Five-year outcome of bone remodelling around implants in the maxillary sinus: assessment of differences between implants placed in autogenous inlay bone blocks and in ungrafted maxilla

The influence of vertical ridge augmentation techniques on peri-implant bone loss: A systematic review and meta-analysis

INTRODUCTION

The primary aim of this systematic review was to investigate and compare the outcomes of different vertical ridge augmentation (VRA) techniques in relation to peri-implant bone loss (PBL), after at least 12 months of functional loading.

MATERIAL AND METHODS

The search was conducted to find all the studies about VRA and measurements of PBL with at least 12 months follow-up. Three pairwise meta-analysis (MA) was performed to completely evaluate the outcomes.

RESULTS

A total of 42 studies were included, of which 11 were randomized clinical trials (RCTs). RCTs were available only for guided bone regeneration (GBR), onlay, and inlay techniques. The weighted mean estimate (WME) of PBL value was found to be 1.38 mm (95% confidence interval [95% CI]: 1.10-1.66) after a mean follow-up of 41.0 ± 27.8 months. GBR, Inlay, Onlay, osteodistraction, and SBB represented in weight 32.9%, 30.6%, 25.0%, 7.6%, and 3.9%, respectively; and their WME (95% CI) were 1.06 (0.87-1.26) mm, 1.72 (1.00-2.43) mm, 1.31 (0.87-1.75) mm, 1.81 (0.87-1.75) mm, and 0.66 (0.55-0.77) mm, respectively. Among the secondary outcomes, the analysis was conducted for vertical bone gain, healing complication rate, surgical complication rate, implant survival, and success rate.

CONCLUSIONS

The primary findings of the meta-analysis, based on the changes between final and baseline values, showed that the peri-implant bone loss could be influenced by the type of intervention but there is a need to evaluate in RCTs the behavior of the peri-implant bone levels after long-term follow-up for all techniques.

15-Year Retrospective Study on the Success Rate of Maxillary Sinus Augmentation and Implants: Influence of Bone Substitute Type, Presurgical Bone Height, and Membrane Perforation during Sinus Lift

Objectives

To evaluate the success rate of bone grafts and implants carried out at the Latin American Institute for Research and Dental Education (ILAPEO), considering the following: (i) the different pure bone substitutes (autogenous, xenogeneic, and alloplastic), (ii) the presurgical bone height, and (iii) how the treatment is compromised when membrane perforation occurs during sinus lift in maxillary sinus surgeries. Material and Methods. The initial sample comprised 1040 records of maxillary sinus lifting surgeries. After evaluation, the final sample retained 472 grafts performed using the lateral window technique with a total of 757 implants. The grafts were divided into 3 groups: (i) autogenous bone (n = 197), (ii) xenogenous bovine bone (n = 182), and (iii) alloplastic material (n = 93). One calibrated examiner classified the sample into two groups based on the residual bone height (<4 mm and ≥4 mm) of the area of interest measured on parasagittal sections of tomographic images. Data on membrane perforation occurrences in each group were collected; qualitative variables were described using frequency, expressed as percentages. The Chi-square test was used to analyze the success of the graft types and the survival rate of the implants as a function of the grafted material and the residual bone height. The Kaplan-Meier survival analysis was used to calculate the survival rate of bone grafts and implants according to the classifications adopted in this retrospective study.

Results

The success rate of grafts and implants was 98.3% and 97.2%, respectively. There was no statistically significant difference in the success rate among the different bone substitutes (p = 0.140). Only 8 grafts (1.7%) and 21 implants (2.8%) failed. There was a greater success rate for both grafts (96.5%) and implants (97.4%) when the bone height was ≥4 mm. The success rate in the 49 sinuses in which the membrane was perforated was 97.96% for the grafts and 96.2% for the implants. The follow-up periods after rehabilitation ranged from 3 months to 13 years.

Conclusions

Within the limitations of the data analyzed in this retrospective study, maxillary sinus lift was a viable surgical technique that enabled implant placement with a predictable long-term success rate, regardless of the type of material used. The presence of membrane perforation did not interfere with the success rate obtained for grafts and implants.

