After 6 weeks a ceramometal or all-ceramic crown was cemented. Radiographic and clinical examinations were made at baseline and at 3, 6, and 12 months. Cortical bone response and peri-implant mucosal responses were evaluated. RESULTS: The marginal bone level at the time of implant placement was preserved. The mean change in marginal bone level was 0.01 mm at 12 months. The mean Periotest value after 360 days was -4. The peri-implant mucosal adaptation to the anatomic form of the provisional crown resulted in a natural esthetic outcome, and a gain in papilla length was observed. One implant failure was recorded because of provisional luting cement impaction. DISCUSSION: Clinical research has shown that immediate loading is a possible treatment modality. The immediate functional loading of implants placed in this study resulted in bone adaptation to loading. A satisfactory success rate with positive tissue responses was achieved. CONCLUSIONS: The results of this limited investigation indicated that immediate loading of unsplinted single-tooth implants in the posterior region may be a viable treatment option with an esthetic outcome.     

Immediate maxillary lateral incisor implants with nonocclusal loading provisional crowns.

This clinical report series describes a treatment modality involving immediately placed dental implants in maxillary lateral incisor sites using noncemented immediate provisional crowns retained with calcinable copings (prosthetic complement used in preparing the metal for the definitive prosthesis). Ten implants were placed in eight patients for the replacement of maxillary lateral incisors: two immediate and eight corresponding to cases of agenesis. All were subjected to immediate rehabilitation with provisional acrylic resin crowns in nonocclusal loading. One implant failed 3 weeks after placement due to acute local trauma. The other nine remained functional within the mouth, with normal clinical and radiological characteristics after a minimum of 12-month follow-up. Immediate placement of implant fixed provisional restorations retained by friction in maxillary lateral incisors offers an esthetic solution, eliminates the need for a removable provisional restoration, and avoids implant failures associated with excess cement or screw loosening. Moreover, in the case of extractions, immediate placement and provisionalization of implants in maxillary lateral incisors can effectively optimize the peri-implant esthetic results by maintaining the existing hard and soft tissue architecture of the replaced tooth. As no cement or screws are required, and the provisional crowns are placed in nonocclusal loading, the risk of complications is minimized.     

Immediate loading versus immediate provisionalization of maxillary single-tooth replacements: a prospective randomized study with BioComp implants.

PURPOSE: The aim of this prospective randomized study was to evaluate the clinical outcome of immediately loaded solid plasma sprayed (TPS) BioComp (BioComp Industries BV, Vught, The Netherlands) implants versus immediate provisionalized but non-loaded BioComp implants in the anterior and premolar region of the maxilla. MATERIALS AND METHODS: Forty-eight patients (31 females and 17 males) with a mean age of 42.3+/-13.1 years (range 19 to 78 years) were included in the study. Fifty threaded TPS implants were placed and provisionalized within 24 hours after surgery. The patients were randomly assigned to 2 groups. In the immediate loaded (IL) group (n=24) the occlusion of the provisional was designed with normal contacts in centric relation and at lateral excursions, while in the non-immediate loaded (IP) group (n=24) the provisional restoration was adjusted to clear all occlusal contacts or contacts at lateral excursions. Patients were instructed to eat a soft diet and to avoid placing food in the area of the provisional crown during the first 6 weeks. Regular clinical and radiographic controls were performed and the survival rate and implant stability quotient (ISQ) values were evaluated at delivery of the definitive restoration at 6 months. At 1 year, radiographic coronal bone defects and gingival esthetics between the 2 groups were assessed. RESULTS: Of the IL group, 2 fixtures were lost, while 3 implants were lost in the IP group. The failing implants showed increasing mobility at 2 to 3 weeks after insertion, and were removed. The remaining 45 implants were stable at every subsequent follow-up examination, and 6 months after implant placement, ISQ values were measured. The mean ISQ value in the IL group was 63.7+/-5.8 versus 63.2+/-4.3 for the IP group (P=.78). The mean mesial marginal bone loss after 12 months in the IL group was 0.27+/-0.2 mm versus 0.28+/-0.22 mm in the IP group (P=.9). The mean distal marginal bone loss after 12 months in the IL group was 0.19+/-0.15 mm versus 0.2+/-0.11 mm in the IP group (P=.87). All implants of the IL group had an ideal gingival buccal margin, versus 91% of the IP group. Full regeneration of the mesial interdental papilla was observed in 70% of the IL group versus 91% of the IP group, while full regeneration of the distal papilla was observed in 91% of both the IL and IP implants. CONCLUSION: No significant differences in ISQ mean values in radiographic bone loss and gingival esthetics were found between immediate non-loaded provisionalization and immediately loaded BioComp implants in the maxilla.     

