Narrow Diameter Implants Research Articles

Mechanical Properties of Ti-Nb-Cu Alloys for Dental Machining Applications.

Titanium has excellent biocompatibility and good corrosion resistance and is extensively used in dental implants and denture bases. However, pure titanium lacks the strength for use in dental prostheses that require relatively high strength. We developed 15 different types of Ti-Nb-Cu alloys and investigated their alloy phases and mechanical properties, including tensile and yield strength, elongation after fracture, and Vickers hardness. The alloy phases of Ti-8%Nb-2%Cu and Ti-13%Nb-2%Cu were α + β, while those of Ti-5%Nb-5%Cu and Ti-10%Nb-5%Cu were α + Ti2Cu. The tensile strength and hardness of these alloys were significantly higher than those of titanium; however, their elongation was less. In particular, the yield strength of these alloys was more than twice that of titanium. These differences in mechanical properties are attributable to solid-solution strengthening and precipitation strengthening. Other compositions with an alloy phase of α + β + Ti2Cu or β + Ti2Cu had high hardness but not high strength. These results suggest that the Ti-8%Nb-2%Cu, Ti-5%Nb-5%Cu, Ti-13%Nb-2%Cu, and Ti-10%Nb-5%Cu alloys can be applied to dental prostheses, which are subject to very high forces from accessories such as long-span bridges, clasps, implant-retained superstructures, and narrow-diameter implants.

Narrow-Diameter Implants for Partial Fixed and Removable Prostheses: A Systematic Review and Meta-Analysis.

To answer the following focus question: Are narrow-diameter implants feasible to support fixed dental prostheses (FDPs) and partial removable dental prostheses (PRDPs)? This review followed the PRISMA statement and was registered in the PROSPERO database (CRD42020153729). Six databases and the gray literature were searched through October 2021 without language, publication time, or follow-up restrictions. The main outcomes were survival, success, and marginal bone loss (MBL). Risk of bias was assessed for each study design, and random-effects meta-analyses were performed (α = .05). Seventeen studies were included in the qualitative analysis, and 3 were included in the meta-analyses. In total, 1,624 NDIs and 339 standard-diameter implants (SDIs) were placed in 1,060 patients. Follow-up varied from 1 to 10 years, and 17 failures (implant loss) were recorded. No differences in survival rate for FDPs supported by NDIs vs SDIs were found (odds ratio [OR] = 0.59, 95% CI: 0.18 to 1.92, P = .38). However, Kaplan-Meier analysis evaluating only NDI performance revealed a higher survival rate of NDIs ≥ 3.3-mm diameter (P = .002), placed with delayed loading (P = .024), and placed in the maxilla (P = .014). FDPs supported by NDIs vs SDIs presented similar success rates (OR = 1.48, 95% CI: 0.41 to 5.34, P = .55); however, MBL was lower in the NDI group (mean difference = -0.23 mm, 95% CI: -0.41 to -0.06, P = .01). Insufficient data regarding PRDPs were available. Despite the limited studies available, FDPs supported by NDIs presented survival and success rates comparable to those supported by SDIs, with slightly lower MBL. For PRDPs, strong conclusions were not possible.

Clinical evaluation of narrow-diameter implants versus standard-diameter implants with lateral bone augmentation in posterior jaws: Three-year results of a randomized controlled trial.

