In vitro comparison of primary stability of two implant designs in D3 bone

Does hyperbaric oxygen therapy pressure reduce mechanical stability of implants?

Hyperbaric oxygen therapy (HBOT) has beneficial effects for patients complaining of poor bone healing such as related to diabetes mellitus. However, it is known that changing pressure conditions might cause dental barotrauma in the oral cavity. The aim of this study was to evaluate implant mechanical stability under HBOT pressure. Thirty-five implants were placed in bone blocks divided into five groups as control, 1, 3, 5, 7 HBOT cycles. In one cycle, 2.4 bar 100% oxygen pressure was performed. Implants' stabilities were measured with resonance frequency analysis (RFA) and removal torque (RT) meter device. Data were analyzed using Shapiro Wilk, ANOVA, and Tukey HSD tests for RFA and RT values considering p < 0.05 as the statistical significance level. RFA and RT values were compared by Pearson correlation coefficiency. RFA values of 5 and 7 HBOT cycles were significantly lower than 1, 3 HBOT and control group (p < 0.001). There was no statistical difference between 5 and 7 HBOT cycles RFA values. HBOT pressure simulation slightly but statistically decreased the stability for the implants exposed to 5 and 7 HBOT cycles. Graphical abstract.

The influence of implant design on implant stability in low-density bone under guided surgical template in inexperienced surgeons: A pilot randomized controlled clinical trial using resonance frequency analysis

INTRODUCTION

There are several factors that greatly influence implant stability with implant design being a paramount factor; however, few studies investigate its impact.

AIM

To investigate the implant stability in relation to two different implant designs, a cylindrical shaped single-threaded design (CS/ST) and a tapered shaped double-threaded design (TS/DT) using resonance frequency analysis over the first 8 weeks after implantation.

MATERIALS AND METHODS

Twenty-eight implants were randomly allocated using computer-generated random numbers into two groups and were placed as single tooth implant in the posterior arch in human jaw as specimens. iCAT™ CBCT scan (Hatfield, PA) was used to determine the bone density according to Misch's Bone classification. The osseotomy sites were prepared and implants were placed with guided surgical template by inexperienced surgeons which were prepared with the same implant planning software (3shape® implant studio). The implant stability was measured using the resonance frequency analysis Osstell® ISQ (Osstell AB, Sweden) on the implant level over the first 8 weeks at three different time intervals. A mean implant stability quotient (ISQ) value was recorded at each measurement time points. The first ISQ of each implant recorded at the time of implant placement were considered as baseline and were the so-called primary stability.

RESULTS

All 28 dental implants were analyzed. A similar pattern of implant stability changes was observed in both implant designs. A significant decreased was found at the first 4 weeks after implantation (p < 0.05) before ascending to maximum cumulative stability by the eighth week (p < 0.05). Between the two groups, TS/DT group had a higher mean ISQ values than that of the CS/ST group at all three observation periods but did not reach statistical significance (p = 0.69). Regarding different types of bone, TS/DT showed a significant difference in mean ISQ values in D4 bone. To date, all 28 implants are in function with no failure/and or complications.

CONCLUSIONS

The difference in implant design did not significantly influence the implant stability. TS/DT shows superiority over CS/ST when placed in D4 bone and offer a significant advantage due to their positive bounce back of the ISQ values by the eighth week after implant installation.

CLINICAL TRIAL REGISTRATION

TCTR20211020005.

An In Vitro Analysis on Polyurethane Foam Blocks of the Insertion Torque (IT) Values, Removal Torque Values (RTVs), and Resonance Frequency Analysis (RFA) Values in Tapered and Cylindrical Implants

Background: Several different dental implant microgeometries have been investigated in the literature for use in low-density bone sites. The polyurethane solid rigid blocks represent an optimal in vitro study model for dental implants, because their composition is characterized by symmetrical linear chains of monomers of hexa-methylene sequences producing a self-polymerization process. The aim of the present investigation was to evaluate the primary stability of cylindrical and tapered implants positioned into low-density polyurethane solid rigid blocks. Materials and Methods: Two different macrogeometries, cylindrical (4 mm diameter and 10 mm length) and tapered dental implants (4.20 mm diameter and 10 mm length), were investigated in the present study. The implants were inserted into 10 PCF and 20 PCF polyurethane blocks, with and without an additional cortical layer. The insertion torque (IT) values, the removal torque values (RTVs), and the resonance frequency analysis (RFA) values were measured and recorded. Results: A total of 80 sites were tested, and a significant increased primary stability (PS) was detected in favour of tapered dental implants when compared to cylindrical implants in all experimental conditions (p < 0.05). Higher IT, RT, and RFA values were measured in tapered implants in 10 and 20 PCF polyurethane blocks, both with and without the additional cortical layer. Conclusions: Both implants showed sufficient primary stability in poor density substrates, while, on the other hand, the tapered microgeometry showed characteristics that could also lead to clinical application in low-density posterior maxillary sites, even with a drastically decreased bone cortical component.

