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.

Cyclooxygenase-2 inhibition selectively attenuates bone morphogenetic protein-6 synthesis and bone formation during guided tissue regeneration in a rat model

OBJECTIVES: Bone formation during guided tissue regeneration is a tightly regulated process involving cells, extracellular matrix and growth factors. The aims of this study were (i) to examine the expression of cyclooxygenase-2 (COX-2) during bone regeneration and (ii) the effects of selective COX-2 inhibition on osseous regeneration and growth factor expression in the rodent femur model. MATERIAL AND METHODS: A standardized transcortical defect of 5 x 1.5 mm was prepared in the femur of 12 male rats and a closed half-cylindrical titanium chamber was placed over the defect. The expression of COX-2 and of platelet-derived growth factor-B (PDGF-B), bone morphogenetic protein-6 (BMP-6) and insulin-like growth factor-I/II (IGF-I/II) was analyzed at Days 3, 7, 21 and 28 semiquantitatively by reverse transcriptase-polymerase chain reaction and immunohistochemistry. The effects of COX-2 inhibition by intraperitoneal injection of NS-398 (3 mg/kg/day) were analyzed in five additional animals sacrificed at Day 14. RESULTS: Histomorphometry revealed that new bone formation occurred in the cortical defect area as well as in the supracortical region, i.e. region within the chamber by Day 7 and increased through Day 28. Immunohistochemical evidence of COX-2 and PDGF-B levels were observed early (i.e. Day 3) and decreased rapidly by Day 7. BMP-6 expression was maximal at Day 3 and slowly declined by Day 28. In contrast, IGF-I/II expression gradually increased during the 28-day period. Systemic administration NS-398 caused a statistically significant reduction (P<0.05) in new bone formation (25-30%) and was associated with a statistically significant reduction in BMP-6 protein and mRNA expression (50% and 65% at P<0.05 and P<0.01, respectively). PDGF-B mRNA or protein expression was not affected by NS-398 treatment. CONCLUSION: COX-2 inhibition resulted in reduced BMP-6 expression and impaired osseous regeneration suggesting an important role for COX-2-induced signaling in BMP synthesis and new bone formation.

Evaluation of a novel biphasic calcium phosphate in standardized bone defects: a histologic and histomorphometric study in the mandibles of minipigs

OBJECTIVE: A novel biphasic calcium phosphate (CaP) granulate consisting of hydroxyapatite (HA) and beta-tricalciumphosphate (TCP) was compared with pure HA and pure TCP and with autograft as positive control. MATERIALS AND METHODS: Four standardized bone defects were prepared in both mandibular angles of 16 minipigs and grafted with autogenous bone chips, HA, HA/TCP (60% : 40%), or TCP. Histologic and histomorphometric analysis of bone formation and graft degradation followed healing periods of 2, 4, 8, and 24 weeks. RESULTS: 2 weeks: more bone formation in defects filled with autograft than with the three CaP materials (P<0.05). 4 weeks: bone formation differed significantly (P<0.05) between all four materials (autograft>TCP>HA/TCP>HA). 8 weeks: more bone formation in defects with autograft and TCP than with HA/TCP (P<0.05), and HA/TCP had more bone formation than HA (P<0.05). 24 weeks: no difference in bone formation between the groups. Autograft and TCP resorbed quickly and almost completely over 8 weeks, whereas HA/TCP and HA showed limited degradation over 24 weeks. CONCLUSION: All defects healed with mature lamellar bone and intimate contact between bone and the remaining graft material. The rate of bone formation corresponded to the content of TCP in the CaP materials.

Clinical field trial examining an implant with a sand-blasted, acid-etched surface

