Effect of interimplant distance (2 and 3 mm) on the height of interimplant bone crest: a histomorphometric evaluation

Background: Implants restored according to a platform‐switching concept (implant abutment interface with a reduced diameter relative to the implant platform diameter) present less crestal bone loss than implants restored with a standard protocol. When implants are placed adjacent to one another, this bone loss may combine through overlapping, thereby causing loss of the interproximal height of bone and papilla. The present study compares the effects of two interimplant distances (2 and 3 mm) on bone maintenance when bone‐level implants with platform‐switching are used. Methods: This study evaluates marginal bone level preservation and soft tissue quality around a bone‐level implant after 2 months of healing in minipig mandibles. The primary objective is to evaluate histologically and histomorphometrically the affect that an implant design with a horizontally displaced implant–abutment junction has on the height of the crest of bone, between adjacent implants separated by two different distances. Results: Results show that the interproximal bone loss measured from the edge of the implant platform to the bone crest was not different for interimplant distances of 2 or 3 mm. The horizontal position of the bone relative to the microgap on platform level (horizontal component of crestal bone loss) was 0.31 ± 0.3 mm for the 2‐mm interimplant distance and 0.57 ± 0.51 mm above the platform 8 weeks after implantation for the 3‐mm interimplant distance. Conclusions: This study shows that interimplant bone levels can be maintained at similar levels for 2‐ and 3‐mm distances. The horizontally displaced implant–abutment junction provided for a more coronal position of the first point of bone–implant contact. The study reveals a smaller horizontal component at the crest of bone than has been reported for non‐horizontally displaced implant–abutment junctions.     

Interproximal tissue dimensions in relation to adjacent implants in the anterior maxilla: clinical observations and patient aesthetic evaluation

Objectives: This clinical study aimed to assess (i) interproximal tissue dimensions between adjacent implants in the anterior maxilla, (ii) factors that may influence interimplant papilla dimensions, and (iii) patient aesthetic satisfaction. Material and methods: Fifteen adults, who had two or more adjacent implants (total of 35) in the anterior maxilla, participated in the study. The study design involved data collection from treatment records, clinical and radiographic assessment, and a questionnaire evaluating aesthetic satisfaction. Results: The median vertical dimension of interimplant papillae, i.e., distance from tip of the papilla to the bone crest, was 4.2 mm. Missing papilla height (PH) at interimplant sites was on average 1.8 mm. Median proximal biologic width at interimplant sites was 7 mm. The most coronal bone‐to‐implant contact at implant–implant sites was located on average 4.6 mm apical to the bone crest at comparable neighbouring implant–tooth sites. The tip of the papilla between adjacent implants was placed on average 2 mm more apically compared with implant–tooth sites. The contact point between adjacent implant restorations extended more apically by 1 mm on average compared with implant–tooth sites. Median missing PH was 1 mm when an immediate provisionalization protocol had been followed, whereas in the case of a removable temporary it was 2 mm. Split group analysis showed that for missing PH≤1 mm, the median horizontal distance between implants at shoulder level was 3 mm. Patient satisfaction with the appearance of interimplant papillae was on average 87.5%, despite a Papilla Index of 2 in most cases. Conclusions: The apico‐coronal proximal biologic width position and dimension appear to determine papilla tip location between adjacent implants. There was a significant association between the provisionalization protocol and missing PH, which was also influenced by the horizontal distance between implants. Patient aesthetic satisfaction was high, despite a less than optimal papilla fill.     

Interimplant papilla preservation in the esthetic zone: a report of six consecutive cases

Simultaneous removal of multiple adjacent teeth in the anterior maxilla often leads to collapse of the labial bony plate as well as flattening of the interproximal bony scallop, resulting in long implant restorations with missing interimplant papillae. An interimplant papilla preservation technique involving alternate immediate implant placement and provisionalization, one following the osseointegration healing period of the other, was introduced. All 14 implants placed in six consecutive patients maintained osseointegration after a mean functioning time of 22.6 months (range 12 to 34 months). A highly satisfactory esthetic outcome and a papilla index score of 3 was observed in all patients.     

