Tactile sensibility of single-tooth implants and natural teeth

AIM: The purpose of this randomized split-mouth clinical trial was to determine the active tactile sensibility between single-tooth implants and opposing natural teeth and to compare it with the tactile sensibility of pairs of natural teeth on the contralateral side in the same mouth (intraindividual comparison). MATERIAL AND METHODS: The hypothesis was that the active tactile sensibilities of the implant side and control side are equivalent. Sixty two subjects (n=36 from Bonn, n=26 from Bern) with single-tooth implants (22 anterior and 40 posterior dental implants) were asked to bite on narrow copper foil strips varying in thickness (5-200 microm) and to decide whether or not they were able to identify a foreign body between their teeth. Active tactile sensibility was defined as the 50% threshold of correct answers estimated by means of the Weibull distribution. RESULTS: The results obtained for the interocclusal perception sensibility differed between subjects far more than they differed between natural teeth and implants in the same individual [implant/natural tooth: 16.7+/-11.3 microm (0.6-53.1 microm); natural tooth/natural tooth: 14.3+/-10.6 microm (0.5-68.2 microm)]. The intraindividual differences only amounted to a mean value of 2.4+/-9.4 microm (-15.1 to 27.5 microm). The result of our statistical calculations showed that the active tactile sensibility of single-tooth implants, both in the anterior and posterior region of the mouth, in combination with a natural opposing tooth is similar to that of pairs of opposing natural teeth (double t-test, equivalence margin: +/-8 microm, P<0.001, power >80%). Hence, the implants could be integrated in the stomatognathic control circuit.     

Threshold of tactile sensitivity perceived with dental endosseous implants and natural teeth

The aim of this study was to determine the threshold of tactile perception of endosseous dental implants and to assess the relative difference of that threshold between implants and teeth. Twenty‐two subjects with implants of the ITI® Dental Implant System were included in the study. All implants served as abutments for single tooth crowns and had been in function for a minimum of 1 year. A strain gauge glued to the shaft of an amalgam plugger served as a force sensor. It transformed the elastic deformation exerted onto the shaft into an electronic signal for recording. By use of the amalgam plugger, a continuously increasing force was exercised on the implants or teeth until the first sensation of touch was indicated by the patient. Statistical analysis revealed threshold values for the implants ranging from 13.2 to 189.4g (1g=0.0lN)(mean 100.6; SD 47.7), while a range of 1.2 to 26.2g (mean 11.5; SD 11.5) was found for control teeth. Thus, the mean threshold values for implants were 8.75 times higher than for teeth. This difference was highly statistically significant. A general linear models procedure was applied to determine the influence of patient age, jaw, implant position and the threshold values of teeth on the measurements obtained for implants. Only gender and the threshold values for contralateral teeth had a significant influence. These 2 parameters together explained 27% of the variability in threshold measurements. It is concluded that a more than 8‐fold higher threshold value for tactile perception exists for implants compared with teeth.     

Comparative evaluation of the oral tactile function bv means of teeth or implant‐supported prostheses

To clarify more of the tactile function of oral implants, both an interocclusal thickness detection and discrimination task were carried out in 4 different test conditions on 37 patients: t (tooth)/t, i (implant)/t, i/i and d (denture)/o (overdenture supported by implants). For the interocclusal detection of steel foils, the 50% detection threshold level (RL) in the 4 conditions was 20, 48, 64 and 108 microns, respectively, which indicates significant differences. The ability to discriminate interdental thickness differences was tested with a 0.2 and 1.0 mm standard. It was evaluated as the 75% discrimination level (DL). In the 0.2 mm discrimination task, corresponding DL-values for the t/t, i/t, i/i and d/o condition were 25, 55, 66 and 134 microns, whereas the 1.0 mm standard gave values of 193, 293, 336 and 348 microns, respectively. All results differed significantly from each other (p less than 0.05) except for the i/i-d/o comparison of the 1.0 mm discrimination task where the difference was negligible. The present findings indicate that the tactile sensibility of implants is reduced with regard to natural teeth. Remaining receptors of the peri-implant tissues might play a compensatory role in the decreased exteroceptive function.     

