Periotest Measurements Research Articles

Comparison of primary stability of used and unused self-tapping and self-drilling orthodontic mini-implants.

Skeletal anchorage has been the subject of study for many years. Recently, orthodontic mini-implants (MIs) were described as effective tools for anchorage and were named temporary anchorage devices (TADs). The success of MIs depends on their primary stability, which is defined as the lack of mobility in the bone after implant insertion, and the relevant factors affecting primary stability. This study aimed to compare the primary stability of used self-drilling (SD) and self-tapping (ST) MIs with unused ones by performing the insertion torque measurement, Periotest and pull-out test. Forty-six used (23 ST, 23 SD) and 46 unused (23 ST, 23 SD) MIs (1.5 mm × 8 mm) were inserted into a synthetic bone with the use of a digital screwdriver. Maximum insertion torque (MIT) values were recorded during the placement of MIs, and then Periotest measurements were made. Following the MIT and Periotest measurements, pull-out tests were performed on all MIs. The median MIT values (Ncm) of the MIs were as follows: used ST: 17.3, unused ST: 18.9, used SD: 24.1, unused SD: 25.2. The median values obtained after the Periotest were (±): used ST: 0, unused ST: -1, used SD: -3, unused SD: -3. Median pull-out values (N) were: used ST: 148.12, unused ST: 168.12, used SD: 173.12, unused SD: 203.20. Statistically, MIT and pull-out values of the used ST and SD implants were significantly lower compared to those of the unused ST and SD implants (p < 0.05). Used orthodontic MIs showed poor performance compared with unused implants when they were inserted again in the in vitro conditions.

Evaluation of reused orthodontic mini-implants on stability: An in-vivo study

During treatment, some patients may need to change the location of mini-implants (MIs). This study investigated the stability of MIs relocated to another position in the same patient using the periotest and torque device. Twenty-nine MIs were applied randomly to 1 side of the maxillary region, and torque and periotest values were recorded. The patients were followed-up at 4-week intervals, and periotest measurements were performed at each session. After recording the torque and periotest values in the fourth session, the MIs were removed. After applying the appropriate sterilization procedure, the same MIs were relocated to the contralateral side of the patients' jaw, and distalization was achieved using a similar procedure for the group of as-received MIs. Negative correlations were obtained between the torque meter and periotest data for both MI groups. We observed no significant effect of the MI group on periotest measurements (P>0.05). The effect of the MI group on torque values and the interaction effect of the MI group and torque values were not statistically significant (P>0.05). It is possible to achieve similar stability values with as-received and retrieved MIs when appropriate cleaning and sterilization protocols are performed.

Non-Destructive Removal of Dental Implant by Using the Cryogenic Method.

Background and Objectives: The gold standard for a successful prosthetic approach is the osseointegration of an implant. However, this integration can be a problem in cases where the implant needs to be removed. Removing the implant with minimal damage to the surrounding tissues is important. Osteocytes cannot survive below −2 °C, but epithelial cells, fibroblasts, and other surrounding tissue cells can. Remodeling can be triggered by cryotherapy at temperatures that specifically affect osteocyte necrosis. In this study, we aimed to develop a method for reversing the osseointegration mechanism and for protecting the surrounding tissues by bone remodeling induced by CO2 cryotherapy. Materials and Methods: In this study, eight 2.8 mm diameter, one-piece mini implants were used in New Zealand rabbit tibias. Two control and six implants were tested in this study. After 2 months of osseointegration, a reverse torque force method was used to remove all osseointegrated implants at 5, 10, 20, and 30 Ncm. The osseointegration of the implants was proven by periotest measurements. Changes in bone tissue were examined in histological sections stained with toluidine blue after rabbit sacrifice. The number of lacunae with osteocyte, empty lacunae, and lacunae greater than 5 µm and the osteon number in a 10,000 µm2 area were calculated. Cryotherapy was applied to the test implants for 1 min, 2 min, and 5 min. Three implants were subjected to cryotherapy at −40 °C, and the other implants were subjected to cryotherapy at −80 °C. Results: Empty lacunae, filled osteocytes, lacunae >5 µm, and the osteon count around the implant applied at −40 °C were not significantly different from the control implants. The application of −40 °C for 1 min was found to cause minimal damage to the bone cells. The implants, which were applied for 1 min and 2 min, were successfully explanted on the 2nd day with the 5 Ncm reverse torque method. Test implants, which were applied cold for 5 min, were explanted on day 1. Tissue damage was detected in all test groups at −80 °C. Conclusions: The method of removing implants with cryotherapy was found to be successful in −40 °C freeze–thaw cycles applied three times for 1 min. To prove implant removal with cryotherapy, more implant trials should be conducted.