Cast-free digital workflow for implant-supported rehabilitation in a completely edentulous patient: A clinical report

Digitalization of edentulous areas restored with dental implants is still considered a demanding procedure, mainly because of the lack of fixed reference landmarks, together with an increased interimplant distance. To overcome such limitations, an auxiliary device is introduced with the 3-fold purpose of stretching the soft tissues with a fixed object connected to the scan bodies, creating areas with nonhomogeneous architectures between the implants, and shortening the interimplant distance with the interposition of solid geometric figures. The rationale was to increase the accuracy of digital scans in a cast-free digital implant workflow.     

Dimension of interproximal soft tissue between adjacent implants in two distinctive implant systems

BACKGROUND: The purpose of this study was to compare the dimension of interproximal soft tissue between adjacent implants in distinctive implant systems. METHODS: This study involved 85 interproximal papillae between two adjacent implants in 50 patients who had implants placed adjacent to each other and who had prosthesis in place for longer than 1 year. The shortest distance between the radiopaque material on the tip of interimplant papilla and the most coronal portion of the interimplant crestal bone was measured (radiographic length of papilla [RL]). The horizontal distance (HD) between the two adjacent implants was measured at the fixture-abutment interface level. Considering the possible effect of interimplant crestal bone resorption on closely implanted sites, HDs were divided into two categories: HD <3 and >or=3 mm. The Mann-Whitney test was performed to find the difference in the dimension of interimplant papilla. RESULTS: In cases of HD <3 mm, RL did not differ statistically in both systems. Also, in cases of HD >3 mm, RL did not show a statistically significant difference in both systems. CONCLUSION: Both systems had similar dimensions of interproximal soft tissue between adjacent implants, irrespective of the horizontal distance of the fixture.     

Implant angulation: a measurement technique,implant overdenture maintenance,and the influence of surgical experience

PURPOSE: The purposes of this study were to develop a technique to measure the angulation between two implants and between each implant and reference planes, to analyze the relationship between the maintenance (adjustments and repairs) of ball-attachment mandibular implant overdentures and implant angulation, and to see if there is any correlation between surgeon experience and implant orientation. MATERIALS AND METHODS: Final casts of 41 patients who had received two-implant ball-attachment mandibular overdentures were used to measure implant angulations using digital photographs and plane geometry. The measured angles were compared with the number of adjustments and repairs of the prostheses and analyzed by surgeon experience for any trends. RESULTS: No significant relationships were found between number of adjustments and repairs and the interimplant angles. However, there was a significantly higher number of repairs when the lingual inclination of an implant was > or = 6.0 degrees (P = .033) or if the facial inclination was < 6.5 degrees (P = .036). Less experienced surgeons had a significantly greater tendency to place implants that diverged from each other in the frontal plane (P = .045) and with a facial or lingual inclination in the sagittal plane (P = .035). CONCLUSION: While interimplant angulation did not appear to affect prosthesis maintenance, individual implants with a lingual inclination > or = 6 degrees and a facial inclination < 6.5 degrees were associated with significantly more prosthesis repairs. There was a tendency for implants placed by less experienced surgeons to demonstrate greater inclination.     

Influence of interimplant distances and placement depth on peri‐implant bone remodeling of adjacent and immediately loaded Morse cone connection implants: a histomorphometric study in dogs

Objectives: The aim of this study was to histomorphometrically evaluate the influence of interimplant distances (ID) and implant placement depth on bone remodeling around contiguous Morse cone connection implants with ‘platform‐shifting’ in a dog model. Material and methods: Bilateral mandibular premolars of six dogs were extracted, and after 12 weeks, each dog received 8 implants, four placed 1.5 mm subcrestally (SCL) on one side of the mandible and four placed equicrestally (ECL) on the other side, alternating the ID of 2 and 3 mm. The experimental groups were SCL with IDs of 2 mm (2 SCL) and 3 mm (3 SCL) and ECL with IDs of 2 mm (2 ECL) and 3 mm (3 ECL). Metallic crowns were immediately installed. After 8 weeks, the animals were euthanized and histomorphometric analyses were performed to compare bone remodeling in the groups. Results: The SCL groups' indices of crestal bone resorption were significantly lower than those of ECL groups. In addition, the vertical bone resorption around the implants was also numerically inferior in the SCL groups, but without statistical significance. No differences were obtained between the different IDs. All the groups presented similar good levels of bone‐to‐implant contact and histological bone density. Conclusion: The subcrestal placement of contiguous Morse cone connection implants with ‘platform shifting’ was more efficient in preserving the interimplant crestal bone. The IDs of 2 and 3 mm did not affect the bone remodeling significantly under the present conditions. To cite this article:
Barros RRM, Novaes AB Jr., Muglia VA, Iezzi G, Piattelli A. Influence of interimplant distances and placement depth on peri‐implant bone remodeling of adjacent and immediately loaded Morse cone connection implants: a histomorphometric study in dogs.
Clin. Oral Impl. Res. 21 , 2010; 371–378.
doi: 10.1111/j.1600‐0501.2009.01860.x     

