One-year follow-up of titanium/zirconium alloy X commercially pure titanium narrow-diameter implants placed in the molar region of the mandible: a randomized controlled trial

Differences in Titanium, Titanium-Zirconium, Zirconia Implants Treatment Outcomes: a Systematic Literature Review and Meta-Analysis

Objectives

The objective of this systematic review is to test the hypothesis that treatment with titanium, titanium-zirconium and zirconia dental implants has different clinical outcomes in survival rate, marginal bone loss, bleeding on probing, plaque control record, and probing depth.

Material and Methods

A systematic electronic search through the PubMed (MEDLINE) and Cochrane Library databases was performed to identify studies published between January 1, 2013 and January 1, 2023 containing a minimum of 10 patients per study comparing titanium (Ti), titanium-zirconium (Ti-Zr), and zirconia (Zr) dental implants. Ti, Ti-Zr, and Zr dental implant clinical outcomes were determined by evaluating survival rate, marginal bone level, bleeding on probing, probing depth, plaque control record. Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool.

Results

A total of 1361 articles were screened, with 10 meeting the inclusion criteria and being utilized for this systematic review and meta-analysis. A total of 301 patients with 637 implants (304 Ti, 134 Ti-Zr, and 199 Zr) were evaluated, showing a survival rate of 97.7% for Ti, 98.6% for Ti-Zr, and 93.8% for Zr implants respectively. In a meta-analysis, no difference in marginal bone level was found between Ti, Ti-Zr, and Zr implants (P = 0.84).

Conclusions

Dental implant survival rate was lower in zirconia group. Assessment of marginal bone loss and bleeding on probing showed better results with titanium-zirconium dental implants. Plaque control result was similar in all groups. Due to limited sample size assessed it was not possible to obtain conclusion on probing depth parameter.

Clinical outcomes of titanium-zirconium alloy narrow-diameter implants for single-crown restorations: a systematic review and meta-analysis

Evidence is limited on whether titanium-zirconium alloy, narrow-diameter implants (Ti-Zr NDIs) have promising clinical outcomes when used to support single crowns. The purpose of this systematic review and meta-analysis was to evaluate clinical evidence, including survival rates, success rates, and marginal bone loss (MBL) on Ti-Zr NDIs that support single crowns. An extensive search was performed in the databases of PubMed/MEDLINE, Scopus, Embase, and the Cochrane Library for studies published in English up to April 2022. Only peer-reviewed clinical studies with at least 10 patients and a follow-up time of at least 12 months were included. Risk of bias in each study was assessed and data extraction was carried out independently by two reviewers. The outcome variables were survival rates, success rates, and MBL. The search returned 779 results. Eight studies were identified for qualitative analysis and seven for quantitative synthesis. Overall, a total of 256 Ti-Zr NDIs were included. Cumulative implant survival rates and success rates were 97.5% (95% confidence interval (CI): 94.5% to 98.9%) and 97.2% (95% CI: 94.2% to 98.7%), respectively, over a maximum follow-up period of 36 months, with no difference between Ti-Zr NDIs and commercial pure titanium (cpTi) implants. Cumulative mean (SD) MBL was 0.44 (0.04) mm (95% CI: 0.36 to 0.52) after one year. Meta-analysis of MBL indicated a mean difference of 0.02 mm (95% CI: -0.23 to 0.10), with no differences between Ti-Zr NDIs and cpTi implants. Short-term results of Ti-Zr NDIs for single-crown restorations are quite promising, although the number of published studies and follow-up periods are insufficient to determine the real benefit for single crowns. Long-term, follow-up clinical studies are needed to verify the excellent clinical performance of Ti-Zr NDIs.

Short-term and long-term success and survival rates of implants supporting single-unit and multiunit fixed prostheses: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Whether placing implants to replace each missing tooth or using implant-supported fixed partial dentures provides better outcomes is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to assess the success and survival rates of implants supporting single-unit and multiunit fixed prostheses by using conventional protocols for placement and loading in short- and long-term follow-ups.

