Papers by Stephen Wallace
PubMed, Feb 1, 2002
Platelet-rich plasma is an autologous product that is derived from whole blood through the proces... more Platelet-rich plasma is an autologous product that is derived from whole blood through the process of gradient density centrifugation. The proposed value of this product in dental implantology and in bone augmentation procedures lies in the ability to incorporate high concentrations of the growth factors PDGF TGF-beta1, TGF-beta2, and IGF as well as fibrin, into the graft mixture. Research has shown an increased bone maturation rate and improved bone density when this product, or its recombinant growth factors, is added to small bony defects or to larger defects that use autogenous bone as the grafting material. This study tested the efficacy of platelet-rich plasma in three bilateral sinus graft cases with grafts of anorganic bovine bone that contained minimal or no autogenous bone. Histomorphometric analysis indicated that the addition of platelet-rich plasma to the grafts did not make a significant difference either in vital bone production or in interfacial bone contact on the test implants.
Revista Internacional de Odontología Restauradora & Periodoncia, 2008
Esta investigacion piloto controlada doble ciego y aleatoria es la primera que compara a nivel hi... more Esta investigacion piloto controlada doble ciego y aleatoria es la primera que compara a nivel histomorfometrico la formacion de hueso vital tras los injertos sinusales bilaterales con fosfato calcico bifasico (FCB)(straumann Bone Ceramic)o matriz osea bovina anorganica (MOBA) (Bio-Oss) a los 6-8 meses de colocar los injertos. Se seleccionaron 12 pacientes. Tras la elevacion de las paredes laterales del seno, se coloco un material en el seno derecho y el otro en el izquierdo, segun marco la aleatorizacion. A los 6-8 meses del injerto (usando el mismo protocolo temporal para cada paciente), se obtuvo una biopsia con aguja gruesa de 21 senos cicatrizados en 12 pacientes. En nueve casos se consiguieron cilindros bilaterales. El analisis histomorfometrico de 10 biopsias tratadas con FCB y 11 con MOBA mostro un promedio de contenido oseo vital del 28, 35% y del 22, 27% respectivamente. El porcentaje medio de particulas residuales del injerto fue del 28, 4% para FCB y del 26% para MOBA. La diferencia en la formacion de hueso vital no alcanzo significacion estadistica (n=9, prueba de la t paralela) entre los senos bilaterales tratados con FCB y con MOBA. Histologicamente ambos materiales parecieron osteoconductores y fomentaron la neoformacion de hueso. Se necesitan mas estudios para confirmar la capacidad de este hueso regenerado de dar soporte para el mantenimiento a largo plazo de los implantes dentales.
Revista Internacional de Odontología Restauradora & Periodoncia, 2002
Título: Efecto del plasma rico en plaquetas sobre el crecimiento óseo y la osteointegración en in... more Título: Efecto del plasma rico en plaquetas sobre el crecimiento óseo y la osteointegración en injertos de seno maxilar en seres humanos: tres informes de casos bilaterales Autores: Froum, Stuart J.; Wallace, Stephen S.; Tarnow, Dennis P.; Cho, Sang-Choon Revista: ...
PubMed, Apr 1, 2010
The objective of the following case reports was to assess whether mineralized bone replacement gr... more The objective of the following case reports was to assess whether mineralized bone replacement grafts (eg, xenografts and allografts) could be added to recombinant human bone morphogenetic protein-2/acellular collagen sponge (rhBMP-2/ACS) in an effective manner that would: (1) reduce the graft shrinkage observed when using rhBMP-2/ACS alone, (2) reduce the volume and dose of rhBMP-2 required, and (3) preserve the osteoinductivity that rhBMP-2/ACS has shown when used alone. The primary outcome measures were histomorphometric analysis of vital bone production and analysis of serial computed tomographic scans to determine changes in bone graft density and stability. Over the 6-month course of this investigation, bone graft densities tended to increase (moreso with the xenograft than the allograft). The increased density in allograft cases was likely the result of both compression of the mineralized bone replacement graft and vital bone formation, seen histologically. Loss of volume was greater with the four-sponge dose than the two-sponge dose because of compression and resorption of the sponges. Vital bone formation in the allograft cases ranged from 36% to 53% but, because of the small sample size, it was not possible to determine any significant difference between the 5.6 mL (four-sponge) dose and the 2.8 mL (two-sponge) dose. Histology revealed robust new woven bone formation with only minimal traces of residual allograft, which appeared to have undergone accelerated remodeling or rhBMP-2-mediated resorption.
