Restoration of posterior teeth by narrow diameter implants in hyperglycemic and normoglycemic patients - 4-year results of a case-control study.

OBJECTIVES: To investigate the four-year clinical outcome and marginal bone loss around narrow-diameter implants in patients with uncontrolled diabetes mellitus type 2 (T2DM) and normo-glycemic individuals. MATERIALS AND METHODS: In 11 T2DM patients with a concentration of glycated hemoglobin (HbA1C) > 6.5% (test group) and 15 normoglycemic patients (HbA1C < 6.0%; control group), one narrow-diameter tissue level implant, placed in the posterior maxilla or mandible, was investigated. The clinical parameters probing depth (PD), bleeding on probing (BOP), attachment loss (CAL), recession, and papilla bleeding index (PBI) were assessed manually after 24 and 48 months of function. The paired digital periapical radiographs were analyzed regarding the change in marginal bone level (MBL) from baseline to 48 months post-op. The technical complications were recorded. RESULTS: In the T2DM group, 11 patients were available for follow-ups. The overall implant survival rate after 48 months was 100%. The differences in means for the clinical parameters and the MBL between the T2DM and normo-glycemic patients for the observation period were statistically non-significant. No technical complications were recorded. CONCLUSIONS: The study demonstrated an encouraging clinical outcome with ND implants in patients with uncontrolled T2DM compared to non-diabetics after 48 months' post loading. CLINICAL RELEVANCE: Patients with HbA1C > 6.5% may benefit from the treatment with narrow-diameter implants by avoiding complex surgical interventions with augmentation procedures. REGISTRATION NUMBER (CLINICALTRIALS.GOV): NCT04630691.

Implantoplasty and the risk of fracture of narrow implants with advanced bone loss: A laboratory study.

OBJECTIVES: To assess the impact of implantoplasty (IP) on maximum implant failure strength of narrow diameter implants of different type/design and material, with simulated advanced bone loss. MATERIALS AND METHODS: Narrow, parallel-walled implants (3.3 mm in diameter × 10 mm long) with an internal connection of different type/design [bone level (BL), tissue level (TL)] and material [Titanium grade IV (Ti), Titanium-Zirconium alloy (TiZr)] from one specific manufacturer were used. Half of the implants were subjected to IP in their coronal 5 mm; the remaining were used as controls (seven implants per group). Dynamic loading prior to maximum load strength testing was included. RESULTS: During dynamic loading, the fracture rate of BL implants was low and independent of IP, while that of TL implants increased significantly with IP compared with controls (p = .001). Maximum implant failure strength reduction (in %) due to IP, was 1.3%-25.4%; TiZr BL implants were least affected. Implants subjected to IP compared to those without IP as well as TL implants compared to BL implants showed a significantly lower maximum implant failure strength (p < .002); implant material was not significant (p = .845). CONCLUSIONS: Based on data from implants of one specific manufacturer, IP has a significant negative impact on the fracture strength of narrow implants suffering from advanced peri-implantitis. TL implants have been more severely affected compared to BL implants and presented an increased risk for failure during normal chewing forces. In addition, this negative impact of IP on TL implants was independent of the implant material (i.e., Ti or TiZr). CLINICAL RELEVANCE: Narrow single TL implants with advanced horizontal bone loss (e.g., 5 mm), when subjected to IP, appear to have an increased fracture risk during normal function.

Four single implant-supported crowns replacing the maxillary incisors: A retrospective report of 10 cases with 2-9 years of follow-up.

