Splinted Implants Research Articles

Influence of Narrow Titanium Dental Implant Diameter on Fatigue Behavior: A Comparison between Unitary and Splinted Implants.

Background: Scientific literature lacks strong support for using narrow diameter implants (NDI) in high masticatory force areas, especially in molars. Implant splinting in cases of multiple missing teeth reduces lateral forces, improves force distribution, and minimizes stress on implants. However, no studies have evaluated the fatigue load resistance of unitary or splinted implants. Methods: This in vitro study compares five groups of new metal alloy implants, including unitary and splinted implants with varying diameters. Mechanical characterization was assessed using a BIONIX 370 testing machine (MTS, Minneapolis, MN, USA) according to ISO 14801. For each of the five study sample groups, (n = 5) specimens underwent monotonic uniaxial compression at break testing and (n = 15) cyclic loading to determine the maximum force (Fmax) and the fatigue life (LF) values. Scanning electron microscopy (SEM) was employed for the fractographic analysis of the fractured samples. Results: The Fmax values for unitary samples ranged from 196 N to 246 N, whereas the two-splinted samples displayed significantly higher values, ranging from 2439 N to 3796 N. Similarly, the LF values for unitary samples ranged from 118 N to 230 N, while the two-splinted samples exhibited notably higher values, ranging from 488 N to 759 N. Conclusions: The observed resistance difference between sample groups in terms of Fmax and LF may be due to variations in effective cross-sectional area, determined by implant diameter and number. Additionally, this disparity may indicate a potential stiffening effect resulting from the splinting process. These findings have significant implications for dental clinical practice, suggesting the potential use of splinted sets of small-sized NDI as replacements for posterior dentition (premolars and molars) in cases of alveolar bone ridge deficiencies.

The effect of frontal trauma on the edentulous mandible with four different interforaminal implant-prosthodontic anchoring configurations. A 3D finite element analysis

PurposeThe present three-dimensional (3D) finite element analysis (FEA) was aimed to assess the biomechanical effects and fracture risks of four different interforaminal implant-prosthodontic anchoring configurations exposed to frontal trauma.Material and methodsA symphyseal frontal trauma of 1 MPa was applied to four dental implant models with different configurations (two unsplinted interforaminal implants [2IF-U], two splinted interforaminal implants [2IF-S], four unsplinted interforaminal implants[ 4IF-U], four splinted interforaminal implants [4IF-S]. By using a 3D-FEA analysis the effective cortical bone stress values were evaluated in four defined regions of interest (ROI) (ROI 1: symphyseal area; ROI 2: preforaminal area; ROI 3: mental foraminal area; and ROI 4: condylar neck) followed by a subsequent intermodel comparison.ResultsIn all models the frontal traumatic force application revealed the highest stress values in the condylar neck region. In both models with a four-implant configuration (4IF-U, 4IF-S), the stress values in the median mandibular body (ROI 1) and in the condylar neck region (ROI 4) were significantly reduced (P <0.01) compared with the two-implant models (2IF-U, 2IF-S). However, in ROI 1, the model with four splinted implants (4IF-S) showed significantly (P < 0.01) reduced stress values compared to the unsplinted model (4IF-U). In addition, all models showed increased stress patterns in the area adjacent to the posterior implants, which is represented by increased stress values for both 2IF-U and 2IF-S in the preforaminal area (ROI 3) and for the four implant-based models (4IF-U, 4IF-S) in the mental foraminal area.ConclusionThe configuration of four splinted interforaminal implants showed the most beneficial distribution of stress pattern representing reduced stress distribution and associated reduced fracture risk in anterior symphysis, condylar neck and preforaminal region.

