The influence of splinting procedures on the periodontal and peri-implant tissue damping characteristics. A longitudinal study with the Periotest device

Implant Stability Changes for Nonsubmerged and Submerged Protocols for a Single Implant Mandibular Overdenture Using Ball Attachment

Objectives

To compare the changes in implant stability for the nonsubmerged (NS) and submerged (S) protocols for the single implant retained mandibular overdenture using ball attachment throughout a 24-month follow-up.

Materials and Methods

Eighty completely edentulous patients were seeking to improve retention of their lower complete denture by installing a single implant in the midline of the completely edentulous mandible. At the day of implant installation, patients were randomized into 2 groups using sealed envelopes: the nonsubmerged (NS) and submerged (S) group. After a 3-month healing period, all patients were randomized using sealed envelopes into ball attachment and CM-LOC attachment. The Periotest readings (PTV) was recorded using the Periotest M device and was recorded every 3 months for the first year and then annually in the second year. The scope of this clinical trial focused only on results of the ball attachment. The Mann–Whitney U test was used for comparison between study groups for independent samples. Two-sided p values less than 0.05 was considered statistically significant.

Results

There was no statistically significant difference in the mean change in PTV reading between the NS and S group at the different follow-up intervals. Initially, at the day of pickup (baseline) and 3-month follow-up, the mean PTV reading for the NS was greater than that of the S group (−4.471 ± 1.489, −4.391 ± 1.4727 (p=0.913)), while the S group has shown a greater improvement in PTV than the NS group after 6-month follow-up and continued throughout the 24-month follow-up (−5.730 ± 1.7804, −50855 ± 1.2581 (p=1)).

Conclusion

Both the nonsubmerged and the submerged healing protocol have shown reliable Periotest readings using ball attachment for a single implant retained overdenture. The submerged group has resulted in a greater improvement in Periotest readings after the 12- and 24-month follow-up period when compared to the nonsubmerged group although this improvement was not statistically significant.

Treatment planning of implants when 3 mandibular posterior teeth are missing: a 3-dimensional finite element analysis

PURPOSE

To analyze the biomechanics of 3 designs of implant treatment for 3 teeth missing in posterior low arch quadrants.

MATERIAL AND METHODS

A posterior portion of the human mandible missing 44, 45, 46 and three 4.1 × 10 mm threaded ITI implants with crowns were used to construct the finite element model. According to 3 implants being single, splinted or 2 implants support fixed partial denture (FPD) fixed in bone segments. Three implant support conditions were prepared with ANSYS 10.0. A load of 100 N was applied at the central fossa of the occlusal surfaces of the crowns at 45 degrees buccolingually along the triangular ridge of the buccal cusp. The von Mises stress and strain distributions in periimplant bone were observed.

RESULTS

The results demonstrated that the von Mises stress in the supporting bone of the 2-implant supported FPD significantly increased compared with that in the 3-implant replacement. Meanwhile, when 3 implants were splinted, only the median implant had a decreased and more homogenous stress distribution, and the other implants did not exhibit significant differences when splinted.

CONCLUSION

This study suggests that when space and cost permit, a 2-implant supported FPD should not be used, and 1 implant for each missing tooth being single is recommended.

Wired/Classic and Wireless/Periotest "M" instruments: an in vitro assessment of repeatability of stability measurements

This in vitro study evaluated agreement among 10 trained evaluators when assessing implant stability with the Wired/Classic and Wireless/Periotest "M." A difference of 1 Periotest value (PTV) between the wired (-7) and wireless (-8) instruments was observed for the pretest calibration ring. No significant differences were found between the instruments and for all evaluators for all tests (analysis of variance, P < .05). Each instrument can provide meaningful and reproducible recordings of stability measurements.

Indications for Splinting Implant Restorations

PURPOSE

The purpose of this article was to review the literature concerning the need to splint implants together when restoring them with a provisional restoration immediately after implant placement.