OBJECTIVE: This retrospective case series aimed to assess the stability of the papilla around four single crowns supported by narrow-diameter implants replacing all maxillary incisors. Secondary objectives included assessment of marginal bone level stability, incidence of technical and biological complications, and patient satisfaction. MATERIALS AND METHODS: Individuals with four adjacent implants in maxillary incisor sites, placed with a 3 mm inter-implant distance and rehabilitated with single crowns were included. Retrospective data were obtained from photographs and radiographs taken at the delivery of the prosthesis (baseline-T0). Patients were then recalled (≥2 years after T0) for clinical and radiographic examination (follow-up-T1). Photographs were obtained and patient satisfaction was assessed using a visual analogue scale. Papilla height and marginal bone level were compared over time. RESULTS: Data from 10 patients with medium-low smile lines and rehabilitated with 40 implants, in function for 5.4 ± 1.9 years, were analyzed. The papilla height between implants (T0: 2.3 ± 0.9 mm; T1: 2.6 ± 0.7 mm; p = .011) and between tooth and implant (T0: 3.4 ± 0.9 mm; T1: 3.8 ± 0.8 mm; p = .025) increased significantly over the years. The marginal bone level remained stable over time (T0: 0.88 ± 0.57 mm; T1: 0.71 ± 0.67 mm; p = .007). Patients were highly satisfied (97.7 ± 0.3%) with the treatment outcome. CONCLUSION: Within its limitations, this study demonstrated that four single implant-supported crowns placed at maxillary incisor sites may exhibit soft tissue and marginal bone stability over a long period of time. This treatment approach, however, should be restricted to few patients as it requires a proper case selection and skillful execution of all surgical and prosthetic steps.

Narrow diameter titanium-zirconium tissue-level implants supporting multi-unit FDPs in the anterior area: A 5-year prospective study.

BACKGROUND: Narrow diameter implants (NDIs) are used in cases of limited mesio-distal space, or if the alveolar ridge does not allow placement of a standard diameter implant. PURPOSE: The aim of this prospective case series study is to present the 5-year clinical-, radiological-, and patient-reported outcome measures (PROMs) of patients with partial edentulism in the anterior area of the jaws requiring the placement of two narrow diameter implants to support a 3- or 4-unit fixed partial denture (FPD). MATERIALS AND METHODS: Thirty partially edentulous patients missing 3 or 4 adjacent teeth in the anterior area of the jaws were included in the study. Two titanium-zirconium tissue-level NDIs were placed in each patient in healed anterior sites (60 implants). A conventional loading protocol was performed to provide a FPD. Implant survival, success, marginal bone-level changes (MBL), clinical parameters, buccal bone stability with CBCT, adverse events and PROMs were recorded. RESULTS: The survival and success rates for the implants were 100%. The mean MBL (±SD) after prosthesis delivery, and 5-year follow-up (mean 58.8 months; range: 36-60) was 0.12 ± 0.22 and 0.52 ± 0.46 mm, respectively. Decementation and screw loosening were the most frequent prosthetic complications, yielding a prosthetic survival and success rates of 100% and 80%, respectively. Patient satisfaction was high with a mean (±SD) score of 89.6 ± 15.1. CONCLUSIONS: The use of tissue-level titanium-zirconium NDIs supporting splinted multi-unit FPDs in the anterior area seems to be a safe and predictable treatment option after a 5-year follow-up period.

Mechanical Resistance of a 2.9-mm-Diameter Dental Implant With a Morse-Taper Implant-Abutment Connection.

Among the complications that can occur at dental implants, the fracture of any implant component is a relatively infrequent but clinically relevant problem. Because of their mechanical characteristics, small diameter implants are at higher risk of such complication. The aim of this laboratory and finite element method (FEM) study was to compare the mechanical behavior of a 2.9- and 3.3-mm-diameter implant with a conical connection under standard static and dynamic conditions, following the International Organization for Standardization (ISO) 14801:2017. Finite element analysis was performed to compare the stress distribution on the tested implant systems under a 300-N, 30° inclined force. Static tests were performed with a load cell of 2 kN; the force was applied on the experimental samples at 30° with respect to the implant-abutment axis, with an arm of 5.5 mm. Fatigue tests were performed with decreasing loads, at 2-Hz frequency, until 3 specimens survived without any damage after 2 million cycles. The emergence profile of the abutment resulted the most stressed area in finite element analysis, with a maximum stress of 5829 and 5480 MPa for 2.9- and 3.3-mm-diameter implant complex, respectively. The mean maximum load resulted in 360 N for 2.9-mm-diameter and 370 N for 3.3-mm-diameter implants. The fatigue limit was recorded to be 220 and 240 N, respectively. Despite the more favorable results of 3.3-mm-diameter implants, the difference between the tested implants could be considered clinically negligible. This is probably due to the conical design of the implant-abutment connection, which has been reported to present low stress values in the implant neck region, thus increasing the fracture resistance.