Comparative In Vitro Evaluation of the Primary Stability in D3 Synthetic Bone of Two Different Shapes and Pitches of the Implant Threads

Background: Implant primary stability can be affected by several factors related to implant macrogeometry, local anatomy, and surgical techniques. The aim of this research was to study primary stability on polyurethane foam sheets of wide-threaded implant design compared to narrow-threaded implants. Materials and methods: Two different implant designs were positioned on D3 density polyurethane blocks in a standardized environment: the wide-threaded implant and the narrow-threaded implant, for a total of 160 specimens. Moreover, for each group, two different sizes were considered: 3.8 mm × 12 mm and 4.8 mm × 12 mm. The insertion torque (IT) values, the removal strength (RT), and the Periotest analyses were evaluated. Results: A significantly higher IT and RT was reported for wide-threaded implants and two-stage implants (p &lt; 0.01), compared to the narrow-threaded implants. The diameters seemed to provide a significant effect on the primary stability for both implants’ geometry (p &lt; 0.01). A higher mean of the one-stage implant was evident in the Periotest measurements (p &lt; 0.01). Conclusions: Both of the implants showed sufficient stability in polyurethane artificial simulation, while the wide-threaded implant design showed a higher primary stability on alveolar cancellous synthetic bone in vitro. Additionally, the prosthetic joint connection seemed to have a determinant effect on Periotest analysis, and the one-stage implants seemed to provide a high stability of the fixture when positioned in the osteotomy, which could be important for the immediate loading protocol.

Effects of a hydroxyapatite coating on the stability of endosseous implants in rabbit tibiae.

A dental implant surface which would promote rapid and strong osseointegration is a key factor of success in modern implantology. To achieve this goal, different implant surface modifications are developed. A hydroxyapatite (HA) coating changing a bioinert titanium surface into bioactive is one of them. The objective of the study was to investigate the effects on bone osseointegration in rabbits resulting from the application of a HA coating deposited on titanium endosseous implants using a modified electrochemical method. Titanium implants with HA coatings and controls with Al2O3 grit-blasted surfaces were embedded into rabbit tibiae. The chemical composition, roughness and morphology of the implants were determined. Implant stability tests were performed, and the Periotest® value (PTV) and the implant stability quotient (ISQ) value for Osstell Mentor were recorded in order to evaluate the osseointegration. The surface characterization of the implants revealed a microstructure with an arithmetical mean height (Sa) in the range of 0.71-1.04 μm. The HA coating was free of contamination, whereas the controls were enriched with corundum. After healing, a statistically significant increase in the mean ISQ and a decrease in the mean PTV for the HA-coated implants was observed. In the case of the control implants, only PTV decreased significantly with time. The present study found that implant surface properties affected implant stability as determined by Osstell and Periotest measurements. The HA coating reported herein was found to have chemical and physical properties which appear to improve osseointegration compared to grit-blasted implants.

