Effect of Flapless Surgery on Single‐Tooth Implants in the Esthetic Zone: A Randomized Clinical Trial

Background: Implant therapy is a highly predictable treatment option; however, insufficient data exist to show whether flapless implant surgery provides better esthetic outcomes and less bone loss than implant surgery with a flap approach. Methods: In this randomized, controlled study comparing the flapless and traditional flap protocol for implant placement, 24 patients received a single implant in the anterior maxillary region. A cone beam computed tomography–aided surgical guide was used for implant placement surgery for both groups. Implants were restored using a one‐piece, screw‐retained ceramic crown at 3 months. Radiographic and clinical measurements were assessed at baseline (implant placement) and at 3 (crown placement), 6, 9, and 15 months. Clinical parameters evaluated were plaque index, gingival index, papillary index (PPI) (0 = no papilla, 1 = less than half, 2 = more than half but not complete, 3 = complete fill, and 4 = overfill), marginal tissue levels, biotype, width of keratinized tissue, and soft tissue thickness. Results: Implant success rate was 92% in both groups. Mean PPI values for the flap control group and flapless test group were 2.38 ± 0.51 versus 2.31 ± 0.48 at crown placement (P = 0.68) and 2.52 ± 0.52 versus 2.64 ± 0.54 at 15 months (P = 0.42), respectively. PPI increased over time in both groups, although the flapless group had a significantly larger change in PPI from crown placement to 6 and 9 months (P <0.01). Crestal bone levels in the flap group were more apical in relation to the implant platform than those in the flapless group for the duration of the study. No differences among groups were noted for all other measurements. Conclusions: Both flapless and flap implant placement protocols resulted in high success rates. A flapless protocol may provide a better short‐term esthetic result, although there appears to be no long‐term advantage.     

Immediate Single‐Tooth Implant Placement in Bony Defects in the Esthetic Zone: A 1‐Year Randomized Controlled Trial

Background: This study aims to assess, with regard to marginal bone level (MBL), whether the outcome of immediate implant placement in bony defects in the esthetic zone was non‐inferior to delayed implant placement after 1 year. Methods: Forty patients with a failing tooth in the esthetic zone and a labial bony defect of ≥5 mm after removal of a tooth were randomly assigned for immediate (n = 20) or delayed (n = 20) implant placement. Second‐stage surgery and provisionalization occurred after 3 months of healing. Follow‐up was at 1 month and 1 year after definitive crown placement. The study was powered to detect a difference in MBL of >0.9 mm. Buccal bone thickness, soft tissue peri‐implant parameters, esthetic indices, and patient satisfaction were also assessed. Results: One year after definitive crown placement, MBL loss was 0.56 ± 0.39 mm mesially and 0.74 ± 0.51 mm distally for the immediate placement group and 0.51 ± 0.43 mesially and 0.54 ± 0.45 distally mm for the delayed placement group, respectively (not significant). Regarding differences in means, non‐inferiority was observed after 1 year (difference in mean for immediate versus delayed: mesially 0.04 mm [95% confidence interval (CI) = ?0.22 to 0.30 mm, P = 0.40]; distally 0.21 mm [95% CI = ?0.10 to 0.51 mm, P = 0.58]). No significant differences in the other outcome variables were observed. Conclusions: Immediate implant placement with delayed provisionalization was non‐inferior to delayed implant placement with delayed provisionalization in labial bony defects of ≥5 mm regarding change in MBL. Although not powered for other outcome variables, no clinically relevant differences were observed in these variables.     

Randomized controlled clinical trial of customized zirconia and titanium implant abutments for canine and posterior single-tooth implant reconstructions: preliminary results at 1 year of function

Objectives: The aim of this study was to test whether or not customized zirconia abutments exhibit the same survival rates in canine and posterior regions as titanium abutments, and to compare the esthetic result of the two abutment types. Material and methods: Twenty‐two patients with 40 implants in posterior regions were included and the implant sites were randomly assigned to 20 customized zirconia and 20 customized titanium abutments. All‐ceramic (AC) and metal–ceramic (MC) crowns were fabricated. In all except two cases, the crowns were cemented on the abutments using resin or glass‐ionomer cements. Two zirconia reconstructions were screw retained. At baseline, 6 and 12 months, the reconstructions were examined for technical and biological problems. Probing pocket depth (PPD), plaque (Pl) and bleeding on probing (BOP) were assessed and compared with natural control teeth. Furthermore, the difference of color (ΔE) of the peri‐implant mucosa and the gingiva of control teeth was evaluated by means of a spectrophotometer (Spectroshade). The data were analyzed with Student's unpaired t‐test, ANOVA and regression analyses. Results: Twenty patients with 19 zirconia and 12 titanium abutments were examined at a mean follow‐up of 12.6±2.7 months. The survival rate for reconstructions and abutments was 100%. No technical or biological problems were found at the test and control sites. Two chippings (16.7%) occurred at crowns supported by titanium abutments. No difference was found regarding PPD (meanPPD_ZrO2 3.4±0.7 mm, mPPD_Ti 3.3±0.6 mm), Pl (mPl_ZrO2 0.2±0.3, mPl_Ti 0.1±1.8) and BOP (mBOP_ZrO2 60±30%, mBOP_Ti 30±40%) between the two groups. Both crowns on zirconia and titanium abutments induced a similar amount of discoloration of the soft tissue compared with the gingiva at natural teeth (ΔE_ZrO2 8.1±3.9, ΔE_Ti 7.8±4.3). Conclusions: At 1 year, zirconia abutments exhibited the same survival and a similar esthetic outcome as titanium abutments.     