Changes in Maxillary Sinus Mucosal Thickening following the Extraction of Teeth with Advanced Periodontal Disease: A Retrospective Study Using Cone-Beam Computed Tomography

Objectives

To explore the alterations in maxillary sinus mucosal thickening after extracting teeth with severe periodontal disease using cone-beam computed tomography (CBCT).

Methods

30 patients with severe periodontal disease of maxillary posterior teeth that needed to be extracted and who were radiographically diagnosed with mucosal thickening (MT) in the maxillary sinus participated in the study. CBCT scans were taken before tooth extraction and 2-29 months after tooth extraction. The postextraction follow-up time was divided into two groups: group 1 (<4 months) and group 2 (≥4 months). Dimensions of maxillary sinus MT, including the MT zone length (SL) and the maximum thickness of the MT zone (ST), were evaluated preextraction and postextraction; the residual ridge height (RRH) was evaluated at the sites of extracted and nonextracted teeth.

Result

Of the 24 patients with unilateral tooth extraction, there was a statistically significant difference in MT between the extraction and nonextraction sides (p < 0.05). The RRH at the site of the extracted teeth was significantly lower than that of the nonextracted teeth (p < 0.05). MT decreased significantly after tooth extraction on the extraction side but not on the nonextraction side. There was no significant difference between group 1 and group 2 regarding the reduction in mucosal thickness over time.

Conclusions

Severe periodontitis can cause MT in the maxillary sinus. The RRH was lower at the sites of extracted teeth. MT reduced quickly by a thorough debridement after tooth extraction in 4 months. MT will not decrease further over time.

Dimensional changes following alveolar ridge preservation in the posterior area using bovine-derived xenografts and collagen membrane compared to spontaneous healing: a 6-month randomized controlled clinical trial

OBJECTIVES

To assess dimensional changes following alveolar ridge preservation using bovine-derived xenograft with 10% collagen and collagen membrane compared to ridge preservation by means of bovine-derived xenograft particles and collagen membrane or spontaneous healing in posterior sites.

MATERIALS AND METHODS

Forty subjects with 40 posterior teeth or roots candidate to extraction and presenting integrity of alveolar bone walls were randomly allocated into three groups. Patients of test group were treated by ridge preservation technique using bovine-derived xenograft with 10% collagen and collagen membrane; patients of control group 1 were treated by means of bovine-derived xenograft particles and collagen membrane while in patients of control group 2, no grafting was performed. Changes in vertical and horizontal bone dimensions were compared at baseline and after 6-month observation time.

RESULTS

Statistically significant differences between baseline and 6 month were observed in all groups in terms of vertical and horizontal bone resorption (p < 0.001), except for vertical resorption in control group 2. After 6-month intergroup comparisons showed not statistically significant changes between test and control groups in terms of alveolar bone changes (p > 0.05).

CONCLUSIONS

Within the limits of this study, the sites grafted using bovine-derived xenograft with 10% collagen in combination with a collagen membrane showed no statistical differences in terms of vertical and horizontal bone resorption compared to control groups.

CLINICAL RELEVANCE

Ridge preservation in posterior area failed to show clinically relevant benefits in sites presenting integrity of alveolar bone walls and adequate buccal bone wall thickness.

Effectiveness of a Piezoelectric-Assisted Distraction Osteogenesis Procedure for the Treatment of Ankylosed Permanent Front Teeth

A common complication of tooth replantation after traumatic avulsion is tooth ankylosis causing dental malpositioning, partial loss of function, tipping of adjacent teeth and worsening of aesthetics. The aim of this study is to evaluate the effects of a repositioning procedure of such ankylosed permanent front teeth by a distraction osteogenesis procedure. Five patients (mean age 13.4 years), with an ankylosed permanent front tooth in the anterior area, were enrolled in the present study. After the pre-operatory orthodontic preparation, each selected site was treated with single-tooth dento-alveolar block osteotomy surgery performed with a piezoelectric surgery device with ultrasonic cuts on the buccal side. Subsequently, a custom distraction device, made by a resin splint and a sector expansion screw, was set in such a way it delivered a force with direction and sense towards the planned position of the tooth as well as the osteotomy's incision. After a latency period of 14 days, the distraction of the dento-alveolar block was started with a rate of distraction of 0.8 mm per day. The average shift obtained by the ankylosed teeth was 7.8 ± 0.75 mm (±SD), and the ankylosed tooth was regularly positioned into the occlusion in 20.4 ± 1.85 days (±SD), with a slight relapse (±0.5 mm) observed after 1 year. This study indicates that a therapeutic approach combining piezoelectric surgery and orthodontic therapy may be useful for the treatment of ankylosed permanent teeth in the frontal area with a long-term follow-up over 5 years.