Periotest measurement of tooth- implant retained bi lateral mandibular distal extension removable prosthesis with ERA Attachments

Aim: The aim of this study was to measure the stability of natural tooth and implant using periotest, in bilateral distal extension base, using ERA-ERA connection on one side and RPI-ERA on the other side.Material and Methods: Ten patients with mandibular bilateral distal extension arches, with second premolar as last standing tooth, were selected for this study. Every patient received one implant placed distally at the region of the second molar bilaterally. The patients received removable prosthesis retained on one side by RPI while the other side received ERA attachment. Both implants were retained to the prosthesis using ERA attachment. Patients were evaluated for tooth and implant stability using Periotest at time of prosthesis insertion, after one month, three months and six months after insertion. The study was a split mouth design.Results: Periotest measurements significantly decreased (increase in stability) with presence of ERA attachments on natural tooth and implants more than when the RPI was used on the natural tooth.Conclusion: It can be concluded that the ERA attachments was more preservative for natural teeth periodontium than RPI clasp retainer. In addition, the stability of implant improved gradually by time.

Insertion torque and Periotest values are important factors predicting outcome after orthodontic miniscrew placement.

Approximately 14% of orthodontic anchor screws (miniscrews) become dislodged regardless of the accuracy of placement. It is therefore important to investigate the factors causing dislodgement. We evaluated the stability of miniscrews after placement to identify factors influencing outcome in orthodontic treatment using miniscrews. We investigated 120 miniscrews (Dual-top Auto Screw III; Jeil Medical, Seoul, Korea) (diameter, 1.4mm; length, 6mm) placed on the buccal or lingual side between the maxillary second premolar and the first molar in women. Patient age and rate and time of screw dislodgement were examined. Insertion torque values and Periotest (Tokyo Dental Industrial, Tokyo, Japan) measurements indicating horizontal and vertical mobility of the inserted screws were compared between groups with and without dislodgement (failure and success groups, respectively). Mean insertion torque values were 10.7±1.9N·cm and 8.5±2.1N·cm in the failure and success groups, respectively. Cortical bone thickness measurements (success group, 1.34±0.35mm; failure group, 0.99±0.09mm) were significantly higher, whereas Periotest values at placement (success group, horizontal, 4.9±1.4; vertical, 4.7±1.3; failure group, horizontal, 7.0±0.8; vertical, 7.1±0.9) were significantly lower in the success group than in the failure group. The Periotest value, together with insertion torque and cortical bone thickness, could serve as an index of initial stability for predicting the outcome of miniscrew placement.

The Evaluation of the Reliability of Periotest for Implant Stability Measurements: An In Vitro Study

Periotest (Medizintechnik Gulden, Modautal, Germany) is a widely accepted implant stability measurement method, although the reliability is not well known. The aim of this in vitro study was to investigate the reliability of the Periotest in implant stability measurements. Thirty implants were placed in 3 cow ribs. The stability of each implant was measured by insertion torque, resonance frequency analyses, and Periotest and then compared. The Periotest values (PTVs) were measured by 4 different examiners. The measurements were repeated twice in both the buccal and mesial directions, for each implant at 2-hour intervals and the intra- and interobserver reliability of Periotest was measured. Results showed that the intraobserver reliability of the Periotest was excellent for the buccal PTVs but fair to poor for the mesial PTVs. The interobserver reliability of the Periotest was excellent for the buccal PTVs but poor for the mesial PTVs. No significance was found between the PTVs and IT values (P = .803) and PTVs and ISQ values, whereas a 47.1% significant correlation was detected between the IT values and ISQ values (P = .009). The present study indicates that only Periotest measurements from buccal result in excellent intra- and interobserver reliability for the quantification of the implant stability.

Parathyroid Hormone: Is It Really the Cause for Increased Tooth Mobility after Orthognathic Surgery?

