Single-tooth Implants Research Articles

A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla

Purpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol.Materials and Methods: Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant.Results: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P < 0.041) compared to fresh surgical extraction sockets (P < 0.540). Significant MBL was observed on the mesial side of the implant after cementation of the provisional (P < 0.007) and after 12 months (P < 0.034) compared to the distal side which remained stable for 3 and 5 years observation period.Conclusions: Within the limitations of this study, responses of local bone to immediately loaded implants placed either in extraction sockets or healed ridges were similar. Functional loading technique by using prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites.

Immediate Placement and Restoration of Dental Implants in the Esthetic Region: Clinical Case Series

The objective of this study was to assess the hard and soft tissue changes following immediate placement and provisional restoration of single-tooth implants in the aesthetic zone. Thirteen patients with immediately placed and restored implants were included in this study. All participating patients underwent the same treatment strategy that involved removal of the failed tooth, flapless surgery, immediate implant placement, and connection of a screw-retained provisional restoration. Three months following implant placement, the temporary crowns were replaced by the definitive restorations. Implant survival rates, and hard and soft tissue changes were measured using periapical X-rays and photographs. The range of the observation period was between 12 and 37 months with a mean period of 23.2 ± 7.6 months. At the time of follow-up, all implants were present with no complications. Radiographic evaluation revealed a mean mesial bone gain of 1.20 ± 1.01 mm and a mean distal bone gain of 0.80 ± 1.14 mm, which reached statistical significance. The mean mid-buccal recession was 0.20 ± 0.78 mm, whereas the mesial and distal papillae height loss was 0.50 ± 1.26 mm and 0.30 ± 0.82 mm, respectively. The changes in the soft tissues did not reach statistical significance. Notwithstanding the limitation of a small sample size, this study shows that immediate implant placement and provisional restoration in the maxillary aesthetic zone can result in favorable treatment outcomes with regards to soft and hard tissues changes over a follow-up period of 23.2 ± 7.6 months. Most clinical trials investigating immediate implant placement and immediate restoration in the maxillary anterior zone have focused on implant survival and implant success, with particular emphasis on radiographically assessed hard tissues changes. However, this study assesses the soft tissue changes associated with this procedure, which is an important area of study given the esthetic demands of implant therapy in the maxillary anterior region.

Cone beam computed tomography evaluation of regenerated buccal bone 5 years after simultaneous implant placement and guided bone regeneration procedures – a randomized, controlled clinical trial

The aim of this controlled clinical study was to compare a polyethylene glycol membrane (PEG) used for bone regeneration of peri-implant defects to a collagen membrane with respect to implant survival rate, dimensions of buccal peri-implant bone and mucosa. Thirty-seven patients who received single tooth implants with simultaneous guided bone regeneration (GBR) in the posterior maxilla or mandible were enrolled in the study. Intra-operative heights of bone defects were assessed prior to bone augmentation. The defects were augmented with xenogenic bone mineral and randomly covered either with a porcine collagen membrane (control) or with a PEG membrane (test). Five years after implant placement, clinical evaluation and cone beam computed tomography (CBCT) scans were performed. Remaining height of bone defect, horizontal bone thickness, level of mucosal margin, and mucosal thickness were assessed in CBCT images. The difference of height of bone defect at implant placement and at 5-year follow-up was calculated. The differences between the two groups were analyzed using two-sided t-test and Mann-Whitney U-test. After 5 years, 32 patients could be included and exhibited an implant survival rate of 100% for both groups. The buccal vertical bone gain between implant placement and 5-year follow-up amounted at 4.3 ± 1.5 (SD) mm and 4.8 ± 2.6 (SD) mm for the control and the test group, respectively (P = 0.493). Neither the bone height nor the thickness reached statistical significant differences between the two groups. The distance between mucosal margin and implant shoulder resulted in 0.8 ± 0.7 (SD) mm in the control and 0.5 ± 0.8 (SD) mm in the test group (P = 0.198). The mucosal thickness reached 1.4 ± 0.5 (SD) mm in the control and 1.3 ± 0.3 (SD) mm in the test group (P = 0.715). There were no significant correlations between height of bone defect at baseline and at follow-up examination and between different 5-year parameters. A polyethylene glycol membrane used for bone regeneration of peri-implant defects performed as successfully as a collagen membrane with respect to implant survival rate and dimensions of the buccal peri-implant bone and mucosa after 5 years.