The Comparison of Survival Rates between Narrow Diameter Implants and Standard Diameter Implants: An Updated Meta-analysis.

Background: One of the key objectives is to update knowledge in order to develop treatment and care recommendations based on research findings. The purpose of the present meta-analysis was to compare the survival rate of narrow dental implants (NDI) with standard dental implants (SDI). Methods: The international databases targeted for conducting a broad search included PubMed (Medline), Scopus, Web of Sciences, and Embase (Elsevier), which were searched to retrieve articles from January 1, 2000, to the end of July 2022. After the search, studies were screened based on the title, abstract, and full text, and finally, information extraction and quality assessment of the articles were performed based on the Newcastle-Ottawa Quality Assessment Scale checklist. All analyzes were conducted in STATA software Version 17. Results: After the screening, 8 retrospective and prospective cohort studies remained in the research for analysis. The outcomes demonstrated that the probability of healthy teeth in the 2 groups of NDI and SDI was not substantially different at least a year after implantation, and the risk ratio of tooth loss in the NDI group was comparable to that of the SDI group (RR, 1.00; 95% CI, 0.98, 1.02; I2: 28.37 %; P = 0.252). In addition, the survival rates in the 2 groups were also measured using meta-analysis and the results showed the survival rates in the 2 groups of NDI and SDI were almost equal. In the SDI group, the survival rate was equal to 94% (95% CI, 90%-98%), and in the NDI group, it was equal to 94% (95% CI, 92%- 98%). Conclusion: Based on the results of the present meta-analysis, the survival rates in the both NDI and SDI groups were almost equal.

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.

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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). DISCUSSION: 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. TRIAL REGISTRATION: Clinicaltrials.gov identifier: ChiCTR1800020426.

Restoration of a wide edentulous posterior site with two small-diameter implants: Biologically-driven alternative treatment.

BACKGROUND/PURPOSE: Crestal bone stability, implant rigidity and occlusal loading are issues with small-diameter implants. This article demonstrates the use of two small-diameter implants replacing a missing wide edentulous site and discusses factors that may affect bone changes. METHODS: Patients who wanted to restore an edentulous space measuring from 12 to 14 mm wide in the posterior region were offered an alternative treatment option, using two narrow or regular-diameter implants instead of one wide implant. In the study, the crestal bone stability of 12 implants in 6 edentulous sites was assessed by cone beam CTs and periapical radiographs in follow-up visits for up to 4 years. RESULTS: The bone level of all the implants was stable at buccal, lingual, mesial and distal sites, with mean values < 1 mm. The average buccal bone thickness was 1.15 ± 1.07 mm and lingual was 1.86 ± 0.89 mm, meaning that implants were surrounded by a sufficient amount of bone. The good treatment outcome may be attributed to the capability of fabricating better emergence profiles, angles (Mean: 20.67 ± 7.82° at the mesial and 20.25 ± 8.23° at the distal site) and cleansable embrasures of prostheses which are key to maintaining good oral hygiene and implant health. CONCLUSION: Using two narrow or regular-diameter implants to replace a single edentulous site measured around 12-14 mm wide in posterior region seemed to be a feasible treatment option. It is especially suitable for sites with ridge atrophy and/or patients suffering from systemic diseases.

Clinical, Radiographic, and Inflammatory Peri-Implant Parameters around Narrow Diameter Implant Crowns among Prediabetic and Non-Diabetic Subjects.

