Minimal Bone Height Research Articles

The Effect of Laser Grooved Implant Retained Overdenture on Bone Height Changes

ABSTRACT Purpose: The aim of the study was to evaluate the crestal bone height changes around laser grooved implants with mandibular overdenture. Materials and Methods: The study sample comprised of 10 completely edentulous male patients with age range between 40-60 years. In each patient, two laser grooved implants were placed in the interforaminal area. Implants were exposed after three months of healing, and ball abutments were used to retain the mandibular dentures. Crestal bone changes were evaluated using long cone paralleling technique after 0, 6 and 12 months. Data were collected, tabulated and statistically evaluated. Results: The results showed that mean change in marginal bone height throughout the 12 months follow-up period was 1.12 mm. T-test showed insignificant difference regarding effect of time on bone height changes from baseline to 6 months, from 6 months to 12 months, and from baseline to 12 m as P > 0.05, Conclusion: From the results of this study, it could be concluded that laser grooved implant retained overdenture showed minimal bone height changes after 1 year from prosthetic loading.

Bone formation following sinus grafting with an alloplastic biphasic calcium phosphate in Lanyu Taiwanese mini-pigs.

To evaluate the new bone formation after grafting with a synthetic biphasic calcium phosphate in sinuses with minimal bone height, the alloplastic and xenograft materials were compared after grafting into Lanyu Taiwanese mini-pig sinuses via split-mouth design. In six mini-pigs, synthetic hydroxyapatite/tricalcium phosphate (HA/TCP) particles were inserted into one of the sinus cavities using the extra-oral approach, where deproteinized bovine bone mineral (DBBM) particles were placed contralaterally. Fluorescent bony labels of Alizarin and Calcein green were delivered at weeks 4 and 8, respectively. Animals were sacrificed at week12 and the augmented tissues were evaluated by cone-beam computed tomography, microcomputed tomography, and histology. By radiographic examination, the mean thicknesses of sinus cortexes for DBBM and HA/TCP groups were similar (0.35versus 0.38cm) and the mean volumes augmented were also indifferent (1.29versus 1.64 cm3 ). The distributions of bones, residual particles, and non-mineralized tissues in augmented masses between groups were undistinguishable. Under microscopy, however, macroporosities of osteons were filled with HA/TCP residual particles, whereas the newly formed bones lay on top of DBBM particle surfaces. Although the mineral deposition rates between groups were indifferent, the mean labeled surface in the HA/TCP group was significantly greater than those in the DBBM group at week4 (35.16%versus 14.00% for HA/TCP and DBBM, respectively) but less than that at week8 (19.33%versus 39.16%, respectively). Sinus augmentation with synthetic HA/TCP and DBBM exhibited similar effectiveness in new bone formation.

Long-Term Effects of Bone Morphogenetic Protein-2-Loaded Calcium Phosphate on Maxillary Sinus Lift Surgery for Delayed and Simultaneous Dental Implantation.

Maxillary sinus lift surgery (MSLS) is considered to be a useful treatment method for patients with atrophic alveolar bone. Choosing a suitable surgical procedure to simultaneously decrease graft absorption and obtain long-term survival of dental implants is still a challenge. In this study, 20 patients received MSLS with graft of bone morphogenetic protein 2 (BMP2)-loaded calcium phosphate. Dental implants were placed simultaneously in 10 patients receiving MSLS (1-stage group), and in 10 patients receiving dental implants with a 3 to 6 months delay (2-stage group). The effects were evaluated based on clinical and radiographic examination during a 4 to 5 years follow-up. The results showed that only 1 perforation of the maxillary sinus mucosa was observed in 1-stage group, and was patched with a collagen membrane. An average bone gain of 6.8 mm was observed, and all implants exhibited no looseness, peri-implantitis, or fracture, all of which were stable during the follow-up and exhibited nice dental function during a 4 to 5 years follow-up. The loss of peri-implant bone height was 1.12 ± 0.47 and 1.10 ± 0.39 mm, the probing depth of periodontal pocket was 1.79 ± 0.62 and 1.81 ± 0.71 mm, the sulcular bleeding index was 1.63 ± 0.47 and 1.72 ± 0.54 in 1-stage group and 2-stage group, respectively, and no significant differences existed between these 2 groups. These findings implied that BMP2-loaded calcium phosphate may be a suitable material for MSLS, especially for patients with minimal bone height. Clinicians can use the 1- or 2-stage technique based on clinical condition, patients' choice and clinicians' experience. In patients where implants cannot be stabilized for patients with minimal bone height, 2-stage surgery may be more suitable.