The aim of this study was to compare the 3-year clinical outcomes of narrow-diameter implants (NDI) with standard-diameter implants (SDI) in conjunction with lateral bone augmentation in atrophic posterior jaws. Fifty patients were included and randomly assigned into two groups: Patients in Group 1 received NDI (Ø3.5 mm); patients in Group 2 received SDI (Ø4.3 mm) with simultaneous lateral bone augmentation. Implant survival rates, complications, crestal bone loss, peri-implant conditions, treatment cost, and patient satisfaction were compared. Three patients dropped out the follow-up. No implant loss was observed. The difference in technical complication rates between the two groups was 3.8% (95% CI: -13.7% to 21.3%). No significant differences in crestal bone loss were found between two groups at 3-year follow-up (0.55 ± 0.76 vs 0.41 ± 0.41 mm, p=.429). A total of 20.8% (5/24) of NDI were diagnosed with mucositis and 8.3% (2/24) with peri-implantitis. A total of 17.4% (4/23) of SDI showed mucositis and (1/23) 4.3% showed peri-implantitis. The total cumulative cost of treatment per patient in Group 1 (2849.6 USD, 95% CI: 2726.8-2972.4) was significantly lower than that in Group 2 (3581.4 USD, 95% CI, 3460.9-3701.9) over the 3-year follow-up (p < .01). The patient satisfaction rating of operation was significantly higher in Group 1 (85.42 ± 7.41 vs 80.48 ± 7.95, p=.033). NDI yielded favorable implant survival, acceptable technical and biological complications, and high patient satisfaction supporting single crowns in the atrophic posterior region after 3-year follow-up. NDI might be a reasonable alternative in horizontally deficient posterior jaws. Clinicaltrials.gov identifier: ChiCTR1800020426.

Microcirculation and neutrophil-related cytokine concentrations are not altered around narrow diameter implants in T2DM patients during wound healing

ObjectivesThe aim of this study was to assess the microcirculation and the expression patterns of wound-healing-related cytokines around narrow-diameter implants in type 2 diabetes mellitus (T2DM) and normo-glycemic patients.Materials and methodsA total of 31 patients, 16 of which diagnosed with T2DM (HbA1c > 6.5) and 15 normo-glycemic patients, received narrow diameter implants in the posterior mandible or maxilla. During the 3-month healing period, soft-tissue perfusion was monitored via laser Doppler flowmetry. Peri-implant fluid (PICF) was harvested and analyzed for concentrations of interleukin-1ß (IL-1ß), interleukin-23 (IL-23), interleukin-17 (IL-17), and granulocyte colony-stimulating factor (G-CSF) by a multiplex, bead-based immunoassay.ResultsMicrocirculatory perfusion patterns during wound healing exhibited no significant differences throughout the observation period. IL-1ß concentrations were expectedly elevated during the early phases of wound healing. At the first visit after surgery, IL-23 concentrations were significantly higher in implants of diabetic patients. This difference was diminished over the course of the observation period. For the other tested analytes, no differences were observable between both groups.ConclusionWound healing after implant surgery was similar in T2DM and healthy patients. Hydrophilic-surface titanium-zirconium implants with reduced diameter may be considered for implant therapy of diabetes mellitus type II patients.Registration numberNCT04630691 (clinicaltrials.gov).

Mechanical stability of angulated zirconia abutments supporting maxillary anterior single crowns on narrow-diameter implants.

To investigate the fracture strength of angulated hybrid abutments supporting anterior single crowns on narrow-diameter implants (NDIs). Zirconia abutment with angulations of labial inclination 0° (TZ0Z), 15° (TZ15Z), 30° (TZ30Z) and palatal inclination 15° (TZ - 15Z) was designed on 3.3-mm titanium-zirconium (Ti-Zr) NDIs. Titanium abutment connected with Ti-Zr implant (TZ0T) and 0° zirconia abutment connected with pure titanium (Ti) implant (T0Z) were control groups. Thirty-six un-restored abutments and 36 abutments restored with highly translucent zirconia (HTZ) crowns were tested. Failure loads were compared among 6 groups, and bending moments were calculated for comparison between un-restored and restored abutments. Failure loads of un-restored abutments were affected by the abutment angle. Sixty-seven percent samples in TZ30Z and 83% samples in TZ - 15Z group fractured at the thinnest part of the zirconia abutment and exhibited lower failure load (p < .05). Failure loads of restored abutments were close to or exceeded the maximum bite force of anterior teeth, and no differences were found among six groups (p > .05). Except TZ15Z and TZ0T group, the bending moment increased with the crown construction, especially for TZ30Z and TZ - 15Z groups (p < .001). The fracture strength of hybrid abutments restored with HTZ crown on Ti-Zr NDIs exceeded the bite forces of anterior teeth for all the groups and were not affected by the abutment angle. In terms of fracture strength, Ti-Zr NDIs combined with angulated hybrid abutments and HTZ crowns can be used in the anterior region.

