David Peñarrocha

Systemic risk factors for peri-implant bone loss: a systematic review and meta-analysis

The aim of this study was to determine the influence of patient-related systemic risk factors (systemic disease, genetic traits, chronic drug or alcohol consumption, and smoking status) on peri-implant bone loss at least 1 year after implant installation and prosthetic loading. An electronic search was performed of MEDLINE, EMBASE, and The Cochrane Central Register of Controlled Trials up to January 2012. One thousand seven hundred and sixty-three studies were identified. After applying a three-stage screening process, 17 articles were included in the qualitative analysis, but only 13 in the quantitative analysis, since smoking was a common exposure. The meta-analysis of these 13 studies (478 smokers and 1207 non-smokers) revealed a high level of heterogeneity and that smoking increases the annual rate of bone loss by 0.164 mm/year. Exposure to smoking had a harmful effect on peri-implant bone loss. However, the level of evidence for oral implant therapy in patients with systemic conditions is very low. Future studies should be improved in order to provide more robust data for clinical application.

Implants Placed in the Nasopalatine Canal to Rehabilitate Severely Atrophic Maxillae: A Retrospective Study With Long Follow-up

To assess the survival rate of implants placed in the nasopalatine canal for the rehabilitation of patients with atrophic maxillae and the level of satisfaction of these patients. A retrospective study was performed between 2000 and 2009 of patients with severe atrophy of edentulous maxillae (Cawood and Howells class V) rehabilitated with implant-supported prostheses with 1 implant placed in the nasopalatine canal. A preoperative computed tomography scan was obtained of all patients and all surgeries were performed by the same surgeon. The following parameters were assessed: neurosensory status of the anterior palate (using the pointed/blunt discrimination method); implant success rate according to criteria described by Albrektsson et al; patient satisfaction with the prosthetic treatment (using visual analogue scales). Thirteen patients with a mean age of 54.8 years were treated, 5 men and 8 women. Seventy-eight implants were placed: 13 in the nasopalatine canal, 6 in the zygomatic bone, 12 in the pterygomaxillary region, 2 in the frontomaxillary buttress and 45 in other locations. Six patients reported a slight decrease in sensitivity in the anterior palate after surgery, which disappeared in all cases within a few weeks. Two early failures (before prosthetic loading) and no late failures (after prosthetic loading) of nasopalatine implants were recorded, yielding a success rate for these implants of 84.6% after a mean follow-up of 70 months (range 24 to 132 months. High patient satisfaction with the prosthetic restoration was generally achieved in terms of comfort, stability, function, esthetics, and ease of cleaning. Residual bone is associated with the nasopalatine canal, even in patients with severe maxillary atrophy. This canal may be considered a possible location for an anterior implant when rehabilitating atrophic patients using implant-supported prostheses.

Piezoelectric vs. conventional drilling in implant site preparation: pilot controlled randomized clinical trial with crossover design

OBJECTIVE To compare implant stability throughout osseointegration, peri-implant marginal bone loss, and success rates of implants placed with conventional and mixed drilling/piezoelectric osteotomy. MATERIALS AND METHODS A pilot randomized-controlled trial was performed on 15 patients. Each patient received two implants in the mandibular molar region. All sites were prepared with conventionally up to the 2.8 mm wide drill. Osteotomies were randomly finalized with a 3 mm diameter drill (control group) or with two consecutive ultrasonic tips (2.8 mm and 3 mm wide, respectively) (test group). Resonance frequency analysis measurements were taken at implant placement and after 1, 3, 8, and 12 weeks. Peri-implant marginal bone loss 12 months after loading was calculated using periapical radiographs. Wilcoxon test for related samples was used to study differences in implant stability and in peri-implant marginal bone loss between the two groups. RESULTS Twenty-nine of 30 implants osseointegrated successfully (one failure in the control group). Stability was significantly higher in the test group at the 8th week assessment; differences were non-significant at all other time-points. Longitudinally, differences were observed between the patterns of implant stability changes: in the test group stability increased more progressively, while in the control group an abrupt change occurred between the 8th and 12th weeks assessments. No difference was found in peri-implant marginal bone loss between the groups. All 29 implants were functionally successful at the 15-month visit. CONCLUSIONS Within the limit of this pilot study (small sample size, short follow-up), data suggested that implant stability might develop slightly faster when implant site osteotomy is performed with a mixed drilling/ultrasonic technique.