BACKGROUND: Conventionally, endosseous dental implants have required 3 to 6 months of uninterrupted healing based on observations for dental implants that were characterized by a relatively smooth machined surface. Many studies have since demonstrated that implants with a roughened surface resulted in greater bone apposition, earlier bone contact, and a stronger bond between the implant and the bone, suggesting that implants with roughened surfaces could be loaded earlier than 3 to 6 months. Formal clinical studies confirmed that implants with rough surfaces can have abutments placed and be loaded occlusally as early as 6 weeks postplacement. The purpose of this prospective, human clinical investigation was to evaluate a large number of implants with a specific rough surface (sand-blasted acid-etched [SLA]) placed in everyday practice under routine private-practice conditions. METHODS: A prospective, multicenter, human clinical observational study was initiated with the goal of recruiting a minimum of 500 patients and 800 implants. The implants were to be placed and restored in predominantly private-practice settings around the world. Ninety-two practitioners in 16 countries agreed to participate, and 86 followed the study design. Patients had to be in good health, have sufficient bone to encase the implant, and agree to return for recall appointments. Exclusion criteria included heavy smoking (>10 cigarettes a day) and bone augmentation procedures at the implant site. All implants were two-piece (an abutment was to be placed after 6 weeks of healing) and were characterized by the presence of a transmucosal polished collar. Each implant had an SLA surface. All implants were positioned using a non-submerged (single-stage) surgical technique. Survival and success rates were calculated by life-table analyses. RESULTS: A total of 706 patients were enrolled and 1,406 implants were placed. In the final analyses, 590 patients with 990 implants (70.4% of those enrolled) met all inclusion criteria, including placement of an abutment and provisional restoration within 63 days of surgical placement. The majority of implants were 10 and 12 mm long (78.7%) and were placed in type II and III bone (87%). Seventy-three percent of the implants were placed in the mandible, and 27% were placed in the maxilla. The cumulative survival rate was 99.56% at 3 years and 99.26% at 5 years. The overall success rate was 99.12% at 3 years and 97.38% after 5 years. CONCLUSIONS: Under private-practice conditions, implants with an SLA surface could be placed and restored predictably within 6 to 8 weeks. Data from this prospective, multicenter, human observational study reinforced the results of more formal clinical studies and demonstrated that implants with the SLA surface can be restored in patients in approximately half of the time of conventional healing periods.

The influence of BMP-2 and its mode of delivery on the osteoconductivity of implant surfaces during the early phase of osseointegration

Osteogenic agents, such as bone morphogenetic protein-2 (BMP-2), can stimulate the degradation as well as the formation of bone. Hence, they could impair the osteoconductivity of functionalized implant surfaces. We assessed the effects of BMP-2 and its mode of delivery on the osteoconductivity of dental implants with either a naked titanium surface or a calcium-phosphate-coated one. The naked titanium surface bore adsorbed BMP-2, whilst the coated one bore incorporated, adsorbed, or incorporated and adsorbed BMP-2. The implants were inserted into the maxillae of adult miniature pigs. The volume of bone deposited within a defined "osteoconductive" (peri-implant) space, and bone coverage of the implant surface delimiting this space, were estimated morphometrically 1-3 weeks later. After 3 weeks, the volume of bone deposited within the osteoconductive space was highest for coated and uncoated implants bearing no BMP-2, followed by coated implants bearing incorporated BMP-2; it was lowest for coated implants bearing only adsorbed BMP-2. Bone-interface coverage was highest for coated implants bearing no BMP-2, followed by coated implants bearing either incorporated, or incorporated and adsorbed BMP-2; it was lowest for uncoated implants bearing adsorbed BMP-2. Hence, the osteoconductivity of implant surfaces can be significantly modulated by BMP-2 and its mode of delivery.

Immediate implant placement with transmucosal healing in areas of aesthetic priority. A multicentre randomized-controlled clinical trial I. Surgical outcomes

OBJECTIVES: To compare the clinical outcomes of standard, cylindrical, screw-shaped to novel tapered, transmucosal (Straumann Dental implants immediately placed into extraction sockets. Material and methods: In this randomized-controlled clinical trial, outcomes were evaluated over a 3-year observation period. This report deals with the need for bone augmentation, healing events, implant stability and patient-centred outcomes up to 3 months only. Nine centres contributed a total of 208 immediate implant placements. All surgical and post-surgical procedures and the evaluation parameters were discussed with representatives of all centres during a calibration meeting. Following careful luxation of the designated tooth, allocation of the devices was randomly performed by a central study registrar. The allocated SLA titanium implant was installed at the bottom or in the palatal wall of the extraction socket until primary stability was reached. If the extraction socket was >or=1 mm larger than the implant, guided bone regeneration was performed simultaneously (Bio Oss and BioGide. The flaps were then sutured. During non-submerged transmucosal healing, everything was done to prevent infection. At surgery, the need for augmentation and the degree of wound closure was verified. Implant stability was assessed clinically and by means of resonance frequency analysis (RFA) at surgery and after 3 months. Wound healing was evaluated after 1, 2, 6 and 12 weeks post-operatively. RESULTS: The demographic data did not show any differences between the patients receiving either standard cylindrical or tapered implants. All implants yielded uneventful healing with 15% wound dehiscences after 1 week. After 2 weeks, 93%, after 6 weeks 96%, and after 12 weeks 100% of the flaps were closed. Ninety percent of both implant designs required bone augmentation. Immediately after implantation, RFA values were 55.8 and 56.7 and at 3 months 59.4 and 61.1 for cylindrical and tapered implants, respectively. Patient-centred outcomes did not differ between the two implant designs. However, a clear preference of the surgeon's perception for the appropriateness of the novel-tapered implant was evident. CONCLUSIONS: This RCT has demonstrated that tapered or standard cylindrical implants yielded clinically equivalent short-term outcomes after immediate implant placement into the extraction socket.