PRIMARY STABILITY IN VARIOUS-LEVELS IMPACTED IMPLANTS: AN EX-VIVO STUDY

The aim of this study was to examine the primary stabilization of different vertically impacted bone implants. Implant stability was measured by resonance frequency analysis. Forty-five dental implants were used and divided into three groups. Group 1 was placed 4 mm (1/3 impacted), Group 2 was placed 8 mm (2/3 impacted), and Group 3 was placed 12 mm (fully impacted). Implant stability quotient values were measured on the longitudinal and transversal axis by two independent researchers. The fully-impacted group showed the significantly highest value among the groups (p < 0.05). There were statistically varying implant-stability quotient values between researchers. None of the 1/3 impacted implants' value reached a 70 implant-stability quotient value.

Relationship between Implant Geometry and Primary Stability in Different Bony Defects and Variant Bone Densities: An In Vitro Study

AIM

This in vitro study aimed to evaluate the effects of implant designs on primary stability in different bone densities and bony defects.

METHODS

Five implant types (tapered-tissue-level, tissue-level, zirconia-tissue-level, bone-level, and BLX implants) were used in this assessment. The implants were inserted into four different artificial bone blocks representing varying bone-density groups: D1, D2, D3, and D4. Aside from the control group, three different types of defects were prepared. Using resonance frequency analysis and torque-in and -out values, the primary stability of each implant was evaluated.

RESULTS

With an increased defect size, all implant types presented reduced implant stability values measured by the implant stability quotient (ISQ) values. Loss of stability was the most pronounced around circular defects. Zirconia and bone-level implants showed the highest ISQ values, whereas tissue level titanium implants presented the lowest stability parameters. The implant insertion without any thread cut led to a small improvement in primary implant stability in all bone densities.

CONCLUSIONS

Compared with implants with no peri-implant defects, the three-wall and one-wall defect usually did not provide significant loss of primary stability. A significant loss of stability should be expected when inserting implants into circular defects. Implants with a more aggressive thread distance could increase primary stability.

Influence of short implants geometry on primary stability

BACKGROUND

A correct design is needed in short implants to improve primary stability (PS) in low quality bone. This study aimed to compare PS of double thread and single thread short implants.

MATERIAL AND METHODS

Thirty implants with single thread design (PHI/SHORT-I) and 30 implants with double thread design (PHIA/SHORT-I) (Radhex®, Inmet-Garnick S.A., Guadalajara, Spain) were placed in 30 randomly selected bovine ribs. PS was assessed in implant stability quotients (ISQ) and periotest values (PV) with Osstell™ and Periotest® devices, respectively. Computed tomographies of the ribs were taken and bone quality was evaluated in Hounsfield Units (HU) using Ez3D Plus software (Vatech Co., Korea). Only implants placed in low quality bone according to Misch and Kircos classification were selected (D3 bone: 350-850 HU; and D4 bone: 150-350 HU). Ten implants were not included in the study for being placed in D1 and D2 bone. Finally, 50 implants were selected: 17 and 9 PHI/SHORT-I in D3 and D4 bone respectively, and 15 and 9 PHIA/SHORT-I in D3 and D4 bone respectively.

RESULTS

The one-way ANOVA showed statistically significant differences in ISQ (61.35 ± 4.77 in PHI/SHORT-I and 66.43 ± 4.49 in PHIA/SHORT-I, P<0.005) and PV (-2.76 ± 0.8 and -4.11 ± 1.24 respectively, P<0.005) between two implant designs in D3 bone, and statistically significant differences in ISQ (53.44 ± 3.34 in PHI/SHORT-I and 60.56 ± 1.53 in PHIA/SHORT-I, P<0.0001) and PV (1.13 ± 0.95 and -2.5 ± 0.61 respectively, P<0.0001) between two groups in D4 bone.

CONCLUSIONS

Double thread design short implants resulted to have higher PS in comparison with single thread design short implants in D3 and D4 bone.