COVID-19: Variants, Immunity, and Therapeutics for Non-Hospitalized Patients.

The continuing transmission of coronavirus disease 2019 (COVID-19) remains a world-wide 21st-century public health emergency of concern. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused greater than 600 million cases of COVID-19 and over 6 million deaths globally. COVID-19 continues to be a highly transmissible disease despite efforts by public health officials and healthcare providers to manage and control the disease. Variants identified in selected worldwide epicenters add to the complexity of vaccine efficacy, overage, and antibody titer maintenance and bioactivity. The identification of the SARS-CoV-2 variants is described with respect to evading protective efficacy of COVID-19 vaccines and breakthrough infections. Vaccines and other therapeutics have prevented millions of SARS-CoV-2 infections and thousands of deaths in the United States. We explore aspects of the immune response in a condensed discussion to understand B and T cell lymphocyte regulatory mechanisms and antibody effectiveness and senescence. Finally, COVID-19 therapies including Paxlovid, Remdisivir, Molnupiravir and convalescent plasma in non-hospitalized patients are presented with limitations for identification, collection, and distribution to infected patients.

Maxillary Sinus Augmentation for Dental Implant Rehabilitation of the Edentulous Ridge: A Comprehensive Overview of Systematic Reviews.

OBJECTIVES: The objective of this systemic review was to perform a comprehensive overview of systematic reviews and meta-analyses of the maxillary sinus augmentation procedure for implant rehabilitation in humans. The following were evaluated in this overview: (1) anatomic variables affecting sinus augmentation, (2) histomorphometric analysis of the grafted sinus, (3) volumetric changes after sinus grafting, and (4) implant survival beyond 1 year. MATERIAL AND METHODS: Electronic databases were searched for systematic reviews and meta-analyses of implant-related sinus augmentation published from 1976 to September 2015. The studies selected must identify itself as a systemic review or meta-analysis in the title or abstract and must pertain to sinus augmentation. RESULTS: Thirty-three publications fulfilled the review criteria. The AMSTAR ratings for the 33 chosen reviews scored greater than 3 of 11, with 8 reviews scoring greater or equal to 8 of 11. CONCLUSION: The outcome of this overview suggested that the following will increase the success of sinus augmentation and survival of implants placed in the grafted sinus: (1) the use of barrier membranes over the lateral window when using a lateral approach to graft the sinus, (2) the use of particulate autogenous bone with or without other substitute graft materials, (3) sinus augmentation without the use of grafting materials may be considered provided that the space between the sinus membrane and floor can be maintained, (4) the use of rough-surfaced implants, (5) simultaneous implant placement with residual bone height greater than 4 mm, and (6) the cessation of smoking.

Medication-related osteonecrosis of the jaws from once per year intravenous zoledronic acid (Reclast): report of 4 cases.

Osteonecrosis of the jaws is a commonly reported side effect with patients prescribed oral antiresorptive medications to treat osteoporosis and osteopenia. Oral antiresorptive agents are considered as the standard of care for the prevention and treatment of women with postmenopausal osteoporosis. Because of patient's noncompliance of the antiresorptive medications, which may require once-weekly or once-monthly oral ingestion, a new once a year intravenous (IV) infusion of zoledronic acid was recently introduced in the management of osteoporosis. Reports of medication-related osteonecrosis of the jaw (MRONJ) have been reported in patients with cancer treated with multiple doses of IV zoledronic acid. However, there is a paucity of reports occurring with the once-yearly infusion of zoledronic acid (Reclast) for the management of osteoporosis. In this article, we report 4 cases of patients who had a history of long-term oral antiresorptive therapy and now were taking the once-yearly IV zoledronic acid (Reclast) and soon developed MRONJ after completing surgery of the maxilla and mandible.

Low-Dose Radiation Risks of Computerized Tomography and Cone Beam Computerized Tomography: Reducing the Fear and Controversy.