Factors affecting soft tissue level around anterior maxillary single‐tooth implants

Background: Peri‐implant soft tissue recession is a major esthetic concern for the anterior implants. The aim of this study was to determine the factors that affected the facial marginal mucosal level and papilla level around single‐tooth implants in the anterior maxilla. Methods: Forty single‐tooth implants in the anterior maxilla were studied. Variables possibly associated with the soft tissue level were obtained from clinical measurements, study models, peri‐apical radiographs, and computerized tomograms. Fisher's exact test, analysis of variance, and binary logistic regression analysis were used to determine the influence of each factor on the facial marginal mucosal level and papilla level. Results: The majority of the implants (75%) replaced the upper central incisors. The facial mucosal margin of the implant was 0.5±0.9 mm more apical than that of the contralateral tooth. Half or more of papilla fill was observed in 89% of the samples. More apical level of the facial mucosal margin at the implant sites was significantly influenced by many factors including a thin peri‐implant biotype, a proclined implant fixture angle, more apical level of the facial bone crest, increased distance from the contact point to the bone crest, contact point to the platform, and contact point to implant bone. A thin biotype was the most significant factor in determining the facial marginal mucosal level. Increased distance from the contact point to the bone crest was the only factor significantly associated with less papilla fill. Conclusions: The papilla level around single‐tooth implants in the anterior maxilla was mainly influenced by the interproximal bone crest level of the adjacent tooth. Facial marginal mucosal level, on the other hand, was affected by multiple factors including the peri‐implant biotype, the facial bone crest level, the implant fixture angle, the interproximal bone crest level, the depth of implant platform, and the level of first bone to implant contact. To cite this article:
Nisapakultorn K, Suphanantachat S, Silkosessak O, Rattanamongkolgul S. Factors affecting soft tissue level around anterior maxillary single‐tooth implants.
Clin. Oral Impl. Res. 21 , 2010; 662–670.
doi: 10.1111/j.1600‐0501.2009.01887.x     

Crestal Bone Changes at Teeth and Implants in Periodontally Healthy and Periodontally Compromised Patients. A 10‐Year Comparative Case‐Series Study

Background: Limited data exist on the longitudinal crestal bone changes around teeth compared with implants in partially edentulous patients. This study sought to compare the 10‐year radiographic crestal bone changes (bone level [BL]) around teeth and implants in periodontally compromised (PCPs) and periodontally healthy (PHPs) patients. Methods: A total of 120 patients were evaluated for the radiographic crestal BL around dental implants and adjacent teeth at time of implant crown insertion and at the 10‐year follow‐up. Sixty patients had a previous history of periodontitis (PCPs), and the remaining 60 were PHPs. In each category (PCP and PHP), two different implant systems were used. The mean BL change at the implant and at the adjacent tooth at the interproximal area was calculated by subtracting the radiographic crestal BL at the time of crown cementation from the radiographic crestal BL at the 10‐year follow‐up. Results: At 10 years after therapy, the survival rate ranged from 80% to 95% for subgroups for implants, whereas it was 100% for the adjacent teeth. In all eight different patient categories evaluated, teeth demonstrated a significantly more stable radiographic BL compared with adjacent dental implants (teeth BL, 0.44 ± 0.23 mm; implant BL, 2.28 ± 0.72 mm; P <0.05). Radiographic BL changes around teeth seemed not to be influenced by the presence or absence of advanced bone loss (≥3 mm) at the adjacent implants. Conclusions: Natural teeth yielded better long‐term results with respect to survival rate and marginal BL changes compared with dental implants. Moreover, these findings also extend to teeth with an initial reduced periodontal attachment level, provided adequate periodontal treatment and maintenance are performed. As a consequence, the decision of tooth extraction attributable to periodontal reasons in favor of a dental implant should be carefully considered in partially edentulous patients.     