Vertical crestal bone changes around implants placed into fresh extraction sockets

BACKGROUND: The aim of this study was to analyze bone healing and vertical bone remodeling for implants placed immediately after tooth removal without guided bone regeneration techniques. METHODS: Twenty patients received 20 implants immediately after the removal of 20 teeth. All implants were placed within the undamaged alveoli confines, and the cervical portion of each implant was positioned at coronal bone level. The distance from implant shoulder and bone crest was measured for each implant at four sites (mesial, buccal, distal, and palatal/lingual). No membranes or filling materials were used. Primary flap closure was performed in all clinical cases. RESULTS: All peri-implant bone defects had healed completely 6 months after implant placement. The pattern of bone healing around the neck of the implants showed an absence of peri-implant defects. The vertical distance between the implant shoulder and bone crest ranged from 0 to 2 mm. CONCLUSIONS: The bone remodeling of implants placed in fresh extraction sockets showed a healing pattern with new bone apposition around the implant's neck and horizontal and vertical bone reabsorption. The vertical bone reabsorption, which has been observed at buccal sites, was not associated with any negative esthetic implications.     

A short-term clinical evaluation of immediately restored maxillary TiOblast single-tooth implants

PURPOSE: The purpose of this study was to evaluate the short-term clinical outcome of single-tooth implants placed in the maxilla and immediately restored using cementless friction-fit temporary crowns. MATERIALS AND METHODS: Twenty-five patients consecutively referred to a private specialist practice for the replacement of failing or missing maxillary teeth were treated by means of immediate temporization of their single-tooth implants. Where teeth were still present, implants were placed immediately following extraction. Provisional crowns were fabricated on a special friction-fit coping by means of autopolymerizing acrylic resin. Definitive crowns were placed a mean of 4.5 months after surgery. Implant survival was recorded along with the level of the marginal bone relative to a fixed reference point 1 year after placement. Any adverse soft tissue changes were also noted. RESULTS: A total of 28 Astra Tech ST dental implants were placed. The overall survival rate at the end of the study was 96.4% for implants which were in function for periods ranging from 15.7 to 27 months. One patient, a smoker, lost 1 implant within 1 month of surgery. Mean marginal bone loss was 0.40 mm (range 0 to 1.53 mm) 1 year after placement of the implants. Many implants (37.5%) had no observed bone loss. No implants or crowns have been lost during the functional loading period. One implant was associated with an unfavorable recession of soft tissues; however, most maintained an esthetic gingival architecture. Eleven of 28 provisional restorations needed treatment; 6 required replacement during the temporization period, and 5 required cementation because of looseness. The ease of removal of the crowns allowed regular access for irrigation with chlorhexidine and thus maintenance of soft tissue health. DISCUSSION: The need to provide provisional restorations for single-tooth gaps often presents challenges. An immediate temporary partial denture or adhesive prosthesis may be unacceptable or impractical. The current study describes a simple method for the immediate temporization of single-tooth implants. The results did not indicate any negative influence on osseointegration or short-term survival once the implants were functionally loaded. CONCLUSION: Immediate temporization of maxillary single-tooth implants can be both safe and predictable, and it appears that the procedure can yield favorable soft tissue esthetics.     