Clinical Performance of Narrow-diameter Implants (NDIs) Supporting Fixed Prostheses in Stress-bearing Posterior Jaws: A Systematic Review

&lt;p&gt;Abstract: Objectives: Narrow-diameter implants (NDIs) may serve as a feasible treatment alternative for the rehabilitation of specific cases. The aim of this review article was to assess the clinical outcomes of restoring stress-bearing posterior edentulous ridges with NDIs. Materials and Methods: An electronic search was conducted in MEDLINE/PubMed and Cochrane Library databases and enriched by hand search. Prospective and retrospective clinical studies, from January 2000 to November 2021, with at least 10 patients and a follow-up period of at least 1-year after functional loading, were included. Marginal bone level (MBL) and implant survival/success rate were set as primary outcome variables. Results: From the initially identified 2,401 articles, 17 clinical studies fulfilled the inclusion criteria and were included. Of the selected studies, mean MBL after loading was within 2 mm at different time intervals up to 10 years. Recorded implant survival rate was 92.6-100%, 95.3-100%, 95.3-100%, and 95.1-97.9% after 1-, 3-, 5-, and 10-year, respectively, while success rate was 92.6-100%, 95-100%, and 95% at 1, 3, and 10 years. Biological and prosthetic complications were observed. Conclusions: Within the limitation of the present study, it could be concluded that the use of NDIs for rehabilitation of posterior jaws is a viable treatment alternative, with comparable MBL and implant survival/success rate to standard-diameter implants (SDIs).&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Biomechanical effects of bone quality and design features in dental implants in long-term bone stability

Abstract This study analyzed the effects of implant design factors (diameter, length, and connection type) and bone quality on the long-term success of implantation via finite element (FE) analysis, considering the bone remodeling process. A total of 36 cases of the three-dimensional FE model, with an implant complex located in the mandibular bone section of the molar region, were considered. An FE analysis considering dental bone remodeling was implemented in the Abaqus UMAT subroutine. A preload of 32 N∙cm and an average biting force of 50 N were applied during the bone remodeling process as the loading conditions. After the bone remodeling process, a maximum biting force of 200 N was applied in the oblique direction. The stability of the peri-implant bone was analyzed by measuring the apparent bone density over time and the principal strain in the cancellous bone. The stability of the peri-implant bone differs depending on the host bone conditions and implant design features. The initial bone condition greatly influenced the final density and maximum principal strain distribution in the cancellous bone surrounding the implant. The need for a stability evaluation considering the bone remodeling process has increased under the conditions of placing short-length and narrow-diameter implants in poor-quality bones.

Narrow diameter implants to replace congenital missing maxillary lateral incisors: A 1-year prospective, controlled, clinical study.

ObjectivesTo report the clinical, radiographic, esthetic, and patient‐reported outcomes after placement of a newly developed narrow‐diameter implant (NDI) in patients with congenitally missing lateral incisors (MLIs).Materials and methodsPatients with MLIs with a mesio‐distal distance between the canine and the central incisor of 5.9–6.3 mm received a dental implant with a diameter of 2.9 mm (Test), while a diameter of 3.3 mm (Control) was used when the distance was 6.4–7.1 mm. After healing, a cement‐retained bi‐layered zirconia crown was fabricated. At the 1‐year follow‐up (T2), implant survival rate, marginal crestal bone level (CBL) changes, biological and technical complications were registered. The esthetic outcome was assessed by using the Copenhagen index score, and the patient‐reported outcomes were recorded using the OHIP‐49 questionnaire.ResultsOne hundred patients rehabilitated with 100 dental implants Ø0.9 mm (n = 50) or Ø3.3 mm (n = 50) were included. One Ø3.3 mm implant was lost, and seven patients dropped out of the study, yielding an implant survival rate of 99% (p = 1.000). At T2 a. CBL of −0.19 ± 0.25 mm (Test) and −0.25 ± 0.31 mm (Control) was detected, with no statistically significant difference between the groups (p = .342). Good to excellent esthetic scores (i.e., 1–2) were recorded in most of cases. Technical complications (i.e., loss of retention, abutment fracture, and chipping of veneering ceramic) occurred once in three patients with no statistically significant difference between the groups (p > .05). OHIP scores did not differ significantly at follow‐ups between groups (p = .110).ConclusionThe use of Ø2.9 mm diameter implants represents as reliable a treatment option as Ø3.3 mm implants, in terms of CBL changes, biological and technical complications. Favorable esthetics and patient‐reported outcomes were recorded for both groups.