Long‐Term Follow‐Up of Turned Single Implants Placed in Periodontally Healthy Patients After 16 to 22 Years: Microbiologic Outcome

Background: Survival rates in implant dentistry today are high, although late failures do occur for many reasons, including peri‐implant infections. The primary objective of this study is to investigate microbiota around single turned implants after 16 to 22 years. Secondary objectives are to compare teeth and implants and to correlate microbiologic, radiographic, and clinical parameters. Methods: A total of 46 patients with single implants were invited for a clinical examination. Clinical data were collected from implants and contralateral natural teeth. Radiographic bone level was measured around implants. Microbiologic samples were taken from implants, contralateral teeth, and the deepest pocket per quadrant. Samples were analyzed with DNA‐DNA hybridization including 40 species. Statistical analysis was performed using Wilcoxon signed‐rank tests, McNemar tests, and Spearman correlation coefficients with a 0.05 significance level. Results: Mean follow‐up was 18.5 years (range 16 to 22 years). Tannerella forsythia (1.5 × 10⁵) and Veillonella parvula (1.02 × 10⁵) showed the highest concentrations around implants and teeth, respectively. Porphyromonas gingivalis, Prevotella intermedia, and T. forsythia were significantly more present around implants than teeth. Mean counts were significantly higher around implants than teeth for Parvimonas micra, P. gingivalis, P. intermedia, T. forsythia, and Treponema denticola. Total DNA count was correlated to interproximal bleeding index (r = 0.409) and interproximal probing depth (r = 0.307). No correlations were present with plaque index or radiographic bone level. Conclusions: In the present study, bacterial counts around single implants in periodontally healthy patients are rather low. Although pathogenic bacteria are present, some in higher numbers around implants than teeth (five of 40), the majority of implants present with healthy peri‐implant tissues without progressive bone loss.     

Perceptual Changes in the Anterior Maxilla after Placement of Endosseous Implants

Background: The innervation of skin and oral mucosa plays a major physiologic role in exteroception. It is also of interest clinically, as illustrated by sensory changes after neurosurgical procedures. Purpose: The goal of this study was to assess the perception of mechanical stimuli applied to the anterior maxilla in denture wearers and subjects rehabilitated with osseointegrated implants compared with that in subjects with a natural dentition. Materials and Methods: Five groups of subjects were selected and tested in the maxillary region only. Test groups included patients with a complete denture, an implant‐supported fixed prosthesis (full or partial), or a single‐tooth replacement. Light‐touch sensation and two‐point discrimination were performed on the buccal side of the alveolar mucosa and vibrotactile function was determined for natural teeth, full dentures, or implant‐supported prostheses. Results: For light‐touch sensation, no significant differences could be found between the groups. For two‐point discrimination, full‐denture patients showed higher threshold levels than the other groups. The threshold levels for vibrotactile function were higher in both full dentures and implant‐supported prostheses compared with natural dentitions. Conclusion: Natural dentitions offer superior vibrotactile function compared to any other dental status. Full dentures often show a stronger deterioration of the (vibro)tactile function compared with implant‐supported prostheses.     

A Rationale For Not Connecting Implants to Natural Teeth

When restoring partially edentulous arches with implants, there are some practitioners who believe it is occasionally beneficial to connect implants to natural teeth. This connection is performed to gain shared support from the natural tooth and implant, prevent rotation of the restoration, or sometimes merely to retain the natural tooth. A discussion and review of the literature concerning this connection is presented, and a patient treatment is shown to illustrate potential complications.     