Regulations for protecting humans against stochastic biological effects from ionizing radiation are based on the linear no-threshold (LNT) risk assessment model, which states that any amount of radiation exposure may lead to cancer in a population. Based on the LNT model, risk from low-dose radiation increases linearly with increasing doses of radiation. Imaging procedures in medicine and dentistry are an important source of low-dose ionizing radiation. The increased use of computerized tomography (CT) and cone beam computerized tomography (CBCT) has raised health concerns regarding exposure to low-dose ionizing radiation. In oral and maxillofacial surgery and implant dentistry, CBCT is now at the forefront of this controversy. Although caution has been expressed, there have been no direct studies linking radiation exposure from CT and CBCT used in dental imaging with cancer induction. This article describes the concerns about radiation exposure in dental imaging regarding the use of CT.

Use of an Intraoral Laser Scanner During the Prosthetic Phase of Implant Dentistry: A Pilot Study.

The accuracy of a digital impression technique to fabricate the implant restoration and abutment for a dental implant using an intraoral laser scanner was evaluated in 36 patients who were missing a single posterior tooth in either the mandible or maxilla that was restored with a single implant. The spatial position of each integrated implant, including the surrounding anatomic hard and soft tissues of adjacent structures, was captured utilizing a special scanning abutment with an intraoral laser scanner. Data from the scanning protocol was then delivered via the Internet in the form of an STL file to the manufacturing site for the production of a custom computer-aided design abutment and crown. All 36 restorations and abutments were delivered to the patients and evaluated for marginal integrity, interproximal contact points, and occlusion. Of the 36 patients, 6 required contact adjustments, 7 required occlusal adjustments, and 3 required a gingivectomy around the implant to completely seat the restoration. Chair time for adjustments did not exceed 15 minutes. The findings suggest that an intraoral laser scanner can be used with confidence to obtain consistent and accurate digital impressions to fabricate custom restorations and abutments for dental implants.

Brisk, pulsatile bleeding from the anterior mandibular incisive canal during implant surgery: a case report and use of an active hemostatic matrix to terminate acute bleeding.

Dental implant surgery in the anterior mandible is considered a relatively routine and safe procedure with minimal morbidity. A case of brisk, pulsatile bleeding from the anterior mandibular incisive canal and its management using an active hemostatic matrix is presented. In addition, a review of the literature regarding the anatomy of this region of the mandible and hemostatic strategy to achieve hemostasis will be discussed.

Use of cone beam computed tomography and a laser intraoral scanner in virtual dental implant surgery: part 1.

OBJECTIVE: To describe a new procedure capable of coupling 2 data sets from cone beam computed tomography (CBCT) and an intraoral laser digital scanner to produce a stereolithographic model and surgical guide. METHODS: Use of DICOM (digital imaging and communications in medicine) format data obtained from CBCT scan images merged with standard triangulation language (STL) file data obtained from digital impressions using an intraoral laser scanner. The 2 data sets were electronically sent to a 3-dimensional imaging and technology software company over the Internet to fabricate a stereolithographic model of the jaws and surgical guide without the use of stone or plaster models obtained from traditional dental impressions. CONCLUSION: STL file data are able to accurately fabricate a stereolithographic model and surgical guide for implant surgery.

Identification and treatment of bisphosphonate-associated actinomycotic osteonecrosis of the jaws.

Osteonecrosis of the jaws (ONJ) is a condition characterized by necrotic exposed bone in the jaws of patients receiving intravenous or oral bisphosphonate therapy. A review of the medical and dental literature reveals that the pathoetiology of ONJ remains unknown and there is no established link that bisphosphonates are the primary cause of this bone pathology. However, there is clinical evidence that Actinomyces may play a critical role in the pathogenesis of bisphosphonate-associated ONJ. Identification and a prolonged course of oral antimicrobial therapy may lead to complete resolution of this actinomycotic osteonecrosis.

The correlation of bone mineral density and histologic data in the early grafted maxillary sinus: a preliminary report.