Long‐Term Follow‐Up of CeraOne™ Single‐Implant Restorations: An 18‐Year Follow‐Up Study Based on a Prospective Patient Cohort

Background: Knowledge on long‐term clinical performance of more than 5 years on the single‐implant CeraOne? (Nobel Biocare AB, Gothenburg, Sweden) concept is limited. Purpose: The aim of this study is to report the long‐term clinical performance of the first CeraOne single‐implant restorations, installed 17 to 19 years ago. Materials and Methods: The group comprised 57 patients provided with 65 CeraOne single‐tooth restorations. Sixty‐two all‐ceramic and three metal‐ceramic crowns were cemented between 1989 and 1991. Patients were followed up clinically and with intraoral radiographs at placement, after 1, 5, and between 17 and 19 years after placement. Results: Data were available for altogether 48 patients, followed up on an average time of 18 years. Excluding deceased patients (n = 2) and failed implant patients (n = 2), only five patients were lost to follow‐up (8.8%). Two implants failed, resulting in an 18‐year implant cumulative success rate (CSR) of 96.8%, and altogether eight original single‐crown restorations were replaced (CSR 83.8%). The most common reason for crown replacement was infra‐position of the implant crown (n = 3). Many of the remaining original crowns showed various signs of implant crown infraposition at the termination of the study. In general, the soft tissue at the restorations was assessed to be healthy and comparable with the gingiva at the adjacent natural teeth. Bone levels were on an average stable with only few patients exhibiting bone loss of more than 2 mm during 18 years in function. Conclusion: This long‐term follow‐up study of single‐implant restorations shows encouraging results with few implant failures and minimal bone loss over an 18‐year period. Original single‐crown restorations were replaced more frequently, because of, for example, implant crown infraposition and veneer fractures. The CeraOne concept proved to be a highly predictable and safe prosthodontic treatment.     

Single‐Tooth Implants with Different Neck Designs: A Randomized Clinical Trial Evaluating the Aesthetic Outcome

Aim: To evaluate the aesthetic outcome of single‐tooth implants in the aesthetic zone with different neck designs from a professional's and patient's perception. Materials and Methods: Ninety‐three patients with a missing anterior tooth in the maxilla were randomly assigned to be treated with an implant with a smooth neck, a rough neck with grooves or a scalloped rough neck with grooves. Implants were installed in healed sites. One year after definitive crown placement (18 months post‐implant placement), photographs were taken and the aesthetic outcome was assessed according to two objective aesthetic indexes: pink esthetic score/white esthetic score (PES/WES) and implant crown aesthetic index (ICAI). A questionnaire was used to assess the aesthetic outcome and general satisfaction from a patient's perception. Standardized radiographs were taken to measure marginal bone level changes. Results: One implant was lost. Although there was a significant difference in marginal bone loss between the different implant neck designs (smooth neck 1.19 ± 0.82 mm, rough neck 0.90 ± 0.57 mm, scalloped neck 2.01 ± 0.77 mm), there were no differences in aesthetic outcome. According to the professional's assessments using PES/WES and ICAI, 79.3% and 62% of the cases showed acceptable crown aesthetics, and 59.8% and 56.5% of the cases showed acceptable mucosa aesthetics. Overall, patients were satisfied about the aesthetics of the mucosa (81.5%) and crown (93.3%), and general patient satisfaction was high (9.0 ± 1.0 out of a maximum of 10). According to the professional's assessment, a pre‐implant augmentation procedure was associated with less favorable aesthetics of the mucosa. Conclusion: This study shows that the aesthetics of single‐tooth implants in the maxillary aesthetic zone appears to be independent of the implant neck designs applied but dependent on the need for pre‐implant surgery.     