CAD/CAM Glass Ceramics for Single-Tooth Implant Crowns

To evaluate the load distribution of CAD/CAM mono-ceramic crowns supported with single-tooth implants in functional area. A 3-dimensional numerical model of a soft tissue-level implant was constructed with cement-retained abutment to support glass ceramic machinable crown. Implant-abutment complex and the retained crown were embedded in a Ø 1.5 × 1.5 cm geometric matrix for evaluation of mechanical behavior of mono-ceramic CAD/CAM aluminosilicate and leucite glass crown materials. Laterally positioned axial load of 300 N was applied on the crowns. Resulting principal stresses in the mono-ceramic crowns were evaluated in relation to different glass ceramic materials. The highest compressive stresses were observed at the cervical region of the buccal aspect of the crowns and were 89.98 and 89.99 MPa, for aluminosilicate and leucite glass ceramics, respectively. The highest tensile stresses were observed at the collar of the lingual part of the crowns and were 24.54 and 25.39 MPa, respectively. Stresses induced upon 300 N static loading of CAD/CAM aluminosalicate and leucite glass ceramics are below the compressive strength of the materials. Impact loads may actuate the progress to end failure of mono-ceramic crowns supported by metallic implant abutments.

Modified roll flap a handy technique to augment the peri-implant soft tissue in the esthetic zone: A randomized controlled clinical trial

The esthetic outcome of single-tooth implants in the esthetic zone has become increasingly important concern in the current literature. Deficient or thin per-implant labial soft tissue thickness seriously and adversely affects the esthetic outcome of such situations. The modified roll flap (MRF) is a pedicle flap designed to make use of the gingival tissue overlying the covering screw to expand the thickness of the labial soft tissue instead of discarding it as in flapless technique. The current randomized control trial assesses the efficiency of the MRF technique for augmenting the labial peri-implant soft tissue during stage-two implant surgery. The outcome measures include the measurement of the labial soft tissue thickness and the implant esthetic score system (IES). Methods12 out of 14 patients (8 males and 4 females) aged from 20 to 50 years old were included. All patients were suffering a missing tooth in the esthetic zone and surrounded by a thin gingival biotype classified according to TRAN technique and direct method. At stage II surgery, patients were randomly split to: Control group using a standard crestal incision and MRF study group. All surgical procedures were performed by a single operator the principal author*. Thickness was measured by the direct method using periodontal probe with endodontic stopper via a special stent with a fixed hole to ensure reproducible measurements. A modified form of the IES system composed of the summation of four parameters individually measured was used to assess esthetics. All assessments were performed by a single Co-author who was blinded to the group under evaluation. ResultsThe MRF group showed a statistically significant difference over the control group regarding thickness at baseline, 3 month (P = 0.01) and 6 month postoperatively (P = 0.03). The IES score showed a statistically significant difference in favor of MRF at 3 and 6 month (P < 0.05), while, the baseline measurement was not significant (P > 0.05). ConclusionMRF is a cost effective convenient technique that can effectively augment the thickness of the labial peri-implant soft tissue and help to achieve better appearance in the esthetic zone.

Single-tooth implants with different neck designs: a randomized clinical trial evaluating the aesthetic outcome

Although the mucosal aesthetic adjacent to implants was often suboptimal, this did not concern patients.

Single-Tooth Replacement in the Anterior Maxilla by Means of Immediate Implantation and Early Loading: Clinical and Aesthetic Results at 5 Years

The hypothesis of the present study was that the early loading of single implants-supported restorations, replacing single extracting teeth in the anterior region of the maxilla in case of fresh extraction sockets with residual hard and soft tissue preservation, could be a successful procedure. Twenty-one implants were placed into maxillary anterior fresh extraction sockets using a flapless technique. Temporary restorations, which were fabricated from the impression taken immediately after implant placement, were connected within 2 weeks. These temporary restorations were adjusted in order to avoid any direct occlusive contacts. Six months after implantation, the implants were restored with single-teeth all-ceramic prostheses. Patients were followed for 5 years. Radiographic and clinical examinations were made at baseline, at time of definitive crowns delivery, and each subsequent year. Survival rate, cortical bone responses, and peri-implant mucosal responses were evaluated. One implant was lost at 6 months. Clinical osseointegration of 20 implants was achieved (95.2% implant survival rate after 5 years) with minimal gingival recession and papillae preservation. The mean change in marginal cortical bone level was 0.40 mm at 6 months and 0.83 mm at 5 years. Within the limit of the present study, the data indicate that, under a strictly controlled oral hygienic regimen, single-tooth implants, with immediate placement and early loading protocol, may be used in anterior maxillary fresh extraction sockets with residual hard and soft tissues preservation, if patients are selected carefully and if high primary stability is strictly followed.

