Autogenous Mineralized Dentin versus Xenograft granules in Ridge Preservation for Delayed Implantation in Post-extraction Sites: A Randomized controlled clinical trial with an 18 months follow-up

OBJECTIVES

To test primary stability of delayed implants placed in post-extraction ridges preserved with autogenous mineralized dentin matrix (MDM) versus xenograft granules. Clinical, histological and pain experience outcomes were further assessed.

MATERIAL AND METHODS

From March 2018 to July 2020, patients requiring ridge preservation in preparation for delayed implant placement in post-extraction sites were included. Participants were randomly allocated to either the test (MDM) or control group (xenograft granules) prior to ridge preservation. Visual analogue scale and analgesic consumption were measured every day for a week. Six months after preservation, trephine cores were harvested for histomorphometry prior to implant placement. Implants were then placed, and implant stability was measured immediately as well as two months after placement. Marginal bone loss and presence of mucositis/peri-implantitis were registered up to 18 months after prosthetic loading.

RESULTS

Fifty-two patients (66 implants) completed the study. MDM and xenograft groups presented similar primary (77.1 ± 6.9 versus. 77.0 versus. 5.9) and secondary (81.8 ± 5.1 versus. 80.1 ± 3.8) implant stabilities. The percentage of newly formed bone in MDM (47.3%) was significantly higher than xenograft (34.9%) (p < .001), and the proportion of residual graft was significantly lower (12.2% in MDM and 22.1% in xenograft) (p < .001). No significant differences were found as far as clinical, radiographic and patient-related outcomes.

CONCLUSIONS

Implants placed in sites preserved with MDM had similar primary stability in comparison to xenograft granules. MDM showed a significantly higher quantity of newly formed bone and lower amount of residual graft in histomorphometry results and equal clinical and patient-related outcomes.

CROI 2019: neurologic complications of HIV disease

Investigators reported many new neuroHIV research findings at the 2019 Conference on Retroviruses and Opportunistic Infections (CROI). These findings included confirmation that HIV-associated neurocognitive disorder (HAND) remains common with an increasingly recognized role for comorbidities (eg, obesity) and neurodegenerative conditions (eg, Alzheimer's disease), especially as persons living with HIV (PLWH) advance into their seventh decade of life and beyond. HAND is increasingly recognized as a heterogeneous disorder that differs between individuals (eg, by sex) in the trajectory of specific neurocognitive abilities (eg, executive functioning). A more recent focus at this year's conference was toxicity of combination antiretroviral therapy: neurocognitive performance and neuroimaging data from several studies were presented but did not consistently support that integrase strand transfer inhibitors are associated with worse neurologic outcomes. Neuroimaging studies found that white matter changes reflect a combination of the effects of HIV and comorbidities (including cerebrovascular small vessel disease) and best correlate with blood markers of inflammation. The pathogenesis of HIV in the central nervous system (CNS) was the focus of a plenary lecture and numerous presentations on HIV compartmentalization in the CNS and cerebrospinal fluid viral escape. Novel findings were also presented on associations between HIV-associated neurologic complications and glycomics, neuron-derived exosomes, and DNA methylation in monocytes. This summary will review findings from CROI and identify new research and clinical opportunities.

Autogenous demineralized dentin matrix from extracted tooth for the augmentation of alveolar bone defect: a prospective randomized clinical trial in comparison with anorganic bovine bone

OBJECTIVES

The aim of this study was to prospectively evaluate the clinical efficacy and histological outcome of the autogenous tooth graft material (AutoBT) compared to that of anorganic bovine bone (Bio-Oss^® , Geistlich, Switzerland) in post-extraction alveolar bone augmentation.

PATIENTS AND METHODS

A total of 33 graft sites in 24 patients were included in this study. AutoBT was used in 21 sites of 15 patients and Bio-Oss^® was used in 12 sites of 9 patients for alveolar bone augmentation 2-4 weeks after dental extraction. Vertical dimension of grafted bone was measured both at the time of graft placement and at implant fixture placement after 6 months. Trephine cores were harvested for the histomorphometric evaluations during implant placement when feasible. The primary stability of implant fixture was also measured.

RESULTS

Infection of graft material or graft bed was not observed and graft sites healed without any notable complications in both groups. The vertical dimensions of alveolar bone increased by 5.38 ± 2.65 mm in AutoBT group and 6.56 ± 3.54 mm in Bio-Oss^® group at 6 months post-extraction. Histomorphometrically, new bone formation of AutoBT-grafted site was 31.24 ± 13.87% while that of Bio-Oss^® was 35.00 ± 19.33%. The implant stability quotient (ISQ) of implants placed in AutoBT-grafted sites measured 72.80 ± 10.81 while those placed in Bio-Oss^® -grafted sites measured 70.0 ± 12.86. There were no statistically significant differences between measurements of the two groups.

CONCLUSION

Autogenous demineralized dentin matrix from extracted tooth grafted to extraction sockets for the augmentation of vertical dimension was as effective as augmentation using anorganic bovine bone. Both groups showed favorable wound healing, similar amount of implant stability, and histologically confirmed new bone formation. Thus, the results of this study suggest that autogenous tooth graft material is a viable option for alveolar bone augmentation following dental extraction.

Maxillary sinus grafting with autograft vs. fresh frozen allograft: a split-mouth histomorphometric study

BACKGROUND

Surgical techniques as sinus floor augmentation have made it possible to increase the bone volume of the posterior maxilla so that implant placement may be feasible. A large variety of bone grafting materials have been utilized for sinus floor augmentation. A good alternative is allograft. Fresh frozen bone is harvested from live or cadaveric donors and then immediately frozen and stored at -80 °C. To date, studies about the effect of fresh frozen bone are scarce.

OBJECTIVE

Evaluation of new bone formation, following maxillary sinus grafting with autograft vs. fresh frozen allograft.

MATERIALS AND METHODS

A split-mouth edentulous design including 15 patients was used. Sinus floor augmentation was carried out using either autogenous bone harvested from the ramus area or fresh frozen bone from allogeneic femoral heads. The choice was determined randomly, using a randomized table. The grafted sinus was left to heal for 6 months. Biopsies were harvested from the lateral wall. The biopsies were used for bone histology and histomorphometric analysis. After collection of the biopsy, dental implants were placed. After a healing period of 6 months, the implants were loaded.

RESULTS

Implant survival, histology, and histomorphometry of sinuses grafted with autogenous or fresh frozen bone were similar. The new bone formation took place predominantly around and in-between particles.

CONCLUSIONS

The findings of the present study support the use of fresh frozen bone allografts for sinus floor augmentation.