The influence of interimplant distance and attachment type on the retention characteristics of mandibular overdentures on 2 implants: initial retention values

PURPOSE: This in vitro study aimed to investigate the influence of (1) the interimplant distance and (2) the type of attachment on the retention of mandibular overdentures on 2 implants. MATERIALS AND METHODS: Three stone casts were fabricated, each with 2 implant analogues embedded at distances of 19, 23, and 29 mm apart. Three different interchangeable mandibular overdenture attachments were secured onto the analogues: Hader bars, ball abutments, and stainless steel keepers for new generation neodymium-iron-boron magnets. In total, 45 groups of paired attachments were tested for initial vertical peak tensile load at the 3 interimplant distances. RESULTS: Interimplant (interclip) distance played a significant role only in the retention produced by the Hader bar/red clip configuration. At 19 and 23 mm, the ball/socket attachments were statistically more retentive than the yellow clips, white clips, and magnets, but not compared to the red clips. At 29 mm, the ball abutments showed statistical superiority compared with all other attachments. Mean clinical intercanine distance for conventional full dentures was 22.88 mm. CONCLUSION: Interimplant distance can affect the initial retention of mandibular overdentures on 2 implants depending on the type of attachment used. For a predetermined interimplant distance, attachment performance varies greatly.     

Interimplant papilla reconstruction: assessment of soft tissue changes and results of 12 consecutive cases

BACKGROUND: Loss of soft tissue between adjacent implants is a frequent occurrence. Reconstruction of the papilla between adjacent implants is often necessary where there are esthetic demands. The purpose of this article is to describe a fixed and reproducible reference line which can be used to measure changes in the height of the interimplant papillae. A surgical technique carried out at the time of the abutment connection surgery is also described to show the changes that may occur over a 12-month period. Assessment of changes in the soft tissue dimension is shown following a modified flap technique at the time of abutment connection. METHODS: With the aid of clinical photographs taken preoperatively, a reference line can be drawn between the highest point of the gingival margins on teeth distal to the intended site of soft tissue surgery. This reference line can be reproduced on clinical photographs postoperatively. Using this reference line, the changes in soft tissue height using a modified flap technique in 12 consecutive patients are presented. Assessment of the vertical height of the interimplant papillae before and after treatment is described. RESULTS: Four patients showed an increase in the height of the papillae when reviewed 12 months following abutment connection. One patient showed no change in the height of the papillae, and 7 patients showed a loss in papillary height. There was an average loss of 0.5 mm in height of the interimplant soft tissue. CONCLUSIONS: Use of a fixed reference line to assess the outcome of treatment is necessary when evaluating vertical changes in soft tissue. This reference line is used to assess a soft tissue flap technique carried out at the time of implant exposure.     