Patient satisfaction and esthetic outcome after immediate placement and provisionalization of single‐tooth implants involving a definitive individual abutment

To assess patient satisfaction and esthetic outcome after immediate placement and provisionalization of single-tooth implants involving a definitive individual abutment and a provisional crown followed by later placement of a definitive crown. In private practice, a single-tooth implant was placed immediately after tooth extraction in the esthetic zone of 54 patients. A definitive individual abutment and a provisional crown were mounted in the same visit. The definitive crown was placed after a mean period of 7months. After a mean follow-up period of 33months, the subjective and professional evaluation of the total implant treatment, peri-implant soft tissues, and implant crown were assessed on a 10-cm visual analog scale (VAS). The professional esthetic treatment outcome was also evaluated using pink esthetic score (PES), white esthetic score (WES), and total score of PES/WES. The evaluation of total implant treatment, peri-implant soft tissues, and implant crown demonstrated a significantly higher subjective than professional score for all 3 parameters (P<0.001), for example, for the overall treatment, the mean scores were 9.4 and 7.0, respectively. A significant positive correlation was revealed between the professional VAS scores and the PESs and WESs. Immediate placement and provisionalization of single-tooth implants involving a definitive individual abutment and provisional crown followed by later placement of a definitive crown demonstrated high subjective and professional satisfaction. Generally, the professionals seem to be more critical than the patients. A strong correlation was observed between the professional VAS scores and the PES and WES scoring systems.

The influence of customized abutments and custom metal abutments on the presence of the interproximal papilla at implants inserted in single‐unit gaps: a 1‐year prospective clinical study

To assess and compare the papilla presence mesially and distally to dental implants restored with customized abutments and custom metal abutments in the anterior maxilla. Thirty-eight patients receiving 38 single-tooth implants, restored with 26 customized abutments and 12 custom metal abutments in the anterior maxillary region were enrolled in this study. The cases where did not existed contact point were excluded. Presence/absence of the interproximal papilla, inter-tooth-implant distance (ITD) and distance from the base of the contact point to dental crest bone of adjacent tooth (CPB) were accessed. Global P-values were determined for changes in CPB and papilla score over time (P<0.05). Thirty-six patients with 36 implants were available for the 12-month follow-up. The abutments and reconstruction survival rate was 100% with no fracture or crown loss. A mean mesial CPB of 5.71±1.54mm and distal CPB of 4.01±1.73mm were assessed in the customized abutment group for an overall mean papilla presence of 1.69±0.46. A mean mesial CPB of 5.41±1.31mm and distal CPB of 4.77±1.21mm were assessed in the control group for an overall mean papilla presence of 1.08±0.65. The restoration of single-implants using computer-assisted design/computer-assisted manufacturing abutments appears to help maintaining a regular papillary filling although the variations of the implant positioning or the restoration/teeth relation.

Esthetic evaluation of single‐tooth implants in the anterior mandible

Single-tooth replacement of anterior mandibular teeth is frequently complicated by insufficient bucco-lingual bone width and limited mesio-distal space available for implant placement. The aim of the present study was to assess implant esthetics in the partially edentulous anterior mandible. Esthetic evaluation of 43 anterior mandibular single-tooth implants in 15 women and 28 men was performed using esthetic indices (PES=Pink Esthetic Score, PI=Papilla Index, SES=Subjective Esthetic Score) as well as subjective patients' Visual Analogue Scale (VAS) ratings. Clinical and radiological parameters (implant and crown dimensions, pocket depth, bleeding on probing, plaque, keratinized mucosa, marginal bone level, and distance to adjacent teeth) were tested for influence. Implant esthetics were judged satisfactory (PES ≤10) in 42% of implants compared with a patient satisfaction rate of 87%. Correlation between objective indices (PES/PI: rs =0.62, PES/SES: rs =-0.73, PI/SES: rs =-0.48) was highly significant (P≤0.001); however, no association to subjective patients' ratings could be observed. Type of prosthetic restoration (single crown vs. tulip-shaped double crowns), mesio-distal crown width as well as anatomic crown length significantly affected esthetic scores. Patients' judgment, by contrast, could not be associated to any prognostic factor. Subjective patient satisfaction with implant esthetics in the partially edentulous anterior mandible is high, however, remains hard to predict or objectively quantify.

