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.     

The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla.

This study was designed to determine whether the distance from the base of the contact area to the crest of bone could be correlated with the presence or absence of the interproximal papilla in humans. A total of 288 sites in 30 patients were examined. If a space was visible apical to the contact point, then the papilla was deemed missing; if tissue filled the embrasure space, the papilla was considered to be present. The results showed that when the measurement from the contact point to the crest of bone was 5 mm or less, the papilla was present almost 100% of the time. When the distance was 6 mm, the papilla was present 56% of the time, and when the distance was 7 mm or more, the papilla was present 27% of the time or less.     

Effect of the vertical and horizontal distances between adjacent implants and between a tooth and an implant on the incidence of interproximal papilla

BACKGROUND: The interproximal dental papilla is considered an essential component of the anterior and posterior regions of the maxilla and mandible. The absence of this structure has esthetic and phonetical consequences and lateral food impaction problems occur with the implant-supported prosthesis. The aims of the present study were to: 1) evaluate the effect of the vertical and horizontal distances between adjacent implants (group 1) and between a tooth and an implant (group 2) on the presence of the interproximal dental papilla; and 2) determine whether the interaction between the vertical and horizontal distances might be associated with the incidence of the papilla. METHODS: In 48 patients, 96 interproximal sites in group 1 and 80 in group 2 were examined. The distance from the base of the contact point to the bone crest (D1), the distance between tooth and implant or between two implants (D2), and the distance from the base of the contact point to the tip of the papilla (D3) were measured. RESULTS: In both groups, when D2 was 3, 3.5, or 4 mm, the papilla was present most of the time (P < 0.05), and when D2 was 2 or 2.5 mm, the papilla was absent 100% of the time (P < 0.05). Further, in group 2, when D1 was between 3 and 5 mm, the papilla was present most of the time (P < 0.05). However, in Group 1, only when D1 was 3.0 mm was the papilla present most of the time (P < 0.05). For both groups, analysis of the interaction between D1 and D2 showed that when D2 was < or = 2.5 mm, the papilla was absent; otherwise, when D2 was > or = 3 mm, there was an interaction between D1 and D2. CONCLUSIONS: We conclude that the ideal distance from the base of the contact point to the bone crest between adjacent implants is 3 mm and, between a tooth and an implant, 3 mm to 5 mm. The ideal lateral spacing between implants and between tooth and implant is 3 mm to 4 mm. Further, there is an interaction between horizontal and vertical distances when the lateral spacing is greater than 3 mm.     

The effects of interproximal distance between roots on the existence of interdental papillae according to the distance from the contact point to the alveolar crest

BACKGROUND: This study investigated the existence of interdental papillae at certain distances from the contact point to the alveolar crest, depending on the interproximal distance between roots. METHODS: A total of 206 papillae from 80 patients were examined after the inflammation of the papillae had been minimized using non-surgical periodontal therapy. The existence of the interdental papillae was determined using the following categorization: 1) papillae were deemed to be absent if they did not extend all the way up to the contact point between the teeth; and 2) papillae were determined to be present if they filled up to the entire proximal space. The interproximal distance between roots and the distance from the contact point to the alveolar crest were measured when a full-thickness flap was used. The number of papillae present interproximally between roots, according to the distance from the contact point to the alveolar crest, was analyzed using the x2 analysis method, and the linear-by-linear association analysis method was used for trend analysis. RESULTS: The number of papillae that filled the interproximal space decreased with increasing distance from the contact point to the alveolar crest (P <0.05). In addition, the number of papillae that filled the interproximal space decreased with increasing interproximal distance between roots (P <0.05) and became more prominently decreasing with the increasing distance from the contact point to the alveolar crest (especially 4, 5, and 6 mm) (P <0.05). CONCLUSION: The results suggest that the interproximal distance between roots and the distance between the contact point and the alveolar crest have an independent and combined effect on the existence of interproximal papillae.     