Rotational Load Fatigue Performance of Titanium vs Titanium-Zirconium Implant-Abutment Connections.

Titanium-zirconium (Ti-Zr) alloy has been developed to strengthen the implant body, but clinically relevant information is still limited. The aim of this in vitro study was to compare the rotational load fatigue performance of implant-abutment connections in narrow-diameter (3.3-mm) and regular-diameter (4.1-mm) implants made with commercially pure grade 4 titanium alloy (CPTi-G4) and Ti-Zr. Narrow-diameter (N) and regular-diameter (R) implants with CPTi-G4 (Ti) or Ti-Zr (Tz) materials were tested. This resulted in four test groups: NTi, NTz, RTi and RTz. Five specimens were made for each group (n = 5). Abutments used were milled from titanium-aluminum-niobium alloy abutment blanks. A rotational load fatigue machine applied a sinusoidally varying load at an angle of 45 degrees to produce an effective bending moment of 35 Ncm at a frequency of 14 Hz in air at 20°C. The number of cycles to failure was recorded. The upper limit was set as 5 million cycles. Results were evaluated using analysis of variance (ANOVA) and Tukey post hoc tests. Failure locations and patterns were evaluated with scanning electron microscope (SEM). All regular-diameter test groups reached the upper limit of 5 million cycles without failure. All narrow-diameter test groups failed within the range of 402,530 cycles to 3,374,353 cycles. It could be observed that NTz showed a higher mean cycle count as compared to NTi. NTi test group recorded two implants damaged, one implant fracture, five abutment fractures, and four screw fractures. NTz test group showed only abutment fractures at the level of implant platform, with no damage to the implant bodies. Significant difference was found between implants of different diameters. There was no significant difference between implants of different materials. Regular-diameter implants performed significantly better than narrow-diameter implants, regardless of material, while no significant difference in cyclic load to failure was found between groups of different alloys. All NTz failures were at the abutment only, without damage to the implant. This failure pattern can potentially be clinically advantageous in terms of retrieval and subsequent replacement of a failed prosthesis.

Comparison of bone loss around implants using radiographs

This article presents an original-research conducted at Pushpagiri College of Dental sciences, Thiruvalla, Kerala to compare and evaluate the vertical crestal bone changes around implants with different surface coatings and diame-ter using CBCT and RVG taken at the time of loading and one year after loading. Thirty-six samples were divided in 4 group; based on 3 parameters: implant surface coating, implant diameter, and single versus multiple implants sup-ported bridges. Length of all implants is kept standardised at 10 mm. Data were statistically analyzed by Students paired t-test and comparison between CBCT and RVG is done using interclass correlation test. The mean crestal bone loss has increased statistically significant from the time of loading and after one year of loading. The average crestal bone loss on single implants were less compared to multiple implants supported bridges at both timings. CBCT shows more accurate and reliable values than RVG both clinically and statistically. It was concluded that crestal bone loss was less among single implants with calcium phosphate surface coating and wider diameter than alumina blasted and narrow diameter implants. Single implant shows less bone loss than multiple implants. The CBCT shows a reliable method of detecting circumferential peri-implant bone defects than RVG.