A Prospective Study on the Accuracy of Mucosally Supported Stereolithographic Surgical Guides in Fully Edentulous Maxillae

Background: Flapless implant placement using guided surgery is widespread, although clinical publications on the precision are lacking. Purpose: The purpose of this study was to evaluate the accuracy of mucosal‐supported stereolithographic guides in the edentulous maxillae. Materials and Methods: Seventy‐eight OsseoSpeed? implants (Astra Tech AB, Mölndal, Sweden) of 3.5 to 5 mm width and 8 to 15 mm length were installed consecutively in 13 patients. Implants were functionally loaded on the day of surgery, and implant location was assessed with a computed tomography scan. Mimics 9.0 software (Materialise N.V., Leuven, Belgium) was used to fuse the images of the virtually planned and actually placed implants, and the locations, axes, and interimplant distances were compared. Results: One implant was lost shortly after insertion because of abscess formation caused by remnants of impression material. Seventy‐seven implant locations were analyzed. The deviation at the entrance point ranged between 0.29 mm and 2.45 mm (SD: 0.44 mm), with a mean of 0.91 mm. Average angle deviation was 2.60° (range 0.16–8.86°; SD: 1.61°). At the apical point, the deviation ranged between 0.32 mm and 3.01 mm, with a mean of 1.13 mm (SD: 0.52 mm). The mean deviation of the coronal and apical interimplant distance was respectively 0.18 mm (range 0.07–0.32 mm; SD: 0.15) and 0.33 mm (range 0.12–0.69 mm; SD: 0.28). These deviations are lower than the global coronal and apical deviations. Conclusion: The present study is the first to investigate the accuracy of stereolithographic, full, mucosally supported surgical guides in the treatment of fully edentulous maxillae. Clinicians should be warned that angular and linear deviations are to be expected. Short implants show significantly lower apical deviations compared with longer ones. Reasons for implant deviations are multifactorial; however, it is unlikely that the production process of the guide has a major impact on the total accuracy of a mucosal‐supported stereolithographic guide.     

The all-on-4 modified polyetheretherketone treatment approach: A clinical report

A modified polyetheretherketone (PEEK) implant framework material in combination with prefabricated high-impact poly(methyl methacrylate) (PMMA) veneers was used as an alternative material for the fabrication of a complete maxillary arch implant-supported fixed restoration. The elastic performance of the PEEK framework (elastic modulus of 4 GPa) combined with PMMA veneers may reduce the occlusal forces, protecting the implant-supported restoration and the opposing dentition, especially in all-on-4 treatments, where lack of proprioception and wide interimplant distance are present. Long-term clinical evidence is required before recommending the application as an alternative restorative material for such a prosthesis.     

Dimension of keratinized mucosa and the interproximal papilla between adjacent implants

BACKGROUND: The interproximal papilla between two adjacent implants is gaining critical interest in the implant dentistry. The aims of this study were to evaluate the effect of 1) the width of keratinized mucosa, 2) the distance from the base of the contact point to the crestal bone, and 3) the horizontal distance between two implants on the radiographic dimension from the tip of the papilla to the crestal bone between two implants. METHODS: This study involved 72 interproximal papillae between two adjacent implants (interimplant papilla) in 52 patients who had implants placed adjacent to each other and had a prosthesis in place more than 1 year. The shortest distance between the radiopaque material on the tip of the interimplant papilla and most coronal portion of the interimplant crestal bone was measured (the radiographic length of the papilla [RL]). The width of keratinized mucosa from the tip of the papilla was measured (WK). The vertical distance between the base of the contact point and the interimplant crestal bone was measured (CC). The horizontal distance between the two adjacent implants was measured at the fixture-abutment interface level (HD). Multiple regression analysis was performed between WK-RL, CC-RL, and HD-RL. RESULTS: RL had a significant relation with WK between two adjacent implants (P = 0.001). However, RL was not related with other variables, such as CC and HD (CC, P = 0.641; HD, P = 0.901). CONCLUSION: The results of this study suggest that the width of keratinized mucosa between two adjacent implants might be related to the dimension of the interproximal papilla between two adjacent implants.     

Equicrestal and subcrestal dental implants: a histologic and histomorphometric evaluation of nine retrieved human implants

Background: Stability of peri‐implant crestal bone plays a relevant role relative to the presence or absence of interdental papilla. Several factors can contribute to the crestal bone resorption observed around two‐piece implants, such as the presence of a microgap at the level of the implant–abutment junction, the type of connection between implant and prosthetic components, the implant positioning relative to the alveolar crest, and the interimplant distance. Subcrestal positioning of dental implants has been proposed to decrease the risk of exposure of the metal of the top of the implant or of the abutment margin, and to get enough space in a vertical dimension to create a harmoniously esthetic emergence profile. Methods: The present retrospective histologic study was performed to evaluate dental implants retrieved from human jaws that had been inserted in an equicrestal or subcrestal position. A total of nine implants were evaluated: five of these had been inserted in an equicrestal position, whereas the other four had been positioned subcrestally (1 to 3 mm). Results: In all subcrestally placed implants, preexisting and newly formed bone was found over the implant shoulder. In the equicrestal implants, crestal bone resorption (0.5 to 1.5 mm) was present around all implants. Conclusion: The subcrestal position of the implants resulted in bone located above the implant shoulder.     

