Continuous periprosthetic bone loss but preserved stability for a collum femoris-preserving stem: follow-up of a prospective cohort study of 21 patients with dualenergy X-ray absorptiometry and radiostereometric analysis with minimum 8 years of follow-up

Background and purpose — We previously described a decrease in bone mineral density (BMD) in the calcar region 2 years after insertion of the collum femoris-preserving (CFP) stem, but the implants were stable. Now we have examined the long-term changes in periprosthetic BMD and stability of the CFP stem. Patients and methods — We conducted a minimum 8-year follow-up of 21 patients from our original investigation. We examined periprosthetic BMD by dual-energy X-ray absorptiometry (DEXA) and implant stability by radiostereometric analysis (RSA). Results — Between 2 and 8 years 1 stem was revised due to aseptic loosening. Between 2 and 8 years we found a 14% (95% confidence interval [CI] 9–19) reduction in BMD in Gruen zone 6 and 17% (CI 6–28) in Gruen zone 7. From baseline the reduction in BMD was 30% (CI 23–36) in Gruen zone 6, 39% (CI 31–47) in Gruen zone 7, and 19% (CI 14–23) in Gruen zone 2. Between 2 and 8 years, RSA (n = 17) showed a mean translation along the stem axis of 0.02mm (CI –0.02 to 0.06) and a mean rotation around the stem axis of 0.08° (CI –0.26 to 0.41). From baseline mean subsidence was 0.07 mm (CI –0.16 to 0.03) and mean rotation around the stem axis was 0.23° (CI –0.23 to 0.68) at 8 years. Interpretation — There was continuous loss of proximomedial BMD at 8 years while the CFP stem remained stable. Proximal periprosthetic bone loss cannot be prevented by this stem.

Bone Damage during Dental Implant Insertion: A Pilot Study Combining Strain Gauge and Histologic Analysis

Besides alveolar bone quality, the drilling protocol applied in conjunction with the design of an implant are the major determinants of primary implant stability. Surgical trauma and bone compression resulting from implant insertion may constitute one cause for marginal bone resorption. Inserting two current bone-level implant designs (Astra; Straumann; n = 5) in bovine ribs, primary stability, strain development on the buccal bone plate and histologic signs of bone damage were recorded. Besides comparing the implant designs (Welch t-tests), all measurement parameters were checked for potential correlations (Pearson product moment correlation coefficients) with the level of significance set at α = 0.05. Considerable numbers of crack formation and plastic deformation of bone were observed after implant insertion. Straumann implants showed slightly greater values for insertion torque (p = 0.772), strain development (p = 0.893) and implant stability (p = 0.642). Significantly greater bone to implant contact (cortical p = 0.014; trabecular p = 0.016) was observed in Straumann implants, while Astra implants caused a significantly greater number of microcracks in cortical bone (p = 0.020). In Straumann implants, insertion torque correlated with bone to implant contact in the cortical area (p = 0.029) and the number of macrocracks in trabecular bone correlated with bone to implant contact (p = 0.029). In Astra implants, insertion torque and bone to implant contact in the trabecular area correlated (p = 0.007) as well as the number of macrocracks in trabecular bone and implant stability (p = 0.016). Additionally, in the area of cortical bone, the number of macrocracks correlated with bone to implant contact (p = 0.019). Implant placement results in bone damage of varying magnitude, which is governed by the drill protocol, implant macrodesign and bone quality.

Immediate Vs. Early Loading of Bone Level Tapered Dental Implants with Hydrophilic Surface in Fully Edentulous Maxilla:Clinical and Patient-Centered Outcomes

ABSTRACT The aim was to: (i) compare changes among primary and secondary implant stability between immediate and early loaded implants in edentulous maxilla, (ii) evaluate oral health related quality of life (OHRQoL) and (iii) determine patient satisfaction with 6-implant supported fixed full-arch dentures. A prospective, randomized controlled clinical trial was conducted on 24 edentulous maxilla patients. The BLT SLActive® implants in 12 patients were immediately loaded with temporary restorations while12 patients did not receive temporary restorations. Definitive (final) dentures were delivered to all patients after 6 weeks. Stability of the implants were assessed by Insertion Torque (IT) and Resonance Frequency Analysis (RFA). Oral Health Impact Profile-19 ( OHIP-19) questionnaire was used to evaluate OHRQoL and a Visual Analogue Scale (VAS) for patient satisfaction. The IT value of implants assigned for immediate and early loading group was 27.17±9.55Ncm and 25.01±11.06Ncm, respectively. Changes in implant stability from baseline to week 6 were similar in both groups when measured by Penguin ® (p=0.881) and Ostell ® (p= 0.828). Patients in the immediate load group reported significantly lower OHIP physical pain scores (p=0.016), OHIP psychological disability score (p=0.046) and significantly higher VAS function score (p=0.009) and VAS aesthetics score (p=0.009). Implant loading protocols don’t have a significant effect on the change in implant stability 6 weeks after implantation, however, immediate loading significantly improves OHRQoL and satisfaction of patients with maxillary edentulism treated by fixed full-arch dentures. Future trials will determine the role of immediate loading protocol in clinical scenarios with various amounts of available jaw bone using different numbers of implants to retain a fixed prosthetic restoration in the edentulous maxilla.