Introduction: Following orthognathic surgery, increased tooth mobility is observed clinically and is utilized for postsurgical orthodontic tooth movement. It was suggested that the increase may result from a surgery-associated alteration of parathyroid hormone (PTH) and calcium metabolism. Materials and Methods: 30 young adult patients were divided into a mandibular osteotomy group (Group A, n = 20) and an untreated control group (Group B, n = 10). Tooth mobility was evaluated using the Periotest device. Tooth mobility, serum PTH and calcium levels were determined repeatedly for both groups. Results: The tooth mobility was increased significantly in the Group A patients in the first 10 days post-surgery. All serum PTH and calcium mean levels were within normal ranges. No significant differences were found between the measurements of both groups. The serum calcium levels recorded at the 1st post-surgery day were slightly lower in the operated patients compared to the control group. Conclusion: It can be concluded that the increased facility of orthodontic tooth movement immediately post-surgery was confirmed by Periotest measurements, while no association was found with surgery-related altered levels of PTH and calcium. Since dietary effects can be ruled out, the increase of clinical tooth mobility may rather result from preoperative orthodontic forces and/or the post-surgical elimination of masticatory muscular influences.

Primary stability and histomorphometric bone-implant contact of self-drilling and self-tapping orthodontic microimplants

The aim of this study was to evaluate the primary stability and the histomorphometric measurements of self-drilling and self-tapping orthodontic microimplants and the correlations between factors related to host, implant, and measuring technique. Seventy-two self-drilling and self-tapping implants were placed into bovine iliac crest blocks after computed tomography assessments. Insertion torque values, subjective assessments of stability, and Periotest (Medizintecknik Gulden, Modautal, Germany) measurements were performed for each implant. Twelve specimens of each group were assigned to histologic and histomorphometric assessments. The differences between insertion torque values, most Periotest values, and subjective assessments of stability scores were insignificant (P >0.05). The bone-implant contact percentage of the self-drilling group (87.60%) was higher than that of the self-tapping group (80.73%) (P <0.05). Positive correlations were found between insertion torque value, cortical bone thickness, and density in both groups (P <0.05). Negative correlations between insertion torque values and Periotest values were mostly observed in the self-drilling group (P <0.05). Positive correlations were found between bone-implant contact percentages, cortical bone densities, and insertion torque values in both groups (P <0.05). The differences between insertion torque values and corresponding subjective assessments of stability scores were different in both groups (P <0.05). The differences in insertion torque values, Periotest values, and subjective assessments of stability scores of self-drilling and self-tapping implants were insignificant. Self-drilling implants had higher bone-implant contact percentages than did self-tapping implants. Significant correlations were found between parameters influencing the primary stability of the implants.

Histologic and histomorphometric evaluation of early and immediately loaded implants in the dog mandible

New bone formation around US III OSSTEM implants after early and immediate loading was evaluated in this study. Three premolars and the first and second molars were first removed from the left mandible of five dogs. At 3 weeks after extraction of the teeth in the left mandible, the corresponding teeth in the right mandibles were removed. After 12 weeks of bone healing, five implants were placed in the left mandible. At 3 weeks after placement of implants in the left mandible, another five were placed in the right mandible. At the time of placing implants in the right mandible, four implants on each side were restored using a fixed provisional restoration. The anterior-most implant was not loaded and was used as controls. Periotest measurements performed immediately after implantation and after 16 weeks loading indicated implant stability for all groups tested. At 16 weeks after loading, the rate of peri-implant bone formation for the early loaded, immediately loaded (IL), and control implants were observed to be 75.00, 73.37, and 62.04%, respectively. It was thus concluded that early stability was achieved in early and IL implants using fixed provisional restoration, thereby resulting in the high rate of peri-implant bone formation.