Interimplant distance and crestal bone resorption: a histologic study in the canine mandible

Background: Crestal bone loss has been shown to occur around dental implants. This crestal bone resorption may determine a more apical position of the gingival margin. A clear trend of increased bone loss with increased interimplant distance has been reported. Purpose: The aim of the present study was to evaluate, in the canine mandible, the crestal bone behavior around dental implants inserted with different interimplant distances. Materials and Methods: Sandblasted and acid‐etched implants (Bone System, Milano, Italy) were placed in the mandibles of six beagle dogs. Each dog received 10 implants in the mandible (five in the right side and five in the left side). A total of 60 implants was used in this study. The implants were divided in four groups: group I, with a 2 mm interimplant distance; group II, with a 3 mm interimplant distance; group III, with a 4 mm interimplant distance; and group IV, with a 5 mm interimplant distance. The dogs were killed after 12 months. Results: No statistically significant differences were found in regard to vertical bone loss whereas on the contrary, statistically significant differences were found in regard to lateral bone loss (p= .0001). Statistically significant differences also were found in regard to vertical crestal bone loss (p= .0001). In fact vertical crestal bone loss decreased, from 1.98 mm in group I to 0.23 mm in group IV. Conclusions: The clinical significance of these data lies in the fact that the increased crestal bone loss results in an increase in the distance between the base of the contact points of the neighboring implants and the crest of bone, and this fact could determine whether the papilla is present or absent between two implants.     

Outcome analysis of immediately placed, immediately restored implants in the esthetic area: the clinical relevance of different interimplant distances

BACKGROUND: The purpose of this study was to compare and evaluate bone and soft tissue levels between immediately placed, immediately restored implants positioned in the esthetic anterior region with different interimplant distances (IID). METHODS: Forty-nine patients requiring multiple implant restorations in the anterior regions received 152 implants, which were restored immediately. Periapical radiographs and digital images of 99 interimplant sites were taken at the regular follow-up examinations at 0, 6, 12, and 24 months after surgery. They were digitally recorded and analyzed. The presence of the interproximal papilla was assessed and compared to the distances between the bone crest and the contact point between the natural teeth and the restoration crowns. RESULTS: Implants with an IID <2 mm seemed to lose less bone laterally. When the IID was <2 mm, vertical crestal bone loss was significantly greater than in the group with IID >4 mm. The percentage of the interproximal papilla presence decreased when the distance between the bone crest and the contact point between the two restoration crowns was >6 mm and when two implants were placed at a distance > or =4 mm. CONCLUSIONS: To guarantee a better esthetic result in immediately placed, immediately restored implants, the contact point between the two prosthetic crowns should be placed at 3 to 4 mm, and never >6 mm, from the bone peak. Two adjacent implants should be placed at a distance >2 and <4 mm.     

Influence of the interimplant distance on crestal bone resorption and bone density: a histomorphometric study in dogs

BACKGROUND: The position of gingival soft tissues depends on the position and health of the underlying alveolar bone. The aim of this study was to evaluate the influence of different interimplant distances on crestal bone resorption after prosthetic restoration with a 5-mm distance between the contact point and the bone crest. METHODS: The mandibular bilateral premolars of six dogs were extracted and, after 12 weeks, each dog received eight implants, totaling 48 implants in the experiment. Two pairs, one in each hemiarch, were separated by 2 mm (group 1) and two by 3 mm (group 2). After 12 weeks, the implants received temporary acrylic prostheses. After 4 more weeks, metallic crowns substituted the temporary prostheses. After 4 more weeks, the animals were sacrificed, and their hemimandibles were removed, dissected, and processed. RESULTS: For groups 1 and 2, respectively, the mean of interimplant bone resorption (IIBR) analyzed histologically was 2.03 and 1.98 mm (P >or=0.05), and the mean of the distal extension bone resorption was 2.04 and 1.92 mm for groups 1 and 2, respectively (P >or=0.05). The crestal bone resorption between the implants was 0.13 mm (P >or=0.05) for both groups. The mean of IIBD for groups 1 and 2 was 79% and 80%, respectively. When the IIBD was compared to the distal extension bone density for group 1 (79% and 64%) and group 2 (80% and 62%), statistically significant differences were obtained for both groups (P 相似文献   