Effect of different implant angulations on the biomechanical performance of prosthetic screws in two implant-supported, screw-retained prostheses: A numerical and experimental study

Statement of problemA mesiodistal angle frequently forms between 2 splinted implant-supported, screw-retained fixed dental prostheses (TIS-FDPs). Mechanical complications commonly occur in prosthetic screws. Studies regarding the effect of the degree of implant angulation on the biomechanical performance of prosthetic screws in TIS-FDPs are sparse. PurposeThe purpose of this numerical and experimental study was to investigate the effects of different implant angulations on the biomechanical performance, including stress distribution, stability of the screw joint, and surface morphology change of the prosthetic screws in TIS-FDPs. Material and methodsTIS-FDPs were classified into 4 groups: 0, 10, 20, and 30 degrees based on the degree of mesiodistal angle between the long axes of the 2 implants. In the finite element analysis (FEA), 4 series of 3D models were constructed and loaded with simulated occlusal forces. The von Mises stresses and rotational angles of the prosthetic screws were then calculated. In the mechanical test, each group of 5 TIS-FDPs with 10 prosthetic screws was tested under 1 million loading cycles by using a universal testing machine. The removal torque values (RTVs) and the surface roughness of the prosthetic screws were measured after cyclic loading. The normality of the outcome variables was assessed by the Shapiro-Wilk test. Analysis of variance and the Kruskal-Wallis test were used for further analysis (α=.05). ResultsThe FEA results showed that the von Mises stresses of the prosthetic screws were concentrated in the first screw thread crest engaged with the abutment, and the maximum values of the threads and the rotation angles of the prosthetic screws increased in the 2-implant mesiodistal angulation from 0 to 30 degrees. The mechanical tests showed that the RTVs of the prosthetic screws in each group were not significantly different after 1 million loading cycles (P=.107). The surface roughness of the crest of the first 2 threads of the prosthetic screws in the 30-degree group changed significantly compared with those in the other groups. ConclusionsWhen TIS-FDPs were delivered, larger angulations of the 2 splinted implants seemed to increase the stress concentrated on the crest of the first engaged thread and the rotation angles of the prosthetic screws. After 1 million loading cycles, significant surface adhesive wear was identified on the crest of the first 2 threads of the prosthetic screws in the 30-degree group compared with groups with a smaller angulation.

Splinting or Nonsplinting Adjacent Implants? A Retrospective Study Up to 15 Years: Part II-Success and Survival Rate Analysis.

To analyze the success and survival of splinted and nonsplinted implants. A total of 423 patients (n = implants: 888) were included in the study. The success and survival of implants for 15 years were analyzed using a multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. The cumulative success rate was 34.2%: 33.2% in nonsplinted (NS) and 34.8% in splinted implants (SP). The cumulative survival rate was 92.9% (94.1%, NS; 92.3%, SP). Whether to splint was not related to the success and survival of implants. The smaller the implant diameter, the lower the survival rate. The crown length and implant length were significantly associated only with NS implants: The longer the crown length and the shorter the implant length, the greater the risk of implant failure. The emergence angle (EA) and the emergence profile (EP) had a significant effect on only the SP implants: EA3 showed a higher risk than EA1, and EP2 and EP3 had a higher risk of implant failure. Crown length and implant length affected only the nonsplinted implants: The higher the crown length and the shorter the implant length, the greater the risk of implant failure. A significant effect for emergence contour was found only in SP implants: the implants restored with prostheses with EA ≥ 30 degrees on both the mesial and distal sides, and convex EP on at least one side had higher risks of failure. Int J Oral Maxillofac Implants 2023;38:443-450. doi: 10.11607/jomi.10054.

Splinting or Nonsplinting Adjacent Implants? A Retrospective Study Up to 15 Years: Part I-Biologic and Mechanical Complication Analysis.