Stress distribution and microgap formation in angulated zirconia abutments with a titanium base in narrow diameter implants: A 3D finite element analysis

This in vitro study aimed to use failure stress and implant abutment interface (IAI) microgap size to find the compromised axial angle range of angulated zirconia abutments with a titanium base in narrow diameter implants in the esthetic region. A three-dimensional (3D) finite element model of maxillary central incisor implant prosthesis was reconstructed. Angulated zirconia abutments (0°, 15°, 30°, and - 15°) with a titanium base in narrow diameter implants (3.3*12 mm, Bone level, Roxolid SLActive, Straumann AG, Switzerland) were designed to simulate clinical scenarios of buccal inclination 0°, 15°, and 30°, and palatal inclination 15° of the implant long axis. Straight titanium abutment and pure titanium implant were used as two control groups. An oblique force at 30° inclination to the long axis of the crown was applied 3 mm below the incisal edge on the palatal surface of the prosthesis. Under simulated dynamic chewing force, the stress distribution of the implant components and surrounding bone were investigated. The relative micromotion displacement between the implant and abutment models at the IAI area was recorded, and the influence of tightening torque on the IAI microgap was evaluated. The angulation of the zirconia abutment could affect the stress value and IAI microgap of implant restorations. When the zirconia abutment angle increased from -15 °to 30°, the stress on the central screw, titanium base, and surrounding bone tissue gradually increased by 9%, 20%, and 23%, respectively. The stress levels of the 30° zirconia abutment group showed the risk of exceeding the threshold. When the long axis of the implant was inclined in the palatal direction, the -15° angle abutment reduced the stress by 3% and reduced the strain level of the implant system by 17% and the surrounding bone tissue by 26%. Under simulated dynamic chewing load, the displacement between the implants and the abutment occurred in each group of the implant system, and the amplitude of the micromotion fluctuated with the change in the load. The horizontal displacement caused a 0.075-1.459 μm palatal microgap and 0.091-0.945 μm distal microgap in the IAI. The microgap between the lip and palate was more evident, and the vertical displacement difference was manifested as the abutment sliding down the implant. In cases of upper implant restoration with difficulties such as small gaps and axial defects in the esthetic zone, the abutment angle is highly recommended to be in a slightly palatal-inclined direction or to not exceed 15° when the implant is inclined to the labial side to avoid mechanical damage and leakage caused by the appearance of excessively large micromotion gaps. This article is protected by copyright. All rights reserved.

Implant stability of narrow diameter implants in hyperglycemic patients-A 3-month case-control study.

ObjectivesThe aim of this prospective case–control study was to compare the development of implant stability quotients of narrow diameter implants in patients with type 2 diabetes mellitus (T2DM) and healthy individuals within the first 3 months after implant insertion.MethodsSixteen patients with T2DM (HbA1C > 6.5%) as test group and 16 nondiabetic patients (HbA1C < 5.9%) as the control group were evaluated. All patients received narrow‐diameter tissue level implants in an edentulous area posterior to the canine. The implant stability was measured by means of resonance frequency analysis after 3 days, 7 days, 4 weeks, and 3 months postplacement. Statistical analysis of intergroup differences and correlation to HbA1c values and treated jaw was performed in PRISM 8.ResultsThe means for implant stability quotients showed a significant increase between Day 3 and 3‐month assessment in both groups. No significant differences between study groups and no correlation of implant stability to HbA1c were found.ConclusionThe present study shows encouraging clinical outcomes for narrow‐diameter implants inserted in the posterior zone in patients with uncontrolled T2DM.

Esthetic and functional outcomes of narrow-diameter implants compared in a cohort study to standard diameter implants in the anterior zone of the maxilla.