PubMed, Apr 1, 2005
A prospective clinical research study of various graft materials used for the augmentation of hum... more A prospective clinical research study of various graft materials used for the augmentation of human maxillary sinuses is currently in progress at New York University Department of Implant Dentistry. This interim case report describes the healing response after a sinus augmentation procedure using a new mineralized cancellous bone allograft. The results after 9 months of healing demonstrated a vital bone content of 25.2% in the grafted sinus, as ascertained from a trephine core taken from the superior aspect of the lateral window area. Although the vital bone requirement for implant survival in an augmented sinus is unknown, the 25.2% vital bone demonstrated in this case compares favorably with that reported in the literature for other augmentation materials, including xenografts, alloplasts, and autogenous bone.
International Journal of Periodontics & Restorative Dentistry, Nov 1, 2013
The purpose of this study was to histomorphometrically evaluate the percentage of vital bone afte... more The purpose of this study was to histomorphometrically evaluate the percentage of vital bone after grafting of maxillary sinuses using two different concentrations of recombinant human bone morphogenetic protein/acellular collagen sponge (rhBMP-2/ACS) combined with mineralized cancellous bone allograft (MCBA) and to compare the results to a control sinus grafted with MCBA only. Thirty-six sinuses in 18 patients had two of three of the graft combinations including: (1) control, MCBA only; (2) test one, MCBA + 5.6 mL of rhBMP-2/ACS (containing 8.4 mg of rhBMP-2); or (3) test two, MCBA + 2.8 mL of rhBMP-2/ACS (containing 4.2 mg of rhBMP-2). Histologic cores were taken 6 to 9 month following sinus augmentation. The results showed no statistically significant differences in vital bone between the two test groups compared to the control sinus group treated with MCBA alone. Future studies involving more cases and evaluating survival of implants placed in these augmented sinuses are needed to verify the results of this randomized prospective study.
PubMed, Jun 1, 2008
This blinded, randomized, controlled pilot investigation is the first to histomorphometrically co... more This blinded, randomized, controlled pilot investigation is the first to histomorphometrically compare vital bone formation following bilateral sinus grafting with a biphasic calcium phosphate (BCP) (Straumann Bone Ceramic) to an anorganic bovine bone matrix (ABBM) (Bio-Oss) 6 to 8 months following graft placement. Twelve patients were selected. Following elevation of the lateral sinus walls, one material was placed in the right sinus and the other material was placed in the left sinus, as determined by randomization. Six to 8 months after grafting (with the same time frame used for each patient), a trephine core was taken from the grafted area and sent for histomorphometric analysis. Cores were obtained from 21 healed sinuses in 12 patients. Nine patients provided bilateral cores. Histomorphometric analysis of 10 BCP cores and 11 ABBM cores revealed an average vital bone content of 28.35% and 22.27%, respectively. The average percentage of residual graft particles was 28.4% in the BCP cores and 26.0% in the ABBM cores. The difference in vital bone formation was not significantly different (n = 9 patients, paired t test) between bilateral sinuses treated with the BCP and those treated with the ABBM. Histologically, both materials appeared to be osteoconductive and support new bone formation. Future studies are needed to confirm the ability of this regenerated bone to support dental implant maintenance over time.
PubMed, Dec 1, 2006
The present blinded, randomized, controlled investigation histomorphometrically evaluated the vit... more The present blinded, randomized, controlled investigation histomorphometrically evaluated the vital bone formed following bilateral grafting with two different materials--Puros, a mineralized cancellous bone allograft (MCBA), and Bio-Oss, an anorganic bovine bone matrix (ABBM)--at 26 to 32 weeks following graft placement. Thirteen patients were selected who required bilateral sinus augmentation. Following elevation of the lateral sinus walls, one material was placed in the right sinus and the other in the left sinus, as determined by randomized choice. Twenty-six to 32 weeks after grafting (the same time frame was used for each individual patient), a trephine core was taken from the previously elevated lateral wall area and sent for histomorphometric analysis. Cores were obtained from 22 healed sinus augmentations in 11 patients. Eight patients provided bilateral cores, two patients had intact MCBA cores but inadequate ABBM cores, and another patient had an intact ABBM core but an inadequate MCBA core. Histomorphometric analysis of 10 MCBA cores and 9 ABBM cores revealed average vital bone content of 28.25% and 12.44%, respectively. The average percentage of residual nonvital bone was 7.65% in the MCBA cores and 33.0% in the ABBM cores. Significantly more bone was formed in the MCBA sites (n = 8 patients, paired t test). Histologically, both MCBA and ABBM particles were surrounded by new bone, osteoid, and osteoblasts. A higher average percentage of new vital bone was seen around the MCBA particles than around the ABBM particles.