PURPOSE: : Implant success in the grafted maxillary sinus is dependent on the formation of new vital autogenous bone and its mineral density. Different bone graft materials and graft combinations have been used in the sinus augmentation procedure to support dental implants under occlusal loads. The goal of this study was to determine whether it is possible to observe a direct correlation between bone mineral density and histologic data in the grafted maxillary sinus. Based on the observed histological findings, we propose a bone mineral density classification that has 3 rather than 4 types of bone. MATERIALS AND METHODS: : A total of 15 patients participated in this study, all of which had only 1 sinus grafted. A total of 34 dental implants were placed in the grafted sinuses. In 7 patients, designated as group A, a 50:50 composite ratio of autogenous and allogeneic bone was used to graft the sinuses. Four patients had the sinuses grafted with a 50:50 composite ratio of a naturally occurring marine algae hydroxyapatite graft material and autogenous bone. One patient had the sinus grafted with 100% autogenous bone. In this group of patients, a total of 25 dental implants were surgically placed 14 to 20 weeks after sinus grafting. The implants were restored 12 weeks later. No implant failures were observed over a 52-week period. The last 3 patients, designated as group B, completed implant surgery beyond the 52-week end point of the study for various reasons. They provided a unique opportunity to histologically observe bone maturation at 68, 88, and 260 weeks, respectively. Using cone beam computed tomography (CT) technology and 3D-CT interactive software, bone mineral density in Hounsfield unit values were recorded during different healing time periods. RESULTS: : In all 15 patients, bone mineral density was observed to steadily increase during the 52-week observation period and beyond, as evidenced by the increase in Hounsfield unit values and the formation of new, vital autogenous trabecular bone. CONCLUSION: : Histologic and histomorphometric data demonstrate a definite correlation with the formation of new, vital autogenous trabecular bone and bone mineral density (quality) that permits early loading of implants in the grafted maxillary sinus.

Brisk, prolonged pulsatile hemorrhage during the sinus graft procedure: a case report with discussion on intra-operative hemostatic management.

The maxillary sinus graft procedure is the treatment of choice to increase the vertical bone height in the atrophic posterior maxilla to place dental implants. It is considered as a routine surgical procedure with predictable results. However, complications have been reported with this grafting procedure. With any surgical procedure, complications may arise, and the surgeon must be prepared to effectively manage the complication. In addition to detailed knowledge of the maxillofacial anatomy, recognition of surgical emergencies and its management is critical for the implant surgeon. A case of brisk, prolonged pulsatile hemorrhage during the sinus graft procedure is described, and its intra-operative management with topical Thrombin is presented.

CTX biochemical marker of bone metabolism. Is it a reliable predictor of bisphosphonate-associated osteonecrosis of the jaws after surgery? Part II: a prospective clinical study.

Biochemical markers of bone metabolism have been used in medicine to evaluate and provide treatment to patients with metabolic bone diseases, such as osteoporosis. Serum cross-linked C-telopeptide of type I collagen (CTX) is a marker of osteoclast activity and is used to assess the level of bone resorption. Recently, in oral and maxillofacial surgery, it was proposed that the levels of serum CTX may predict the subsequent risk of developing osteonecrosis of the jaws (ONJ) after oral surgery procedures for patients taking oral bisphosphonates (BPs). The goal of this study was to determine whether this specific serum marker of bone resorption could preoperatively predict the risk of developing ONJ from oral BPs.We hypothesized that there is no clinical correlation between the observed preoperative serum CTX values and the risk of developing ONJ. The authors examine the scientific basis (validity) of the morning fasting serum CTX test in 163 consecutive patients who underwent various oral surgery procedures in the office. The authors also review the laboratory test results and the recommended protocol based on the test values. One hundred sixty-three patients (mean age, 75.9 years) were divided into 2 groups. Group I was the control group that consisted of 109 patients taking oral BPs who did not take the CTX test preoperatively. Group 2 consisted of 54 patients taking BPs and who elected to have the CTX test performed to assess their level of risk of developing ONJ, preoperatively. Both groups of patients were observed for a period of 8 weeks for signs and symptoms of BP-associated ONJ after surgery. The clinical data at 8 weeks and beyond revealed that there was no evidence of BP-associated ONJ in all participants. We conclude that the serum CTX is not a valid preoperative test to accurately assess the level of risk of developing ONJ and is not indicated in the oral surgery patient.