The aim of this study was to evaluate functional and esthetic clinical outcomes and patient satisfaction with narrow-diameter implants in comparison to standard-diameter implants in the anterior zone of the maxilla in a follow-up examination after 1 to 6 years. The study was designed as a retrospective cohort study investigation including 27 patients receiving a 3.3-mm diameter single implant (NDI, n = 14) or a standard-diameter 4.1-mm single implant in the anterior zone of the maxilla (SDI, n = 16). Descriptive and analytical statistics were performed comparing both groups with regard to clinical examination including esthetic outcome, sulcus fluid flow-rate, crown esthetics, patients' satisfaction on visual analog scales, occurrence of biologic or technical complication, probing pocket depths (Fisher exact test), pink esthetic score (PES) and Periotest (Mann-Whitney U test). The level of significance was set at α = .05. The mean observation period was 4.8 years after crown insertion in the NDI group, and 4.9 years in the SDI group. Significant differences were observed for Periotest values in favor of the 4.1-mm implants (P = .014). No differences were found with regards to esthetics (PES; P = .27) or sulcus fluid flow-rate (P = 0.73) and probing pocket depths (P = .35). Overall patient satisfaction was high for both groups with visual analog scale scores of 9.3 ± 1.1 for NDI and 9.4 ± 1.0 for SDI (P = .39). Clinical outcome with narrow-diameter implants was comparable to standard-diameter implants in the anterior zone of the maxilla with similar esthetic assessments and patients' satisfaction.

Analysis of fractured dental implant body from five different implant systems: a long-term retrospective study

The aim of this study was to perform an analysis of the incidence of implant body fracture and to identify possible risk factors. A long-term follow-up retrospective evaluation of 3477 patients who received 8588 implants from five implant systems was performed. Overall, 2810 patients who received 7502 implants, with an average follow-up of 6.9 years, were included in the analysis. The overall body fracture rate was 0.49% (37/7502), among which 32.4% (12/37) were implants with a reduced diameter. The estimated cumulative fracture rate was 1.24%. Fractures were observed in two patients with three Brånemark implants, 13 patients with 15 Nobel Replace implants, eight patients with eight Camlog implants, eight patients with 11 Ankylos implants, and none of the patients with Thommen implants. Most fractures occurred in the molar region (29/37) and in single implant-supported restorations (30/37). The results showed significant differences between splinted and unsplinted restorations (P = 0.005) and between regular and narrow diameter implants (P = 0.009). Within the limitations of this retrospective analysis, a narrow implant diameter is a potential risk factor for implant body fracture in the posterior region. Furthermore, unsplinted restorations appear to be associated with a higher rate of implant fracture.

Marginal Bone Loss and Pink Esthetic Evaluation of Narrow-Diameter Dental Implants for Single Crowns: 1-Year Prospective Clinical Study.

The aims of this study were: (1) to quantify the marginal bone loss (MBL) of 3.3-mm narrow-diameter, bonelevel, titanium-zirconia (Ti-Zr) implants with two different surfaces in single restorations after a 1-year follow-up; (2) to analyze the combinations of different variables that may influence MBL; and (3) to record the Pink Esthetic Score (PES) value and its correlation with MBL. This is a prospective longitudinal clinical study with a 1-year follow-up after crown placement. Two different implant surfaces (sandblasted acid-etched and modified sandblasted acid-etched) were used. All bone-level and bone level-tapered implants had a diameter of 3.3 mm. Different healing and prosthetic abutments were used. Clinical, radiographic, and photographic records were taken 6 months and 1 year after placement of the restorations, and the survival rate, MBL, PES, clinical parameters, and biologic and/or mechanical complications were assessed. The correlations between the variables and MBL were verified. A total of 30 narrowdiameter implants were placed in 30 patients; 18 implants had a sandblasted acid-etched surface, and 12 implants had a modified sandblasted acid-etched surface. The measured MBL at 1 year after implant function had a mean value of -0.36 mm, ranging from 0 mm to -1.77 mm. There was no implant loss. A statistically significant relationship was observed between implant shape (design and length), implant placement level, healing abutment, prosthetic abutment size, gingival thickness, and MBL. The mean PES values recorded at the beginning and end of the study were 7.58 and 11.37, respectively. Narrow-diameter implants showed reduced MBL values, with the surrounding tissues remaining stable after 1 year of follow-up. The MBL did not show different values on two implant surfaces. MBL does not seem to influence esthetic outcome.