Immediate Nonfunctional Loading of NobelPerfect Implants in the Anterior Dental Arch in Private Practice – 5‐Year Data

Background: The concept of scalloped implants to maintain the natural contour of the alveolar ridge has been a source of controversy for many years. Purpose: This study examined the long‐term clinical performance of the scalloped NobelPerfect implant in a one‐stage procedure (immediate loading in the esthetic zone). Materials and Methods: In 20 patients, immediate prosthetic restorations were placed on 31 NobelPerfect implants in a private practice and followed for up to 78 months. Twenty‐one implants were placed immediately after extraction, seven implants were placed after osseous consolidation of the extraction sockets, and three implants were placed secondary to extended alveolar ridge augmentation procedures. All implants were provisionalized on the day of implant placement and adjusted to clear all contacts in centric occlusion and during eccentric movements. Outcome variables were success rates, marginal bone levels, and pink esthetic score (PES) assessed per implant. Results: One implant failed after 1.4 months. Five patients with six implants in total were scored in the 5‐year follow‐up as dropouts. Mean follow‐up period of remaining 24 implants was 65 months (range, 55–78 months). Cumulative success rates according to the criteria specified by Smith and Zarb were 96.8%. Marginal bone levels averaged 1.1 mm above the first thread. Mean PES ratings were 10.5 (range, 3–13). Conclusions: Survival rates, marginal bone levels, and esthetic results suggest proof of principle for the preservation of the interproximal bony lamella with a scalloped implant design in long‐term data.     

Peri-implant tissue response of immediately loaded, threaded, HA-coated implants: 1-year results

STATEMENT OF PROBLEM: Although high success rates have been reported with immediately loaded implants, the peri-implant tissue response has not been well documented. PURPOSE: This study evaluated implant success and peri-implant tissue response of immediately loaded, threaded, hydroxyapatite (HA)-coated root-form implants supporting mandibular bar overdentures with opposing conventional maxillary complete dentures in humans. MATERIAL AND METHODS: Five patients (3 men, 2 women; mean age 61 years) each received 4 HA-coated endosseous root-form implants in the interforaminal region in the mandible. The implants were rigidly splinted with a metal framework within 24 hours. The final EDS clip prosthesis was placed 1 to 2 weeks thereafter. The implants and peri-implant tissues were evaluated clinically and radiographically 0, 1, 3, 6, and 12 months after prosthesis placement. Data were analyzed with a repeated measures 1-way analysis of variance (P<.05). RESULTS: All implants were stable at the end of the observation period (mean Periotest value = -5.9 +/- 1.4). No peri-implant radiolucencies were noted, and no implants were lost. The mean marginal bone changes were -0.42 plus minus 0.34, -0.84 +/- 0.55, -1.14 +/- 0.80, and -1.16 +/- 0.89 mm at the 1-, 3-, 6-, and 12-month follow-ups, respectively (P<.001). Significant declines in the rates of marginal bone changes at each time interval were noted (P<.001). In addition, there were significant decreases in probing depth (P<.001) and plaque index (P<.001) but no significant difference in the frequency of bleeding upon probing (P=.64). CONCLUSION: Within the limitations of this study, the peri-implant tissue response of immediately loaded, HA-coated implants was favorable and comparable to that of conventional, delayed-loaded implants after 1 year.     

Evaluation of peri-implant bone loss around platform-switched implants

This clinical and radiographic prospective study evaluated bone loss around two-piece implants that were restored according to the platform-switching protocol. One hundred thirty-one implants were consecutively placed in 45 patients following a nonsubmerged surgical protocol. On 75 implants, a healing abutment 1 mm narrower than the implant platform was placed at the time of surgery. On the remaining implants, a healing abutment of the same diameter as the implant was inserted. All implants were positioned at the crestal level. Clinical and radiographic examinations were performed prior to surgery, at the end of surgery, 8 weeks after implant placement, at the time of provisional prosthesis insertion, at the time of definitive prosthesis insertion, and 12 months after loading. The data collected showed that vertical bone loss for the test cases varied between 0.6 mm and 1.2 mm (mean: 0.95 +/- 0.32 mm), while for the control cases, bone loss was between 1.3 mm and 2.1 mm (mean: 1.67 +/- 0.37 mm). These data confirm the important role of the microgap between the implant and abutment in the remodeling of the peri-implant crestal bone. Platform switching seems to reduce peri-implant crestal bone resorption and increase the long-term predictability of implant therapy.     