The Effect of Recipient Jaw and Implant Dimensions on Pre- and Post- Loading Dental Implant Stability: A Prospective Clinical Study

Background: Implant stability is a mandatory factor for dental implant (DI) osseointegration and long-term success. The aim of this study was to evaluate the effect of implant length, diameter, and recipient jaw on the pre- and post-functional loading stability. Materials and methods: This study included 17 healthy patients with an age range of 24-61 years. Twenty-two DI were inserted into healed extraction sockets to replace missing tooth/ teeth in premolar and molar regions in upper and lower jaws. Implant stability was measured for each implant and was recorded as implant stability quotient (ISQ) immediately (ISQ0), and at 8 (ISQ8) and 12 (ISQ12) weeks postoperatively, as well as post-functional loading (ISQPFL). The pattern of implant stability changes throughout the study period and its correlation with the recipient jaw and the DI dimensions were evaluated. Results: There was a significant difference in ISQ values throughout the study. DI stability in the maxilla was significantly higher than that in mandible for the ISQ0, with no significant effect for the rest time points. The effect of implant diameter was significant with DI of 4.1mm diameter being more stable. While for the length, there was no significant difference regarding its effect on ISQ values through-out the study period. Conclusions: DI inserted in the maxilla demonstrated better primary stability with no effect of recipient jaw on secondary stability and after functional loading, also DI with wider diameter had better stability throughout the study whereas DI length showed no significant effect on stability

Implant Stability Changes for a Single Implant Mandibular Overdenture

Objectives To compare the changes in implant stability for the nonsubmerged and submerged protocols for a single-implant retained mandibular overdenture using Cendres and Metaux Locator attachment throughout a 24-month follow-up. Materials and Methods Eighty edentulous patients who were seeking to install a single implant in the midline of the completely edentulous mandible. At the day of implant installation, patients were randomized into two groups using sealed envelopes: the nonsubmerged and submerged groups. After 3 months of healing period, randomization using sealed envelopes was performed and patients were randomized to receive the Cendres and Metaux Locator attachment. The periotest readings were recorded using the Periotest M device, every 3 months for the first year and annually in the second year. The scope of this clinical trial focused only on results of the Cendres and Metaux attachment. Statistical Analysis The Mann–Whitney U-test was used for comparison between study groups for independent samples. Two-sided p-values less than 0.05 were considered statistically significant. Results There was no statistically significant difference between the mean periotest readings of both groups throughout the 24-month follow-up. Both groups showed an improvement in mean periotest readings with the submerged group tending to show greater stability at 6, 12, and 24-month follow-ups. Conclusions The nonsubmerged and the submerged healing protocols resulted in reliable periotest readings with the submerged group showing greater improvement than the nonsubmerged, although this improvement is nonsignificant when using the Cendres and Metaux attachment for a single mandibular overdenture.

Stability of dental implants with sandblasted and acid-etched (SLA) and modified (SLActive) surfaces during the osseointegration period

Background. The surface properties of implants are effective factors for increasing the osseointegration and activity of osteoprogenitor cells. This study compared the stability of dental implants with sandblasted and acid-etched (SLA) and modified surfaces (SLActive) using the resonance frequency analysis (RFA). Methods. In a split-mouth design, 50 dental implants with either SLA surface properties (n=25) or modified (SLActive) surface properties (n=25) were placed in the mandibles of 12 patients with a bilateral posterior edentulous area. Implant stability was measured using RFA (Osstell) at implant placement time and every week for 1, 2, and 3 months before the conventional loading time. Results. One week following the implantation, implant stability increased from 70 to 77.67 for SLA and from 71.67 to 79 for SLActive (P<0.05). Stability improved each week except in the 4th week in SLActive surface measurements. No significant differences were observed between the groups at 2 and 3 months (P>0.05). Conclusions. For both implant surfaces, increased stability was observed over time, with no significant differences between the groups.

Usage of E-Polytetrafluoroethylene (e-PTFE) Membrane for Managing Trabeculectomy Flap- Related Over-Filtration Due to Unavailability of Scleral Patch Graft during Nation-Wide Lockdown

Scleral flap tears during trabeculectomy are difficult to repair in a predictable fashion. Donor scleral flap reinforcements are commonly preferred for managing trabeculectomy flap-related over-filtration, leading to shallow anterior chamber (AC). Due to the advent of COVID-19 lockdown, especially in the initial phases, eye banking activities almost came to a standstill, with almost no corneal and/or scleral tissue retrievals. Hence, in this manuscript we have presented a mini case series with follow-up of two of our cases; where Gore-Tex (e-polytetrafluoroethylene) implant was used as an alternative to scleral patch graft, for managing trabeculectomy flap-related over-filtration, with their pros and cons. Though Gore-Tex implant stability in both cases were contentious, it still served the purpose of managing the flap-related over- filtration and subsequent shallow AC.