MATERIAL AND METHODS

An electronic search was conducted in PubMed, Scopus, and Web of Science for studies published up to March 17, 2022. Comparative studies that reported the success or survival rates of both single-unit and splinted multiunit prostheses were considered for qualitative and quantitative analyses.

RESULTS

A total of 68 publications comprising 11 271 implants were included. Compared with the single prostheses, the splinted multiunit group showed no significant differences in implant success rates in the short-term (risk difference=-0.004; 95% confidence interval (CI)=-0.033 to 0.025; P=.780) and long-term (risk difference=0.003; 95% confidence interval (CI)=-0.029 to 0.034; P=.874) follow-ups. Significant statistical differences were also not found in terms of the survival rates of the 2 groups (short-term risk difference=-0.004; 95% CI=-0.031 to 0.023; P=.779, long-term risk difference=-0.002; 95% CI=-0.029 to 0.025; P=.887).

CONCLUSIONS

Implants supporting single-unit or splinted multiunit prostheses seem to be a predictable treatment in terms of survival and success over short and long periods. Nonetheless, it seems that cantilever and nonsplinted multiunit prostheses should be used with more caution.

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.

Clinical Performance Comparing Titanium and Titanium–Zirconium or Zirconia Dental Implants: A Systematic Review of Randomized Controlled Trials

Objectives: This study aimed to compare clinical results between titanium (Ti), zirconia (Zr), or titanium–zirconium (TZ) dental implants and to analyze survival rate (SR), bleeding on probing (BoP), marginal bone loss (MBL), and/or probing depth (PD). Data source: Manual and electronic searches were conducted (PubMed and Web of Science) to identify randomized controlled trials that compared the outcomes of at least two implant types (control and test group) within the same study. The focused question was determined according to the PICOT strategy. Seven studies were included out of 202 research studies initially found. The follow-up periods ranged from 12 to 80 months, and the mean age was from 43.3 to 65.8 years old. The SR for Ti, TZ, and Zr implants ranged from 92.6% to 100%, 95.8% to 100%, and 87.5% to 91.25%, respectively; MBL for Ti, TZ, and Zr implants varied from −1.17 mm to −0.125 mm for Ti, −0.6 mm to −0.32 mm for TZ, and −0.25 mm to −1.38 mm for Zr. Studies showed a low incidence of mucositis and peri-implantitis; however, BoP for Zr was 16.43%, Ti ranged between 10% and 20%, and TZ from 10% to 13.8%. PD for Ti ranged from 1.6 mm to 3.05 mm, TZ was 3.12 mm (only one study), and Zr ranged from 2.21 mm to 2.6 mm. Conclusion: All three types of implants showed similar tissue behavior. However, the TZ group had better results when compared with Ti and Zr for SR, MBL, and BoP, except for PD. Furthermore, the worst SR was found in the Zr implants group.

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

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

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.

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.

Implant-prosthetic rehabilitation of patients with severe horizontal bone deficit on mini-implants with two-piece design-retrospective analysis after a mean follow-up of 5 years

BACKGROUND

As a consequence of tooth loss due to trauma or extraction, a reduced alveolar crest volume limits the deployment of standard implants in certain patient cases. For this reason, minimal-invasive treatment with mini-dental implants (MDI) might be an option to allow implant treatment even in cases with severe horizontal bone loss without augmentation measures. The aim of this retrospective cohort study was to investigate clinical and radiological implant, as well as patient-related parameters after treatment with MDI.

RESULTS

Clinical and radiological records of 19 female (82.6%) and 4 male patients (17.4%) (N = 23), who received 52 mini-dental implants with a two-piece design in a single surgical center between November 2011 and October 2018, were retrospectively analyzed. Implants were submitted to conventional loading on different types of screwed superstructures. Crestal bone loss was measured on standardized periapical radiographs. Patient-related outcome parameters (PROMs) were recorded during follow-up period. Mean clinical and radiological follow-up was 69.6 months (5.8 years) and 51.6 months (4.3 years), respectively. Three implants were lost in two patients, leading to an implant survival rate of 94.2%. Mean radiological crestal bone loss was 1.6 mm. Both amount of peri-implant recession and crestal bone loss were significantly correlated (r = 0.65; p < 0.001). Likewise, a significant correlation was observed between deeper probing depths and increased peri-implant bone loss (r = 0.41; p = 0.012). Alveolar ridges with a reduced alveolar crest width were significantly correlated with higher peri-implant bone loss as well (r = - 0.33; p = 0.011). No prosthetic complications were reported during follow-up. Extent of midfacial recession and papilla height loss had a significant negative impact on most of the PROMs.