The effect of inter-implant distance on the height of inter-implant bone crest

BACKGROUND: The biologic width around implants has been well documented in the literature. Once an implant is uncovered, vertical bone loss of 1.5 to 2 mm is evidenced apical to the newly established implant-abutment interface. The purpose of this study was to evaluate the lateral dimension of the bone loss at the implant-abutment interface and to determine if this lateral dimension has an effect on the height of the crest of bone between adjacent implants separated by different distances. METHODS: Radiographic measurements were taken in 36 patients who had 2 adjacent implants present. Lateral bone loss was measured from the crest of bone to the implant surface. In addition, the crestal bone loss was also measured from a line drawn between the tops of the adjacent implants. The data were divided into 2 groups, based on the inter-implant distance at the implant shoulder. RESULTS: The results demonstrated that the lateral bone loss was 1.34 mm from the mesial implant shoulder and 1.40 mm from the distal implant shoulder between the adjacent implants. In addition, the crestal bone loss for implants with a greater than 3 mm distance between them was 0.45 mm, while the implants that had a distance of 3 mm or less between them had a crestal bone loss of 1.04 mm. CONCLUSIONS: This study demonstrates that there is a lateral component to the bone loss around implants in addition to the more commonly discussed vertical component. The clinical significance of this phenomenon is that the increased crestal bone loss would result in an increase in the distance between the base of the contact point of the adjacent crowns and the crest of bone. This could determine whether the papilla was present or absent between 2 implants as has previously been reported between 2 teeth. Selective utilization of implants with a smaller diameter at the implant-abutment interface may be beneficial when multiple implants are to be placed in the esthetic zone so that a minimum of 3 mm of bone can be retained between them at the implant-abutment level.     

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.     

Gingival papilla dimensions in anterosuperior regions adjacent to single-tooth implants

This study compared the dimensions of gingival papillae in anterosuperior areas presenting at natural teeth (teeth sites) or single-tooth implants adjacent to natural teeth (implant-tooth sites) by analyzing determined distances. A total of 45 teeth and 46 implant-tooth sites were carefully selected. Clinical evaluation consisted of visual and quantitative analyses with millimeter grids on radiographs. Implant-tooth sites showed a smaller gingival papilla dimension than tooth sites (P < .01). Both evaluated distances (contact point to bone crest and between the roots of adjacent teeth or implant platform to root of adjacent tooth) in all groups significantly influenced the presence/absence of gingival papillae (P < .01).     

Stress in bone adjacent to dental implants

summary Finite element analysis (FEA) was employed to assess patterns of stress in bone adjacent to an implant after application of loads through an attached distal extension cantilever. Under all loading conditions, the highest stresses occurred at the distal cervical bone margin adjacent to the cantilever. In clinical studies, this is not consistently the site of the greatest bone changes seen radiographically. This suggests that extrapolation of FEA studies to clinical implantology should be approached with caution until further data become available on both mechanical properties of bone and patterns of bone remodelling induced by defined functional stresses in mandible and maxillae.     

Inter-implant bone height changes in anterior maxillary immediate and non-immediate adjacent dental implants

BACKGROUND: The purpose of this study was to evaluate inter-implant bone crest height changes between immediate and non-immediate dental implants placed in the anterior maxillary region. METHODS: A retrospective study was conducted on consecutively treated patients requiring at least two adjacent implants in the anterior maxillary region that were placed in the same operation during 1994 to 2004. Files of 45 healthy patients reporting 200 implants were reviewed. Age, gender, smoking status, and implant characteristics (coating and dimensions) were recorded. Inter-implant bone measurements were taken on two panoramic radiographs from each patient: one after implant placement and the other at the last follow-up. The distance between adjacent implants was measured at the implant-abutment interface (implant platform). RESULTS: Overall, 130 inter-implant gaps were found. Follow-up ranged from 8 to 146 months. Two-tailed Pearson correlation tests revealed a negative correlation between inter-implant distance and bone loss (P = 0.036). Mean peak-crest bone loss for immediate implants was higher than for delayed implants (P = 0.026). There was more bone loss when hydroxyapatite (HA)-coated implants were used, although no statistical significance was observed. No statistically significant difference was found between the different locations in the anterior maxilla. No correlation was found between patient's age, smoking habits, and bone loss or between follow-up time and bone loss. CONCLUSIONS: A negative correlation was found between inter-implant distance and bone loss at the inter-implant bone crest in the anterior maxillary region. Bone loss was small in this study cohort.     