Rehabilitation of the Atrophic Posterior Maxilla With Pterygoid Implants: A Review

The purpose of this article is to review the literature published and to assess the success of treatment of patients with atrophic posterior maxilla with pterygoid implants. Studies from 1992 to 2009 on patients with atrophic posterior maxilla rehabilitated with pterygoid implants were reviewed. Those reporting clinical series of at least 5 patients with atrophic posterior maxilla (Class IV and V of Cawood and Howell), rehabilitated with pterygoid implants and fixed prosthesis, and with 12 months minimum follow-up were included. In each study the following were assessed: number of patients, number of implants, surgical technique, prosthetic rehabilitation, success rate, bone loss, complications and patient satisfaction. Thirteen articles were included, reporting a total of 1053 pterygoid implants in 676 patients. The weighted average success of pterygoid implants was 90.7%; bone loss evaluated radiographically ranged between 0 and 4.5 mm. No additional complications compared with conventional implants were found, and patient satisfaction level with the prosthesis was high. Pterygoid implants have high success rates, similar bone loss levels to those of conventional implants, minimal complications and good acceptance by patients, being therefore an alternative to treat patients with atrophic posterior maxilla. Two anatomical locations in which implants are placed in the retromolar area can be distinguished: the pterygoid process and the pterygomaxillary region. Implant lengths and angulations vary between these two techniques.

Symptoms Before Periapical Surgery Related to Histologic Diagnosis and Postoperative Healing at 12 Months for 178 Periapical Lesions

PURPOSE To compare the preoperative signs and symptoms with the histologic diagnosis and postoperative healing at 12 months for 178 periapical lesions. MATERIALS AND METHODS A total of 152 patients who had undergone periapical surgery from 2005 to 2008 were studied. The study included patients presenting with signs and symptoms before periapical surgery with a sufficient tissue sample (periapical lesion) for histologic analysis and a minimal follow-up of 12 months. The signs and symptoms present in the soft tissues at the initial examination were recorded. The histologic analysis established the diagnosis as granuloma, cyst, or scar tissue. The postoperative healing at 12 months was evaluated according to the criteria of von Arx and Kurt. RESULTS Of the 152 patients, 147, with 178 periapical lesions, were included in the present study. No significant relationship was found between the preoperative signs and symptoms, lesion type, and evolution. However, scar tissues were asymptomatic in 78.1%, and 36.4% of granulomas were painful. Of the 8 cysts, 50% were asymptomatic and 50% caused pain. Fibrous scars created no soft tissue alterations in 68.7%. Granulomas had fistulized in 31.7%, and 75% of cysts had produced no alterations. The lesions with swelling had worse healing, and those with no soft tissue alterations had better postoperative healing. CONCLUSIONS Chronic periapical lesions (granuloma, cyst, and scar tissue) are usually asymptomatic and do not create soft tissue alterations. However, they can deteriorate, producing pain and fistulization. Worse postoperative healing was observed for lesions with swelling, although the difference was not significant.

Post-traumatic trigeminal neuropathy. A study of 63 cases.

Introduction. Trigeminal neuropathy is most often secondary to trauma. The present study explores the underlying causes and the factors that influence recovery. Material and methods. A retrospective case study was made involving 63 patients with trigeminal neuropathy of traumatologic origin, subjected to follow-up for at least 12 months. Results. Fifty-four percent of all cases were diagnosed after mandibular third molar surgery. In 37 and 19 patients the sensory defect was located in the territory innervated by the mental and lingual nerve, respectively. Pain was reported in 57% of the cases, and particularly among the older patients. Regarding patient disability, quality of life was not affected in three cases, while mild alterations were recorded in 25 subjects and severe alterations in 8. Partial or complete recovery was observed in 25 cases after 6 months, and in 32 after one year. There were few recoveries after this period of time. Recovery proved faster in the youngest patients, who moreover were the individuals with the least pain. Conclusion. Our patients with trigeminal neuropathy recovered particularly in the first 6 months and up to one year after injury. The older patients more often suffered pain associated to the sensory defect. On the other hand, their discomfort was more intense, and the patients with most pain and the poorest clinical scores also showed a comparatively poorer course. Key words:Post-traumatic trigeminal neuropathy.

Rehabilitation of Reabsorbed Maxillae With Implants in Buttresses in Patients With Combination Syndrome

PURPOSE To assess the success and marginal bone loss, after 1 year of loading, of implants placed in anatomic buttresses of atrophic maxillae to rehabilitate patients with combination syndrome. MATERIALS AND METHODS A case series retrospective study of 22 patients with combination syndrome who were treated with implants in anatomic buttresses in the atrophic maxilla was performed. The inclusion criteria were Classes IV and V Cawood and Howell maxillary atrophy, rehabilitation with implants placed in anatomic buttresses, the presence of anterior remnant teeth in the mandible, and a minimum follow-up of 12 months after implant loading. The criteria of Buser et al were used to evaluate implant success, and marginal bone loss was measured on periapical radiographs. Statistical analysis was performed to relate implant success and marginal bone loss to gender, degree of maxillary atrophy, implant technique, and prosthesis type. RESULTS A total of 18 patients fulfilled the inclusion criteria. A total of 117 implants were placed; 32 were placed with the conventional technique in the alveolar ridges with enough height and width, 35 were positioned palatally, 30 were tilted in the frontomaxillary buttress, 10 were placed in the pterygomaxillary area, 6 were placed in the nasopalatine canal, and 4 were zygomatic implants. The follow-up ranged from 1 to 7 years after implant loading. Of the 117 implants, 7 failed, for an implant success rate of 94%. The mean marginal bone loss was 0.63 mm. A statistically significant relation was found between bone loss and implant placement technique and the level of maxillary atrophy, being greater in tilted implants and in Class V Cawood and Howell maxillary atrophy. CONCLUSIONS Implants in anatomic buttresses allow rehabilitation of atrophic maxillae in patients with combination syndrome. The implant success rate was high, and a mean marginal bone loss of 0.63 mm was recorded.