Impact of pore size on the vascularization and osseointegration of ceramic bone substitutes in vivo

The repair of bone defects with biomaterials depends on a sufficient vascularization of the implantation site. We analyzed the effect of pore size on the vascularization and osseointegration of biphasic calcium phosphate particles, which were implanted into critical-sized cranial defects in Balb/c mice. Dense particles and particles with pore sizes in the ranges 40-70, 70-140, 140-210, and 210-280 mum were tested (n = 6 animals per group). Angiogenesis, vascularization, and leukocyte-endothelium interactions were monitored for 28 days by intravital microscopy. The formation of new bone and the bone-interface contact (BIC) were determined histomorphometrically. Twenty-eight days after implantation, the functional capillary density was significantly higher with ceramic particles whose pore sizes exceeded 140 mum [140-210 mum: 6.6 (+/-0.8) mm/mm(2); 210-280 mum: 7.3 (+/-0.6) mm/mm(2)] than with those whose pore sizes were lesser than 140 mum [40-70 mum: 5.3 (+/-0.4) mm/mm(2); 70-140 mum: 5.6 (+/-0.3) mm/mm(2)] or with dense particles [5.7 (+/-0.8) mm/mm(2)]. The volume of newly-formed bone deposited within the implants increased as the pore size increased [40-70 mum: 0.07 (+/-0.02) mm(3); 70-140 mum: 0.10 (+/-0.06) mm(3); 140-210 mum: 0.13 (+/-0.05) mm(3); 210-280 mum: 0.15 (+/-0.06) mm(3)]. Similar results were observed for the BIC. The data demonstrates pore size to be a critical parameter governing the dynamic processes of vascularization and osseointegration of bone substitutes. (c) 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007.

Oral implants placed in bone defects treated with Bio-Oss, Ostim-Paste or PerioGlas: an experimental study in the rabbit tibiae

OBJECTIVES: To compare the histological features of bone filled with Bio-Oss, Ostim-Paste or PerioGlas placed in defects in the rabbit tibiae by evaluating bone tissue composition and the integration of titanium implants placed in the grafted bone. MATERIAL AND METHODS: Two cylindrical bone defects, about 4 mm in diameter and 6 mm in depth, were created in the tibiae of 10 rabbits. The defects were filled with either Bio-Oss, PerioGlas, Ostim-Paste or left untreated, and covered with a collagen membrane. Six weeks later, one titanium sandblasted and acid-etched (SLA) implant was inserted at the centre of each previously created defect. The animals were sacrificed after 6 weeks of healing. RESULTS: Implants placed in bone previously grafted with Bio-Oss, PerioGlas or Ostim-Paste obtained a larger extent of osseointegration, although not statistically significant, than implants placed in non-grafted bone. The three grafting materials seemed to perform in a similar way concerning their contribution towards implant osseointegration. All grafting materials appeared to be osteoconductive, thus leading to the formation of bridges of mineralized bone extending from the cortical plate towards the implants surface through the graft scaffold. CONCLUSIONS: Grafting with the above-mentioned biomaterials did not add any advantage to the osseointegration of titanium SLA implants in a self-contained defect.

A systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation

OBJECTIVES: The objectives of this systematic review were to assess the survival rate of grafts and implants placed with sinus floor elevation. MATERIAL AND METHODS: An electronic search was conducted to identify studies on sinus floor elevation, with a mean follow-up time of at least 1 year after functional loading. RESULTS: The search provided 839 titles. Full-text analysis was performed for 175 articles resulting in 48 studies that met the inclusion criteria, reporting on 12,020 implants. Meta-analysis indicated an estimated annual failure rate of 3.48% [95% confidence interval (CI): 2.48%-4.88%] translating into a 3-year implant survival of 90.1% (95% CI: 86.4%-92.8%). However, when failure rates was analyzed on the subject level, the estimated annual failure was 6.04% (95% CI: 3.87%-9.43%) translating into 16.6% (95% CI: 10.9%-24.6%) of the subjects experiencing implant loss over 3 years. CONCLUSION: The insertion of dental implants in combination with maxillary sinus floor elevation is a predictable treatment method showing high implant survival rates and low incidences of surgical complications. The best results (98.3% implant survival after 3 years) were obtained using rough surface implants with membrane coverage of the lateral window.

Two-year outcome with Nobel Direct implants: a retrospective radiographic and microbiologic study in 10 patients

INTRODUCTION: The Nobel Direct implant (Nobel Biocare AB, Göteborg, Sweden) was developed to minimize marginal bone resorption and to result in "soft tissue integration" for an optimized aesthetic outcome. However, conflicting results have been presented in the literature. The aim of this present study was to evaluate the clinical and microbiologic outcomes of Nobel Direct implants. MATERIALS AND METHODS: Ten partially edentulous subjects without evidence of active periodontitis (mean age 55 years) received 12 Nobel Direct implants. Implants were loaded with single crowns after a healing period of 3 to 6 months. Treatment outcomes were assessed at month 24. Routine clinical assessments, intraoral radiographs, and microbiologic samplings were made. Histologic analysis of one failing implant and chemical spectroscopy around three unused implants was performed. Paired Wilcoxon signed-rank test was used for the evaluation of bone loss; otherwise, descriptive analysis was performed. RESULTS: Implants were functionally loaded after 3 to 6 months. At 2 years, the mean bone loss of remaining implants was 2.0 mm (SD +/- 1.1 mm; range: 0.0-3.4 mm). Three out of 12 implants with an early mean bone loss >3 mm were lost. The surviving implants showed increasing bone loss between 6 and 24 months (p = .028). Only 3 out of the 12 implants were considered successful and showed bone loss of <1.7 mm after 2 years. High rates of pathogens, including Aggregatibacter actinomycetemcomitans, Fusobacterium spp., Porphyromonas gingivalis, Pseudomonas aeruginosa, and Tanerella forsythia, were found. Chemical spectroscopy revealed, despite the normal signals from Ti, O, and C, also peaks of P, F, S, N, and Ca. A normal histologic image of osseointegration was observed in the apical part of the retrieved implant. CONCLUSION: Radiographic evidence and 25% implant failures are indications of a low success rate. High counts and prevalence of significant pathogens were found at surviving implants. Although extensive bone loss had occurred in the coronal part, the apical portion of the implant showed some bone to implant integration.

Enhancement of titanium implants via bioengineered periodontal tissues

Osseointegration of titanium dental implants into the jaw bone, which is required for maintenance of the implant in the jaw, results in ankylosis. Dental implants are therefore very unlike natural teeth, which exhibit significant movement in response to mechanical forces. The ability to generate periodontal ligament (PDL) tissues onto dental implants would better mimic the functional characteristics of natural teeth, and would likely improve implant duration and function. OBJECTIVES: The objective of this study was to investigate the feasibility of bioengineering PDL tissues onto titanium implant surfaces. METHODS: Bilateral maxillary first and second molars of 8-week old rats were extracted and used to generate single cell suspensions of PDL tissues, which were expanded in culture. Immunohistochemistry and RT-PCR were used to identify putative PDL progenitor/stem cell populations and characterize stem cell properties, including self-renewal, multipotency and stem cell maker expression. Cultured rPDL cells were harvested at third passage, seeded onto Matrigel-coated titanium implants (1.75 mm x 1 mm), and placed into healed M1/M2 extraction sites. Non-cell seeded Matrigel-coated titanium implants served as negative controls. Implants were harvested after 8, 12, or 18 weeks. RESULTS: Cultured rPDL cells expressed the mesenchymal stem-cell marker STRO-1. Under defined culture conditions, PDL cells differentiated into adipogenic, neurogenic and osteogenic lineages. While control implants were largely surrounded by alveolar bone, experimental samples exhibited fibrous PDL-like tissues, and perhaps cementum, on the surface of experimental implants. CONCLUSIONS: PDL contains stem cells that can generate cementum/PDL-like tissue in vivo. Transplantation of these cells might hold promise as a therapeutic approach for the bioengineering of PDL tissues onto titanium implant. Further refinement of this method will likely result in improved dental implant strategies for use of autologous PDL tissue regeneration in humans. This research was supported by CIMIT, and NIH/NIDCR grant DE016132 (PCY), and TEACRS (YL).