Background and Objectives: To compare the clinical, radiographic, and inflammatory peri-implant parameters around narrow diameter implants (NDI) supported single and splinted crowns in non-diabetics and prediabetes. Materials and Methods: The clinical and radiographic parameters and the levels of IL-6 and TNF-α in the peri-implant crevicular fluid (PICF) of narrow diameter single (NDISCs) and splinted (NDISPs) crown implants were assessed both in non-diabetics and participants with prediabetes. The glycemic state of the patient was assessed using glycated hemoglobin (HbA1c) levels. The peri-implant soft tissue indices (Plaque index (PI), bleeding on probing (BoP), probing depth (PD)) and marginal bone loss were recorded and compared between the groups. Success of the prosthesis was assessed by the frequency of technical complications and patient satisfaction. Inter-group comparison was performed using ANOVA (one-way analysis of variance) while the normal distribution of dependent variables was calculated using Shapiro-Wilk. A p-value of less than 0.05 was considered to be statistically significant. Results: Sixty participants (30 non-diabetics and 30 with prediabetes) with a total of 178 (118 NDISCs and 60 NDISPs) platform-switched NDIs were a part of the study. Of the 118 NDISCs, 56 were placed in the non-diabetic individuals and 62 were placed in the prediabetes group whereas 30 NDISPs each were placed in both the study groups. The clinical parameters of PI, BoP and PD in the single crown and splinted crown groups showed comparable results. However, a statistically significant difference (p-value of less than 0.05) in PI, BoP and PD and in the values of IL-6 and TNF-α was found when a comparison was made between the non-diabetes and prediabetes group. A total of 91% of the patients were satisfied with the esthetics of the implants while 79% of the patients showed satisfaction with function. Conclusions: All the clinical and radiographic parameters were statistically similar in both single and splinted types of narrow diameter implants. However, the bone loss, probing depth, plaque index, and levels of inflammatory markers were statistically higher in prediabetes as compared to non-diabetes implying that a slight hyperglycemic state impacts peri-implant health.

The Accuracy of Digital Implant Impressions when Using and Varying the Material and Diameter of the Dental Implant Scan Bodies.

The effects of using and varying the material and diameter of implant scan bodies (ISBs) on the level of accuracy of digital implant impressions is unclear. The purpose of this study was to investigate these effects on the level of accuracy of scans made by an extraoral scanner (EOS) and intraoral scanner (IOS). A stone cast with two sets of ISBs was used. ISBs were made of titanium (TI) or polyether ether ketone (PEEK). Each set consisted of two narrow diameter (ND) and two regular diameter (RD) ISBs. Sixtysix scans were performed and imported into an inspection and metrology software to conduct the three-dimensional (3D) comparisons (N=140) and obtain root mean square (RMS) values. RMS values were analyzed with descriptive and inferential non-parametric statistics (α=.05). The use of ISBs did not improve the overall EOS and IOS scans accuracies. Also, varying the ISBs' diameter and material influenced the EOS and IOS accuracies. For the EOS, the precision in descending order was as follows RD TI, ND TI, RD PEEK, ND PEEK. In contrast, for the IOS an inverse relationship was noted. Finally, precision assessment should always be performed for any reference scanner under the proposed test conditions.

Need for lateral bone augmentation at two narrow-diameter implants: A prospective, controlled, clinical study.

OBJECTIVES: To detect the potential influence of implant diameter and anatomic factors on the need for bone augmentation procedures (BAPs) when replacing congenitally missing lateral incisors (MLIs). MATERIALS AND METHODS: Patients with congenitally missing MLIs with a mesio-distal distance between the canine and the central incisor of 5.9-6.3 mm received a Ø2.9 mm implant while Ø3.3 mm implants were placed when the distance was 6.4-7.1 mm. The following linear measurements were recorded using a calliper: width of the alveolar process (WAP), width of the bony alveolar ridge (WAR) and thickness of the facial bone after implant osteotomy (TFB). Guided bone regeneration was performed in case of fenestration- or dehiscence-type defects or a thin TFB (<1.7 mm). RESULTS: Fifty Ø2.9 mm and 50 Ø3.3 mm were included in 100 patients. WAP and WAR did not differ between the groups (p > .05). TFB was statistically significant larger in the Ø2.9 group (1.75 ± 0.59 mm) compared to the Ø3.3 group (1.5 ± 0.63 mm) (p = .041). Fenestration-type defects (p = .005) and a thin facial bone wall (p = .045) was observed more frequently in the Ø3.3 compared to the Ø2.9 group. Correspondingly, BAP was indicated more frequently in the Ø3.3 compared to the Ø2.9 group (p = .017). WAP, MD and WAR were statistically significant correlated to the need for BAP (p < .001). As independent variable, only WAR influenced the probability of BAP (p < .001). CONCLUSION: The use of 2.9 diameter implants was correlated to a reduced frequency of BAP compared to 3.3 mm implants, without reaching a statistically significant difference. Measurement of the WAP provides the clinician useful information to predict BAP.