平台转换技术用于上颌前牙种植修复的临床研究

目的 评估应用平台转换技术种植修复上颌前牙区牙列缺损的临床效果,探讨该技术的临床应用特点.方法 2001年1至12月就诊于北京大学口腔医学院·口腔医院口腔种植中心上颌前牙区牙列缺损患者17例,共植入Frialit-2系统种植体26枚,Ⅱ期手术后应用平台转换技术修复.随访时间24～74个月,平均56.3个月,观察方法为临床检查和x线检查,评价种植体周骨高度丧失,进行红色美学评分.结果 全部患者至最后一次随访,均未见严重并发症,应用平台转换技术的种植体修复临床效果满意.种植修复完成1年和5年后边缘骨吸收分别为0.13(-0.12～0.55)mm和0.27(-0.04～0.77)mm;相邻种植体间牙槽骨高度丧失分别为0.14(0～0.30)mm和0.21(0.09～0.31)mm.按Jemt牙间乳头分类本组36个位点中达Ⅰ度3个位点,Ⅱ度23个位点,Ⅲ度10个位点.单牙种植修复Fürhauser红色美学评分为10～14,平均11.8分.结论 上领前牙区应用平台转换技术操作简单可靠,短期临床效果满意,可减少种植体边缘骨吸收、增进种植修复美学效果.     

Verification jig for implant-supported prostheses: A comparison of standard impressions with verification jigs made of different materials

STATEMENT OF PROBLEM: Implant verification jigs are routinely used during the fabrication of implant-supported prostheses. The dimensional accuracy of these jigs is unknown. PURPOSE: The purposes of this study were to (1) compare the dimensional accuracy of verification jigs with that of conventional impression procedures and (2) measure the dimensional accuracy of 3 resin materials used to fabricate verification jigs. MATERIALS AND METHODS: Thirty verification jigs and 20 impressions were made of 3 externally hexed Steri-Oss implants in a master stone base according to the following groups (n = 10 per group): (Group 1) Jig: GC pattern resin; (Group 2) Jig: Duralay resin; (Group 3) Jig: Triad gel resin; (Group 4) Impression: closed-tray impression copings; and (Group 5) Impression: open-tray impression copings. A stone base was fabricated for each experimental jig and impression. Master stone base and experimental stone bases were measured with the following methods: X and Y coordinates of each implant center were obtained with a traveling microscope by averaging the X and Y coordinates of the implant external hex corners. The origins of the coordinates during measurement of each base were arbitrary. Distances between implant center points were calculated by use of the Pythagorean theorem. Vertical measurements (Z-plane) were obtained with a digital caliper at the 2 terminal-implant locations. Interimplant distances and vertical measurements were subtracted from those of the master base, and the resultant distortion values were analyzed with analysis of variance and Tukey Studentized range tests. Statistical significance was set at P<.05. RESULTS: Verification jigs were not significantly more accurate than standard impression procedures. Open-tray impressions showed a significantly greater vertical distortion (Z-R location: 262 +/- 158 microm; P=.0001; Z-L location 333 +/- 189; P=.0001) compared with the other groups. Triad gel jigs showed a significantly greater distortion in one interimplant distance (C-L) than closed-tray impressions (P=.04), whereas Duralay jigs exhibited significant greater distortion than closed-tray and open-tray impressions in the interimplant distance R-C (P=.006). Although not significantly different from other groups, the closed-tray group showed the lowest mean distortion values in all measurements. CONCLUSION: Within the limitations of this study, the accuracy provided by verification jigs was not significantly superior to standard impression procedures. The results suggest that jig fabrication does not improve the dimensional accuracy of stone casts. Open-tray impressions showed a significantly greater inaccuracy in the vertical plane.     