The effect of pulsed jet lavage in vertebroplasty on injection forces of polymethylmethacrylate bone cement, material distribution, and potential fat embolism: a cadaver study

STUDY DESIGN: In vitro testing of vertebroplasty techniques including pulsed jet-lavage for fat and marrow removal in human cadaveric lumbar and thoracic vertebrae. OBJECTIVE: To develop jet-lavage techniques for vertebroplasty and investigate their effect on cement distribution, injection forces, and fat embolism. SUMMARY OF BACKGROUND DATA: The main complications of cement vertebroplasty are cement leakage and pulmonary fat embolism, which can have fatal consequences and are difficult to prevent reliably by current vertebroplasty techniques. METHODS: Twenty-four vertebrae (Th8-L04) from 5 osteoporotic cadaver spines were grouped in triplets depending on bone mineral density (BMD). Before polymethylmethacrylate (PMMA) vertebroplasty, a pulsatile jet-lavage for removal of intertrabecular fat and bone marrow was performed in 2 groups with 8 specimens each, performing radial and axial irrigation from the biopsy needles. One hundred mL of Ringer solution were injected through 1 pedicle and regained by low vacuum via the contralateral pedicle. Eight control vertebrae were not irrigated. All specimens underwent standardized PMMA cement augmentation injecting 20% of the vertebral volume. Injection forces, cement distribution, and extravasations were quantified. RESULTS: All irrigation solution could be retrieved with the vacuum applied. A Kruskal-Wallis test revealed significantly higher injection forces of the control group as compared with the irrigated groups (P = 0.021). Dilatation of the syringe at forces above 300 N occurred in 75% of the untreated compared with 12.5% of the lavaged specimens. CT distribution analysis showed more homogenous cement distribution of the cement and significantly less extravasation in the irrigated specimens. CONCLUSION: The developed lavage technique for vertebroplasty showed to be feasible and reproducible. The reduction of injection forces would allow the use of more viscous PMMA cement lowering the risk for cement embolization and results in a safer procedure. The wash-out of bone marrow and the possible reduction of pulmonary fat embolism have to be verified with in vivo models.

Maxillary sinus floor elevation using the (transalveolar) osteotome technique with or without grafting material. Part I: Implant survival and patients' perception

OBJECTIVES: To analyze the survival and success rates of implants installed utilizing the (transalveolar) osteotome technique, to compare peri-implant soft tissue parameters and marginal bone levels of osteotome-installed implants with implants placed using standard surgical procedures, and to evaluate patient-centered outcomes. MATERIAL AND METHODS: During 2000 to 2005, 252 Straumann dental implants were inserted in 181 patients. The surgical technique was a modification of the original osteotome technique presented by Summers. In addition to the clinical examination, the patients were asked to give their perception of the surgical procedure, utilizing a visual analogue scale. RESULTS: The cumulative survival rate of the osteotome-installed implants after a mean follow-up time of 3.2 years, was 97.4% (95% confidence intervals: 94.4-98.8%). From the 252 implants inserted, three were lost before loading and another three were lost in the first and second year. According to residual bone height the survival was 91.3% for implant sites with < or =4 mm residual bone height, and 90% for sites with 4 mm and 5 mm, when compared with that of 100% in sites with bone height of above 5 mm. According to implant length the survival rates were 100% for 12 mm, 98.7% for 10 mm, 98.7% for 8 mm and only 47.6% for 6 mm implants. Soft tissue parameters (pocket probing depth, probing attachment level, bleeding on probing and marginal bone levels) did not yield any differences between the osteotome-installed and the conventionally placed implants. More than 90% of the patients were satisfied with the implant therapy and would undergo similar therapy again if necessary. The cost associated with implant therapy was considered to be justified. CONCLUSION: In conclusion, the osteotome technique was a reliable method for implant insertion in the posterior maxilla, especially at sites with 5 mm or more of preoperative residual bone height and a relatively flat sinus floor.