One-year performance of posterior narrow diameter implants in hyperglycemic and normo-glycemic patients-a pilot study.

OBJECTIVES: The aim of the study was to compare the performance of narrow diameter implants in patients with uncontrolled diabetes mellitus type 2 (T2DM) and normo-glycemic individuals during the first 12 months after implant loading. MATERIAL AND METHODS: In 16 T2DM patients with HbA1C > 6.5% (test group) and 16 normo-glycemic patients (HbA1C < 6.0%; control group), one to two narrow diameter tissue level implants were placed in the posterior maxilla or mandible. After 3-month lasting integration period, implants were loaded by fixed dentures. The clinical parameters probing depth (PD), bleeding on probing (BOP), attachment loss (CAL), recession and papilla bleeding index (PBI) were assessed manually at loading and after 12 months of function. The paired digital periapical radiographs were analyzed with regard to the change in marginal bone level (MBL) from baseline to 12 months' control. The mean values calculated for both patient groups were statistically analyzed. The technical complications were recorded. RESULTS: The T2DM group accounted 13 patients due to 3 dropouts. The overall implant survival rate after 12 months was 100%. The differences in means for the clinical parameters and the MBL were statistically non-significant between the T2DM and normo-glycemic patients for the short period of loaded function reported here. No technical complications were recorded. CONCLUSIONS: The study demonstrated an encouraging clinical outcome with narrow diameter implants in patients with uncontrolled T2DM compared to non-diabetics after 12 months post loading. For the short observation period, no biological and technical complications were reported regardless the glycemic status. CLINICAL RELEVANCE: Patients with HbA1C > 6.5% may benefit from the treatment with narrow diameter implants by avoiding complex surgical interventions with augmentation procedures. TRIAL REGISTRATION: Clinicaltrials.gov : NCT04630691.

Evaluation of the implant diameter on the initial-stability of narrow- and standard-diameter implants placed in simulated Type-I and Type-IV bone-blocks.

OBJECTIVE: A comparison of the initial stability of narrow- and standard-diameter implants (SDIs) placed in Type-I and Type-IV bone-blocks is not yet reported. The aim was to evaluate in-vitro the influence of implant diameter on the initial stability of narrow- and standard-diameter implants (SDIs) placed in simulated Type-I and Type-IV bone-blocks. METHODS: The present experimental in-vitro study was performed between July and September 2020 at the Specialist Dental Practice, Riyadh, Saudi Arabia. Narrow- and standard-diameter implants were placed 3-mm apart in simulated soft (Type-IV) and dense (Type-I) bone blocks by a trained and calibrated investigator. In groups A (Type-IV bone blocks) and B (Type-I bone blocks), implants were inserted using an insertion-torque and drilling-speed of 15-30 Ncm and 1000-1500 rpm, respectively with the implant collar at the crest of simulated bone blocks. In all samples, initial-stability was recorded using resonance frequency analysis (RFA). Sample-size estimation was done and group-comparisons were carried out. A P-value of 0.01 or less reflected statistical significance. RESULTS: In Groups-A and -B, 44 (22 NDIs and 22 SDIs) and 44 (22 NDIs and 22 SDIs) were placed. In group-A, the mean RFA values for NDIs and SDIs were 68.5 ± 3.5 and 69.1 ± 2.4, respectively. In Group-B, the mean RFA values for NDIs and SDIs were 78.06 ± 9.6 and 75.3 ± 5.2. RFA values among NDIs and SDIs in groups A and B were similar. CONCLUSION: The NDIs and SDIs show comparable initial-stability when positioned in simulated Type-I and Type-IV bone blocks.

Clinical outcomes and bone-level alterations around one-piece mini dental implants retaining mandibular overdentures: 5-year follow-up of a prospective cohort study.