CONCLUSIONS

Treatment with MDI seems to be a successful alternative treatment option, especially for elderly patients with reduced crest width at implant sites. Due to the good clinical results and high survival and success rates, this treatment option was associated with high patient satisfaction. Despite the promising results, particular consideration should be given to appropriate treatment planning in these patients due to the strong correlation between peri-implant soft-tissue parameters, crestal bone loss, and reduced alveolar crest width.

Influence of implant location on titanium-zirconium alloy narrow-diameter implants: A 1-year prospective study in smoking and nonsmoking populations

STATEMENT OF PROBLEM

Titanium-zirconium (Ti-Zr) alloy (Roxolid) narrow-diameter implants (NDIs) have been widely used for implant-supported prostheses in anterior and posterior regions in the jaws. However, the relationship between implant location and clinical outcome remains unclear.

PURPOSE

The purpose of this clinical study was to evaluate and compare the clinical and radiographic outcomes of NDIs placed in different regions of the jaws in both smokers and nonsmokers.

MATERIAL AND METHODS

Eighty-four participants scheduled to receive NDIs for tooth rehabilitation were included, and the inserted NDIs were divided into 3 groups depending on their locations: implants used to restore anterior teeth, implants used to restore premolars, and implants used to restore molars. Crestal bone loss (CBL), implant survival and success rates, bleeding on probing (BOP), and pocket probing depth (PPD) were evaluated 6 and 12 months after implant loading (α=.017 for implant survival and success rates after Bonferroni correction, α=.05 for other parameters).

RESULTS

Statistical analysis of 6- and 12-month CBL of all participants presented no statistically significant difference among the 3 groups. For smokers, the molar group presented significantly more CBL than the premolar group (0.90 ±0.94 versus 0.16 ±0.27 mm, P=.027) at the 6-month examination. The implant survival rates were 95.65%, 100%, and 100% for anterior, premolar, and molar regions, respectively (P=.283). No statistically significant difference was observed regarding periodontal parameters (P>.05).

CONCLUSIONS

Implant location has no influence on the clinical and radiographic parameters of Ti-Zr NDIs placed in a nonsmoking population. However, the combination of posterior location and smoking may induce higher risk of crestal bone loss. Caution should be taken when restoring molars for smokers with NDIs.

A Pilot Study with Randomised Controlled Design Comparing TiZr Alloy Dental Implants to Ti Implants

Objectives

Evidence on the clinical performance of recently introduced dental implants in titanium-zirconium alloy is sparse. The aim of the present pilot study with randomized controlled design is to compare changes in supporting structures around dental titanium-zirconium alloy implants to commercially pure titanium implants.

Material and Methods

The present material includes consecutive patients referred to a specialist clinic in Sweden. Two patient groups treated with dental implants in two different materials - titanium (Ti) and titanium-zirconium (TiZr) - were defined after block randomisation for smoking. In total, 40 implants installed in 21 patients were available for one-year follow-up. Marginal bone level, soft tissue height and width of keratinised mucosa were registered at baseline and at one-year follow-up.

Results

At implant level, the test group (TiZr) yielded significant marginal bone loss (P < 0.001) after one year. Additionally, marginal bone loss after one year was significantly higher for TiZr implants (P < 0.001) as compared to traditional Ti implants. Soft tissue dimensions were stable throughout the evaluation time for both implant materials.

Conclusions

One-year results indicate more pronounced initial marginal bone loss for dental implants in titanium-zirconium alloy as compared to implants made of commercially pure titanium.

Clinical and radiographic assessment of narrow-diameter and regular-diameter implants in the anterior and posterior jaw: 2 to 6 years of follow-up

Purpose

The present retrospective clinical study aimed to evaluate and compare the clinical and radiographic parameters, complications, and satisfaction in patients who received fixed prostheses supported by narrow-diameter implants (NDIs) in the anterior and posterior jaw.