A systematic review assessing soft tissue augmentation techniques

AIM: The aim of the present review was to systematically assess the dental literature in terms of soft tissue grafting techniques. The focused question was: is one method superior over others for augmentation and stability of the augmented soft tissue in terms of increasing the width of keratinized tissue (part 1) and gain in soft tissue volume (part 2). METHODS: A Medline search was performed for human studies focusing on augmentation of keratinized tissue and/or soft tissue volume, and complemented by additional hand searching. Relevant studies were identified and statistical results were reported for meta-analyses including the test minus control weighted mean differences with 95% confidence intervals, the I-squared statistic for tests of heterogeneity, and the number of significant studies. RESULTS: Twenty-five (part 1) and three (part 2) studies met the inclusion criteria; 14 studies (part 1) were eligible for comparison using meta-analyses. An apically positioned flap/vestibuloplasty (APF/V) procedure resulted in a statistically significantly greater gain in keratinized tissue than untreated controls. APF/V plus autogenous tissue revealed statistically significantly more attached gingiva compared with untreated controls and a borderline statistical significance compared with APF/V plus allogenic tissue. Statistically significantly more shrinkage was observed for the APF/V plus allogenic graft compared with the APF/V plus autogenous tissue. Patient-centered outcomes did not reveal any of the treatment methods to be superior regarding postoperative complications. The three studies reporting on soft tissue volume augmentation could not be compared due to lack of homogeneity. The use of subepithelial connective tissue grafts (SCTGs) resulted in statistically significantly more soft tissue volume gain compared with free gingival grafts (FGGs). CONCLUSIONS: APF/V is a successful treatment concept to increase the width of keratinized tissue or attached gingiva around teeth. The addition of autogenous tissue statistically significantly increases the width of attached gingiva. For soft tissue volume augmentation, only limited data are available favoring SCTGs over FGG.

Outcome evaluation of early placed maxillary anterior single-tooth implants using objective esthetic criteria: a cross-sectional, retrospective study in 45 patients with a 2- to 4-year follow-up using pink and white esthetic scores

BACKGROUND: To validate the concept of early implant placement for use in the esthetically sensitive anterior maxilla, clinical trials should ideally include objective esthetic criteria when assessing outcome parameters. METHODS: In this cross-sectional, retrospective 2- to 4-year study involving 45 patients treated with maxillary anterior single-tooth implants according to the concept of early implant placement, a novel comprehensive index, comprising pink esthetic score and white esthetic score (PES/WES; the highest possible combined score is 20), was applied for the objective esthetic outcome assessment of anterior single-tooth implants. RESULTS: All 45 anterior maxillary single-tooth implants fulfilled strict success criteria for dental implants with regard to osseointegration, including the absence of peri-implant radiolucency, implant mobility, suppuration, and pain. The mean total PES/WES was 14.7 +/- 1.18 (range: 11 to 18). The mean total PES of 7.8 +/- 0.88 (range: 6 to 9) documents favorable overall peri-implant soft tissue conditions. The two PES variables facial mucosa curvature (1.9 +/- 0.29) and facial mucosa level (1.8 +/- 0.42) had the highest mean values, whereas the combination variable root convexity/soft tissue color and texture (1.2 +/- 0.53) proved to be the most difficult to fully satisfy. Mean scores were 1.6 +/- 0.5 for the mesial papilla and 1.3 +/- 0.5 for the distal papilla. A mean value of 6.9 +/- 1.47 (range: 4 to 10) was calculated for WES. CONCLUSIONS: This study demonstrated that anterior maxillary single-tooth replacement, according to the concept of early implant placement, is a successful and predictable treatment modality, in general, and from an esthetic point of view, in particular. The suitability of the PES/WES index for the objective outcome assessment of the esthetic dimension of anterior single-tooth implants was confirmed. However, prospective clinical trials are needed to further validate and refine this index.