OBJECTIVES: To report on the clinical outcomes of one-piece mini dental implants (MDIs) retaining mandibular implant overdentures (IODs), including marginal bone-level alterations (ΔMBLs), clinical peri-implant parameters, and technical- and biological complications during a 5-year follow-up. The null hypothesis was that ΔMBLs would be equal in subjects older than 65 years relative to younger subjects. MATERIALS AND METHODS: Four 1.8-mm diameter one-piece MDIs with ball attachments were placed in the interforaminal region of 20 edentulous subjects. The existing complete dentures were converted to IODs. Standardized radiographs of each implant were taken at implant placement (baseline) and during the five-year follow-up. ΔMBLs and potential influencing factors were evaluated, and peri-implant parameters, and biological and technical complications were recorded. RESULTS: The implant and prosthetic survival rates were both 100%. IODs fractured in seven participants. The overall mean ΔMBL after 5 years was -1.18 mm (standard deviation: 0.79 mm). ΔMBLs per month were most pronounced within the first 3 months after implant placement. ΔMBLs were not influenced by the implant location, the presence of keratinized mucosa, or gender. However, ΔMBLs were significantly smaller in subjects older than 65 years (p = .007). CONCLUSIONS: One-piece MDIs retaining mandibular IODs with O-ring attachments are a predictable treatment option, providing stable peri-implant bone and soft tissue conditions over a mid-term follow-up. Incorporating a metal reinforcement can prevent denture fracturing when converting a complete denture into an IOD. The presence of keratinized mucosa does not necessarily lead to decreased bone-level changes. Advanced age might be beneficial in terms of peri-implant bone stability.

Mapping of inflammatory biomarkers in the peri-implant crevicular fluid before and after the occlusal loading of narrow diameter implants.

OBJECTIVE: To monitor the cytokine release patterns in the peri-implant crevicular fluid (PICF) and to investigate which factors affect the success rate of narrow diameter implants (NDI) during the first year. MATERIAL AND METHODS: Mandibular implant overdentures (IOD) retained by 2 NDI were installed in 16 clinically atrophic edentulous patients. The following parameters were monitored during the first year: (i) peri-implant health parameters (plaque index (PI), calculus presence (CP), gingival index (GI), probing depth (PD) and bleeding on probing (BoP); (ii) cytokine concentrations in the PICF (TNF-α, IL-1ß, IL-6, IL-10); (iii) implant stability quotient (ISQ); (iv) marginal bone level (MBL) and bone level change (BLC); (v) implant success. The insertion torque, bone type, mandibular atrophy, time since edentulism, and smoking habits were also recorded. All data were analyzed using multivariable multilevel mixed-effects regression models. RESULTS: The variability in the TNF-α release patterns temporarily reduced at weeks (w) 8-12, while the IL-1ß concentrations remained low until they peaked at w48 [p < 0.05; + 177.55 pg/µl (+ 96.13 - + 258.97)]. Conversely, IL-10 release decreased significantly at w48 [p < 0.05; - 456.24 pg/µl (- 644.41 - - 268.07)]. The PD and ISQ decreased significantly (p < 0.05) over the follow-up period, while the MBL was stable after w48 with a BLC of 0.12 ± 0.71 mm. The overall success rate was 81.3%, and was influenced by TNF-α, IL-1ß, IL-10, PI, GI, PD, smoking, and time since edentulism. CONCLUSION: Pro- and anti-inflammatory cytokine release was balanced during the first 24 weeks. The GI, smoking, and time since edentulism are the most important factors determining the implant success. CLINICAL RELEVANCE: The study contributes to the understanding of the osseointegration process in a clinically atrophic population rehabilitated with IOD, and highlights the importance of monitoring clinical peri-implant health-related parameters, smoking habit, and time since edentulism to predict implant success rates.

Evaluation of Stress in Tilted Implant Concept With Variable Diameters in the Atrophic Mandible: Three-Dimensional Finite Element Analysis.