To analyze the biologic and mechanical complications of splinted and nonsplinted implant restorations. A total of 423 patients (n = implants: 888) were included in the study. Biologic and mechanical complications that occurred for 15 years were analyzed using the multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. Biologic complications occurred in 38.7% of implants: 26.4% of nonsplinted implants (NS) and 45.4% of splinted implants (SP). Mechanical complications occurred in 49.2% of implants: 59.3% NS and 43.9% SP. Implants splinted with both mesial and distal adjacent implants (SP-mid) had the highest risk of peri-implant diseases. As the number of implants splinted increased, the risk of mechanical complications decreased. Long crown lengths increased the risk of both biologic and mechanical complications. Splinted implants had a higher risk of biologic complications and lower risk of mechanical complications. The implant splinted to both adjacent implants (SP-mid) had the highest risk of biologic complications. The greater the number of implants splinted, the lower the risk of mechanical complications. Long crown lengths increased the risk of both biologic and mechanical complications. Int J Oral Maxillofac Implants 2023;38:435-442. doi: 10.11607/jomi.10053.

Influence of low insertion torque values on survival rate of immediately loaded dental implants: A systematic review and meta-analysis.

The aim was to systematically evaluate the effect of low insertion torque values on the survival rate of immediately loaded dental implants. The protocol was registered with PROSPERO (ID CRD42020189499). An electronic search was performed in PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials until June 2022 in English and Spanish. Studies analysing the failure or survival rate of immediately loaded dental implants according to different insertion torque values were included. Five-hundred seventy-three articles were assessed for eligibility, of which seven articles, four randomized clinical trials (RCTs), one controlled clinical trial, and two prospective case series studies were included in the qualitative analysis. The RCTs were classified as having low risk of bias and the non-RCTs as having moderate and serious risk of bias. The mean survival rate for implants with low insertion toque (≤35 Ncm) was 96% (p> .001, 95% confidence interval [CI]: 0.91-0.98) and that for implants with medium or high insertion torque (>35 Ncm) was 92% (p> .001, 95% CI: 0.86-0.96) (incidence rate ratio [IRR]= 1.05, 95% CI: 0.79-1.39, p= .175, I2 = 0.0%). Splinted implants with insertion torque >20 Ncm and single implants with insertion torque >35 Ncm had a higher survival rate than implants with lower insertion torque values (IRR=1.05, 95% CI: 0.78-1.43, p= .956, I2 = 0.0%, and RR=0.92, 95% CI: 0.48-1.75, p= .799, I2 = 0.0%, respectively). Different insertion torque values achieved equivalent outcomes. The mean follow-up was 24 months. Low insertion torque values have no significant effect on survival rates of immediate loading implants at a mean follow-up of 24 months.

Comparison between bone height changes around the splinted and non-splinted OT bridge system implants in edentulous mandibles rehabilitated with all-on four full arch prosthesies a randomized clinical trial

Objectives: the aim of this study was to compare the difference in marginal bone loss around the splinted and non-splinted implants supported on OT bridge system in full arch implant mandibular restoration using the All-On -Four concept. Materials and methods: This study was conducted on 12 completely edentulous patients having 48 implants. All patients were treated with a mandibular implant supported fixed restoration. Four implants were placed interforaminally for each patient and restored with immediately loaded restoration following the All-On-Four concept. Comparison was made between the splinted implants and non-splinted implants of immediately loaded temporary conversion prosthesis using OT bridge system regarding the marginal bone loss (MBL) using digital periapical radiograph at base line and after 3 months. Results: The marginal bone loss around both groups splinted and non-splinted implants after 3 months of immediate loading was similar with no statistically significant difference. Conclusion: Both techniques are considered as reliable methods for immediate loading of a full arch screw retained implant restoration with no preference of one approach regarding marginal bone loss around implants.

Is the degree of physiological bone remodeling a predictive factor for peri-implantitis?