螺钉固位种植固定义齿修复单个后牙缺失

对23例无磨牙症失牙患者植入58枚两段式(two-stage)种植体，修复47个缺失后牙作一回顾性研究。采用抗旋转上部结构进行单冠修复，并以螺钉固位，追踪观察2年．结果表明：2枚种植体愈合阶段松动拔除，种植体累计成功率为94.8％．修复后成功率97.2％，种植体固位螺钉松动1～2次者占23.6％。近期观察证明．一个或两个种植体支持单个后牙缺失修复是可行的。本文对螺钉松动的原因进行了阐述．并提出预防和处理措施。     

Incidence of inter-proximal papilla between a tooth and an adjacent immediate implant placed into a fresh extraction socket: 1-year prospective study

Background: Implant single‐tooth replacement with a natural appearance is a challenging and demanding procedure. The aim of this prospective study was to identify the factors affecting the presence of an inter‐proximal papilla between a tooth and an implant. Methods: Forty‐six patients with a total of 46 teeth scheduled for tooth extraction and immediate implant placement into fresh sockets were included in the study. Immediate implants were positioned after teeth removal. After 4 months of healing, the implants were restored with single crown fixed prostheses. The following parameters were assessed: (1) presence/absence of the inter‐proximal papilla, (2) gingival index, (3) inter‐implant–tooth distance (ITD) and (4) distance from the base of the contact point to the inter‐dental bone (CPB). A computerized analysis was performed to determine ITD and CPB values after converting perioapical radiographs to digitalized images. Statistical analyses were performed to determine the effect of ITD and CPB on the presence or absence of the inter‐proximal papilla. Results: All the implants were restored, so that a 100% of implant survival rate was observed after 12 months of function. Mean values were recorded for ITD and CPB parameters, respectively. When ITD was 3–4 mm, and CPB was 3–5 mm, the inter‐proximal papilla was significantly present (P<0.05). Conclusions: The recommended inter‐proximal space dimensions are 3–4 mm between an implant and the adjacent tooth, and 3–5 mm between the base of the CPB. The interaction between the surgical and prosthetic plans represents the key factor to optimize the edentulous site for predictable anterior single‐implant esthetics.     

In vivo measurements of some functional aspects with mandibular fixed prostheses supported by implants

Maximal occlusal force and oral tactile sensibility were recorded in 21 edentulous patients wearing maxillary complete dentures and mandibular fixed prostheses supported 1 by Brånemark implants. Bite force was measured with a miniature force transducer between antagonistic molars and premolars, and the passive tactile sensibility of the fixtures was recorded in the horizontal and vertical directions with spring balances. The active tactile sensibility was tested using steel foils 100 to 10 . The range of maximal occlusal force recorded was from 35 to 330N with highest values observed on the second premolars (mean 143N). Significantly lower forces were found on molars and first premolars ( p <0.01). The detection threshold of minimal pressure was about 330g in the horizontal, and 388g in the vertical direction. This difference was not statistically significant. The average number of incorrect assessments when testing steel foils was 16.6 errors, out of 100 recordings. Similar results when using these 3 test modalities had been found on overdentures supported by two mandibular implants and occluding with maxillary complete dentures. The results of this study suggest that mandibular implants supporting fixed prostheses are not likely to improve oral tactile sensibility and maximal occlusal force in the presence of maxillary complete dentures.     

Dimensional profile of oral mucosa around combined tooth-implant-supported bridgework in macaque mandible