Effect of platelet-rich plasma in alveolar distraction osteogenesis: a controlled clinical trial

We have evaluated the effect of the use of platelet-rich plasma in alveolar distraction osteogenesis. Fourteen patients who were partly edentulous in the anterior premaxilla region were selected and randomised into two groups (n=7 in each group). Those in the experimental group were give platelet-rich plasma at the time of distraction, and the control group had only distraction. Selected cases had defects in the alveolar ridge of more than 3mm, and a minimal bone height of 7mm from the alveolar ridge crest to important anatomical structures. The plaque index and gingival index were recorded on days 3, 7, 14, 21, 28, 45, 60, 75, 90, and 105 postoperatively. There was a strong negative correlation between the gingival index and augmentation of bone, and a strong positive correlation between the mean gingival index and loss of bone from the transported segment. The addition of platelet-rich plasma had a protective effect on the mucosa around the distractor, which decreased the potential for complications.

Is furcation involvement in maxillary molars a predictor for subsequent bone augmentation prior to implant placement? A pilot study

The aim of this pilot study was to analyze the interfurcal bone height in relation to the possible need for subsequent sinus floor elevation in patients with advanced periodontitis and furcation involvement of first and/or second maxillary molars. Seventeen dentate patients, who received cone beam computed tomography (CBCT) for detailed preoperative diagnosis and planning of surgical interventions at periodontally involved maxillary molars (17 first and 15 second molars), were consecutively recruited for the study. The minimal bone height in the interfurcal region was measured from CBCT and related to furcation involvement, residual bone above the root tips, and the clinical probing pocket depth (PPD). The minimal interfurcal bone height measured 4.1 ± 2.6 mm on average with 75% of maxillary molars having ≤ 6 mm and almost 60% having only ≤ 4 mm bone height left below the sinus floor. A higher risk for reduced interfurcal bone height of ≤ 4 mm was given when residual PPD of ≥ 6 mm was remaining at two or more tooth sites (OR 0.10; 0.11). The majority of periodontally involved maxillary molars had a substantially reduced interfurcal bone height, particularly with at least two sites with residual PPD ≥ 6 mm. This was a predictor for a subsequent need for sinus floor elevation when tooth replacement with a dental implant is desired.

Vertical splitting of the mandibular body as an alternative to inferior alveolar nerve lateralization

The aim of this study was to present and evaluate a modified technique to inferior alveolar nerve lateralization (IANL) that allows the placement of longer implants in the posterior mandibular region. One hundred and forty-three consecutive patients were enrolled in this study; these patients had between 1.8 and 8mm residual crestal height above the mandibular canal. Vertical splitting of the mandibular body was performed using piezoelectric surgery followed by bone expansion and insertion of special conical implants of 10 and/or 12mm in length. Two hundred and sixty-nine osteotomies were performed and 636 implants were inserted, with a survival rate of 99% at the end of 12 months. Immediately postoperative there was an alteration of sensation in the lip/chin area in 8.5% of cases; 4.1% regained full sensation within 10–14 days, 2.6% after 8 weeks, and 0.7% had persistent paresthesia that did not affect their daily activities. Progressively increasing pain and numbness was present in 1.1%; the implants were removed 6 months postoperatively. This is a relatively simple procedure that has no limitations in clinical situations with minimal bone height. It allows for greater implant stability, and the risk of neurological disturbance is minimal.

The eligibility of the free fibula graft for masticatory rehabilitation using monocortical implants insertion—a morphologic and biomechanical study

The use of the vascularized fibula graft has already been established for reconstruction of the mandible following ablative surgery. In order to reconstruct the vertical height of the alveolar process and improve implant position as well as angulation, some therapeutic options are available, including primary use of the fibula as a double-barrel graft and vertical distraction as well as later augmentation with avascular bone grafts. We analyzed the anatomic and morphologic features in 40 fibula bones of 20 cadavers and provided the mean cortical thickness of different transplant sites. Furthermore, we investigated the primary implant stability of dental implants inserted monocortically in harvested fibula segments using established biomechanical methods as well as Periotest(®). The minimal bone height of the clinically relevant segments of the fibula transplant measured 9.06 ± 0.45 mm, which was assessed in the most distal part. In contrast, a maximal total bone height of 15.46 ± 0.78 was observed in the middle segment of the fibula bone. We assessed sufficient primary stability in all inserted implants as well as a reliable relative micro-movement of the implants in the fibula bone. Fibula graft as a single-barrel graft alone may provide through monocortical implant insertion a further refinement of the method to fit complex requirements and shorten prolonged therapeutic procedures. Monocortical implant insertion in the fibula graft would simplify oral rehabilitation after ablative surgery of the jaw and reduce costs as well as therapy period.

RESIDUAL ALVEOLAR RIDGE RESORPTION IN COMPLETELY EDENTULOUS PATIENTS INFLUENCED BY PATHOPHYSIOLOGIC FACTORS: RESORPSI TINGGI TULANG ALVEOLAR PADA PASIEN TIDAK BERGIGI YANG DIPENGARUHI OLEH FAKTOR PATOFISIOLOGI