The amount of initial physiological bone remodeling (IPBR) after implant placement varies and the ways it may play a role in peri-implantitis development remains unknown. The aim of this retrospective study was to investigate the association between the amount of IPBR during the first year of implant placement and incidence of peri-implantitis as well as the pattern of progressive bone loss. Clinical and radiographic documentation of implants at the time of implant placement (T0), 1 year ± 6 months after crown placement (T1), and at a ≥2-year follow-up from implant placement (T2) were retrospectively collected. IPBR was defined as the bone loss occurring from implant placement to the end of the bone remodeling (T1). Cases were grouped into those diagnosed with (test) or without peri-implantitis (PIm) (control). Linear regression model under generalized estimation equation approach was estimated to assess correlation between marginal bone loss (MBL) rates in both periods (T1-T0) and (T2-T1). Receiver operating characteristics curve was estimated to explore an optimal cut-off point of T1-T0 MBL to discriminate between PIm and no-PIm implants. A total of 45 patients receiving 57 implants without PIm and 40 with PIm were included. There were no associations between PIm and IPBR (p&gt;0.05), nor between BML of (T2-T1) and (T1-T0). However, arch and total follow-up showed significant influence on the probability of PIm. Splinted implants showed an MBL rate of 0.60-mm/year higher than non-splinted implants (p&lt;0.001) from T1 to T2. No statistically significant association was found between IPBR and incidence of peri-implantitis.

Mechanical complications of implant-supported restorations with internal conical connection implants: A 14-year retrospective study

Statement of problemInternal conical connections have become the primary choice for implant-supported restorations. However, studies that identified the risk indicators for mechanical complications and diagnosed the prognosis of the implant-supported restorations are lacking. PurposeThe purpose of this retrospective clinical study was to evaluate the incidence and consequences of mechanical complications in components of internal conical connection implants and to analyze the risk indicators. Material and methodsA total of 428 patients with 898 internal conical connection implants were included in the study, and mechanical complications over the 14-year observation period were evaluated. The Cox proportional hazard regression model was used to analyze significant effects on mechanical complications, which were presented as hazard ratio and 95% confidence interval. ResultsMechanical complications occurred in 430 (47.9%) implants and 248 (57.9%) patients: screw loosening (46.4% of implants, 56.8% of patients); screw fracture (2.6% of implants, 4.4% of patients); abutment fracture (11.4% of implants, 21.3% of patients); and implant fracture (3.5% of implants, 5.4% of patients). Implant restorations replacing molars showed the highest risk for mechanical complication (hazard ratio 12.82; 95% confidence interval 2.73-60.31) and for fracture of all components. Men had a higher risk of mechanical complication than women (hazard ratio 2.00; 95% confidence interval 1.55-2.59), and the risk of fracture was higher in all components. With increased splinted implants, the risk of mechanical complication (hazard ratio 0.67; 95% confidence interval 0.49-0.93) and component fracture (hazard ratio 0.73; 95% confidence interval 0.29-0.89) decreased. Gold screws had a lower risk of screw loosening (hazard ratio 0.74; 95% confidence interval 0.58-0.94) than titanium screws, but a higher risk of fracture (hazard ratio 3.45; 95% confidence interval 1.42-8.36). The smaller the implant diameter, the higher the risk of implant fracture (hazard ratio 0.01; 95% confidence interval 0.00-0.05). ConclusionsAbutments were most frequently fractured among the components of internal conical connection type implants. Molar implant-supported restorations and male patients had higher risks of mechanical complications, and as the number of splinted implants in a prosthesis increased, the risk decreased. Gold screws showed less risk of screw loosening and higher risk of fracture than titanium screws. Narrow-diameter implants had a higher risk of fracture.

A Retrospective Study of Bone-Level Stability Around 335 Hybrid Implants Placed with an Immediate or Delayed Protocol.

This retrospective study evaluated 335 hybrid implants placed in edentulous ridges; 167 were placed with an immediate implant protocol (IIP) and 168 were placed with a delayed implant protocol. Radiographic bone level changes were measured 1 to 23 years after loading. The average bone loss between implant placement and second-stage loading was 0.16 mm in the delayed group and 0.12 mm in the IIP group. Average bone loss from implant loading to the final radiograph was 0.26 mm in the IIP group and 0.13 mm in the delayed group. There was statistically significantly more bone loss in the IIP group, in patients taking amoxicillin (vs those taking azithromycin), in sites with splinted implants (vs nonsplinted implants), and in smokers (vs nonsmokers). However, even when statistically significant, bone loss would be considered clinically insignificant by most clinicians over the 1- to 23-year follow-up.