Efficacy of a drug composed of herbal extracts on postoperative discomfort after surgical removal of impacted mandibular third molar: a randomized, triple-blind, controlled clinical trial

OBJECTIVES

This study investigated and compared the effectiveness of a phytotherapeutic drug composed of herbal extracts on postsurgical discomfort after mandibular third molar surgery.

MATERIALS AND METHODS

Eighty-two patients requiring the surgical removal of a mandibular third molar were randomly assigned to receive placebo (group 1), ibuprofen (group 2), and a phytotherapeutic drug (composed of baicalin, 190 mg; bromelain, 50 mg; escin, 30 mg) (group 3). Drugs were administered after tooth extraction twice a day for 5 days. The primary outcome, pain, was evaluated using a visual analogue scale at 2 h, 6 h, 12 h, 24 h, 48 h, and 7 and 10 days after surgery. The secondary outcomes were the changes in maximum mouth opening and facial contours (mm) between baseline and at 24 h, 72 h, and 7 and 10 days after surgery.

RESULTS

Compared to the baseline, all treatments demonstrated an improvement in the primary and secondary outcomes. Moreover, compared to groups 1 and 2, patients in group 3 yielded a significant reduction of the postoperative pain score at 12 h (p < 0.001), 24 h (p = 0.010), and 48 h (p = 0.048) after surgery. The mean reduction of the swelling and trismus was similar between groups.

CONCLUSIONS

The results of this study suggest that a postoperative administration of a phytotherapeutic drug was found to be effective in postoperative pain management after the surgical removal of impacted mandibular third molars.

CLINICAL RELEVANCE

The phytotherapeutic drug composed of herbal extract determined a decrease in the severity of postoperative pain compared to ibuprofen and placebo.

Computed tomography-aided descriptive analysis of maxillary and mandibular atrophies

INTRODUCTION

The aim of the present retrospective chart review was to analyze by Computed Tomography (CT) scan technique the degree of maxillomandibular atrophies, searching for differences between totally- and partially-edentulous subjects, and possibly identify and classify maxillomandibular atrophy staged patterns for implant planning in both totally- and partially- edentulous jaws.

MATERIAL AND METHODS

CT scans of 89 mandibles and 77 maxillae from 111 patients were classified according to six different patterns of residual ridge resorption and to two different groups of edentulism (totally- and partially-edentulous). Maxillomandibular absolute linear dimensions were calculated and results compared for statistically significant differences by Wilcoxon tests.

RESULTS

Maxillomandibular CT cross-section interpretation showed different patterns of linear bone remodelling (height values) between the two groups of edentulism joined with specific positions in the maxilla or mandible. The judgment of the investigator was uncertain in the analysis of the mandibular posterior areas with similar percentages for both totally- and partially-edentulous groups (12.5% and 11.5%, respectively).

DISCUSSION

The 3D analysis is self-explanatory and easy to apply, aided by CT scans. The measurements between the referring planes and inviolable anatomical structures (nasal floor NFD, lower border of mandible LBD, inferior alveolar nerve AND, and sinus floor SFD), showed that class III may not guarantee an optimal implant placement, especially in the totally-edentulous group, due to a major degree of pneumatisation.

Craniofacial Tissue Engineering

The craniofacial complex is composed of fundamental components such as blood vessels and nerves, and also a variety of specialized tissues such as craniofacial bones, cartilages, muscles, ligaments, and the highly specialized and unique organs, the teeth. Together, these structures provide many functions including speech, mastication, and aesthetics of the craniofacial complex. Craniofacial defects not only influence the structure and function of the jaws and face, but may also result in deleterious psychosocial issues, emphasizing the need for rapid and effective, precise, and aesthetic reconstruction of craniofacial tissues. In a broad sense, craniofacial tissue reconstructions share many of the same issues as noncraniofacial tissue reconstructions. Therefore, many concepts and therapies for general tissue engineering can and have been used for craniofacial tissue regeneration. Still, repair of craniofacial defects presents unique challenges, mainly because of their complex and unique 3D geometry.