Methods

Patients aged ≥30 years who had NDI-supported fixed prostheses in the anterior or posterior region of either jaw for at least 2 years were included. Complications such as chipping of the crown; loosening or fracture of the screw, crown abutment, or implant; and loss of retention were recorded. Clinical peri-implant outcomes and crestal bone loss (CBL) were measured. A questionnaire was used to record responses regarding the aesthetics and function of the fixed restorations. Analysis of variance was used to assess the significance of between-group mean comparisons. The log-rank test was performed to analyze the influence of location and prosthesis type on technical complications.

Results

Seventy-one patients (mean age: 39.6 years) provided informed consent with a mean follow-up duration of 53 months. Only bleeding on probing showed a statistically significant difference between NDIs in the anterior and posterior regions. The complication rate for NDIs in the posterior region was significantly higher than that for NDIs in the anterior region (P=0.041). For NDIs, CBL was significantly higher around splinted crowns than single crowns (P=0.022). Overall mean patient satisfaction was 10.34±3.65 on a visual analogue scale.

Conclusions

NDIs in the anterior and posterior jaws functioned equally well in terms of peri-implant soft and hard tissue health and offered acceptable patient satisfaction and reasonable complication rates.

Clinical and radiographic peri-implant health status around narrow diameter implant-supported single and splinted crowns

BACKGROUND

Studies assessing and comparing clinical and radiographic peri-implant status around narrow diameter implant-supported single crowns (NDISCs) and splinted crowns (NDISPs) are scarce.

OBJECTIVE

The aim of this retrospective study was to estimate and compare complication rates, patient satisfaction, peri-implant status and peri-implant bone loss (PBL) of NDISCs and NDISPs.

MATERIALS AND METHODS

Patients receiving narrow diameter implants (NDIs) in the posterior mandible were assessed. Technical complication and patient satisfaction were recorded. Clinical peri-implant plaque index (PI), bleeding on probing (BoP), probing depth (PD) and PBL were assessed. Technical complications and patient satisfaction were recorded. Log-rank test was computed to evaluate the influence of prostheses type and NDIs location on technical complications. P-value less than 0.05 was regarded as significant.

RESULTS

Seventy-eight patients (43 male and 35 females) agreed to follow up. The mean follow-up duration of the patients was 3.6 years. A total of 102 (43 NDISCs and 59 NDISPs) NDIs with moderately rough surfaces were included. No significant differences in PI, BoP, or PD were observed between NDISCs and NDISPs. The average PBL score was 1.17 (range: 0.03-4.15) at implant level and 1.14 (range: 0.03-4.14) at patient level. Seven implants and three patients showed peri-implantitis. The rates of technical complication of single crowns were significantly higher than those of splinted crowns (P = 0.036). PBL was significantly higher in molar sites than those in premolar sites (P = 0.041). A total of 67 patients (85.9%) were satisfied with the esthetics of the crowns, while a total of 59 patients (75.6%) were satisfied with the function of the crowns.

CONCLUSION

NDISCs and NDISPs offer high patient satisfaction and tolerable complication rates. Peri-implant conditions and peri-implant bone levels were comparable around NDISCs and NDISPs. However, bone loss of implants was higher in molar sites than those implants in premolar sites.

Dose-response effect of chlorhexidine on a multispecies oral biofilm formed on pure titanium and on a titanium-zirconium alloy

This study aimed to test the dose-response effect of chlorhexidine on multispecies biofilms formed on commercially pure titanium (cpTi) and titanium-zirconium (TiZr) alloy. Biofilms were formed on cpTi and TiZr discs and treated two times per day with five different chlorhexidine concentrations (0.12, 0.20, 0.50, 1, 2%). The biofilms were collected for microbiological, biochemical and microscopic analyses. The significance of differences among groups was evaluated by linear regression, ANOVA, Bonferroni and Tukey tests. The mean number of colony-forming units decreased as the chlorhexidine concentration increased for both cpTi and TiZr (p < 0.05). The maximum effect was observed with the 0.5% concentration. Confocal microscopy images suggested an increase in the number of dead bacterial cells with increased chlorhexidine concentration. The biofilm pH increased after chlorhexidine exposure (p < 0.05). Chlorhexidine showed an antimicrobial dose-response effect in controlling biofilm on cpTi and TiZr. 0.5% chlorhexidine can be used to achieve the maximum antimicrobial effect on both materials.