Active Tactile Sensibility of Single‐Tooth Implants versus Natural Dentition: A Split‐Mouth Double‐Blind Randomized Clinical Trial

Unlike passive sensitivity of implants/teeth that is assessed more, only three controversial studies have compared active tactile sensibility (ATS) of implants and teeth. We aimed to explore the difference between the ATS of teeth and single-tooth implants. The ATS of single-tooth implants and contralateral teeth was measured in 25 patients after they bit on gold and placebo foils 0- to 70-μm thick, each for five times, in a random order blinded to patients and assessor, carried out at two sessions. Based on the experimental range of 0 μm (mock trials) to 70 μm, the sigmoid shape of psychometric curve was estimated to locate the 50% values as the ATS thresholds for each tooth or implant. ATS Data were analyzed using paired and unpaired t-tests and multiple linear regression (α = 0.05, β ≤ 0.1). Also, equivalence testing approach was used to assess semi-objectively the clinical significance. Average ATS values for teeth and implants were 21.4 ± 6.55 μm and 30.0 ± 7.55 μm, respectively (p = .0001 [paired t-test]). None of the geometric characteristics of implants nor duration of implant in function were correlated with the ATS (p > .4 [regression]). Age was positively associated with the ATS of both implants and teeth (p ≤ .019 [regression]). Tooth ATS (but not implant ATS) was significantly higher in males compared with females (p = .050 [unpaired t-test]), which contributed to a generalizable tooth-implant difference higher than 8-μm clinical equivalence margin in females. The ATS was not significantly different between arches or between anterior/posterior regions (p > .6). There was a slight but statistically significant difference between implant and tooth tactile sensitivities.

Marginal Bone Levels and Soft Tissue Conditions Around Single-Tooth Implants with a Scalloped Neck Design: Results of a Prospective 3-Year Study

Scalloped implants were developed to better maintain marginal bone. Therefore, this study evaluated marginal bone levels (MBLs) and soft tissue around single implants with scalloped necks in the esthetic zone prospectively over a 3-year period. MBLs were compared to those of conventional flat-platform implants at 1 and 3 years. Patients received anterior single-tooth implants and were divided into two groups; the test group included implants with a scalloped neck design and the control group included conventional rough-surface implants with external hex. MBLs were compared radiographically at 1 and 3 years after crown insertion. For the test group, soft and hard tissue assessments were made at six different time points, beginning at abutment connection. Mesial and distal interproximal papillae and probing depths were assessed clinically. Data were analyzed with the Student t test and repeated measures analysis of variance on ranks (P < .05). Twenty-four patients (17 men, 7 women) took part; each group included 12 implants. The test group had significantly more marginal bone resorption than the control group at each time point (P < .001). With respect to changes in MBL values over time, a significant difference was detected between groups mesially (P < .001) but not distally. Statistical analyses demonstrated obvious significant increases with time (P < .001) in bone resorption and mesial papilla index. A significant increase over time in probing depths was demonstrated distally (P = .003) but not mesially. The scalloped implant did not stabilize interproximal bone remodeling and caused more bone loss than conventional implants. Soft tissue levels were not maintained around the scalloped implants.

Factors Affecting Outcomes for Single-Tooth Implants and Endodontic Restorations

Factors Affecting Outcomes for Single-Tooth Implants and Endodontic Restorations

The impact of implant treatment on oral health related quality of life in a private dental practice: a prospective cohort study