Використання лазерного зварювання під час негайної реабілітації стоматологічних пацієнтів при повній відсутності зубів

Necessary to take into account the effect of occlusal and non-axial loading in orthopedic treatment and rehabilitation of patients with edentulous jaws with implant-supported structures. Immediate stabilization, which achieved by intraoral welding, increases the posebility of success of implant osseointegration, and using immediate loading even in cases of bone atrophy for allows implants to be stabilized. The presented review of scientific literature on the use of laser welding in dentistry, the features of the application and the practical feasibility of immediate loading when splinting implants using intraoral welding. Many authors have investigated the use and effect of the parameters of a pulsed solid-state Nd:YAG laser for Ti and dental alloys. Scientists have proven the safety and effectiveness of using a dental Nd:YAG laser for welding metals directly in the oral cavity. The main risk for immediate loading implants is bone overload in the implants area during the first postoperative weeks, which can lead to their disintegration. Splinting prevent micro-displacement, distributes forces across multiple implants and shows highly effective immediate loading protocols. The expediency of immediate loading and the use of implant splinting with the intraoral welding prevents possible implant tilt and overload. The problem of using the method of immediate loading of implants with intraoral welding in dental orthopedic treatment has not been finally solved, and the well-known developments of the authors require further research and improvement.

Rehabilitation of extremely atrophic edentulous mandible in elderly patients with associated comorbidities: a case report and proof of concept

BackgroundOral rehabilitation of the atrophic mandible is, most of the time, a challenging procedure, especially in elderly patients with associated comorbidities.Case presentationThis clinical report describes the rehabilitation of an extremely atrophic mandible using an overdenture supported by four splinted implants, two of which are placed in the interforaminal region and the other two bypassing the inferior alveolar nerve at the level of the antegonial notch. A passive-fit bar structure splinting the four inserted implants was designed to compensate for mandibular flexure, to reduce the amount of strain on the implants, and avoid bone resorption and prosthetic failure. The 14-month postoperative cone-beam computed tomography (CBCT) and the clinical follow-up showed the bilateral integrity of the inferior alveolar nerve and the successful restoration of the atrophic edentulous mandible with a significant improvement in the patient’s quality of life.ConclusionsThe applied technique depicts several benefits such as a minimally invasive approach, reduced number of surgical interventions, reduced total treatment time, reduced treatment costs, and higher psychological acceptability.

Effect of different geometric changes in the dental implant abutment body on the amount of residual excess cement and retention in a cemented implant-supported prosthesis.

Fixed implant-supported restorations are mainly used in dental implantology. In comparison with screw-retained implants, cement-retained prostheses have the following advantages: the ease of splinting implants; increased passive casting; and procedural similarity to conventional tooth-supported fixed partial dentures. Furthermore, they show reduced fracturing of components with better esthetic outcomes and an improved force direction, along with a reduced cost and less chairside time. The aim of this study was to evaluate the effect of different geometric changes in the dental implant abutment body on the amount of residual excess cement (REC) and the retention of cemented implant-supported prostheses. Seventy-two straight abutments were categorized into 4 groups: vertical groove; 1 horizontal groove; 2 horizontal grooves; and ccontrol (with no geometric changes in the abutment). The access hole was partially filled and the cast copings were cemented using Temp-Bond™ NE, a non-eugenol cement. The difference in weight before and after removing the excess cement was considered as REC. Furthermore, the retention of the cast coping was measured as the force that was required to separate the cemented cast coping from the abutment. The mean REC values of the groups with 1 and 2 horizontal grooves were significantly different as compared to the control group (p < 0.05). This study shows that the presence of 1 or 2 horizontal grooves in the abutment body significantly reduces the amount of REC in comparison with control.