PubMed, Dec 1, 1998
One of the goals of the sinus elevation procedure is the creation of vital bone to effect the oss... more One of the goals of the sinus elevation procedure is the creation of vital bone to effect the osseointegration of dental implants placed in the posterior maxilla. With this goal in mind, in 1993 the Department of Implant Dentistry at New York University College of Dentistry began a long-term clinical, histologic, histomorphometric, and radiographic study of the sinus elevation procedure. The primary parameters included the effects of graft material selection, time allowed for graft maturation, and the effect of barrier membrane placement on the creation of vital bone in the sinus cavity. The effects of these and other parameters on implant survival rates were also to be evaluated. This paper reports the data collected on a subgroup of 113 sinus elevations that used anorganic bovine bone matrix (OsteoGraf/N) alone or in combination with autogenous bone and/or demineralized freeze-dried bone as a graft material. This is the second in a proposed series of papers that will result from this ongoing research project. The results of this study indicate that: OsteoGraf/N appears to be an effective graft material with a 98.2% implant survival rate to date: vital bone formation increased with time; vital bone formation increased moderately when demineralized freeze-dried bone allograft was added, and increased substantially when intraoral autogenous bone was added or when an expanded polytetrafluoroethylene membrane was used; and the increased height achieved by the procedure was stable over a 3-year period. Because of the high overall implant survival rate, it was not possible to determine the relationship between vital bone formation or membrane usage and implant survival.
Revista Internacional de Odontología Restauradora & Periodoncia, 2007
La tecnica de elevacion sinusal a traves de una ventana lateral se ha convertido ya en un tratami... more La tecnica de elevacion sinusal a traves de una ventana lateral se ha convertido ya en un tratamiento preprotesico rutinario y de excelentes resultados que se utiliza para aumentar e volumen de hueso en la parte posterior del maxilar superior antes de la insercion de implantes dentales. Se han propuesto numerosas tecnicas quirurgicas que permiten acceder al seno maxilar a traves de la pared lateral para elevar la membrana sinusal. Entre esas tecnicas cabe destacar las multiples variantes de las tecnicas de charnela y osteotomia comleta, para las que se utilizan instrumentos de corte rotatorios durante la antrostomia. La complicacion intraoperatoria mas frecuente durante estas intervenciones quirurgicas es la perforacion de la membrana de Schneider, habiendose publicado unos porcentajes de perforacion que oscilan entre el 14% y el 56%. En la mayoria de los casos, la perforacion se produce al utilizar los instrumentos rotatorios para abrir la ventana o al emplear instrumentos manuales para lograr el acceso inicial antes de proceder a elevar la membrana de las paredes sinusales. En este articulo presentamos una tecnica alternativa en la que se utiliza un instrumento piezoelectrico para la elevacion sinusal. Aunque esta tecnica es nueva en Estados Unidos, ya ha sido utilizada con exito en Europa durante muchos anos. En esta serie de 100 casos consecutivos en los que se ha utilizado la tecnica piezoelectrica se ha conseguido reducir el porcentaje medio de perforacion de la membrana del 30% con instrumentos rotatorios al 7%. Ademas, todas las perforaciones causadas con la tecnica piezoelectrica se produjeron durante la fase de instrumentacion manual y no utilizar el aparato piezoelectrico.
International Journal of Periodontics & Restorative Dentistry, Mar 1, 2022
Maxillary sinus elevation by the lateral window approach has been shown to be a highly predictabl... more Maxillary sinus elevation by the lateral window approach has been shown to be a highly predictable surgical procedure for increasing bone volume in the posterior maxilla. There are occasions, however, where this procedure may be difficult or impossible to perform in a highly predictable manner. There are many presurgical conditions and anatomical features that can make lateral window access difficult, leading to an increase in intraoperative complications and procedural failures. These complicating factors include complex internal sinus anatomy (multiple septa, anteroposterior septa), a narrow available window space, a thin or absent labial plate on adjacent teeth, and the presence of a root apex in the proposed window area, or it may be due to iatrogenically created defects, such as a previous failed sinus elevation, a healed oroantral fistula, or defects created by difficult extractions. While not frequently used or routinely reported in the literature, the palatal window approach may negate many of these obstacles. When it is reported, success rates are similar to those of lateral window procedures, and as an added advantage, postoperative morbidity is dramatically reduced, allowing the patient to wear a removable appliance immediately after surgery. There are, however, anatomical limitations that dictate when this procedure can be used. This case report is unique in that many of the lateral window complicating factors are present, and the palatal anatomy proved ideal for performing the technique.