The Influence of Prosthesis Design on the Outcomes of Tooth Implants Immediately Placed and Loaded by Means of One-Piece Titanium Machined Restoration

Our purpose was to evaluate the occurrence of complications and the degree of bone loss in a cohort of patients treated with fixed prostheses supported by immediately loaded dental implants. The primary aim was to compare partial versus full-arch fixed dental prostheses. We then tested the effect of sinus lifting. In the present retrospective cohort study, the patients had their implants restored with fixed dental prostheses supported by dental implants positioned in the posterior maxilla and mandible. When necessary, the maxillary sinuses were grafted with particulate autogenous bone. Patients were then ranked according to the following predictors: length of prosthesis, crown-to-implant ratio, number of crowns to number of implants ratio, and presence of sinus lifting. Outcomes were evaluated for up to 2 years regarding the peri-implant marginal bone loss and implant/prosthesis survival rates. Fifty-eight subjects (209 implants) were rehabilitated with 25 fixed full-arch prostheses and 33 partial fixed dental implant bridges (16 supported by implants placed in grafted sinus). The mean marginal bone loss for implants supporting partial fixed dental prostheses amounted to 0.81 mm, whereas that for implants within the group of full-arch fixed dental prostheses was 1.21 mm; the comparison of the levels in the 2 groups showed a significant difference ( P = .0055). A statistically significant difference ( P = .0006) was found between the bone loss around maxillary implants (1.53 mm) and the bone loss around mandibular implants (1.10 mm). Two implants and 4 prostheses failed; 2-year survival rates of partial and of full-arch fixed dental prostheses, respectively, were 94.1% and 96%. Bone loss in full-arch prostheses appeared to be higher than in that of partial prosthesis. Implant-supported prostheses in the maxillae exhibited a bone loss higher than that registered in mandibles.

Early volumetric changes after vertical augmentation of the atrophic posterior mandible with interpositional block graft versus onlay bone graft: A retrospective radiological study

PURPOSE

The aim of this study was to evaluate volumetric and clinical outcomes of atrophic posterior mandibles treated with inlay or onlay bone grafting techniques.

MATERIALS AND METHODS

In posterior mandibles, alveolar ridges were treated either with interpositional equine cancellous bone block (inlay group) or with onlay autogenous bone block (onlay group). Bone volumes at baseline and at 4 months after surgery were measured by computed tomography.

RESULTS

A total of 20 subjects were enrolled in the present study: 10 in the inlay group and 10 in the onlay group. After surgery, atrophic posterior mandibles showed a mean vertical augmentation height of 6.0 mm in the inlay group and 7.4 mm in the onlay group. No significant differences were recorded between the two groups regarding volume loss of the grafted bone or decrease in vertical bone height of the augmented site (29% and 1.9 mm for the onlay group, and 35% and 1.7 mm for the inlay group) during healing. Two complications (1 wound dehiscence and 1 mandibular fracture) occurred postoperatively in the inlay group; on the other hand, the onlay group had three complications (wound dehiscence). A total of 80 dental implants were placed in augmented areas: 46 in the inlay group with a peri-implant marginal bone loss of 0.8 mm, and 34 in the onlay group with a peri-implant marginal bone loss of 1.3 mm (p = 0.0006).

CONCLUSIONS

Inlay xenogeneic grafts showed volumetric bone remodeling similar to that recorded for onlay autogenous bone. The success of the autogenous onlay blocks (82.4%) appeared to be lower than that registered for the inlay group (93.8%), but the difference was not significant.

Clinical and Histological changes after ridge preservation with two xenografts: preliminary results from a multicentre randomized controlled clinical trial

OBJECTIVES

To evaluate and compare clinical and histological changes after ridge preservation procedures with those of spontaneous healing.

MATERIALS AND METHODS

Ninety patients were enrolled in the present randomized controlled clinical trial and underwent single-tooth extraction in the premolar/molar areas. Thirty sites were grafted with collagenated cortico-cancellous (coll), 30 sites with cortical (cort) porcine bone and 30 sites underwent natural healing. Primary (vertical and horizontal bone changes after 3 months) and secondary outcomes (histomorphometric after 3 months) were evaluated at implant placement.