Purpose: A stable oral mucosa is crucial for long‐term survival and biofunctionality of implants. Most of this evidence is derived from clinical and animal studies based solely on implant‐supported prosthesis. Much less is known about the dimensions and relationships of this soft tissue complex investing tooth‐implant‐supported bridgework (TISB). The aim here was to obtain experimental evidence on the dimensional characteristics of oral mucosa around TISB with two different abutment designs. Methods: Sixteen 3‐unit TISB were constructed bilaterally in the mandible of eight adult Macaca fascicularis. An implant system with a standard progressive thread design was the bone‐anchoring implant in the second mandibular molar region while the second mandibular premolar served as the natural tooth abutment. Eight implants were connected with the tapered abutment, the remaining with butt‐joint abutment, in a split‐mouth design. These were allowed to functional load for 6 months before sacrification for histomorphometry. Six soft tissue indices were scored: coronal gingival mucosa‐to‐implant top distance (DIM); sulcus depth (SD); junctional epithelium (JE); connective tissue contact (CTC); implant top to first bone‐to‐implant contact distance (DIB); and biologic width (BW=SD+JE+CTC); corresponding parameters in the natural tooth abutment were also measured. Results: Mucosal dimensions in tapered implants (^*BW=3.33±0.43; SD=1.03±0.24; JE=1.08±0.13; CTC=1.22±0.23 mm) were comparable with those of natural tooth abutments (BW=3.04±0.18; SD=0.93±0.1; JE=0.78±0.1; Attachment=1.33±0.09 mm), but differed from butt‐joint implants (^*BW=4.88±1.24; SD=1.47±0.38; JE=1.49±0.4; CTC=1.92±0.93 mm) (^*P<0.05). Conclusions: Results suggested that soft tissue dimensions around TISB are influenced by the implant–abutment interface and abutment material used. Mucosa investing tapered abutment tends to recapitulate soft tissue physiologic dimensions of natural tooth. To cite this article:
Siar CH, Toh CG, Ali TBT, Seiz D, Ong ST. Dimensional profile of oral mucosa around combined tooth‐implant‐supported bridgework in macaque mandible.
Clin. Oral Impl. Res. 23 , 2012 438–446.
doi: 10.1111/j.1600‐0501.2010.02145.x     

Transmission of Periodontopathic Bacteria from Natural Teeth to Implants

Purpose: Prevention of peri‐implantitis is essential for the success of implant rehabilitation. Infection by periodontopathic bacteria is a major cause of peri‐implantitis. The aim of the present study was to identify the source of peri‐implant colonization by periodontopathic bacteria. Materials and Methods: Twenty‐one patients with implants were enrolled in the study. Subgingival plaque samples from the adjacent, occluding, and contralateral natural teeth were collected prior to second‐stage surgery. Samples from implant sulci were then obtained 2 weeks later. Detection of periodontopathic bacteria was performed by the polymerase chain reaction. Results: The detection rates for Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum in all subgingival samples from natural teeth were similar to that in the peri‐implant sulci. Multiple logistic regression analysis revealed an association between the detection of A. actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, and F. nucleatum in the gingival crevices of adjacent teeth and that of the peri‐implant sulcus, but no association for Tannerella forsythia. Conclusions: The present findings suggest that colonization by A. actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, and F. nucleatum at the implant sulcus was affected by these microorganisms in the gingival crevice of adjacent teeth rather than those on occluding and contralateral teeth.     

Comparison of fit accuracy between Procera custom abutments and three implant systems

Background: Although increase of misfit has been reported when associating implant and abutment from different manufacturers, Procera® (Nobel Biocare?, Göteborg, Sweden) custom abutment has been universally used in clinical practice. Purpose: The purpose of this investigation was to compare the vertical gap of zirconia Procera abutment associated with implants from the same manufacturer (Nobel Biocare) and two other implant systems. Materials and Methods: Twenty‐four zirconia Procera abutments were produced using computer‐assisted design and manufacture (CAD/CAM) and paired with (1) eight MK Iii RP 4.1 × 10 mm implants (Nobel Biocare) – GNB group; (2) eight Try on, 4.1 × 10 mm implants (Sistema de Implantes, São Paulo, Brazil) – ES group; and (3) eight Master screw, 4.1 × 10 mm implants (Conexão Sistema de Prótese, São Paulo, Brazil) – EC group. A comparison of the vertical misfit at the implant‐abutment interface was taken at six measuring sites on each sample using scanning electron microscopy with a magnification of 408×. One‐way analysis of variance was used to test for differences, and Tukey's test was used for pairwise comparison of groups (α = 0.05). Results: Significant differences relative to average misfit were found when Procera abutments were associated with other implant manufacturers. The ES group and EC group did not differ significantly, but both demonstrated significantly larger average misfit than the GNB group (p = .001). The average misfit was 5.7 µm ± 0.39, 9.53 µm ± 0.52 and 10.62 µm ± 2.16, respectively, for groups GNB, ES, and EC. Conclusion: The association of Procera zirconia abutment with other implant systems different from its manufacturer demonstrated significant alteration of vertical misfit at implant‐abutment interface.     