Histologic Healing Following Tooth Extraction With Ridge Preservation Using Mineralized Versus Combined Mineralized‐Demineralized Freeze‐Dried Bone Allograft: A Randomized Controlled Clinical Trial

Background: Mineralized and demineralized freeze‐dried bone allografts (FDBAs) are used in alveolar ridge (AR) preservation; however, each material has advantages and disadvantages. Combinations of allografts aimed at capitalizing on the advantages each offers are available. To date, there is no evidence to indicate if a combination allograft is superior in this application. The primary objective of this study is to histologically evaluate and compare healing of non‐molar extraction sites grafted with either mineralized FDBA or a 70:30 mineralized:demineralized FDBA combination allograft in AR preservation. The secondary objective is to compare dimensional changes in ridge height and width after grafting with these two materials. Methods: Forty‐two patients randomized into two equal groups received ridge preservation with either 100% mineralized FDBA (active control group) or the combination 70% mineralized: 30% demineralized allograft (test group). Sites were allowed to heal for 18 to 20 weeks, at which time core biopsies were obtained and dental implants were placed. AR dimensions were evaluated at the time of extraction and at implant placement, including change in ridge width and change in buccal and lingual ridge height. Histomorphometric analysis was performed to determine percentage of vital bone, residual graft, and connective tissue/other non‐bone components. Results: There was no significant difference between groups in AR dimensional changes. Combination allograft produced increased vital bone percentage (36.16%) compared to the FDBA group (24.69%; P = 0.0116). The combination allograft also had a significantly lower mean percentage of residual graft particles (18.24%) compared to FDBA (27.04%; P = 0.0350). Conclusions: This study provides the first histologic evidence showing greater new bone formation with a combination mineralized/demineralized allograft compared to 100% mineralized FDBA in AR preservation in humans. Combination allograft results in increased vital bone formation while providing similar dimensional stability of the AR compared to FDBA alone in AR preservation.     

Effect of Healing Time on New Bone Formation After Tooth Extraction and Ridge Preservation With Demineralized Freeze‐Dried Bone Allograft: A Randomized Controlled Clinical Trial

Background: Clinicians and patients continually search for procedures to decrease time from tooth extraction to restoration. Evidence to date is limited concerning timing of ridge preservation healing and reentry for implant placement. The first objective of this study is to histologically evaluate new bone formation 8 to 10 weeks versus 18 to 20 weeks after extraction of non‐molar teeth and ridge preservation using demineralized freeze‐dried bone allograft (DFDBA). The second objective is to compare dimensional changes including ridge width and height at the two healing time points. Methods: Forty‐four patients had tooth extraction and ridge preservation with DFDBA that was obtained from a single donor. Clinical measurements were made to evaluate ridge height and width. Patients were randomly allocated to short‐term (8 to 10 weeks) and long‐term (18 to 20 weeks) healing groups. Sites were reentered at the appropriate healing time, core biopsy was obtained, and a dental implant was placed. The same ridge dimensions were measured at time of implant placement. Histomorphometric analysis was performed to determine percentage of new vital bone formation, residual graft, and connective tissue (CT)/other. Results: A significantly higher percentage (47.41%) of new vital bone formation was found in the long‐term healing group compared with the short‐term healing group (32.63%) (P = 0.01). There was no significant difference in percentage of residual graft, percentage of CT/other, or ridge dimensional changes. Conclusion: This study indicates significantly greater new vital bone formation occurs after tooth extraction and ridge preservation with DFDBA when sites healed for 18 to 20 weeks compared with 8 to 10 weeks prior to dental implant placement.     

Local Sinus Lift for Single‐Tooth Implant. I. Clinical and Radiographic Follow‐Up

Background: For single‐tooth implant replacement in the posterior maxilla, it is often necessary to do an augmentation of the alveolar process because of post‐extraction resorption and include part of the maxillary sinus. Purpose: The purpose of this study is to present a technique for a local sinus lift with autogenous bone in a one‐stage procedure. Additionally, volume changes of the grafted area were evaluated radiographically up to 2 years. Materials and Methods: Twenty patients, 12 female and 8 males, were included in the study. Single‐tooth replacement was made in the second premolar area in 7 cases and in the molar area in 13 cases. Local sinus lift and implant installation were made simultaneously. Abutment connection was made after 6 months of healing. Results: Two years of clinical and radiographic follow‐ups have been made in all patients. The survival rate was 100%. The residual bone volume in the actual area was 2–5 mm preoperatively, after sinus lifting in mean 13 mm, after 1 year in mean 11.4 mm, and 2 years postoperatively in mean 10.6 mm. Conclusions: Local sinus lift with simultaneous bone augmentation and single‐tooth replacement in the posterior maxilla is a predictable method although a certain bone volume reduction around the implant was evident at the 2‐year follow‐up.