The International Journal of Periodontics & Restorative Dentistry
Recently, the Low Window technique was proposed to facilitate sinus augmentation and reduce posts... more Recently, the Low Window technique was proposed to facilitate sinus augmentation and reduce postsurgical patient discomfort. It was shown to be both safe and effective. This case series evaluates the postsurgical discomfort of patients undergoing Low Window sinus augmentation, the bone gain achieved, and whether these factors correlate with the osteotomy area. Records of patients (n = 26) who underwent a sinus elevation using the Low Window approach (n = 34 interventions), followed by implant placement and prosthetic rehabilitation (n = 97 implants), were assessed retrospectively. The analyzed outcomes were the medial, middle, and lateral bone gain ≥ 9 months after augmentation; pain at 5 to 6 hours postsurgery, evaluated on a visual analog scale (VAS; 0 to 100); pain, swelling, and hematoma formation every day up to 7 days postsurgery, evaluated by VAS; implant and prosthetic success and survival rates; and rate of complications. The average follow-up time was 62.1 ± 14.9 months. No intraoperative sinus membrane perforations or other complications occurred. Medial, middle, and lateral bone gains were 10.1 ± 1.7 mm, 11.6 ± 0.8 mm, and 10.7 ± 0.9 mm, respectively. At the last follow-up, the implant success rate was 99%. Postsurgical VAS pain 5 to 6 hours postsurgery was 12.3 ± 8.0 and decreased significantly thereafter. Swelling prevalence was 29.4% at 1 day postsurgery, 20.6% at 2 days, and 2.9% the following day. No swelling was observed from day 4 onward. Prevalence of hematoma was 8.8% for 2 days postsurgery, 2.9% the day after, and no hematoma was observed thereafter. Only the osteotomy area correlated with immediate postsurgical pain, but not with other discomfort outcomes or with bone gain. Low Window sinus elevation might allow bone gain and medium-term implant and prosthetic success rates similar to that of other access window designs. Prospective, comparative studies are needed to investigate whether the technique is more advantageous than traditional approaches.
The International Journal of Periodontics & Restorative Dentistry, 2021
Maxillary sinus grafting is generally a safe procedure. However, intraoperative complications, as... more Maxillary sinus grafting is generally a safe procedure. However, intraoperative complications, as well as early and late postoperative complications, may occur. Included in the latter group are graft infections that can be triggered by peri-implantitis. The aim of the present study was to report three cases of late maxillary sinus graft infections and to histologically evaluate the effects of peri-implantitis in the grafted area. In peri-implantitis cases in grafted sinuses, the sole removal of the implant along with accompanying debridement of the infected area may not be sufficient to resolve the infection, and a more-aggressive treatment may be necessary. Int J
Periodontology 2000, 2019
Maxillary sinus augmentation is the most predictable of the pre‐prosthetic surgical procedures. T... more Maxillary sinus augmentation is the most predictable of the pre‐prosthetic surgical procedures. There are, however, known and well‐documented complications that can and do occur. The most common are the intraoperative complications of sinus membrane perforation and bleeding, and the postoperative complications of sinus graft infections, sinus infections, and sinusitis. The majority of these complications can be prevented, or their incidence greatly reduced, through a thorough understanding of maxillary sinus anatomy, the multifaceted etiologies of these conditions, and the steps that can be taken to avoid them. This volume of Periodontology 2000 will discuss both the preoperative and intraoperative procedures that will prevent these untoward outcomes and the necessary treatment modalities that will limit their adverse effects.
The International journal of periodontics & restorative dentistry, 2000
In 1993 the Department of Implant Dentistry at New York University College of Dentistry began a l... more In 1993 the Department of Implant Dentistry at New York University College of Dentistry began a long-term clinical, histologic, histomorphometric, and radiographic study of the sinus elevation procedure. One of the parameters under evaluation in this study is the effect of barrier membrane placement on the creation of vital bone in the grafted sinus cavity. This report presents a histologic and histomorphometric evaluation of healing with and without the placement of an expanded polytetrafluoroethylene (e-PTFE) barrier membrane over the lateral window at the time of sinus grafting. The data were collected from 12 patients who underwent bilateral sinus elevation surgery. In each of these 12 patients the same grafting material was used in both sinuses, making the presence or absence of an e-PTFE barrier membrane the only controlled variable. Under the conditions of this study, the results indicate that (1) placement of the barrier membrane tends to increase vital bone formation; (2) p...