Augmentation of the posterior atrophic edentulous maxilla with implants placed in the ulna: a prospective single-blind controlled clinical trial

To evaluate a new method to treat the posterior atrophic edentulous maxilla: dental implants placed in the ulna and transplanted with their surrounding bone blocks as inlays into the sinus. Conventional sinus augmentation with particulated autogenous bone grafts served as a control procedure.Fifty-two implants were placed in the ulnas of 20 patients. After 6 weeks, bone blocks containing 1 to 3 implants were harvested and transplanted into the sinuses protruding 3 to 4 mm. Implants were left to heal for 6 weeks. Twenty patients with similar treatment indications treated with particulated bone grafts from the mental symphysis, tibia, or iliac crest acted as controls. Grafts were allowed to heal for 6 months in the control group. Fifty-two control-group implants were allowed to heal for 4 months. The main outcome measures were prosthetic and implant success. Stability of individual implants was assessed with Osstell and Periotest at baseline and after 6 and 12 months of loading. Independent sample chi-square tests, t tests, and paired t tests were used with a significance level of .05.No patient dropped out or withdrew; no prosthesis or implant failed. No major surgical complications were occurred. There were no differences between the 2 groups at any time point in implant stability. Both modalities resulted in a significant increase of implant stability at 6 and 12 months. The mean change (SD) from baseline to 1 year in Periotest measurements was 1.44 (0.48) in the test and 1.29 (0.58) in the control (paired t tests; P < .001). For the Osstell, these values were -5.88 (4.18) and -5.48 (3.93) for the test and control groups, respectively (paired t tests: P < .001).Ulna implant block grafting represents an alternative to conventional sinus augmentation, particularly when vertical augmentation is desirable or large iliac crest grafts are needed.

Validity and clinical significance of biomechanical testing of implant/bone interface

The aim of this paper was to review the clinical literature on the Resonance frequency analysis (RFA) and Periotest techniques in order to assess the validity and prognostic value of each technique to detect implants at risk for failure. A search was made using the PubMed database to find clinical studies using the RFA and/or Periotest techniques. A limited number of clinical reports were found. No randomized-controlled clinical trials or prospective cohort studies could be found for validity testing of the techniques. Consequently, only a narrative review was prepared to cover general aspects of the techniques, factors influencing measurements and the clinical relevance of the techniques. Factors such as bone density, upper or lower jaw, abutment length and supracrestal implant length seem to influence both RFA and Periotest measurements. Data suggest that high RFA and low Periotest values indicate successfully integrated implants and that low/decreasing RFA and high/increasing Periotest values may be signs of ongoing disintegration and/or marginal bone loss. However, single readings using any of the techniques are of limited clinical value. The prognostic value of the RFA and Periotest techniques in predicting loss of implant stability has yet to be established in prospective clinical studies.

A Prospective Clinical Study on Titanium Implants in the Zygomatic Arch for Prosthetic Rehabilitation of the Atrophic Edentulous Maxilla with a Follow‐Up of 6 Months to 5 Years

Prosthetic rehabilitation with implant-supported prostheses in the atrophic edentulous maxilla often requires a bone augmentation procedure to enable implant placement and integration. However, a rigid anchorage can also be achieved by using so-called zygomatic implants placed in the zygomatic arch in combination with regular implants placed in residual bone. The aim of the present study was to report on the clinical outcome of using zygomatic and regular implants for prosthetic rehabilitation of the severely atrophic edentulous maxilla. Sixty-nine consecutive patients with severe maxillary atrophy were, during a 5-year period, treated with a total of 69 fixed full-arch prostheses anchored on 435 implants. Of these, 131 were zygomatic implants and 304 were regular implants. Fifty-seven bridges were screw-retained and 12 were cemented. The screw-retained bridges were removed at the examination appointments and each implant was tested for mobility. In addition, the zygomatic implants were subjected to Periotest (Siemens AG, Bensheim, Germany) measurements. The patients had at the time of this report been followed for at least 6 months up to 5 years in loading. Two regular implants failed during the study period giving a cumulative survival rate of 99.0%. None of the zygomatic implants was removed. All patients received and maintained a fixed full-arch bridge during the study. Periotest measurements of zygomatic implants showed a decreased Periotest values value with time, indicating an increased stability. Three patients presented with sinusitis 14-27 months postoperatively, which could be resolved with antibiotics. Loosening of the zygomatic implant gold screws was recorded in nine patients. Fracture of one gold screw as well as the prosthesis occurred twice in one patient. Fracture of anterior prosthetic teeth was experienced in four patients. The results from the present study show that the use of zygomatic and regular implants represents a predictable alternative to bone grafting in the rehabilitation of the atrophic edentulous maxilla.

