Volumetric changes and graft stability after lateral window sinus floor augmentation: A randomized clinical trial.

INTRODUCTION: The present investigation compared the stability and volumetric changes of two different grafting material used for lateral window sinus floor augmentation (LWSFA). METHODS: Sixteen patients with a total 20 maxillary sinuses in need of LWSFA were included in the present study. The sinuses were grafted with either 100% anorganic bovine bone mineral (ABBM) alone (Group 1) or a mixture (0.8:1 ratio) of ABBM and mineralized cortical allograft (MCA) (Group 2). Cone beam computer tomography (CBCT) was obtained pre-operatively, and at 2-weeks, and 6-months after LWSFA to perform linear measurements including lateral window dimensions, sinus anatomy, residual bone height/thickness (RBH/RBT), and Schneiderian membrane thickness (SMT), among others. Three-dimensional segmentation analysis was used to evaluate changes of bone graft volume/height (GV/GH). RESULTS: A total of 10 sinuses per group were included in the analysis. No statistically significant difference was found in between groups regarding mean reduction of GV (Group 1: 14.87% ± 16.60%, Group 2: 18.06% ± 9.81%, p = 0.33). Among the linear measurements, only SMT revealed a significant increase after 2-weeks more pronounce in Group 1 (8.70 mm) when compared with Group 2 (5.70 mm) with plausible effect upon LWSFA outcomes. Sinus width showed weak positive correlation with GH reduction after 6 months. CONCLUSION: This study demonstrated that both ABBM alone and ABBM + MCA represent suitable alternatives for LWSFA with adequate graft stability as they revealed similar volumetric and linear dimensional changes 6 months postoperatively.

Incidence of nasopalatine canal perforation in relation to virtual implant placement: A cone beam computed tomography study.

BACKGROUND: The nasopalatine canal (NPC) is of special importance when considering implant therapy in the maxillary central incisors' region. PURPOSE: To investigate the incidence of NPC perforation in relation to virtual immediate implant placement. MATERIALS AND METHODS: A search through the cone beam computed tomography (CBCT) database of The University of Oklahoma-College of Dentistry was conducted. First, canal related measurements were conducted. Second, digital prosthetic planning was performed. Then, immediate implants were virtually placed and additional measurements were performed. Perforation rate was assessed. Last, data obtained was statistically analyzed. RESULTS: A total of 217 scans fulfilled the inclusion criteria. Only 8% of cases showed NPC perforation. The perforation occurred at mid-third of the implant or at the mid and apical third in 33% and 22% of the cases, respectively. A statistically significant association was found between perforation of NPC and bone width palatal to the root of the central incisor (P < .0001) as well as canal angulation (P = .0196). NPC angulation (°) and palatal bone width (mm) predisposed to a higher risk of perforation. Only 27.78% of the perforations could be overcome by the installation of shorter implants. CONCLUSIONS: Low incidence of NPC perforation could be expected when immediately placing implants in the maxillary incisor region.

Influence of Microtextured Implant Surfaces on Peri-implantitis and Its Treatment: A Preclinical Trial.

PURPOSE: The prevalence of peri-implantitis has increased significantly, forcing clinicians to search for ways to prevent it. Laser-microtextured surfaces promote soft tissue attachment and provide a tight seal around implants. Hence, the aim of this study was to examine the clinical, radiographic, and histologic features of ligature-induced peri-implantitis, as well as the effect of surgical treatment of these induced peri-implantitis lesions on laser-microtextured implants in a controlled animal model. MATERIALS AND METHODS: Six mini-pigs (three males/three females) received 6 implants each (3 resorbable blast textured [RBT] implants and 3 laser-microtextured [LM] implants) in mandibular premolar sites, for a total of 36 implants. Two groups were identified based on the time point of sample analysis. After osseointegration was achieved, metal wire ligatures were placed and left for 12 weeks. Group 1 samples were then obtained, and group 2 samples received rescue therapy following a guided bone regeneration (GBR) protocol. Sample collection in group 2 was completed 12 weeks after the samples were submerged and treated. All samples were analyzed histologically and measurements were taken. RESULTS: Four implants (three RBT, one LM) were lost at early time points because of implant instability. Interimplant distances and soft tissue thicknesses varied subtly between groups. More notable was the mean (± standard error of the mean) crestal bone loss (group 1: 1.860 ± 1.618 mm [LM] and 2.440 ± 2.691 mm [RBT]; group 2: 2.04 ± 1.613 mm [LM] and 3.00 ± 2.196 mm [RBT]) (P < .05), as demonstrated by a paired t test. Histologic pocket depth was also greater at RBT sites than at LM sites (4.448 ± 2.839 mm and 4.121 ± 2.251 mm, respectively, in group 1; and 3.537 ± 2.719 mm and 2.339 ± 1.852 mm, respectively [P < .005] in group 2). CONCLUSION: LM implants had less crestal bone loss and shallower histologic pocket depth compared with their RBT counterparts. Also, LM implants had higher bone fill when a rescue therapy (GBR) was performed.

Surgical periodontal therapy with and without initial scaling and root planing in the management of chronic periodontitis: a randomized clinical trial.

