Conditions: Tooth Loss
Keywords: Alveolar Bone Alveolar Ridge Bone Resorption Bone Grafting Barrier Membrane
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 17
Healthy volunteers: yes

Brief summary:
PURPOSE The purpose of this case series is to clinically, radiographically and histologically evaluate the treatment of dehiscence defects in extraction sockets using a minimally-invasive GBR technique that involves the application of a particulate bone allograft and a non-resorbable PTFE membrane.

METHODS Subjects with single-rooted teeth indicated for extraction and interested in future implant therapy for tooth replacement will be recruited on the basis of an eligibility criteria. A buccal or lingual dehiscence defect must strongly be suspected or confirmed upon clinical examination in order for the subject to qualify for study inclusion. A cone-beam computer tomography (CBCT) scan of the arch containing the tooth to be extracted will be obtained prior to tooth extraction. Following minimally invasive tooth extraction and debridement, the socket will be evaluated to verify the presence of a dehiscence defect affecting at least 50% of the bony plate height. After creating a soft tissue 'pouch' using tunneling instruments, a non-absorbable dense-PTFE (dPTFE) barrier membrane that will be trimmed to a size and shape that would allow for complete extension over the existing defect will be tucked between the mucosa and the alveolar bone. Then, the extraction socket will be grafted with particulate allograft and the access to the socket will be sealed with an extension of the membrane and an external cross mattress suture. Subjects will be recalled at 1, 2 and 5 weeks to monitor healing and assess the level of discomfort using a visual analog scale at the end of each visit. At the 5-week visit, the membrane will be gently removed and the exposed area will be left to heal by secondary intention. At 20 weeks after tooth extraction a second CBCT will be obtained to radiographically evaluate the site for implant placement. Bone volumetric reconstructions of the alveolar ridge at baseline and at 20 weeks will be made using the CBCT data to assess changes affecting the bone housing. If the site has healed adequately, implant placement will be planned at 24 weeks after tooth extraction. A bone core biopsy will be obtained at the time of implant placement in order to histologically analyze the characteristics of the grafted substrate. Upon implant placement with primary stability a healing abutment will be placed and sutures will be given to achieve primary wound closure, as necessary. Subjects will return for the final study visit at 2 weeks following implant placement to evaluate the healing prior to being referred back to the restorative dentist.

Detailed description:
Visit 1 - Screening visit After reading and signing this informed consent form, you will complete a detailed medical and dental history form. We will review this form with you to ensure you can safely participate in the study. You will also have an oral exam to determine if you qualify for the study. If you are a woman of childbearing age, you will be tested for pregnancy. If you are pregnant or trying to become pregnant, you cannot participate in the study. You will also have one digital dental x-ray of the area for tooth extraction, if not available already, which is standard of care. You will also have dental impressions (molds of your teeth), which are made in a non-invasive manner to collect data for some of the research measurements. This visit will last between 1 and 1.5 hours.

Visit 2 - Baseline visit In less than 10 weeks after the screening visit, you will have the tooth extraction and bone grafting, which will be just like the procedure performed for patients who are not enrolled in the study and present a similar clinical scenario. Before the surgical procedure, a special dental x-ray scan known as cone beam computed tomography (CBCT) will be taken for the purpose of collecting research measurements. The CBCT scan generates 3D images of your teeth and surrounding tissues. After numbing the area, clinical measurements will be gathered. These measurements are non-invasive (do not involve cutting your body or putting instruments inside it) and will not harm the gums or surrounding teeth. The extraction (removal of the tooth) will be performed and the tooth socket (the area surrounding the tooth that was removed) will be cleaned, which is what would happen to patients who are not enrolled in the study. At this time, additional measurements of the area will be taken. These measurements will not cause you any extra discomfort, since that area will be numbed. Then, the socket grafting technique will be performed. The treatment will consist on the combination of a bone grafting material from a human donor (EnCore, Osteogenics Biomedical Inc.) and a non-dissolvable barrier membrane (Cytoplast TXT-200, Osteogenics Biomedical Inc.), to protect the bone graft and that will be removed in 5 weeks. You will be given prescriptions for an antibiotic, a pain reliever and a mouth rinse. You will also receive home care instructions before you leave. This visit will last about between 1.5 to 2 hours.