Influence of immediate implant loading on peri-implant soft tissue morphology in the edentulous maxilla

PURPOSE: This study investigates the pre- and posttreatment morphology of the mucosa around immediately loaded implants in the edentulous maxilla. MATERIALS AND METHODS: Implants were placed and immediately loaded in edentulous maxillae; pre- and posttreatment impressions were obtained. The resulting casts were digitalized into 3-dimensional images, and the pre- and posttreatment images were superimposed. The width and height of the maxillary alveolar process were measured at central and interproximal implant sites in a vertical section of the superimposed holograms. For statistical analysis, the Delta value (d) was defined as the difference between the pre- and posttreatment images for all measurements. RESULTS: Sixty-seven Straumann implants placed in 9 patients and immediately restored with provisional fixed restorations were analyzed. An increase in width at all measurement sites was observed after treatment. Width increased for both central implant (1.51 +/- 1.16 mm, P < .001) and interproximal implant sections (1.02 +/- 1.21 mm, P < .001). Mean d for height was found to be decreased at central implant sites (-1.21 +/- 1.67 mm, P = .012) and at interproximal sections (-0.72 +/- 1.68 mm, P = .098). DISCUSSION AND CONCLUSION: Clinically, it has been observed that the placement of an immediate provisional affects the peri-implant tissue morphology according to its emergence profile. The result after treatment was a wider contour of the peri-implant soft tissue, located in a more apical position than the original mucosal level. The most coronal part of the papilla-like mucosa at interproximal sites would be nearest to the original mucosal level before treatment. The scalloped mucosal configuration obtained was consistent along the rehabilitated arch. Statistically significant dimensional changes of the peri-implant mucosa were observed with an immediate loading approach.     

Peri-implant bone loss around posterior mandible dental implants placed after distraction osteogenesis: preliminary findings

BACKGROUND: The present study evaluates implant survival and peri-implant bone loss around posterior mandible dental implants placed at sites of distraction osteogenesis. METHODS: On removal of the distraction devices, 34 dental implants were inserted into 14 posterior mandible sites in 10 healthy, non-smoking female patients. Prosthetic treatment was performed 4 months after implant placement using fixed implant prostheses. After 6 to 16.5 months, periapical radiographs were taken and evaluated for peri-implant bone loss and radiolucency. The distance between the implant margin and the first visible bone-implant contact was measured on the mesial and distal aspects of the implants using imaging software. Radiographic dimensional distortion was corrected as a function of the known true dimension of the implant. RESULTS: Of the 34 implants placed, two (5.9%) failed to integrate at reentry surgery. Both were replaced and restored during the course of the study so that a total of 34 implants was followed for 12.1 +/- 3.8 months post-restoration and 16.1 +/- 3.8 months post-insertion. Mean loss of marginal bone height was 2.6 +/- 1.0 mm. During the follow-up period, radiolucent lines along the implant surface were absent. CONCLUSIONS: The mean peri-implant bone loss in areas of alveolar bone distraction was 1.9 mm/year. A high implant survival rate was observed.     

微创拔牙即刻种植的牙龈美学效果观察

目的探讨微创拔牙即刻种植技术的临床特点及修复后的牙龈美学效果。方法21例上前牙单个缺失病例，行不翻瓣微创拔牙同期23颗种植体即刻植入，并且同期安装愈合基台直接暴露于口腔，即非埋入式种植术式，种植体愈合6个月后进行永久修复。种植永久修复后观察时间平均27．6个月（13～51个月）。根据Jemt牙龈乳头指数（papilla index score，PIS）观察种植体永久修复12个月后的近远中牙龈乳头状况，根据Flirhauser的改良红色美学指数观察种植体永久修复1年后与相邻天然牙唇侧龈缘位置的协调性；唇侧软组织与相邻天然牙唇侧牙龈色泽协调性。结果23颗种植体均获得良好的骨结合；种植修复体近远中PIS均为Ⅱ级以上。种植修复体与相邻天然牙唇侧牙龈缘水平位置协调性一致的15颗，8颗不协调；唇侧软组织色泽与相邻天然牙协调一致的18个牙位，5个牙位有轻度差异。结论微创拔牙即刻种植术是一项要求较高的技术，多因素影响软组织美学效果，严格掌控适应证，才能获得理想修复效果。