BackgroundVery few studies on the impact of implant therapy on Oral Health Related Quality of Life (OHRQoL) in partially edentulous patients have been published.AimThis study aimed at analysing the improvement of OHRQoL of patients who underwent dental implant treatment using the “functional”, “psychosocial” and “pain and discomfort” categories of the Geriatric Oral Health Assessment Index (GOHAI).MethodsWithin a prospective cohort of patients rehabilitated with Straumann dental implants, the OHRQoL of 176 patients (104 women and 72 men) was assessed using the GOHAI questionnaire, at two different times, before and after implant placement. The degree of oral treatment was categorised into three classes: “Single Tooth Implant” (n = 77), “Fixed Partial Denture” (n = 75), “Fixed or Retained Full Prostheses” (n = 24). The participants’ characteristics (gender, age, tobacco habits, periodontal treatment, time between both evaluations) were assessed.ResultsBefore treatment, the GOHAI score was lower for participants with fewer teeth (F = 19, P < 0.001). After treatment, no difference was observed between participants; significant improvements were observed in the GOHAI scores obtained (repeated measures, analysis, (F = 177, P < 0.001)) for each of the GOHAI fields studied (functional, psychosocial and pain & discomfort), regardless of the degree of treatment. The best improvement was observed in patients who needed complete treatment (P < 0.001). The presence of preliminary periodontal treatment, tobacco habits, age and gender of the participants did not have a significant impact on OHRQoL. Changing the time between the two evaluations (before and after treatment) had no impact on the changes in the GOHAI score.ConclusionsImplants enhanced the OHRQoL of participants that needed oral treatment.

Treating congenitally missing teeth with an interdisciplinary approach

Congenitally missing teeth are frequently presented to the dentist. Interdisciplinary approach may be needed for the proper treatment plan. The available treatment modalities to replace congenitally missing teeth include prosthodontic fixed and removable prostheses, resin bonded retainers, orthodontic movement of maxillary canine to the lateral incisor site and single tooth implants. Dental implants offer a promising treatment option for placement of congenitally missing teeth. Interdisciplinary approach may be needed in these cases. This article aims to present a case report of replacement of bilaterally congenitally missing maxillary lateral incisors and right mandibular second premolar with dental implants.

Esthetic Outcome and Tissue Stability of Maxillary Anterior Single-Tooth Implants Following Reconstruction with Mandibular Block Grafts: A 5-Year Prospective Study

The aim of this prospective study was to evaluate the hard and soft tissue stability and esthetic outcomes of single-tooth implants placed in the anterior atrophic maxilla, following augmentation with mandibular block grafts covered with bovine hydroxyapatite and a resorbable collagen membrane, over a 5-year period. Patients with a bony deficiency of ≥ 3 mm horizontally and ≤ 3 mm vertically were treated consecutively with reconstructive procedures and implant placement 6 months afterward. Alveolar ridge dimensions were measured before and after augmentation using computed tomography. Clinical and radiographic measurements of soft and hard tissue levels and esthetic parameters (pink esthetic score [PES]) were performed annually to assess treatment outcomes. Twenty-nine patients were treated. One patient had partial graft exposure after 1 month that required regrafting at the time of implant placement. Mean bone gain was 4.23 ± 0.69 mm horizontally and 1.71 ± 0.75 mm vertically. The implant cumulative success rate was 100%, according to the criteria of Albrektsson et al. Mean crestal bone resorption after 5 years was low (0.61 ± 0.33 mm). Moderate recession of the facial mucosa (-1.12 ± 0.4 mm) was observed during the study period, while mesial and distal papilla heights increased slightly (0.13 ± 0.17 and 0.19 ± 0.37 mm, respectively). Mean PES ratings remained stable, varying from 9.07 ± 1.49 at the moment of definitive crown delivery to 8.61 ± 1.55 at 5 years. Only two cases (7%) were considered slightly below the defined threshold (PES = 8) of marginal esthetic acceptability. This study demonstrated that implants placed in anterior atrophic maxillae augmented with mandibular block grafts showed stable hard and soft tissue levels and reasonable esthetic outcomes over the medium term, although ongoing recession of the facial mucosa was observed.

Implant screw fracture

The stability of the connection between different implant parts is important for the overall success of the prosthesis. This is especially true for single-tooth restorations, where a strong interlock between the implant and abutment is necessary. A common problem associated with single-tooth implants has been the loosening of abutment or fracturing of retaining screws. Inadequate torquing force applied to the screw is the most important reason for screw loosening and fracture. Structural inadequacy can also lead to screw fracture. Screw fracture occurs more readily with a loose screw as it is more prone to excessive lateral loads. Screw loosening can be an inconvenience to the patient and the practitioner. It is a fact that screw loosening occurs in single-implant restorations regardless of the implant-abutment connection geometry even if proper antirotational features and torque are provided. The management of a patient who had reported with fracture of an abutment screw is presented in this article.