Patient satisfaction and survival of maxillary overdentures supported by four or six splinted implants: a systematic review with meta-analysis

BackgroundImplant-supported overdentures offer enhanced mechanical properties, which lead to better patient satisfaction and survival rates than conventional dentures. However, it is unclear whether these satisfaction levels and survival rates depend on the number of implants supporting the overdenture. Therefore, this systematic review aimed to compare maxillary overdentures supported by four or six splinted implants in terms of patient satisfaction, implant survival, overdenture survival, and prosthodontic complications.MethodsCochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (PubMed), and EMBASE databases were systematically searched and complemented by hand searching from 2000 to 2019, employing a combination of specific keywords. Studies comparing the use of four versus six implants for supporting overdentures with at least one-year of follow-up after prosthesis installation and including ten fully edentulous patients were included. The risk of bias (RoB) was analyzed with Cochrane’s RoB 2 and Newcastle–Ottawa tools. Implants and prosthesis survival rates were analyzed by random-effects meta-analysis and expressed as risk ratios or risk differences, respectively, and by the non-parametric unpaired Fisher’s test.ResultsA total of 15 from 1865 articles were included, and reported follow-up times after implant placement ranged from 1 to 10 years. Irrespective of the number of implants used, high scores were reported by all studies investigating patient satisfaction. Meta-analysis and non-parametric Fisher’s test showed no statistical differences regarding the survival rate of implants (P = 0.34, P = 0.3) or overdentures (P = 0.74, P = 0.9) when using 4 versus 6 splinted implants to support overdentures, and no significant differences regarding prosthodontic complications were found between groups. Randomized studies presented high RoB and non-randomized studies presented acceptable quality.ConclusionsWithin the limits of this systematic review, we can conclude that the bar-supported overdenture on four implants is not inferior to the overdenture supported by six implants for rehabilitating the edentulous maxilla, in terms of patient satisfaction, survival rates of implants and overdentures, and prosthodontic complications.

Influence of Implant Distribution and Palatal Coverage on the Strain of Splinted Implant and Overdenture in Maxillary Implant Overdentures.

Implant overdentures with splinted attachments have been used in clinical practice, and the effect of splinting on implants has been reported frequently. However, the effect of implant configuration of more than four implants and covering the palate with an overdenture has not been sufficiently examined. The purpose of this study was to reveal the effects of implant configuration and palatal coverage on both implant and denture strain in maxillary implant overdentures using splinted implants. Six implants were placed in the anterior, premolar, and molar areas in a maxillary edentulous model. Four strain gauges were attached to the implant surface, and Dolder bar attachments were used to splint implants distributed in various configurations. Two types of maxillary experimental dentures (with/without palatal coverage) were fabricated, and two strain gauges were attached at the midline. A vertical load of 98 N was applied, and the strains on the dentures and implants were measured. The strain measurements were compared using one-way analysis of variance and t test (P = .05). When comparing the implant strains, the strain was significantly smaller on the anterior and premolar implants when six implants were used, but there was no significant difference among the different implant configurations in the strain on the molar implants. Strains on anterior implants of the palateless overdenture were significantly greater than those of the overdenture with palatal coverage. When four implants were used, the strain on the palatal side of dentures without palate was significantly greater than that on those with palatal coverage. When six implants were used, there was no significant difference in the strain on either side between two types of dentures. When implants were splinted to each other using a denture without palatal coverage, the strain of dentures when six or two anterior and two posterior implants were used was lower. The difference of denture strains between two types of dentures was not significant when six implants were used, but was significant for all other configurations. Also, the difference of implant strains between two dentures was significant in anterior implants regardless of implant configuration.