Influence of Implant Diameter and Taper on Virtual Implant Placement in the Maxillary Central Incisor Position: A CBCT Analysis.

This study aimed to assess the influence of implant diameter and taper on the proximity of virtually planned maxillary central incisor implants to the nasopalatine canal and adjacent anatomical structures. Virtual implant planning was performed in the maxillary central incisor position. The distance between the implant and the incisive canal (IC) and the thickness of the surrounding buccal and palatal bone walls were measured. Implants were categorized as having an exposed implant surface, thin bone, or moderate/thick bone. Measurements were repeated for regular-/narrow-diameter and parallel/tapered implants. A total of 60 patients were included, and 240 implants (60 of each type: 3.3-bone level [BL], 3.3-bone level tapered [BLT], 4.1-BL, and 4.1-BLT) were planned. The percentages of implants with between 0 and 0.5 mm of remaining bone in the coronal aspect of the IC were 31.6% for 4.1-BL/BLT and 6.6% for 3.3-BL/BLT (P < .001). The percentage of implants with IC exposure was 13.3% for 4.1-BL/BLT and 6.6% for 3.3-BL/BLT (P < .001). The frequency of sites that required bone augmentation at the coronal facial aspect (< 1 mm) was 52.6% and 33.9% for 4.1-BL/BLT and 3.3-BL/BLT, respectively. At the apical portion, the percentages of sites requiring bone augmentation at the facial aspect were 59.9%, 49.9%, 31.6%, and 23.3% for 4.1-BL, 3.3-BL, 4.1-BLT, and 3.3-BLT, respectively (P < .001). The proximity of the nasopalatine canal is often < 0.5 mm from regular-diameter virtually planned implants at the most coronal aspect in the maxillary central incisor position. In these situations, the selection of narrowdiameter implants significantly lowers the incidence of implant exposure and the need for additional management of the nasopalatine canal and also results in greater residual buccal and lingual bone thicknesses surrounding the implant. As expected, tapered implants reduced the risk of implant exposure through the buccal cortex at the apical aspect.

Use of narrow-diameter implants in the posterior segments of the jaws: A retrospective observational study of 2 to 11 years

Statement of problemThe placement of narrow-diameter implants (NDIs) in the posterior region is still debated in view of the high biomechanical risks in these areas. PurposeThe purpose of this retrospective observational study was to evaluate the success and survival rates of NDIs restored with fixed prostheses in the posterior region (primary outcome) and analyze whether splinting multiple units (prosthesis design) affects the biological and mechanical complications (secondary outcome). Material and methodsDental records from 2 private clinics were reviewed for NDIs in the posterior region installed between 2009 and 2018. Ninety study participants (58 women and 32 men) aged between 21 and 84 years (mean age 49.9 years) were recalled for the assessment of implant survival and success of 160 NDIs previously provided for partial posterior edentulism associated with moderate horizontal bone loss or reduced interradicular space (105 premolars and 55 molars). The implants were restored with metal-ceramic single crowns or splinted multiple-unit prostheses, either screw-retained or cemented on custom (n=100) or stock titanium abutments (n=60). Peri-implant probing depth (PPD), bleeding on probing (BOP), bone quality, type of edentulism, and patient satisfaction were scored. The chi-squared test for independence and 2-sample Welch t test were performed for statistical analysis (α=.05). ResultsThe overall success rate was 89.37%. One implant had been removed 4 years after loading, another after 9 years, yielding a cumulative survival rate of 98.75%. Fourteen implants exhibited PPD > 5 mm. One implant and 1 abutment screw fractured, and 16 restorations demonstrated porcelain chipping. The chi-squared test showed no significant relationship between prosthetic design and complications whether biological (P=.087) or mechanical (P=.805). Eighty-two percent of patients were satisfied with esthetics, 76% with function, 85% with total duration of treatment, and 90% with overall treatment cost. ConclusionsWithin the limitations of this retrospective study, NDIs may be considered a reliable option to replace posterior teeth. The prosthetic design had no significant impact on biological or mechanical complications.