Evaluation of Active Tactile Perception of Single Tooth Implant Prosthesis

Purpose: The phenomenon of developing a certain tactile sensibility through osseointegrated dental implants is called osseoperception. Active tactile sensibility can be tested by having the subject bite on test bodies. The aim of the study was to assess the active tactile sensibility of osseointegrated single tooth dental implants according to psychophysical method of constant stimuli. Materials and methods: Twenty subjects (10 male and 10 female) with single tooth implants located in the posterior region with natural, healthy antagonistic teeth were included in the study. Ten implants were located in the maxilla and 10 in the mandible. The subjects were also divided into two age groups 30 to 40 years and 40 to 50 years, and the active tactile perception was studied according to the psychophysical method of constant stimuli. Results: The active tactile perception of osseointegrated single tooth dental implants with natural healthy antagonist revealed a threshold ranging between 24 ± 8 μ. The active tactile perception of healthy natural tooth with natural healthy antagonist revealed a threshold ranging between 12 ± 4 μ. No statistically significant results were found between different age groups (30-40 years age group and 40-50 years age group). The threshold for tactile perception was found to be similar in both male and female subjects. No statistical significance was found in the threshold between different implant locations (maxilla and mandible). Conclusion: Active tactile sensibility of implants with natural antagonistic teeth is similar to that of teeth. Implant-supported prosthesis restores jaw function more appropriately, with improved psychophysiological discriminatory ability.

Immediate Placement Implant in Fresh Extraction Socket: A Clinical Study of Seven Cases

Aims and objectives: To reduce the prolonged waiting period post tooth extraction for rehabilitation with implants. This study was carried out to determine the outcome of implants placed into fresh extraction sockets with the simultaneous use of particulate bone graft. Patient response to rehabilitation with immediate placement single tooth implants was monitored clinically and radiographically. Materials and methods: Among seven patients, with the average age of 28 years were treated for single tooth replacement in fresh extraction sockets in the esthetic zone by means of 2 stage immediate placement of implant. Bioactive glass particulate bone graft was used as bone graft material. Reason for teeth loss was caries, trauma and internal resorption. All patients were followed clinically and radiographically for 1 year after loading of implant. Results: Follow-up was done after stage I surgery (placement of implant) for pain, soft tissue dehiscence, inflammation, altered sensation at site of implant placement monthly for 4 to 6 months. After giving final prosthesis, patients were evaluated for bleeding index (Muhlemann and Son), plaque index (TureskyGilmoreGlickman) gingival index (Loe and Silness), marginal bone loss (parallel cone technique using IOPA) with follow-up at 6th and 12th months. All the implants were osseointegrated at the time of abutment placement. Radiographic examination showed only slight marginal bone around the implants. Conclusion: Hence, implants can be placed successfully in fresh extraction socket using bioactive glass (perioglass) particulate bone graft material to fill gap between implant and bone through a submerged (2 stage) surgical technique.

Zirconia and Titanium Implant Abutments for Single-Tooth Implant Prostheses After 5 Years of Function in Posterior Regions

To verify, in a medium-term follow-up, whether or not zirconia (Zr) abutments show similar survival outcomes as titanium (Ti) abutments in posterior areas. A two-stage surgical protocol was used. Each patient was followed for 5 years after the definitive prosthesis insertion. Clinical and radiographic parameters were assessed at the yearly follow-up visit, and prosthetic complications were recorded. Statistical analysis (Wilcoxon signed rank test) was used to compare any difference in biologic and radiographic parameters between implants and the natural contralateral teeth. Descriptive statistics were used to analyze the changes over time (from baseline to the last follow-up) of clinical and radiographic parameters. A total of 85 patients with a single posterior tooth gap were treated with 85 implants supporting 47 Ti and 38 Zr abutments, respectively. All-ceramic (38) and metal-ceramic (47) single crowns were fabricated. Four patients were classified as dropouts. Eighty-one implants supporting 44 Ti and 37 Zr abutments completed the 5-year follow-up examination. No implant, reconstruction, or abutment failures were recorded. Therefore, the prosthetic survival after 5 years of function was 100% for all the abutments and restorations. No significant differences in biologic and radiographic indexes were found between Ti and Zr abutments when compared with each other and with the natural teeth after 5 years. No significant marginal bone loss was found between the baseline and the last follow-up, both for Zr and Ti abutments. The medium-term survival of Zr abutments in posterior regions was comparable with that of Ti abutments. Long-term evaluations are needed to confirm this finding.