Visits 3, 4, 5 and 6 - Post-operative follow up visits You will return to the clinic at 1, 2, 5 and 20 weeks, which is standard of care in many cases of tooth extraction and grafting. In these visits, you will have an oral exam, check-up, and the researchers will monitor how well you are healing. These visits will last approximately 30 minutes.

At the 5-week visit, the barrier membrane will be removed. You will not have to be numbed for this.

Additionally, only at the 20-week visit after tooth extraction, a second CBCT x-ray scan will be obtained to determine how much bone is available after the healing period to plan the implant placement and for research measurements. The second CBCT x-ray scan will allow your surgical doctor to evaluate the amount of bone volume and is standard of care when planning for dental implant placement. A dental impression (mold) will be made to collect information about the gum tissue. Recommendations on further treatment, including the potential for implant therapy or possible additional grafting, will be provided based on the findings from this visit.

Visit 7 - Implant placement visit If you can receive the implant, a surgical placement visit will be scheduled at approximately 24 weeks after tooth extraction. After numbing the area, a small gum flap will be opened to access the area underneath that was bone grafted. A bone sample biopsy will be taken and analyzed for research purposes. This bone would be disposed otherwise, since a bed must be created in the bone to allow for implant placement. After an adequate space for implant placement is created in your bone, the implant will be placed. If implant primary stability (sufficient retention) is not achieved, the doctor may need to place a larger implant (in length, diameter or both) or, if this is not possible, discontinue the procedure and plan for delayed implant placement at another time. If this is the case, the study will cover the costs associated with additional grafting and implant placement. Upon implant placement, your gums will be stitched and you will be given prescriptions for an antibiotic, a pain reliever and a mouth rinse. You will also receive home care instructions before you leave. This visit will last between 1.5 and 2 hours.

Visit 8 - Post-operative follow up visit You will be seen by your surgical doctor for a postoperative visit at approximately 2 weeks after the implant is placed to monitor the healing and to remove sutures, which is standard of care. You will have an oral exam, check-up, and the researchers will monitor how well you are healing. These visits will last approximately 30 minutes. This is the last visit of the study.

Arms:
arm 1: Treatment of dehiscence defects at the time of tooth extraction using a minimally-invasive GBR technique that involves the application of a particulate bone allograft and a non-resorbable PTFE membrane.

Interventions: intervention 1: Alveolar Ridge Reconstruction
Intervention descriptions: intervention 1: Reconstruction of dehiscence defects in extraction sockets with a minimally invasive technique using a particulate bone allograft and a non-absorbable dense polytetrafluoroethylene (dPTFE) membrane

Protocol document:
Prot_SAP_000.pdf: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Treatment of Post-Extraction Dehisced Socket - A Case Series Study 
 
NCT02980211 
 
Updated on December 26th, 2019 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


Experimental Design and Center 
 
This clinical study was designed as a prospective case series and it was conducted in compliance 
with the Preferred Reporting of Case Series in Surgery (PROCESS) guidelines. 
 
Eligibility Criteria and Recruitment Adult subjects with tooth-bound, single-rooted teeth, except 
for mandibular incisors, that were indicated for extraction, and also presented with a large 
dehiscence defect affecting at least the coronal third of the buccal bone, were eligible to 
participate in the study. Exclusion criteria were as follows: 1) any periodontal attachment loss 
greater than 1 mm affecting the interproximal sites of neighboring teeth; 2) current heavy tobacco 
use, defined as greater than 10 cigarettes per day; 3) uncontrolled diabetes mellitus, defined as 
HbA1c>7.0; 4) severe hematologic disorders; 5) organ failure; 6) uncontrolled or severe metabolic 
bone diseases or disorders; 7) previous head and neck radiotherapy or chemotherapy within the 
past 12 months; 8) intake of medications known to largely influence bone metabolism; 9) subjects 
who were pregnant at the time of screening or trying to conceive; 10) mental disabilities that may 
interfere with reading, understanding and signing the informed consent and/or with following 
studyrelated instructions. Potential subjects were required to read, understand and sign the 
consent form. In the screening visit, candidates were informed of the purpose, design and timeline 
of the study, as well as expected benefits and possible risks associated with their participation. 
 