Circumferential bone level and bone remodeling in the posterior mandible of edentulous mandibular overdenture wearers: influence of mandibular bone atrophy in a 3-year cohort study.

Evaluate circumferential bone level and morphological alterations in the posterior mandibular ridge of atrophic (AP) and non-atrophic (NAP) patients using implant-retained mandibular overdentures (MO) over 3years. Twenty-six edentulous patients categorized according to mandibular atrophy (AP = 13/NAP = 13) received two narrow diameter implants (Facility, 2.9 × 10mm) in the anterior region of mandible. The vertical and horizontal bone level was measured along with bone remodeling at 4 distances from the mental foramen in the posterior region of the mandible (L1-L4) via CBCT. NAP showed significantly higher total height and medullary height in all posterior regions at 1 and 3years (p ≤ 0.01). Cortical height and width were significantly higher (p ≤ 0.05) in this group at distances L1 and L4, respectively, in year 1. NAP shows a significantly higher % of medullary height at distances L1 (p ≤ 0.05), L2 (p ≤ 0.01), and L3 (p ≤ 0.05) after 1year, and at all distances (p ≤ 0.05) after 3years. Bone remodeling in the groups differed significantly (p ≤ 0.05) in terms of cortical width and % medullary width at L3. AP and NAP showed similar vertical and horizontal bone level. Bone resorption in the posterior ridge was stabilized by MO over 3years; however, AP are more susceptible to the long-term substitution of medullary bone by cortical bone. This study is the first to longitudinally evaluate bone dimensions in atrophic and non-atrophic two-implant MO users by CBCT and revealed that MO is a predictable treatment based on the stabilization of the posterior bone resorption.

EAO‐374/PO‐SU‐012 | Immediate provisionalization in the esthetic zone with narrow diameter implants: 5‐year results

EAO‐374/PO‐SU‐012 | Immediate provisionalization in the esthetic zone with narrow diameter implants: 5‐year results

Prosthetic aftercare, mastication, and quality of life in mandibular overdenture wearers with narrow implants: A 3-year cohort study

ObjectivesThis cohort study investigated clinical, functional, and quality of life outcomes, along with prosthetic maintenance events in mandibular overdenture (MO) wearers for 3 years. MethodsThirty MO wearers with narrow diameter implants (NDIs) and locking taper stud abutments (Facility-Equator system) were annually monitored by registering the visible plaque index (VPI), peri‑implant inflammation (PI), calculus presence (CP), probing depth (PD), bleeding on probing (BOP), secondary implant stability (ISQ), marginal bone loss (MBL), masticatory performance and dental impact in daily life (DIDL) questionnaire domains. Multilevel mixed-effects linear regression was performed to analyse changes over time. Chi-square tests were performed to analyse the relationship between the appearance of prosthetic complications and maintenance occurrences. The survival rate of patients with NDIs was calculated using the Kaplan–Meier test. ResultsTwenty-six individuals attended all follow-ups, the survival rate of 83.3% in the first year was maintained, and no one implant was lost over the 3-year period. There were significant differences for PD between 1 and 3 years (p ≤ 0.01) and between 2 and 3 years for PI (p ≤ 0.01), GI (p ≤ 0.01), ISQ (p = 0.02), and MBL (p ≤ 0.01). All masticatory performance outcomes showed significant differences (p ≤.01). Prosthetic maintenance events decreased significantly over time. Appearance, general performance, and eating and chewing domains presented high effect sizes. ConclusionContinued changes were observed in the clinical parameters of MO users over the 3-year period. In addition, most functional parameters, except for particle homogenization, improved significantly over time. The positive impact on quality of life is likely related to the significant reduction in prosthetic maintenance events. Clinical significancePeriodic returns to assess peri‑implant tissues and MO maintenance should be performed to ensure the success of rehabilitation to assure improvements in masticatory function and oral health-related quality of life.