CTX biochemical marker of bone metabolism. Is it a reliable predictor of bisphosphonate-associated osteonecrosis of the jaws after surgery? Part I: biological concepts with a review of the literature.

Biochemical markers of bone metabolism have been used in medicine to evaluate and provide treatment to patients with metabolic bone diseases, such as osteoporosis. Serum cross-linked C-telopeptide of type I collagen is a marker of osteoclast activity and is used to assess the level of bone resorption. Recently, in oral and maxillofacial surgery, it was proposed that the levels of serum cross-linked C-telopeptide of type I collagen may predict the subsequent risk of developing osteonecrosis of the jaws after oral surgery procedures for patients taking oral bisphosphonates. The astute clinician must critically review the scientific literature and must decide if biochemical markers of bone resorption are of benefit in managing the oral surgery patient on bisphosphonates.

Sinus grafting with a natural fluorohydroxyapatite for immediate load: a study with histologic analysis and histomorphometry.

The goal of this retrospective study was to evaluate the survival rates of dental implants placed in sinuses grafted with a 50:50 composite ratio of autogenous bone and a natural flourohydroxyapatite (FHA) combined with platelet-rich plasma (PRP) using an immediate-load protocol. The authors hypothesized that a 50:50 composite ratio of FHA and autogenous bone combined with PRP would permit immediate loading without compromising implant survival rates. Eleven patients with bilateral partial edentulism of the posterior maxilla were enrolled in this retrospective study. Autogenous bone used in the graft procedure was harvested from the tibia of the left lower extremity. Each patient was grafted with a 50:50 composite ratio of autogenous bone and FHA. Membranes were not used to cover the lateral wall osteotomy site. Platelet-rich plasma was added to the graft material to accelerate and enhance bone regeneration. Four to 6 months after the grafting procedure, 37 hydroxyapatite-coated dental implants were surgically placed and immediately loaded between 72 hours and 5 days later with custom titanium abutments and acrylic provisional restorations placed out of functional occlusion. Six months later, definitive ceramometal restorations were cemented on to the custom abutments. Patients were observed over a 52-week period. The overall implant survival rate was 97.3%. Histologic and histomorphometric analysis of core samples revealed formation of new vital bone in different graft specimens ranging from 23% to 34%. In each core bone sample, 100% of the bone sample was determined to be vital. In the grafted maxillary sinus, the natural FHA combined with autogenous bone in a 50:50 composite ratio with PRP is a suitable graft material permitting immediate load without compromising implant survival rates while decreasing the overall healing time.

Immediate loading of the grafted maxillary sinus using platelet rich plasma and autogenous bone: a preliminary study with histologic and histomorphometric analysis.

OBJECTIVE: The goal of this clinical study was to evaluate dental implant survival rates using the concept of a nonfunctional, immediate loading protocol with nonsplinted dental implants in the grafted maxillary sinus during a 52-week period. Random histomorphological and histomorphometric analysis was completed to evaluate the early healing effect of platelet rich plasma (PRP) and 50% autogenous bone combined with 3 different substitute graft materials. MATERIALS: Four to 8 months after grafting the sinus with PRP sprayed autogenous bone combined with 3 different substitute graft materials in a 50:50 composite ratio, 27 hydroxyapatite- coated dental implants were surgically placed in 41 patients and immediately loaded between 48 hours and 5 days later with custom titanium abutments and acrylic provisional restorations placed out of functional occlusion. Six months later, definitive ceramometal restorations were cemented on to the custom abutments. RESULTS: During a 52-week observation period, no implants were lost. Between 4 and 8 months of graft healing time, histologic and histomorphometric analysis revealed formation of new vital bone in different graft specimens ranging from 77% to 100%. CONCLUSION: The preliminary results of this clinical study indicate that immediate nonfunctional loading using PRP and 50% autogenous bone combined with different substitute graft materials is a predictable protocol in the grafted maxillary sinus as early as 4 months of postgrafting. The high implant survival rate is due to the early formation of large percentages of new vital bone as confirmed by using histologic and histomorphometric analysis.