Implant stability and histomorphometry: a correlation study in human cadavers using stepped cylinder implants.

The aim of the present study was to determine the correlation between the primary stability of dental implants placed in edentulous maxillae and mandibles, the bone mineral density and different histomorphometric parameters. After assessing the bone mineral density of the implant sites by computed tomography, 48 stepped cylinder screw implants were installed in four unfixed human maxillae and mandibles of recently deceased people who had bequeathed their bodies to the Anatomic Institute I of the University of Erlangen-Nuremberg for medical-scientific research. Peak insertion torque, Periotest values and resonance frequency analysis were assessed. Subsequently, histologic specimens were prepared, and bone-to-implant contact, the trabecular bone pattern factor (TBPf), the density of trabecular bone (BV/TV) and the height of the cortical passage of the implants were determined. The correlation between the different parameters was calculated statistically. The mean resonance frequency analysis values (maxilla 6130.4+/-363.2 Hz, mandible 6424.5+/-236.2 Hz) did not correlate with the Periotest measurements (maxilla 13.1+/-7.2, mandible -7.9+/-2.1) and peak insertion torque values (maxilla 23.8+/-2.2 N cm, mandible 45.0+/-7.9 N cm) (P=0.280 and 0.193, respectively). Again, no correlations could be found between the resonance frequency analysis, the bone mineral density (maxilla 259.2+/-124.8 mg/cm(3), mandible 349.8+/-113.3 mg/cm3), BV/TV (maxilla 19.7+/-8.8%, mandible 34.3+/-6.0%) and the TBPf (maxilla 2.39+/-1.46 mm-1, mandible -0.84+/-3.27 mm-1) (P=0.140 and 0.602, respectively). However, the resonance frequency analysis values did correlate with bone-to-implant contact of the oral aspect of the specimens (maxilla 12.6+/-6.0%, mandible 35.1+/-5.1%) and with the height of the crestal cortical bone penetrated by the implants in the oral aspect of the implant sites (maxilla 2.1+/-0.7 mm, mandible 5.1+/-3.7 mm) (P=0.024 and 0.002, respectively). The Periotest values showed a correlation with the height of the crestal cortical bone penetrated by the implants in the buccal aspect of the implant sites (maxilla 2.5+/-1.2 mm, mandible 5.4+/-1.2 mm) (P=0.015). The resonance frequency analysis revealed more correlations to the histomorphometric parameters than the Periotest measurements. However, it seems that the noninvasive determination of implant stability has to be improved in order to give a more comprehensive prediction of the bone characteristics of the implant site.

Movement behavior of teeth and dental implants in periotest measurement in occlusion--an in vitro study

Early diagnosis of periodontal disease is essential for the planning of restorative, prosthetic and surgical treatment. The usual clinical methods are mostly subjective. Although the Periotest device has been specially developed for the diagnosis of periodontal disease, it can also be used to aid occlusal adjustment after insertion of inlays or artificial crowns. To investigate this application of the Periotest, a jaw model with idealized dental crowns incorporating motion and force sensors has been constructed. Motion and force are recorded during measurements with the Periotest. The maximum amplitudes in the apical (vertical) direction obtained with unpolished occlusal points increased with increasing occlusal load. With polished contact points, the maximum values in the apical direction revealed no dependence on occlusal load. The maximum amplitudes of movement and force in the oral (horizontal) direction decrease with increasing occlusal load both with polished and unpolished contact points. With the first, the teeth appear to slide one upon the other such that the overall distance between them remains unchanged, and no additional apical forces develop. In the case of rough contact points, additional forces develop, and falsify Periotest measurements.