METHODS

The literature is reviewed concerning the rationale for splinting teeth and reports concerning the efficacy of splinting implants together. Based on this team's experience with a prospective series of consecutive 2 to 5 unit provisionalization cases, guidelines are included with case examples for understanding the technique.

CONCLUSION

As long as canine guidance is present, and occlusion is stable, multiunit single quadrant restorations do not need to be splinted when provisionalized.

Humanex vivobone tissue strains around natural teeth vs. immediate oral implants

PURPOSE

To compare ex vivo bone tissue strains around natural teeth with immediate implants supporting unsplinted and splinted fixed prostheses.

MATERIAL AND METHODS

Six linear strain gauges were bonded on the labial marginal bone of bilateral maxillary anterior teeth in two fresh-frozen human cadavers. The natural teeth were loaded in centric occlusion via an occlusal splint with integrated miniature load cells. Strain measurements were performed at a sample rate of 10 kHz and under a maximum load of 100 N, simultaneously monitored from a computer connected to data acquisition system. Upon extraction of the anterior teeth, Ø 4.1 mm and Ø 4.8 mm ITI dental implants were placed into sockets of incisors and canines, respectively. Installation torque value (ITV) of each implant was measured by a custom-made torque wrench and resonance frequency analyses (RFA) were also undertaken. Strain measurements were performed for (1) single-tooth implant restorations, (2) unilateral splinted anterior implants, and (3) bilateral splinted anterior implants. Finally, an autopolymerizing acrylic resin was injected into the implant sockets for simulation of osseointegration and strain measurements were performed.

RESULTS

Microstrains of all groups were statistically comparable (P>0.05), although lower strains were elicited for implants in sockets of incisors in comparison with natural teeth. Microstrains around canine implants were comparable or higher than those induced around natural canines. For all groups, microstrains around canines were higher than those around lateral (P<0.05) and central incisors (P<0.01), which had similar strain levels (P>0.05). The RFA values of implants were comparable. The ITVs of implants in sockets of lateral incisors and canines were similar and were higher than those of implants in central incisor regions.

CONCLUSION

The labial marginal bone having no contact with immediate implants may experience strain gradients within physiologic levels due to deformation of bone under load. Although one prosthetic design does not seem to have clear advantages over another, splinting of implants may be considered as a safety measure for immediately loaded immediate implants, if possible.

Implant design and intraosseous stability of immediately placed implants: a human cadaver study

OBJECTIVE

The objective of this study was to explore effects of implant macrodesign and diameter on initial intraosseous stability and interface mechanical properties of immediately placed implants.

MATERIAL AND METHOD

Mandibular premolars of four fresh-frozen human cadavers were extracted. Ø 4.1/4.8 mm ITI TE, Ø 4.1 and 4.8 mm solid screw synOcta ITI implants were placed into freshly prepared extraction sockets. Resonance frequency analysis was conducted to quantify primary implant stability quotient (ISQ). Installation torque value (ITV) and removal torque value (RTV) of the implants were measured using a custom-made strain-gauged torque wrench connected to a data acquisition system at a sample rate of 10,000 Hz. The vertical defect depth around the collar of each implant was measured directly by an endodontic spreader. The bone-implant contact was determined in digitalized images of periapical radiographs and expressed as percentage bone contact.

RESULTS

The ISQ values of the TE implant was higher than the Ø 4.1 mm implant (P<0.01), and comparable with the Ø 4.8 mm implants (P>0.05). ITVs and RTVs of TE and Ø 4.8 mm implants were higher than the Ø 4.1 mm implant, although the differences between groups were statistically insignificant (P>0.05). The vertical defect depths around all types of implants were similar. In the radiographic analyses, percentage bone-implant contact of the TE and Ø 4.8 mm implants were comparable at the marginal bone region and both were higher than that of the Ø 4.1 mm ITI implant. Nonparametric correlations between groups revealed a significant correlation between ITV and RTV (r=0.838; P<0.001), but not between ISQ values and ITVs and RTVs (P>0.05).

CONCLUSION

Immediately placed ITI TE implant leads to initial intraosseous stability and interface mechanical properties comparable with a wide diameter implant.