The beneficial mechanical properties provided by greater diameter or short implants increases their usage in the tilted implant concept. The aim of the present study is to compare the stress distribution of 4 different treatment models including variable implant numbers and diameters under a static loading protocol in the atrophic mandible using 3-dimensional finite element analysis. Three models included 2 tilted and 2 vertically positioned implants with different diameters, whereas 2 distally placed short implants were added to the fourth model. The von Mises stress as well as the maximum and minimum principal stress values were evaluated after applying 200 N bilateral oblique loads to the first molar teeth with the inclination of 45° to the longitudinal axis. Tilted implants were associated with higher stress values when compared with vertical implants in all models. The lowest stress values were obtained in the fourth model, including short implants. Although all stress values showed slight increases by descending implant diameters, the stress values of the model including implants with 3.3-mm diameter were within physiologic limits. All in all, an increasing number or diameter of implants may have a positive effect on implant survival. In addition, when narrow-diameter implants need to be inserted in the tilted implant concept, combination with short implants may be recommended for long-term success.

The Clinical Performance of Narrow Diameter Implants Versus Regular Diameter Implants: A Meta-Analysis.

The purpose of this study is to analyze 1- and 3-year clinical performances of narrow diameter implants (NDIs) versus regular diameter implants (RDIs). A search of electronic databases and a manual search was performed for the time period January 2000 to April 2018. A meta-regression was used to evaluate the effects of the "fixed effects" model on the implant survival rates, prosthesis success rates and marginal bone loss (MBL) with follow-up time of 1 year and 3 years. Of the 11 studies included, the overall combined 1-year implant survival rates were 98.14% for NDIs and 98.20% for RDIs. The overall combined 3-year implant survival rates were 98.71% for NDIs and 98.84% for RDIs. The corresponding values for 1-year prosthesis success rates were 96.94% for NDIs and 99.25% for RDIs. The corresponding values for 3-year prosthesis success rates were 89.25% for NDIs and 96.55% for RDIs. The meta-regression showed no significant differences between NDIs and RDIs regarding implant survival rates, prosthesis success rates, and MBL in 1-year and 3-year follow-up (P > .05). The results of this meta-analysis concluded that the implant diameter did not affect its survival rates, prosthesis success rates, and MBL in 1 and 3 years. The use of NDIs instead of bone augmentation procedures with RDIs did not affect its survival rates, prosthesis success rates, and MBL in the short-term and middle-term. However, more high-quality randomized controlled trials and long follow-up studies are needed on this topic.

Narrow- and regular-diameter implants in the posterior region of the jaws to support single crowns: A 3-year split-mouth randomized clinical trial.

OBJECTIVES: The objective of this 3-year split-mouth randomized controlled clinical study was to compare narrow-diameter implants (NDIs) to regular-diameter implants (RDIs) in the posterior region of the jaws (premolars and molars) in regards to (i) the marginal bone level (MBL) and (ii) implant and prosthesis survival and success rates. MATERIAL AND METHODS: A total of 22 patients were included in the study. Each patient received at least one implant of each diameter (Ø3.3 and Ø4.1 mm), placed either in the maxilla or mandible to support single crowns. A total 44 implants (22 NDIs and 22 RDIs) were placed and included in the study. Twenty-one implants were placed in the premolar, whereas 23 were placed in molar areas. Radiographic evaluations to access the MBL were performed immediately after implant placement, 1 and 3 years after implant loading. Peri-implant clinical variables including probing pocket depth (PPD) and bleeding on probing (BoP) were obtained after crown delivery, 1 and 3 years after loading. Furthermore, the survival and success rates of the implants and prosthesis were also evaluated. RESULTS: Twenty patients were able to complete the study. There was no statistically significant difference regarding MBL between groups at implant placement (p = .084), 1-year (p = .794) and 3-year (p = .598) time intervals. The mean peri-implant bone loss at 3-year follow-up was -0.58 ± 0.39 mm (95% CI: -0.751 to -0.409) and -0.53 ± 0.46 mm (95% CI: -0.731 to -0.329) for NDIs and RDIs, respectively. BoP was present at 15% and 10% of NDIs and RDIs, respectively, at 3-year follow-up. PPD >5 mm was observed in 5% and 0% of the implants of NDIs and RDIs, respectively, at 3-year follow-up. At the 3-year examination, the implant success rates were in the NDIs and RDIs sites, respectively, 95% and 100%. The corresponding values for prosthesis success rates were 90% for NDIs and 95% for RDIs. CONCLUSION: The present study demonstrated that NDIs placed to support single crowns in the posterior region did not differ to RDIs in regards to MBL, implant survival, and success rates.