Immediate Loading of Four Guided Unsplinted Narrow Implants Supporting a Maxillary Overdenture: A Minimally Invasive Approach

Little evidence is available on the loading protocols for implant-supported overdentures in the treatment of the edentulous maxilla. There are only a few case-reports available to document the feasibility of immediate loading for maxillary overdenture, and the majority of the publications include the use of splinted implants. This paper presents a case report of immediately loaded narrow diameter implants supporting a maxillary overdenture using Locator abutments. A 64-year-old, fully edentulous patient presented with a maxillary complete removable denture. A dual cone beam computed tomography scan was obtained, and the surgical planning was performed. Four 3.3 mm diameter implants were placed at the lateral incisor and second premolar positions, using a guided and flapless approach. Locator abutments were placed, and the denture was connected immediately. The patient was instructed not to remove the prosthesis for 1 week and to follow a soft diet regimen for 2 weeks. Clinical and radiographic evaluation showed positive results at 12 months, with neither prosthetic nor implant complications. This is a proof of principle case report, which demonstrates the possibility of immediately loading four guided narrow diameter implants supporting a maxillary overdenture using a Locator retention system.

Effect of different design of abutment and implant on stress distribution in 2 implants and peripheral bone: A finite element analysis study

Statement of problemHow adjacent dental implants with different sizes, designs, and abutment connection shapes affect stress on the prosthetic structure is unclear. PurposeThe purpose of this finite element analysis (FEA) study was to analyze stress distribution around bone and around 2 implants with different sizes, diameters, shapes, and loading directions placed next to each other in splinted and unsplinted prostheses. Material and methodsOn 3D FEA models representing the posterior right lateral segment of the mandible, 1 implant (Ø3.5×12 mm) and 1 implant (Ø5.5×8 mm) were placed adjacent. Three different contemporary implant models were created with different teeth, pitch, spiral numbers, and self-taping features, and different abutments for them were modeled in 3D. The implant-abutment connection was internal hexagonal (MIH), stepped conical (MSC), and internal conical (MIC). Vertical and oblique loads of 365 N for molar teeth and of 200 N for premolar teeth were applied as boundary conditions to the cusp ridges and grooves in a nonlinear FEA. ResultsThe MIH implants resulted in improved stress conditions. According to the von Mises stresses occurring on the screw, abutment, and implant, especially under oblique loads, MIH was exposed to less stress than MSC, and MSC was exposed to less stress than MIC. ConclusionsWhen a standard implant and a short implant were placed adjacent and splinted by crowns, the implants, abutments, and screws had unfavorable stress levels; therefore, adjacent splinted implants should be of similar size. The form of the implant-abutment junction is also an important factor affecting stress.

Comparison of Periodontally Compromised Splinted Teeth and Implant Supported Fixed Partial Denture: A Three-Dimensional Finite Element Analysis on Bone Response.

Introduction - This study aimed to compare the amount and pattern of stress and strain distributed around periodontally compromised splinted teeth and the two-implant abutments supported six-unit fixed partial denture (FPD) using finite element analysis (FEA). Methods and Materials - Six mandibular anterior teeth of a dental model were scanned and the scans were transferred to 3D CAD design and finite element software. Jaw bone was also designed and the teeth were splinted by fiber-reinforced composite (FRC) band. In another model, two implants were placed at the site of canine teeth and a six-unit FPD was designed over them. Models were transferred to finite element software and after meshing and fixing, they were subjected to 100- and 200-N loads under 0 and 30° angles. Results - Apical areas and crestal bone showed the highest accumulation of stress and strain in periodontally compromised splinted teeth. Crestal bone and bone between crestal microthread and the first thread of implant body had the highest accumulation of stress and strain in the implant supported six-unit FPD. Conclusion - The results showed significantly higher shear stress, von Mises stress and von Mises strain in peri-implant bone compared with bone around periodontally compromised teeth. Increase in applied load magnified this difference. Also, a greater difference was noted in stress and strain in bone around teeth and implants when oblique load was applied.

Open Proximal Contact with Implant-Supported Fixed Prostheses Compared with Tooth-Supported Fixed Prostheses: A Systematic Review and Meta-analysis.