The predictive value of microbiological findings on teeth, internal and external implant portions in clinical decision making.

AIM The primary aim of this study was to evaluate 23 pathogens associated with peri-implantitis at inner part of implant connections, in peri-implant and periodontal pockets between patients suffering peri-implantitis and participants with healthy peri-implant tissues; the secondary aim was to estimate the predictive value of microbiological profile in patients wearing dental implants using data mining methods. MATERIAL AND METHODS Fifty participants included in the present case─control study were scheduled for collection of plaque samples from the peri-implant pockets, internal connection, and periodontal pocket. Real-time polymerase chain reaction was performed to quantify 23 pathogens. Three predictive models were developed using C4.5 decision trees to estimate the predictive value of microbiological profile between three experimental sites. RESULTS The final sample included 47 patients (22 healthy controls and 25 diseased cases), 90 implants (43 with healthy peri-implant tissues and 47 affected by peri-implantitis). Total and mean pathogen counts at inner portions of the implant connection, in peri-implant and periodontal pockets were generally increased in peri-implantitis patients when compared to healthy controls. The inner portion of the implant connection, the periodontal pocket and peri-implant pocket, respectively, presented a predictive value of microbiologic profile of 82.78%, 94.31%, and 97.5% of accuracy. CONCLUSION This study showed that microbiological profile at all three experimental sites is differently characterized between patients suffering peri-implantitis and healthy controls. Data mining analysis identified Parvimonas micra as a highly accurate predictor of peri-implantitis when present in peri-implant pocket while this method generally seems to be promising for diagnosis of such complex infections.

Soft Tissue Response to Titanium Abutments with Different Surface Treatment: Preliminary Histologic Report of a Randomized Controlled Trial

The aim of this preliminary prospective RCT was to histologically evaluate peri-implant soft tissues around titanium abutments treated using different cleaning methods. Sixteen patients were randomized into three groups: laboratory customized abutments underwent Plasma of Argon treatment (Plasma Group), laboratory customized abutments underwent cleaning by steam (Steam Group), and abutments were used as they came from industry (Control Group). Seven days after the second surgery, soft tissues around abutments were harvested. Samples were histologically analyzed. Soft tissues surrounding Plasma Group abutments predominantly showed diffuse chronic infiltrate, almost no acute infiltrate, with presence of few polymorphonuclear neutrophil granulocytes, and a diffuse presence of collagenization bands. Similarly, in Steam Group, the histological analysis showed a high variability of inflammatory expression factors. Tissues harvested from Control Group showed presence of few neutrophil granulocytes, moderate presence of lymphocytes, and diffuse collagenization bands in some sections, while they showed absence of acute infiltrate in 40% of sections. However, no statistical difference was found among the tested groups for each parameter (p > 0.05). Within the limit of the present study, results showed no statistically significant difference concerning inflammation and healing tendency between test and control groups.

Guided implant surgery with modification of the technique involving the raising of a semicircular miniflap: a preliminary study.

Objective: An evaluation is made of pain, swelling and peri-implant attached mucosal width after implant-based rehabilitation involving guided surgery and a modification of the technique with the raising of a semicircular miniflap, in single and partial replacements. Study design: A case-control study was carried out. The study group consisted of 12 patients with the placement of 19 implants using a guided surgery and miniflap technique. The control group consisted of 12 patients with the placement of 22 implants using the conventional technique. Each patient scored postoperative swelling and pain by means of a visual analog scale (VAS). Attached vestibular mucosa width was evaluated 12 weeks after implant placement. Results: Twelve operations were carried out in each group. Immediate aesthetics were established for all implants of the study group. One implant failed in each group. Maximum pain was recorded after 6 hours in both groups (mean VAS score 4 and 4.9 in the study and control group, respectively). Maximum swelling was recorded after 24 hours (mean VAS score 2.5) in the study group and on the second day (mean VAS score 3.4) in the control group. The mean attached vestibular mucosa width was 2.9 mm in the study group and 3.2 mm in the control group. Conclusion: In this preliminary study, guided implant surgery with a semicircular miniflap in single and partial replacements resulted in slightly less postoperative pain and swelling than with the conventional implant technique. The attached vestibular mucosa width was greater in the control group, though the differences were very small. Key words:Guided surgery, flapless surgery, miniflap, peri-implant mucosa.