Journal of Periodontology, Apr 1, 2000
Background: The biologic width around implants has been well documented in the literature. Once a... more Background: The biologic width around implants has been well documented in the literature. Once an implant is uncovered, vertical bone loss of 1.5 to 2 mm is evidenced apical to the newly established implant-abutment interface. The purpose of this study was to evaluate the lateral dimension of the bone loss at the implant-abutment interface and to determine if this lateral dimension has an effect on the height of the crest of bone between adjacent implants separated by different distances. Methods: Radiographic measurements were taken in 36 patients who had 2 adjacent implants present. Lateral bone loss was measured from the crest of bone to the implant surface. In addition, the crestal bone loss was also measured from a line drawn between the tops of the adjacent implants. The data were divided into 2 groups, based on the inter-implant distance at the implant shoulder. Results: The results demonstrated that the lateral bone loss was 1.34 mm from the mesial implant shoulder and 1.40 mm from the distal implant shoulder between the adjacent implants. In addition, the crestal bone loss for implants with a greater than 3 mm distance between them was 0.45 mm, while the implants that had a distance of 3 mm or less between them had a crestal bone loss of 1.04 mm. Conclusions: This study demonstrates that there is a lateral component to the bone loss around implants in addition to the more commonly discussed vertical component. The clinical significance of this phenomenon is that the increased crestal bone loss would result in an increase in the distance between the base of the contact point of the adjacent crowns and the crest of bone. This could determine whether the papilla was present or absent between 2 implants as has previously been reported between 2 teeth. Selective utilization of implants with a smaller diameter at the implant-abutment interface may be beneficial when multiple implants are to be placed in the esthetic zone so that a minimum of 3 mm of bone can be retained between them at the implant-abutment level.
The International Journal of Periodontics & Restorative Dentistry, 2022
Maxillary sinus elevation by the lateral window approach has been shown to be a highly predictabl... more Maxillary sinus elevation by the lateral window approach has been shown to be a highly predictable surgical procedure for increasing bone volume in the posterior maxilla. There are occasions, however, where this procedure may be difficult or impossible to perform in a highly predictable manner. There are many presurgical conditions and anatomical features that can make lateral window access difficult, leading to an increase in intraoperative complications and procedural failures. These complicating factors include complex internal sinus anatomy (multiple septa, anteroposterior septa), a narrow available window space, a thin or absent labial plate on adjacent teeth, and the presence of a root apex in the proposed window area, or it may be due to iatrogenically created defects, such as a previous failed sinus elevation, a healed oroantral fistula, or defects created by difficult extractions. While not frequently used or routinely reported in the literature, the palatal window approach may negate many of these obstacles. When it is reported, success rates are similar to those of lateral window procedures, and as an added advantage, postoperative morbidity is dramatically reduced, allowing the patient to wear a removable appliance immediately after surgery. There are, however, anatomical limitations that dictate when this procedure can be used. This case report is unique in that many of the lateral window complicating factors are present, and the palatal anatomy proved ideal for performing the technique.
The International journal of periodontics & restorative dentistry
The most frequent intraoperative complication with sinus elevation is perforation of the schneide... more The most frequent intraoperative complication with sinus elevation is perforation of the schneiderian membrane. In most instances, the repair of this perforation is necessary to contain particulate grafting material and complete the procedure. New techniques are presented here for the management of large perforations of the schneiderian membrane. A bioabsorbable collagen membrane is stabilized outside the antrostomy and then folded inward to create either a new superior wall that can obliterate a large perforation or a "pouch" that can completely contain the particulate material. This can make it possible to complete a procedure that otherwise may have had to be aborted by preventing dispersion of the particulate graft within the sinus cavity. Clinical cases are shown, along with follow-up at 6 to 9 months, demonstrating histologic and/or radiographic evidence of success, continued sinus health, and superior vital bone formation. The authors have used this technique on 20 ...
The British journal of oral & maxillofacial surgery, Jan 24, 2016
Several systematic reviews have shown that maxillary sinus augmentation is a predictable and effe... more Several systematic reviews have shown that maxillary sinus augmentation is a predictable and effective procedure for augmentation of an atrophic posterior maxilla. However, we know of no reviews that have covered all the clinical aspects. We searched the PubMed, EMBASE, Cinhal, and Cochrane databases up to January 2015 to select relevant studies that cover the different objectives of this review, including the anatomy of the maxillary sinus, surgical techniques, biomaterials used in the sinus augmentation, and potential complications.
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Papers by Stephen Wallace