Comparison of interproximal soft tissue height for single implants and contra-lateral natural teeth

Objective: To compare the interproximal soft tissue dimensions adjacent to single implant restorations in the premolar–molar position with those adjacent to the contra-lateral natural teeth.
Material and methods: Twenty-five patients with a single-tooth implant in premolar–molar position and healthy contra-lateral teeth were enrolled in this retrospective cross-sectional study. The reason for the extraction was periodontitis. Radiographs were used to measure the shortest distance from the tip of the papilla to the crestal bone in single implants and contra-lateral teeth. A Wilcoxon's signed-ranks test was used to examine the differences between the interproximal soft tissue dimensions adjacent to the single-tooth implant restorations (IS-STI) from those of the contra-lateral natural teeth (IS-NT).
Results: We found no significant difference between the mesial IS-STI and the mesial IS-NT (3.28±0.83/3.31±0.62; P =0.861), or between the distal IS-STI and the distal IS-NT (3.09±0.72/3.3±0.63; P =0.263).
Conclusions: The interproximal soft tissue height adjacent to single-implant-supported restorations in the premolar–molar position is similar to that adjacent to the contra-lateral natural teeth.     

相邻牙间的邻面接触与食物嵌塞的关系

食物嵌塞是口腔科的常见病征,也是口腔修复的常见并发症,常给患者带来极大的痛苦。其病因复杂,发病机制不明,至今仍缺乏有效的治疗方法。已有研究表明：相邻牙间的邻面接触不良是食物嵌塞的主要原因,并指出食物嵌塞治疗的根本是恢复正常的、紧密的邻面接触并在咀嚼功能运动过程中维持紧密的邻面接触不分离。本文就影响相邻牙邻面接触区的因素,邻面接触的检测手段及邻面接触异常与食物嵌塞的关系作一综述。     

De novo alveolar bone formation adjacent to endosseous implants

OBJECTIVE: To describe a model for the investigation of different phases of wound healing that are involved in the process resulting in osseointegration. MATERIAL AND METHODS: The implants used for the study of early healing had a geometry that corresponded to that of a solid screw implant with an SLA surface configuration. A circumferential trough had been prepared within the thread region (intra-osseous portion) that established a geometrically well-defined wound compartment. Twenty Labrador dogs received 160 experimental devices totally to allow the evaluation of healing between 2 h and 12 weeks. Both ground sections and decalcified sections were prepared from different implant sites. RESULTS: The experimental chamber used appeared to be conducive for the study of early phases of bone formation. The ground sections provided an overview of the various phases of soft and hard tissue formation, while the decalcified, thin sections enabled a more detailed study of events involved in bone tissue modeling and remodeling. The initially empty wound chamber became occupied with a coagulum and a granulation tissue that was replaced by a provisional matrix. The process of bone formation started already during the first week. The newly formed bone present at the lateral border of the cut bony bed appeared to be continuous with the parent bone, but woven bone was also found on the SLA surface at a distance from the parent bone. This primary bone that included trabeculae of woven bone was replaced by parallel-fibered and/or lamellar bone and marrow. Between 1 and 2 weeks, the bone tissue immediately lateral to the pitch region, responsible for primary mechanical stability of the device, became resorbed and replaced with newly formed viable bone. Despite this temporary loss of hard tissue contact, the implants remained clinically stable at all times. CONCLUSION: Osseointegration represents a dynamic process both during its establishment and its maintenance. In the establishment phase, there is a delicate interplay between bone resorption in contact regions (between the titanium body and mineralized bone) and bone formation in 'contact- free' areas. During the maintenance phase, osseointegration is secured through continuous remodeling and adaptation to function.     

Vertical alveolar crest bone maintenance around implants in two-stage surgery: an in situ study in dogs

The aim of this study was to evaluate in situ changes in the alveolar crest bone height around immediate implant-supported crowns in comparison to tooth-supported crowns (control) with the cervical margins located at the bone crest level, without occlusal load. In Group I, after extraction of 12 mandibular premolars from 4 adult dogs, implants from Branemark System (MK III TiU RP 4.0 x 11.5 mm) were placed to retain complete acrylic crowns. In Group II, premolars were prepared to receive complete metal crowns. Sixteen weeks after placement of the crowns (38 weeks after tooth extraction), the height of the alveolar bone crest was measured with a digital caliper. Data were analyzed statistically by the Mann-Whitney test at 5% significance level. The in situ analysis showed no statistically significant difference (p=0.880) between the implant-supported and the tooth-supported groups (1.528 + 0.459 mm and 1.570 + 0.263 mm, respectively). Based on the findings of the present study, it may be concluded that initial peri-implant bone loss may result from the remodeling process necessary to establish the biological space, similar to which occurs with tooth-supported crowns.     