AIM: To compare the outcomes of surgical periodontal therapy with and without initial scaling and root planing. METHODS: Twenty-four patients with severe chronic periodontitis were enrolled in this pilot, randomized controlled clinical trial. Patients were equally allocated into two treatment groups: Control group was treated with scaling and root planing, re-evaluation, followed by Modified Widman Flap surgery and test group received similar surgery without scaling and root planing. Clinical attachment level, probing depth and bleeding on probing were recorded. Standardized radiographs were analysed for linear bone change from baseline to 6 months. Wound fluid inflammatory biomarkers were also assessed. RESULTS: Both groups exhibited statistically significant improvement in clinical attachment level and probing depth at 3 and 6 months compared to baseline. A statistically significant difference in probing depth reduction was found between the two groups at 3 and 6 months in favour of the control group. No statistically significant differences in biomarkers were detected between the groups. CONCLUSIONS: Combined scaling and root planing and surgery yielded greater probing depth reduction as compared to periodontal surgery without initial scaling and root planing.

Ridge width gain with screw spreaders: a cadaver study.

BACKGROUND: The aim of this cadaver study was to evaluate the amount of ridge expansion with screw spreaders. METHODS: Eleven edentulous maxillae providing 20 eligible sites were used. Ridges with initial width of 3 to 6 mm were expanded using a set of 6 screw spreaders, and implants (ø3.7 × 10 mm) were subsequently placed. Ridge width at 2 mm apical to the crest was measured at the baseline, after expansion, and implant placement. Buccal plate thickness and incidence of buccal dehiscence after implant placement were measured. RESULTS: The mean initial ridge width was 3.97 ± 0.82 mm. After the expansion, the mean ridge width increased to 4.76 ± 0.77 mm (Δ = 0.79 mm). Majority of sites (7/9 sites) with an initial ridge width of <4 mm had a buccal dehiscence after implant placement. A buccal plate thickness of ≥1 mm was consistently present in cases with an initial ridge width of ≥4.5 mm after implant placement. CONCLUSIONS: The screw spreaders had a modest effect on ridge expansion. Their use might be limited because additional bone augmentation might be required to prevent or correct the bony dehiscence encountered in ridges <4.5 mm wide. Therefore, using this particular instrument kit for horizontal ridge augmentation is only indicated in specific cases.

Effect of flapless surgery on single-tooth implants in the esthetic zone: a randomized clinical trial.

BACKGROUND: Implant therapy is a highly predictable treatment option; however, insufficient data exist to show whether flapless implant surgery provides better esthetic outcomes and less bone loss than implant surgery with a flap approach. METHODS: In this randomized, controlled study comparing the flapless and traditional flap protocol for implant placement, 24 patients received a single implant in the anterior maxillary region. A cone beam computed tomography-aided surgical guide was used for implant placement surgery for both groups. Implants were restored using a one-piece, screw-retained ceramic crown at 3 months. Radiographic and clinical measurements were assessed at baseline (implant placement) and at 3 (crown placement), 6, 9, and 15 months. Clinical parameters evaluated were plaque index, gingival index, papillary index (PPI) (0 = no papilla, 1 = less than half, 2 = more than half but not complete, 3 = complete fill, and 4 = overfill), marginal tissue levels, biotype, width of keratinized tissue, and soft tissue thickness. RESULTS: Implant success rate was 92% in both groups. Mean PPI values for the flap control group and flapless test group were 2.38 ± 0.51 versus 2.31 ± 0.48 at crown placement (P = 0.68) and 2.52 ± 0.52 versus 2.64 ± 0.54 at 15 months (P = 0.42), respectively. PPI increased over time in both groups, although the flapless group had a significantly larger change in PPI from crown placement to 6 and 9 months (P <0.01). Crestal bone levels in the flap group were more apical in relation to the implant platform than those in the flapless group for the duration of the study. No differences among groups were noted for all other measurements. CONCLUSIONS: Both flapless and flap implant placement protocols resulted in high success rates. A flapless protocol may provide a better short-term esthetic result, although there appears to be no long-term advantage.

Influence of thread design on implant positioning in immediate implant placement.

BACKGROUND: It is generally believed that implants placed in extraction sockets have a tendency to shift in the facial direction during insertion. The purpose of this study is to investigate the effect of different thread designs on the final implant position in immediate implant placement. METHODS: In a split-mouth design involving 11 cadaver heads, each specimen received two implants, one with a square and one with a V-shaped thread design, in maxillary incisor extraction sockets. The facio-lingual locations of the drills and the implant were tracked, and the displacements were compared between the two groups. RESULTS: No statistically significant differences were observed between the square and V-shaped thread design groups. The mean displacements of the different groups showed a general tendency of the implants to be positioned facially compared with the initial drill trajectory. This tendency was greater for implants with square thread design. CONCLUSION: There was no significant effect of implant thread design on the positioning of implants in extraction sockets.

Prosthodontic management of an irradiated maxillectomy patient with severe trismus using implant-supported prostheses: a clinical report.

Trismus and limited oral access present a clinical challenge to prosthodontic management. An edentulous patient who developed microstomia after a maxillary tumor resection and radiation therapy is presented. The clinical procedure and the rationale for the treatment approach are discussed. Implanted-supported prostheses were prescribed for this patient.