Influence of interimplant distance on papilla formation and bone resorption: a clinical-radiographic study in dogs

Implant esthetics has been the focus of attention for the past decade, and one vital issue is the effect of interimplant distance on interimplant papilla formation and crestal bone loss. The aim of this study was to evaluate the effect of 1, 2, and 3 mm of interimplant distance on papilla formation and crestal resorption in submerged and nonsubmerged Ankylos implants after prosthetic restoration. Bilateral mandibular premolars of 7 dogs were extracted, and after 12 weeks each dog received 8 implants. Implants were placed so that 3 interimplant distances were created at 1 mm (group 1), 2 mm (group 2), and 3 mm (group 3). The sides and the position of the groups were randomly selected. Twelve weeks after placement, the implants received metallic prostheses that allowed 5 mm of space between the prosthetic contact point (CP) and the crestal bone (CB). After 8 weeks, the distance between the CP and the papilla (CP-P) and the gingival height at the distal proximal aspect of the prosthesis (CP-DE) was clinically measured. Radiographic images were obtained to measure the distance of the CP to the CB within the interimplant surfaces (CP-IP) and adjacent to the edentulous surfaces (CP-ED). The clinical measurement of CP-P for submerged and nonsubmerged implants was 3.57+/-1.17 mm and 3.10+/-0.82 mm for group 1, 3.57+/-0.78 mm and 3.16+/- 0.87 mm for group 2, and 3.35+/- 0.55 mm and 3.07+/-0.93 mm for group 3. The CP-DE was 3.25+/-0.77 mm for submerged and 2.78+/- 0.64 mm for nonsubmerged implants. The CP-IP for the submerged and nonsubmerged implants was 6.91+/-0.95 mm and 7.68+/-2.73 mm for group 1, 7.46+/-1.43 mm and 5.87+/-1.71 mm for group 2, and 7.72+/-0.81 mm and 7.59+/-1.33 mm for group 3. The CP-ED was 6.77+/-1.33 mm for submerged implants and 6.03+/-1.58 mm for nonsubmerged implants. There were no statistical significant differences for any of the measured parameters. We conclude that when the distance from the CP to the CB was 5 mm, interimplant distances of 1 to 3 mm did not affect papilla formation or crestal resorption of submerged or nonsubmerged implants in the dog model.     

The relationship between interimplant distances and vascularization of the interimplant bone

Background: Long‐term success of the implant restorations is based upon the biology and vasculature of the bone surrounding the implants, especially for the bone between two implants. Purpose: The aim of this study was to evaluate how loaded implants placed 2 or 3 mm apart influence bone vessel organization. Material and methods: Six mongrel dogs were used for the study. The four mandibular premolars were extracted and 3 months later, four 4.5 × 10 mm implants were placed on each side of the mandible. The implants were placed so that two adjacent implants were 2 mm (group 1) or 3 mm (group 2) distant from each other. After 12 weeks, the implants were loaded with provisional prostheses, then metallic crowns were placed 4 weeks later. Both temporary and metallic restorations were made so that the distance between the contact point and the bone crest was 5 mm. The animals were sacrificed after 8 weeks. The hemi‐mandibles were removed and prepared for analysis. The interimplant bone vasculature of the two groups was studied using scanning electron microscopic images fractal analysis. The fractal dimension (D_f) was calculated using the box‐counting method. Results: The values of the D_f for the blood vessels were significantly higher (P<.05) in the specimens of the group 2 (1.969±0.169) than the group 1 (1.556±0.246). Conclusion: The presence of more blood vessels in the group 2 is another indication that 3 mm is a preferable distance for contiguous implants than the 2 mm distance. To cite this article:
Traini T, Novaes AB, Piattelli A, Papalexiou V, Muglia VA. The relationship between interimplant distances and vascularization of the interimplant bone.
Clin. Oral Impl. Res. 21 , 2010; 822–829.
doi: 10.1111/j.1600‐0501.2010.01926.x