Residual ridge resorption and remodeling directly affect the function of removable prostheses which relies greatly onthe quantity and architecture of jaw bones. The purpose of this study was to assess the remaining bone height level inrelation to some pathophysiologic factors that may affect on the resorption process. The factors involved in this studywere Diabetes mellitus, periodontitis, menopause, and edentulousness time (more than 10 years). Maxillary andmandibular bone height on 115 dental panoramic radiographs belonged to full edentulous patients were measured andcompared to 35 controls using MB Ruler software. The soft images were collected using the radiographic machines inthe faculty of dentistry. The measurements included maxillary middle anterior and lateral bone heights, middlemandibular dimension, right and left mental bone heights. The results showed that women with completely edentulousarches showed relatively higher rate of bone resorption than men, and control group. Indian patients also demonstratedhigher bone resorption rate, particularly on the mandible, followed by Chinese and Malay. In regard to different healthconditions, edentulousness time for more than 10 years showed the minimal bone height reduction that affected mainlythe mandible sides compared to other conditions and the control group. On the sides of maxilla, periodontitis exhibitedhigher effect on the residual ridge resorption rather than other studied conditions. However, on the middle of maxilla,menopause was associated with maximum bone resorption compared to the others. As conclusions, residual ridgeresorption in completely edentulous patients may be influenced by gender, race and patient’s health conditions.

Gradual and safe technique for sinus floor elevation using trephines and osteotomes with stops: a cadaveric anatomic study

The aim of this study was to develop a new technique for maxillary sinus floor elevation through the crestal approach, using trephines and osteotomes with stops, and to assess the risk of sinus membrane lesion. The study was performed on 30 heads removed from fresh nonpreserved cadavers with subsinus bone height >or=5 mm. The anatomic specimens were sectioned axially on a plane passing 1 cm below the infraorbital foramen, to be able to see and film the sinus floor covered by the membrane. A total of 112 implants were placed using this technique (48 without grafting material and 64 with grafting material). Using this technique, we obtained a 4-6 mm elevation of the sinus membrane without impairing the mucosa. In the 13 cases where membrane lesions were observed, 9 had been performed without grafting material. The greater the initial subsinus bone height, the higher the elevation observed. The success of this technique was due to stops on the trephines and osteotomes, which reduced the risk of invading the sinus cavity and made it possible to lift the membrane gently, fully controlling movements. This technique is indicated for large crests of type III or IV bone and with a minimal bone height of 5 mm.

Use of zygomatic implants to deal with resorbed posterior maxillae.

For some 40 years, osseointegration has been clinically applied in both the maxilla and the mandible. With a high predictability for some systems (19), increased applications have been developed for compromised patients. Unfortunately, restrictions have appeared in the use of oral implants. One of them is the lack of sufficient bone volume, especially in the posterior maxilla. This insufficient bone volume can be due to bone resorption as well as to pneumatization of the sinus or to a combination of both. In any case, insertion of implants in this region remains extremely unpredictable. According to some clinical reports, the minimal bone height for a standard implant in the posterior region should be at least 10 mm (33) to ensure acceptable success rate. This is confirmed by a retrospective study of 660 implants using the Branemark system in the posterior maxilla followed for 5– 12 years showing a cumulative success rate of 94.4% but with a loss of 10 implants on 49 implants with a length of 7 mm and a diameter of 3.75 mm (22). With the introduction of wide implants 5 and 6 mm in diameter (17, 18) the contact surface between implant and bone is increased and assumes a cortical anchorage with an initial stability in bone type IV even if the bone height is no greater than 6 mm. Implants of wide diameter limit the biomechanical complications in the treatment of the posterior maxillas. Pterygomaxillary implants have also been proposed for posterior anchorage in totally edentulous patients (3). Although wide implants could be a solution for crestal heights up to 6 mm, many patients present a maxillary height of 0.8–6 mm (39). For these cases, several solutions have been proposed to augment the volume of bone in this region, such as onlay/inlay bone grafting (33). Although autologous bone grafting remains the gold standard, different types of grafting materials have been proposed for these procedures: demineralized bone from human cadavers, bovine bone and synthetic materials. Although many have claimed good clinical results, there is insufficient long-term data from histologic and histomorphometric investigations to provide real guidelines for these procedures. Contraindications for sinus lifting (33), such as Caldwell Luc operations, Underwood’s septae, severe sinus floor convolutions and narrow sinuses, limit the use of this clinical technique. Perforation of the Schneidarian membrane could also jeopardize the final result. The gold standard for sinus-lifting procedures uses autogenous bone (25) but bone harvesting is most often performed under general anesthesia and, as in a majority of these cases these procedures necessitate a two-stage since surgery, since the implants are not inserted at the moment of the bone grafting. Complications like sinusitis or loss of grafts have also been described with the sinus graft technique. Final results (15) show a success rate of up to 75% for the sinus-lifting procedure together with simultaneous insertion of implants and it is recommended to avoid this one-stage procedure.

Use of a tapered, porous-surfaced dental implant in combination with osteotomes to restore edentulism in the difficult maxilla.

The maxilla is the more difficult arch to restore with endosseous dental implants because of hurdles such as low bone density, narrow buccopalatal width, minimal bone height, and proximity to the maxillary sinus. In this article, a technique to resolve all of these problems using a short, tapered, porous-surfaced implant and a placement protocol using hand osteotomes rather than surgical burs is presented.