BMP stimulation of bone response adjacent to titanium implants in vivo

The objective of this study was to evaluate the effect of bone morphogenetic protein (BMP) on the bond strength of titanium (Ti) implants at the bon-implant interface. Thirty-six Brånemark screw implants (3.75 mm diameter by 15 mm long) were implanted for 3 and 12 weeks. At 3 weeks after implantation, the mean reverse torque value for implants stimulated with BMP delivered using an atelopeptide type-1 collagen carrier (74.2±5.2 N cm) was observed to be statistically greater (P<0.000016) than the mean reverse torque value for control Ti implants (32.8±1.1 N cm). Similarly, at 12 weeks after implantation, the mean reverse torque value for implants stimulated with BMP (89.2±2.7 N cm) was statistically greater (P<0.0042) than the mean reverse torque value for control Ti implants (75.8±2.4 N cm). In addition, hisiomorphometric evaluations indicated more bone contact with the BMP stimulated implant surfaces compared to the controls after 3 weeks implantation. It was concluded from this study that the use of BMP-atelopeptide type-1 collagen mixture is an effective means of obtaining greater bond strength at the bone-implant interface within a shorter time period than Ti implants without BMP.     

Crestal bone changes on platform-switched implants and adjacent teeth when the tooth-implant distance is less than 1.5 mm

Because of the peri-implant bone resorption that occurs when a non-platform switched implant is exposed to the oral environment, it has been recommended to maintain 1.5 mm between the tooth and implant to preserve the bone adjacent to the teeth. Several studies have documented that platform-switched implants have less peri-implant bone resorption than matched implants. This retrospective radiographic analysis studied 70 platform-switched implants placed less than 1.5 mm from an adjacent tooth and with prostheses loaded for a minimum of 6 months. The mean distance between the implant and tooth was 0.99 mm (range, 0.20 to 1.49 mm); the mean horizontal and vertical bone resorption was 0.36 and 0.43 mm, respectively. The mean bone peak reduction was 0.37 mm. The results confirm that the use of platform-switched implants reduces bone resorption after two-piece implants have been uncovered and that it is possible to place this type of implant 1 mm from teeth while maintaining the bone level adjacent to them (the bone peak).     

Radiographic evaluation of crestal bone levels adjacent to nonsubmerged titanium implants

Several parameters have been described to determine success or failure in long-term evaluations of dental implants. One of these parameters is the observation of changes in peri-implant bone levels. Studies on submerged implants have analyzed the bone level changes in the pre- and post-loading phases. No such data exist for intentionally nonsubmerged implants. The purposes of this study were: (1) to test the applicability and reproducibility of a simple computer-assisted method in the evaluation of changes in peri-implant bone levels; (2) to establish a baseline for the longterm radiographic follow-up; and (3) to evaluate changes in crestal bone levels adjacent to nonsubmerged ITI implants between the 1-year and 2-year examination. Standardized periapical radiographs were obtained from 80 implants at the 1-year and 2-year follow-up examinations after their placement. The implants were located in different jaw areas of 55 patients and supported single crowns or short-span fixed partial dentures. For each implant, the distance from implant shoulder to first crestal bone contact (DIB) was measured at the proximal surfaces with a digitizer/computer assembly. Statistically significant greater mean DIB were found at the 1-year (baseline) evaluation for: (1) maxillary sites overall (4.10 x 1.02 mm (SD)) compared with mandibular sites overall (3.61 +/- 1.03 mm); (2) maxillary anterior sites (4.08 +/- 0.97 mm) compared with mandibular posterior sites (3.60 +/- 1.05 mm); and (3) maxillary posterior sites (4.13 +/- 1.12 mm) compared with mandibular posterior sites. No statistically significant changes in DIB occurred in any of the jaw locations between the 1-year and 2-year evaluations.(ABSTRACT TRUNCATED AT 250 WORDS)