[Current trends of the choice and processing of materials for dental implantation]

For assessment of the modern situation about the choice of materials for manufacture of dental implants and the processing of their surface the scientific literature for the last 2 years was study. On the basis of a large number of contradictory results of the researches devoted to each of dental implantation problems it is possible to draw a conclusion that any of primal problems of implantology is finally not solved. There is no unique opinion at the choice of optimum material for manufacture of dental implants, at the way of processing and modification of their surface. The problem of improvement of quality of dental implantation and fight against complications of this procedure cannot be solved simple drawing other substances on the implanted material surface, this task more easily and more successfully is solved via changes of product structure and various modification of implant surface. Up to the present the researches of an opportunity to influence on characteristics of the implanted materials, changing their structure and character of a surface, continue. And the publications reporting about the considerable positive effect of artificially created roughnesses on product surfaces, and the articles claiming that there are no big differences between the rough and polished implants are confirmed by objective measurements with statistical processing of the obtained data. It should be noted that among articles there are very many works of the doubtful plan or with insufficiently valid conclusions. This review leads to the conclusion that further clinical and experimental studies and about the choice of materials for manufacture of implants and at the ways of processing of their surface are necessary.

Clinical Performance of Narrow-Diameter Titanium-Zirconium Implants: A Systematic Review

PURPOSE

Implant-supported prosthetic rehabilitations are in constant augmentation in everyday dental practice. This is largely due to increasing demand from patients for fixed or implant-stabilized prosthesis, although they are frequently reticent to complex preimplant bone augmentation surgeries, whenever bone volume is lacking. Narrow-diameter implants (NDI; ≤3.5 mm) have been developed to offer relatively simple implant solutions in challenging bone-deficient sites. However, concerns regarding their mechanical properties have been raised. Special titanium-zirconium material (Ti-Zr), with superior mechanical resistance, compared with pure titanium alloys has been introduced into the market. The purpose of this systematic review was to determine the available data on clinical performance of Ti-Zr NDI.

MATERIALS AND METHODS

A literature search of all available clinical articles dealing with Ti-Zr NDI has been carried out. After including only prospective clinical trials, 14 papers were retrieved for thorough reviewing.

CONCLUSION

Short-term results from preliminary clinical reports are quite promising, although the number of published studies and the follow-up periods are still insufficient to determine the real benefit of this hybrid material compared with titanium, especially when using NDI.

Histomorphological and Histomorphometric Analyses of Grade IV Commercially Pure Titanium and Grade V Ti-6Al-4V Titanium Alloy Implant Substrates: An In Vivo Study in Dogs

PURPOSE

To evaluate the bone response to grade IV commercially pure titanium (G4) relative to Ti-6Al-4V (G5).

MATERIALS AND METHODS

Implant surface topography was characterized by optical interferometry and scanning electron microscopy (SEM). Thirty-six implants (Signo Vinces, n = 18 per group) were installed in the radius of 18 dogs. The animals were killed at 1, 3, and 6 weeks, resulting in 6 implants per group and time in vivo for bone morphology, bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO) evaluation.

RESULTS

SEM depicted a more uniform topography of G4 than G5. Surfaces were statistically homogeneous for Sa, Sq, and Sdr. At 1 week, new bone formation was observed within the healing connective tissue in contact with the implant surface. At 3 weeks, new bone in direct contact with the implant surface was observed at all bone regions. At 6 weeks, the healing chambers filled with woven bone depicted an onset of replacement by lamellar bone. No significant effect of substrate was detected. Time presented an effect on BIC and BAFO (P < 0.001).

CONCLUSION

Both titanium substrates were biocompatible and osseoconductive at the bone tissue level.