To investigate the odds of developing open proximal contact (OPC) between implant-supported fixed prostheses and adjacent teeth compared with that between tooth-supported fixed prostheses and adjacent teeth. A search was conducted in the Ovid MEDLINE, Embase, and Web of Science databases for clinical studies on OPC developed with implant-supported prostheses or tooth-supported prostheses. A meta-analysis was performed using statistical software to estimate the odds of developing OPC with implant-supported prostheses compared with tooth-supported prostheses, with a 95% confidence interval (CI). The statistical significance was defined as P < .05. The odds ratio (OR) of developing OPC with implant-supported prostheses was 2.46 compared with tooth-supported prostheses (95% CI [1.21 to 5.01]; P = .013]. However, the data were highly heterogenous (τ2 = 0.40, I2 = 95.67%). The total estimates of developing OPC were 41% (95% CI [30% to 54%]) with implant-supported prostheses and 22% (95% CI [18% to 26%]) with tooth-supported prostheses. OPC was more prevalent at the mesial side than at the distal side of implant-supported prostheses (OR = 2.38, 95% CI [0.94 to 6]; P = .066), whereas OPC was more prevalent at the distal side than at the mesial side of tooth-supported prostheses (OR = 1.94, 95% CI [1.09 to 3.45]; P = .024). There was no statistically significant difference in developing OPC with covariates of sex, age, arch, splinting of implants or adjacent teeth, region, and vitality of adjacent teeth, retention type, opposing dentition, occlusal force, parafunctional activities, and follow-up time. OPC was found to increase 9% per year with implant-supported prostheses (OR = 1.09). The estimate of interproximal gap next to implant-supported prostheses was 245.8 μm (95% CI [86.4 to 405.3 μm]). Within the limitations of this systematic review and meta-analysis, the odds of developing OPC were significantly higher with implant-supported prostheses than with tooth-supported prostheses. However, the data were highly heterogenous, and thus, a well-designed randomized clinical study needs to be conducted to validate the results of this systematic review.

Single versus splinted short implants at sinus augmented sites: A systematic review and meta-analysis

ObjectiveThis review primarily evaluated the success, survival and failure rates of implants shorter than 10 mm restored with single-unit or splinted fixed dental prostheses in maxillary sinus augmented sites. Material and methodsTwo reviewers independently performed the systematic search of electronic databases, including MEDLINE, EMBASE and CENTRAL, up to September 2019 with no language restriction. A supplemental hand search consisted of screening 13 journals. The inclusion criteria were: primary studies reporting implant, prosthetic and patient-reported outcome measures (PROMs) of extra-short and short implants placed in conjunction with sinus floor elevation in partially dentate patients, restored with single- and splinted-crowns for direct comparison, with a minimal 1-year follow-up. Weighted arithmetic mean (WAM) of the implant survival was performed according to the type of prosthesis. This was confirmed by using Review Manager software to perform meta-analysis. ResultsTwo observational studies reporting on 106 tapered, press-fit, sintered porous-surfaced implants with a length ranging from 5 mm to 9 mm were included in this systematic review. Of these, 20 and 86 implants were restored with single and splinted prostheses, respectively. The risk ratio (RR) was 1.16 (95% CI: .31–4.30, p = .58, I² = 0%) for individually restored implants failure when compared to splinted implants, indicating that short dental implants restored with single crowns could have a 16% higher possibility of failure if compared to implants with splinted crowns. The heterogeneity value was not statistically significative (p = .58). No statistical difference in the implant survival rate of the two types of analysed prostheses was observed after WAM (p= .923). The level of evidence for the included studies ranged from low (4) to fair (2B). ConclusionSimilar clinical outcomes up to a 9-year follow-up were observed in single and splinted porous-surfaced implants shorter than 10 mm located in sites with sinus lift. However, the conclusion shall be interpreted with caution due to the level of evidence and limited number of included studies included in this systematic review.