Narrow-diameter implants: A systematic review and meta-analysis.

OBJECTIVES: Narrow-diameter implants (NDI) are claimed to be a reasonable alternative to bone augmentation procedures. The aim of this comprehensive literature review was to conduct a meta-analysis comparing the implant survival of NDI and standard diameter implants (SDI) and to provide recommendations and guidelines for application of NDI. MATERIAL AND METHODS: An extensive systematic literature search was performed in the PubMed/MEDLINE and the Cochrane Library databases. NDI were classified into Category 1 (implant diameter <3.0 mm, "mini-implants"), Category 2 (implant diameter 3-3.25 mm) and Category 3 (implant diameters 3.3-3.5 mm). Clinical studies at all levels of evidence with at least 10 patients included and a follow-up time of at least 12 months were included. The primary outcome criterion was the survival rates of NDI. RESULTS: Seventy-six studies were identified for qualitative and 16 studies for quantitative synthesis. Quality assessment illustrated a high risk of bias for the included literature. Mean implant survival rates were 94.7 ± 5%, 97.3 ± 5% and 97.7 ± 2.3% for Categories 1, 2 and 3. Meta-analysis indicated a statistically significant lower implant survival of Category 1 NDI compared to SDI ([OR], 4.54; [CI], 1.51-13.65). For Category 2 and Category 3, no statistical significant differences in implant survival were seen compared to SDI ([OR], 1.06; [CI], 0.31-3.61 and [OR], 1.19; [CI], 0.83-1.70). CONCLUSION: NDI of Category 1 performed statistically significantly worse than SDI and were mainly described for the rehabilitation of the highly atrophic maxilla or mandible. Category 2 and Category 3 NDI showed no difference in implant survival compared to SDI. Category 2 NDI were mostly used for the rehabilitation of limited interdental spaces in anterior single-tooth restorations. NDI of Category 3 were described in all regions, including posterior single-tooth restorations. However, resilient long-term data and data on the possible risk of biological and technical complications with wide platform teeth on NDI are missing so far.

Long-term outcomes of narrow diameter implants in posterior jaws: A retrospective study with at least 8-year follow-up.

OBJECTIVE: The aim of this study was to evaluate the long-term survival, complications, peri-implant conditions, marginal bone loss, and patient satisfaction of fixed dental prostheses supported by narrow diameter implants (NDIs) in the posterior jaws. MATERIALS AND METHODS: This study was designed as a retrospective cohort study with a mean follow-up time of 10.1 years (SD: 2.5 years). Patients receiving NDIs in posterior jaw were reviewed. Implant survival, hardware complication, modified plaque index (mPI), peri-implant probing depth (PPD), percentage of bleeding on probing (BOP%), marginal bone loss (MBL), and patient satisfaction were evaluated. Log-rank test and t test were used to detect the influence of implant location and restoration type. RESULTS: Sixty-seven patients with 98 NDIs (Premolar site: 81, Molar site: 17, Single crowns: 33, Splinted restorations: 65) were included. The overall implant survival rates were 96.9% at implant level and 97.0% at patient level. Veneer chipping was the most common hardware complication. The veneer chipping rates were 19.4% at patient level and 18.4% at implant level. All patients showed acceptable oral hygiene. Thus, the average MBL was 1.19 mm at implant level and 1.15 mm at patient level. Eight implants (8.5%) and six patients (9.2%) were diagnosed with peri-implantitis. Fifty-eight patients (89.2%) were satisfied with the esthetics of the restorations, while 55 patients (84.6%) were satisfied with the function of the restorations. CONCLUSION: Narrow diameter implants could be a predictable treatment option in the long term. High survival rates, high patient satisfaction, acceptable complication rates and marginal bone loss could be achieved. Further long-term studies are needed to evaluate the predictability of NDIs in molar sites.