Maxillary Implants Loaded at 3 Months after Insertion: Results with Astra Tech Implants after up to 5 Years

Background: To date, clinical studies have mainly focused on early loading of mandibular implants. Recently, there has also been considerable interest in early loading of maxillary implants. Purpose: The purpose of this article is to report the outcome of maxillary implants loaded after a 3‐month healing period and followed up to 5 years. Materials and Methods: Seventeen patients (11 males and 6 females) received 44 Astra Tech implants (Molndal, Sweden) for treatment of single‐tooth (13 cases) and partial edentulism (9 cases). The patients were followed up to 5 years after implant placement:50% of the implants were followed for 3 years and 16% have been followed throughout the observation period. Preoperatively, bone height and width were assessed on radiographs. Marginal bone loss was recorded on intraoral radiographs annually. Results: No implant was lost during the observation period. The average marginal bone loss was 0.5 ± 0.7 mm after 1 year, 0.6 ± 0.7 mm after 3 years, and 0.9 ± 1.6 mm after 5 years. There were no soft‐tissue or prosthetic failures recorded during the observation period. Conclusion: Early loading of Astra Tech implants was highly successful in maxillary partial and single‐tooth cases followed up to 5 years in function.     

Direct High‐Frequency Stimulation of Peri‐Implant Rabbit Bone: A Pilot Study

Objective: This study aimed to evaluate the effect of direct high‐frequency mechanical stimulation on the peri‐implant tissue healing. Materials and Methods: A total of 48 custom‐made 2‐mm diameter titanium implants were inserted in the tibial epiphyses of 12 rabbits. Half of the implants were stimulated by direct vibration (60 ± 10 Hz) immediately after insertion for 1 and 4 weeks, respectively. The other half served as controls. The samples were collected after the animals were sacrificed and were histologically processed into paraffin sections and stained with haematoxylin and eosin. The bone fraction was measured in an area of 50 and 400 µm around the implant. To rate significant differences a one‐way analysis of variance was used with α set at 5%. Results: No significant difference in bone fraction was found between test and control groups. When the bone fractions of the 50 and 400 µm peri‐implant regions were compared, a significantly larger bone fraction was found in the 50 µm peri‐implant region for the 4‐week stimulated group. Conclusion: Histomorphometric analyses could not reveal a pronounced effect of direct immediate high‐frequency implant loading.     

Comparison of Fit Accuracy between Procera® Custom Abutments and Three Implant Systems

Background: Although increase of misfit has been reported when associating implant and abutment from different manufacturers, Procera custom abutment has been universally used in clinical practice. Purpose: The purpose of this investigation was to compare the vertical gap of zirconia Procera® abutment associated with implants from the same manufacturer (Procera manufacturer) and two other implant systems. Materials and Methods: Twenty‐four zirconia Procera abutments were produced using computer‐assisted design and manufacture and paired with (a) eight MK III, RP 4.1 × 10 mm implants (Nobel Biocare?, Göteborg, Sweden) – GNB group (Nobel Biocare group); (b) eight Try on, 4.1 × 10 mm implants (Sistema de Implantes, São Paulo, Brazil) – ES group (SIN experimental group) ; and (c) eight Master screw, 4.1 × 10 mm implants (Conexão® Sistema de Prótese, São Paulo, Brazil) – EC group (Conexão experimental group). A comparison of the vertical misfit at the implant–abutment interface was taken at six measuring sites on each sample using scanning electron microscopy with a magnification of 408×. One‐way analysis of variance was used to test for differences, and Tukey's test was used for pair‐wise comparison of groups (α = 0.05). Results: Significant differences relative to average misfit were found when Procera abutments were associated with other implant manufacturers. The ES group and EC group did not differ significantly, but both demonstrated significantly larger average misfit than the GNB group (p = .001). The average misfit was 5.7 µm ± 0.39, 9.53 µm ± 0.52, and 10.62 µm ± 2.16, respectively, for groups GNB, ES, and EC. Conclusion: The association of Procera zirconia abutment with other implant systems different from its manufacturer demonstrated significant alteration of vertical misfit at implant–abutment interface.     