RESULTS

The vertical bone changes at the grafted sockets were significantly (p < 0.0001) lower (0.30 mm for cort group and 0.57 mm for coll group) when compared to non-grafted sockets (2.10 mm for nat group). Moreover, the width reduction of the coll (0.93 mm) and cort (1.33 mm) groups was significantly lower (p < 0.0001) than the non-grafted group (3.60 mm). The analysis of subgroups attested that when premolar and molar sites were compared, the buccal bone loss appeared to be dependent both on tooth position and grafting material employed.

CONCLUSION

The ridge preservation procedures had significantly better outcomes when compared to natural healing. The biomaterials did not differ for maintenance of bone width; even though, the bone height seemed to be better preserved with the cortical porcine bone.

Bilateral maxillary sinus floor augmentation with tissue-engineered autologous osteoblasts and demineralized freeze-dried bone

The pneumatization of the maxillary sinus often results in a lack of sufficient alveolar bone for implant placement. In the last decades, maxillary sinus lift has become a very popular procedure with predictable results. Sinus floor augmentation procedures are generally carried out using autologous bone grafts, bone substitutes, or composites of bone and bone substitutes. However, the inherent limitations associated with each of these, have directed the attention of investigators to new technologies like bone tissue engineering. Bone marrow stromal cells have been regarded as multi-potent cells residing in bone marrow. These cells can be harvested from a person, multiplied outside his body using bioengineering principles and technologies and later introduced into a tissue defect. We present a case where tissue-engineered autologous osteoblasts were used along with demineralized freeze-dried bone for sinus floor augmentation.

A retrospective analysis of the relationship between rhinosinusitis and sinus lift dental implantation

INTRODUCTION

Dental implants have been associated with the occurrence of postoperative rhinosinusitis. In some patients, preoperative sinus lifting must be performed to increase the chances of successful implant placement. This retrospective study examines the relationship of dental implants after sinus lifting with the occurrence of postoperative rhinosinusitis.

METHODS

A total of 268 dental implants were inserted in 94 patients (62 Males, 32 Females) between 2011-2013. The ages ranged from 29-71 (in males) and 33-64 (in females). Additionally, bilateral sinus lifing was performed in 51 patients, and unilateral sinus lifting was performed in 43 of the patients. Patients were evaluated for sinus pathology for a period of 5-47 months postoperatively using a satisfaction questionnaire, conventional radiographic examination, and nasal endoscopic examination.

RESULTS

Four of the patients (4.2%) had a complication of postoperative sinusitis and were treated medically. In one patient, the implant was unsuccessful (even after treatment) and was removed. None of the patients needed surgery due to the sinusitis or any associated complications.

CONCLUSION

The risk for postoperative rhinosinusitis was found to be higher in patients who suffer from chronic sinusitis and in cases in which a large amount of graft was utilized for sinus lifting. These predisposing factors need to be considered when evaluating patients for dental implants and sinus lift procedures.

Bone Forming Potential of An-Organic Bovine Bone Graft: A Cone Beam CT study

PURPOSE

An-organic bovine bone graft is a xenograft with the potential of bone formation. The aim of this study was to evaluate the bone density using cone beam computed tomography scans around functional endosseous implant in the region of both augmented maxillary sinus with the an-organic bovine bone graft and the alveolar bone over which the graft was placed to provide space for the implants.

MATERIALS AND METHODS

Sterile freeze dried bovine bone graft produced by National Tissue Bank, University Sains, Malaysia was used for stage-1 implant placement with maxillary sinus augmentation in a total of 19 subjects with 19 implants. The age of all subjects ranged between 40-60 years with a mean age 51±4.70. All subjects underwent a follow up CT scan using PlanmecaPromax 3D(®) Cone beam computed tomography scanner at the Radiology department, Hospital University Sains, Malaysia. The collected data was then analysed to evaluate bone density in Hounsfield Units using PlanmecaRomexis" Imaging Software 2.2(®) which is specialized accompanying software of the cone beam computed tomography machine.

RESULTS

There was bone formation seen at the site of the augmented sinus. A significant increase (p<0.005) in bone density was reported at the augmented site compared to the bone density of the existing alveolar bone.

CONCLUSION

An-organic bovine bone graft is an osteoconductive material that can be used for the purpose of maxillary sinus augmentation.