Compliant keeper system replication of the periodontal ligament protective damping function for implants: Part II

There are numerous articles regarding implant overloading, interfacial integrity and component failure. A significant amount of literature review supports the concept of the progressive loading and damping, and it should be addressed. This study was designed to correlate durometer measurements of the elastomeric test materials and actual Periotest values (PTV) of the test materials as preloaded sleeve rings in Compliant Keeper abutments to support the Compliant Keeper as a viable implant damping system. A 4-unit fixed-removable implant-supported partial denture was the test model. Sleeve ring combinations replaced "O" rings and 220 Periotest measurements were graphically recorded, then analyzed by least square of means, 2-way analysis of variance, and a Tukey test. There was a correlation between durometer measurements and PTVs of sleeve rings. Finite movement was measured accurately with the Periotest (P =. 0001) so that Compliant Keeper systems can be programmed to match the movement of another implant abutment, because they might be able to match the PTV of a natural abutment. Significant differences exist between the "O" rings and sleeve rings. The sleeve ring, as a controllable damping element, enables the Compliant Keeper system to provide progressive loading and damping for implant-supported prostheses.

Compliant Keeper system replication of the periodontal ligament protective damping function for implants: Part I

Statement of problem. Numerous reports and studies have been published relative to implant overloading, interfacial integrity, and component failure. A significant amount of literature review supports the concept of progressive loading and damping and that it should be addressed. Purpose. This article reviews the literature on load reduction and uses the Periotest instrument to evaluate the viscoelastic materials of the Compliant Keeper implant damping system in vitro. Material And Methods. The test model was a vice-mounted resin mandible replica with a 4-unit fixed-removable implant-supported Compliant Keeper partial denture. Pontics were both cantilevered and bounded. Three 13-gauge measurement extensions were located facially on the gingival, middle, and occlusal thirds of each abutment and pontic for 312 Periotest measurements of O-ring combinations with a titanium O-ring as the null control. Measurements were averaged and recorded. Results. Because the Periotest can measure finite movement below Miller Class I, Periotest values were obtained for O-rings so that they could be used to program a Compliant Keeper system to match the Periotest values of another implant body. Conclusions. Significant loading differences were found with the O-rings. The O-rings controlled the damping element so they enabled the Compliant Keeper system to provide damping and progressive loading for implant-supported prostheses. (J Prosthet Dent 1998;80:565-9.)

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

The aim of the present study was to evaluate the capability of the Periotest device in detecting and monitoring functional changes in the periodontal as well as in the pari-implant damping characteristics. In the first part of this study, 107 teeth were splinted by means of 40 full acrylic fixed prostheses (AFP) and another 37 teeth were splinted by means of 14 ceramometallic fixed prostheses (C-MFP). The Periotest measurements of individual teeth were done the day the fixed prostheses were cemented temporary (PTV 1), and again after a mean observation period of 27.4 days (PTV 2). In the 2nd part, 78 osseointegrated two-stage implants were splinted by means of 23 full acrylic fixed prosthesis (AFP) and other 18 implants were left without it. Using the same abutment length, Periotest measurements were performed, at abutment connections and before installation of the final prosthesis. In a 3rd part, using both implants and teeth as abutments, 29 osseointegrated implants were connected with 25 abutment teeth by means of 7 AFP. The measurements were performed at the beginning of the prosthetic treatment and 2, 4 and 6 weeks later. After splinting teeth by means of AFP for the observation period, no statistically significant reduction in PTVs was found. When on the other hand, a C-MFP was used, PTV 2 showed a significant reduction. The PTVs at abutment connection went down after a period of time, during which some implants were interconnected by means of an AFP and others were not.(ABSTRACT TRUNCATED AT 250 WORDS)