Immediate load and esthetic zone considerations to replace maxillary incisor teeth using a new zirconia implant abutment in the bone grafted anterior maxilla.

The goal of this prospective clinical study is to evaluate a new all-ceramic implant abutment made from zirconium oxide during the immediate load of dental implants placed in the block grafted anterior maxilla. This new zirconia abutment gives the clinician the opportunity to provide the patient with an all-ceramic restorative system (abutment and crown) for an optimum esthetic result and a high level of patient satisfaction. A total of 9 hydroxyapatite-coated dental implants were surgically placed in 9 patients and were immediately loaded 5 to 7 days later with a custom composite provisional restoration that was placed out of functional occlusion. Each prefabricated, natural colored zirconia abutment was shaped and connected to the implant with a titanium screw. Provisional restorations were cemented to the zirconia abutment with the use of temporary cement. Twelve weeks later, the provisional restoration was replaced with an all-ceramic restoration. Over a 52-week observation period, no abutment fractures occurred, and no abutment screw loosening was observed. No implants failed. All 9 patients reported total satisfaction regarding esthetic quality of the all-ceramic restorative system (abutment and implant). Preliminary results of this clinical study indicate that this new zirconia abutment offers the clinician and the patient exceptional strength, optimal esthetics, and simplicity. It is of important clinical significance that use of this all-ceramic abutment eliminates the well-known disadvantages of metal abutments.

Use of platelet-rich plasma in the management of oral biphosphonate-associated osteonecrosis of the jaw: a report of 2 cases.

Bisphosphonates (BP) are nonhormonal medications used in the treatment of various bone malignancies and metabolic conditions. Since 2003, there have appeared a significant and growing number of articles in the worldwide medical and dental literature describing the complication of an osteonecrosis of the jaws associated with the intravenous and, most recently, the oral form of BP medication that has been refractory to any definitive form of treatment. The authors have successfully managed 2 patients taking the oral form of BP with adjunctive treatment using platelet-rich plasma (PRP), and in one case with hyperbaric oxygen (HBO). We were able to obtain complete remission in each case, which is defined as resolution of pain and complete closure of exposed bone in the jaws. The purpose of this report is to describe a treatment protocol and the rationale for using PRP and HBO to obtain complete remission of this new pathologic condition.

Immediate load protocol for anterior maxilla with cortical bone from mandibular ramus.

OBJECTIVE: To evaluate the concept of a nonfunctional immediate load protocol with single implants placed in the anterior maxilla that has been bone grafted with autogenous, block cortical grafts harvested from the ramus of the mandible. METHODS: There were 19 hydroxyapatite-coated dental implants surgically placed in 19 patients, and immediately loaded between 48 hours and 3 days later with a custom acrylic provisional restoration that was placed out of functional occlusion. After 12 weeks, the definitive ceramo metal restoration was cemented to the custom abutment. RESULTS: Over a 1-year observation period, all implants continue to function. CONCLUSION: The preliminary results of this clinical study indicate that immediate, nonfunctional load with single implants is a predictable protocol in the bone grafted anterior maxilla in select cases.

Procurement of autogenous bone from ramus with simultaneous the mandibular third-molar removal for bone grafting using the Cr:YSGG laser: a preliminary report.

Autogenous bone grafting and third-molar removal are surgical procedures routinely performed in dentistry on a daily basis. The purpose of this preliminary report is to describe our clinical experience with the Er, Cr:YSGG laser in the procurement of bone harvested from the ramus and removal of third molars simultaneously from the mandible.

An in-office technique for harvesting tibial bone: outcomes in 8 patients.

The purpose of this report is to describe our experience with performing the tibial bone graft procurement procedure under intravenous sedation and local anesthesia as an in-office procedure and to quantify the amount of bone graft material that can be harvested from the tibia.