A clinical, radiographic, and microbiologic comparison of Astra Tech and Brånemark single tooth implants

Background: The soft tissues around single tooth implants differ fundamentally from the gingiva around natural teeth. There are very limited data comparing soft tissues around different implant systems. Aim: To assess whether the design characteristics of dental implants, particularly the implant‐abutment junction, may affect the dimensions and health of the peri‐implant soft tissues and radiographic bone levels. Subjects and Method: Fifteen Astra Tech and 15 Brånemark single tooth implants that had been in function for a minimum of 2 years in 30 partially dentate subjects were examined for plaque accumulation, probing depth, and bleeding on probing and compared to contralateral healthy teeth. Standardized radiographs were taken to measure the most coronal bone to implant contact on the mesial and distal surfaces. In addition, samples of subgingival plaque were taken on paper points and examined by darkfield microscopy. Results: Significantly higher mean probing depths (p < .001) and higher mean percentage of spirochetes (p= .003) were found at implants compared to teeth. In this sample, the Brånemark implants had significantly higher probing depths than the Astra Tech implants (median and interquartile range: Astra Tech 2.7 mm [2–3], Brånemark 3.3 mm [3–3.7] p= .026) and the most coronal bone to implant contact was closer to the implant–abutment junction in the Astra Tech implants (Astra Tech 0.6 mm [0.2–0.9], Brånemark 1.6 mm [1.4–2.0]. p < .001). Conclusion: Although there were statistically significant differences between the two implant systems, the clinical differences were small and probably reflect differences in the biologic width in relation to the location and design of the implant‐abutment junction.     

Biomarkers and Bacteria Around Implants and Natural Teeth in the Same Individuals

Background: This cross‐sectional study assesses cytokine levels in peri‐implant crevicular fluid (PICF)/gingival crevicular fluid (GCF) and a selection of subgingival/submucosal plaque bacteria from clinically healthy or diseased sites in the same individuals. Methods: Samples from 97 implants/teeth (58 implants [19 healthy, 20 mucositis, 19 peri‐implantitis] and 39 natural teeth [19 healthy, 12 gingivitis, eight periodontitis] in 15 systemically healthy patients were investigated by immunoassay and real‐time polymerase chain reaction. Samples were obtained first, with probing depth, clinical attachment level, bleeding on probing, plaque index scores, and keratinized tissue width then recorded. Data were analyzed by Wilcoxon, Mann–Whitney U, and permutation tests on dependent, independent, and mixed dependent and independent samples and Spearman correlation. Results: Interleukin (IL)‐1β levels were significantly higher in PICF samples of healthy implants than in GCF samples of healthy teeth (P = 0.003), and soluble receptor activator of nuclear factor‐κB ligand (sRANKL) concentrations were significantly higher in the gingivitis than the mucositis group (P = 0.004). Biomarker levels were similar in peri‐implantitis and periodontitis groups (P >0.05). Actinomyces naeslundi and Streptococcus oralis levels were significantly higher in the healthy implant group than in healthy teeth (P <0.05). Prevotella intermedia and Treponema denticola (Td) levels were lower in the mucositis group than the gingivitis group (P <0.05). Prevotella oralis and S. oralis levels were significantly higher in the periodontitis group (P <0.05), and Td levels were significantly higher in the peri‐implantitis group (P <0.05). Conclusion: There were many similarities but, crucially, some differences in biomarker levels (IL‐1β and sRANKL) and bacterial species between peri‐implant and periodontal sites in the same individuals, suggesting similar pathogenic mechanisms.