Clinical Procedures All surgical procedures were performed by the first author (MA). Before 
starting the baseline surgical intervention, a cone beam computed tomographic (CBCT) scan (i-
CAT Next Generation, Imaging Sciences International Inc., Hatfield, PA, USA) was made. The field 
of view was approximately 6 cm at 0.3mm voxel size and the exposure factor settings were fixed 
at 120 kVp and 5 mAs for all scans. All surgical procedures were performed under local anesthesia. 
The vertical extent of the defect was measured by determining the distance from the gingival 
margin to the crestal bone on the mid-buccal using a UNC-15 probe, and subtracting the 2 mm 
that, in average, would correspond to the supracrestal soft tissue. Tooth extraction was completed 
in a minimally traumatic, flapless, fashion. Following extraction, the existence of the suspected 
dehiscence defect was confirmed; absence of a defect resulted in subject exclusion. After carefully 
elevating one papilla, usually the distal, a soft tissue ‘pouch’ was created using tunneling 
instruments around the bony defect. Subsequently, a non-absorbable dPTFE membrane (Cytoplast 
TXT-200, Osteogenics Biomedical, Lubbock, TX, USA), trimmed to the size and shape that would 
allow for complete extension over the defect, was tucked between the mucosa and the alveolar 
bone. A combination particulate bone allograft composed of a mixture of 70% FDBA and 30% 
DFDBA (enCore, Osteogenics Biomedical Inc., Lubbock, TX) was used to fill the socket up to the 
crestal level and the surrounding buccal bone housing. The socket access was sealed with an 
extension of the dPTFE membrane to ensure compartmentalization of the underlying alveolar 
bone and grafting material. An external cross mattress and a simple interrupted suture (Cytoplast 
5/0 suture, Osteogenics Biomedical Inc., Lubbock, TX) were applied to stabilize the marginal 
mucosa and the elevated papilla, respectively. Detailed post-operative instructions were given to 
the subjects, including care to avoid mechanical disturbance or excessive pressure of the surgical 
site and to avoid brushing the area for one week. Additionally, prescriptions were provided to each 
patient for an anti-inflammatory medication (Ibuprofen 600 mg, every 6 to 8 hours for 48 hours, 


then as needed), a systemic antibiotic (Amoxicillin 500 mg every 8 hours for 7 days or, in case of 
penicillin allergy, Clindamycin 300 mg every 6 hours for 7 days) and a mouth rinse (Chlorhexidine 
gluconate 0.12% to be used every 12 hours). Subjects were recalled at 1, 2, 5 and 20 weeks to 
assess healing and level of discomfort. At 1 week, the sutures were removed. At 5 weeks, the 
dPTFE membrane was gently removed from ARP sites using a cotton forceps without 
administration of local anesthesia. At 20 weeks, a second CBCT was obtained for data analysis and 
to plan the implant placement procedure. 
 
Outcome of Interest and Data Collection Alveolar Bone Volume Change Two independent 
examiners assessed the magnitude of volumetric reduction of the alveolar bone in mm 3 to 
express it as a percent of change from baseline to 20 weeks. The CBCT datasets (DICOM files) were 
imported into a software package (Simplant 17 Pro, Materialise, Dentsply Implants, Waltham, MA, 
USA). A constant threshold was used to separate the soft and hard tissue elements and manual 
segmentation using reproducible landmarks was performed to select a volume of interest (VOI) 
on both datasets. The VOI was confined to the following boundaries: a horizontal plane at the 
apical extent of the root tip or guiding landmark at the equivalent location when the tooth was 
not present (apical boundary), the alveolar crest (coronal boundary), the buccal and palatal plates 
of the alveolar bone (bucco-lingual boundaries), and vertical planes placed at the location of the 
interproximal height of contours of the adjacent crowns (mesio-distal boundaries). Volume of each 
VOI was computed automatically. 
 
Statistical Analyses Given the nature of this study, no formal sample size calculation was 
conducted. A minimum sample size of 15 subjects was based on feasibility according to the low 
rate of large dehiscence defects reported in the existing literature. Data was uploaded to a 
statistical analysis software (SAS 9.4, IBM, Armonk, NY, USA). Normality was verified using the 
Shapiro-Wilk test. Measurements obtained by two examiners were averaged. Subsequently, mean 
and standard deviation was calculated for all variables. One sample t-tests were completed to 
determine whether the change in bone volume was significant (alpha was set to 0.05).