Rationale: To determine the effect of alveolar ridge preservation (ARP) versus spontaneous healing (SH) in large buccal bone defects in the posterior mandible. Objective: To evaluate whether ARP using a xenograft (XG) (Cerabone plus) or an allograft (AG) (Maxgraft granules) covered by a membrane (Jason membrane) reduces the need for additional bone augmentation either prior to or during implant placement in the posterior mandible compared to spontaneous healing Study design: Prospective randomized clinical study with 10-year follow-up. Study population: Inclusion criteria: patients are 18 years or older and in need for extraction of a (pre)molar in the posterior mandible with at least one adjacent tooth and a buccal bone defect of \>50%. Exclusion criteria: the presence of active periodontal disease, uncontrolled diabetes mellitus, a history of or current use of chemotherapy or radiation in the head and neck area, history of or current use of medication related to osteonecrosis of the jaw, smoking (\> 5 cigarettes a day, disability (physical and/or mental), making the patient unable to maintain basic oral health or follow the study protocol, pregnancy (in case of pregnancy, the treatment is postponed until after the delivery). Intervention (if applicable): Atraumatic extraction of a (pre)molar in the posterior mandible will be performed. Patients will then be included based on the dimensions of the buccal bone defect (buccal bone defect of \>50%). 66 patients will be randomly divided in either the XG group, the AG group or the SH group (control). In the ARP groups (XG and AG), following tooth extraction, ARP will be performed using either a XG (Cerabone plus) or an AG (Maxgraft granules), both covered by a membrane (Jason membrane). In the control group, the alveolus will be left for spontaneous healing, following tooth extraction. After 4-6 months, a cone bean computed tomography (CBCT) scan will be performed to determine the possibility of implant placement with or without additional augmentation. Implant placement will be performed in all groups with or without guided bone regeneration (GBR). Main study parameters/endpoints: Frequency of additional augmentation at implant placement.
Extraction of the teeth in the posterior region of the mandible may be an indication for the placement of dental implants. However, after extraction of the teeth, the alveolar ridge undergoes changes due to resorption. Resorption is most pronounced on the buccal side and might complicate implant placement as is could lead to proximity issues with the inferior alveolaris nerve of the mandible. Alveolar ridge preservation (ARP) is commonly performed technique aimed at preserving available bone after tooth extraction. It facilitates delayed implant placement, reducing morbidity and providing optimal esthetic outcomes for implant placement. This procedure is performed using autogenous bone grafts, bone substitutes such as xenografts or allografts or a mixture of both. Also, membranes can be used to direct the growth of new bone. A thin buccal bone wall is an indicator for bone loss that may compromise the integrity of the buccal bone and lead to biologic and esthetic complications. When the buccal bone wall has a width of \< 1.5mm, it is considered an indication for ARP. ARP is found to be effective in reducing bone loss and facilitating implant placement after extraction in the anterior region and for multi-rooted sides. However, most available evidence including RCTs, involves patients with at least 50% of buccal bone intact. Consequently, it is uncertain whether the efficacy ARP is also applicable in situations involving damaged sockets (buccal bone loss \>50%).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
66
Alveolar ridge preservation with either xenograft of allograft material
Erasmus MC
Rotterdam, South Holland, Netherlands
The frequency of additional bone augmentation at implant placement.
The frequency of additional bone augmentation at implant placement will be assessed during implant placement.
Time frame: During implant placement
Implant survival
Implant survival is achieved if there is no presence of any mobility of the individual implant and/or any situation dictating implant removal.
Time frame: From the moment of implant placement until 10 years of loading
Profilometric outcome measure
Volumetric changes of the soft tissue
Time frame: after intake, extraction, implant placement, placement of the final crown (after 2 weeks, 1 year, 3 years, 5 years and 10 years)
Prosthetic success
Prosthetic complications will be scored based on the modified United States Public Health Services (USPHS) criteria assessing framework fracture, veneering fracture, occlusal wear, marginal adaptation, anatomical form, cementation gap and patient satisfaction (Bayne \& Schmalz, 2005). Suprastructures scoring delta will be scored as a failure. A suprastructure is scored as successful if all aspects scored only in the alpha or bravo categories (Pol et al., 2022).
Time frame: from placement of the final crown until 10 years of loading
Histological outcome measures
Histological analysis Micro-computed tomography (μCT) analysis
Time frame: After implant placement
Subjective Clinician-reported outcome measures related to the clinician's perception
Clinician questionnaire using an 11-point numeric scale assessing difficulty of the procedure. The lowest score is 0 which indicates extremely easy, the highest score is 10 which indicates extremely hard.
Time frame: After the surgical procedures (extraction and implant placement)
PROMS
Patient questionnaire based on a visual analog scales (VAS) score (0-10) assessing participant satisfaction evaluation during the study will be evaluated that will focus on satisfaction and impact of the surgical procedure and the aesthetic and functional result of the final crown. Score 0 indicates 'least agree' and score 10 indicates 'fully agree'.
Time frame: at intake, after extraction, after implant placement, and 2 weeks, 1 year, 3 years, 5 years and 10 years after placement of the final crown
Chair Time
Chair time in minutes
Time frame: At all surgical procedures (extraction, ARP, implant placement)
Costs
Costs in euros
Time frame: After 10 years of loading
Implant success
Absence of mobility, absence of persistent subjective complaints (pain, foreign body sensation and/or dysesthesia), absence of recurrent peri-implant infection with suppuration, absence of a continuous radiolucency around the implant, the annual vertical bone loss should not exceed 0.2 mm after the first year of service which should not exceed 1.5 mm, no pocket probing depth (PPD) of 5 mm or more with bleeding on probing (BOP) and no PPD of \>5 mm.
Time frame: From one year after implant placement until 10 years of loading
Keratinized mucosal width (KMW)
The width of the attached mucosa on the buccal side measured in the middle of the crown
Time frame: 1-4 weeks, 1 year, 3 years, 5 years and 10 years after placement of the final crown.
Pocket probing depth (PPD)
The distance between the marginal gingival border and the tip of the pocket probe inserted against the implant (mesiobuccal, buccal, distobuccal, mesiopalatal, palatal, distopalatal)
Time frame: 1-4 weeks, 1 year, 3 years, 5 years and 10 years after placement of the final crown
Bleeding on probing (BOP)
Dichotomously (yes/no) at the mesiobuccal, buccal, distobuccal, mesiopalatal, palatal, distopalatal side of the implant.
Time frame: 1-4 weeks, 1 year, 3 years, 5 years and 10 years after placement of the final crown
Surgical complications (swelling, dehiscence, haemorrhage, infection)
swelling (0= no visible oedema, 1 =slight oedema, 2= moderate oedema, 3= severe oedema), mucosal dehiscence (no dehiscence /small dehiscence of less than 2 mm/extensive dehiscence of more than 2mm) haemorrhage (absent/present) and infection (absent/present).
Time frame: 2 weeks post extraction and implant placement
Marginal bone levels (MBL)
Changes in marginal bone level
Time frame: Post implant placement and 1, 3, 5 and 10 years after placement of the final crown.
Volumetric changes of the bone
Volumetric changes of the bone in percentage
Time frame: after extraction, before implant placement, 1 year, 3 years, 5 years and 10 years after placement of the final crown
Orofacial Esthetic Scale (OES-NL)
Orofacial Esthetic Scale in Dutch(OES-NL) questionnaire assessing the esthetics of the teeth. Score 0 indicates very unsatisfied and score 10 indicates highly satisfied.
Time frame: 2-4 weeks after placement, and 1, 3, 5 and 10 years after loading of the final crown
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