Immediate loading of single-tooth implants: immediate versus non-immediate implantation. A clinical report

The hypothesis of the present study was that immediate loading of implant-supported restorations replacing single missing teeth could be a successful procedure. The present study compared the clinical success of immediately loaded single-tooth implants placed in fresh extraction sites to that of immediately loaded single-tooth implants placed in healed sites. From the years 1997 to 1998, 26 patients, ranging in age from 18 to 70 years, presented for the placement of 28 immediately loaded implants intended to support single-tooth ceramometal restorations. Nineteen implants were placed into fresh extraction sites, and 9 implants were placed into healed sites. Temporary prefabricated acrylic resin crowns were prepared and adjusted. At the time of traditional second-stage surgery (3 to 6 months after implantation), the implants were restored with single-tooth ceramometal prostheses. The survival rates were 82.4% and 100% for immediate and non-immediate implants, respectively. Follow-up ranged from 6 to 24 months from the day of implant placement, with a mean of 13 months for the immediate implants and 16.4 months for the non-immediate implants. Radiographic marginal bone loss after 3 to 6 months did not extend beyond the abutment-implant junction. Within the limits of the present investigation, immediate loading of single-tooth implants placed in healed sites is a possible treatment alternative. Immediate loading of single-tooth implants placed in fresh extraction sites carried a risk of failure approximating 20% in this patient population.

Salivary flow dynamics after parotid surgery: a preliminary report

BACKGROUND

Tumors in the parotid gland may affect salivary flow. The effects of tumor on glandular function and postoperative changes in both resected gland and contralateral gland were not formerly reported. We prospectively evaluated salivary flow rates and composition in patients undergoing parotidectomy preoperatively and postoperatively.

METHOD

Stimulated parotid saliva from 17 patients undergoing parotidectomy was collected bilaterally preoperatively and postoperatively by using a parotid cup. Subjective complaints were recorded. Salivary flow rates, sodium, potassium, and amylase levels were evaluated.

RESULTS

None of the patients complained of "dry mouth" before or after surgery. Analysis of the individual results revealed 3 patterns of preoperative and postoperative response, compatible with either a preoperative or postoperative compensatory mechanism in the contralateral gland. The postoperative decrease in flow rate corresponds with the amount of gland removed. Salivary electrolyte composition was unchanged.

CONCLUSION

This study is the first to demonstrate the effects of parotid tumors and their surgery on salivary flow and a compensatory response and its different patterns in human parotid glands after their excision.

Emergency tracheostomy following life-threatening hemorrhage in the floor of the mouth during immediate implant placement in the mandibular canine region

BACKGROUND

The edentulous interforaminal mandibular area is frequently the preferred area for implant placement.

METHODS

A case of emergency tracheostomy following life-threatening hemorrhage in the floor of the mouth during immediate implant placement in the mandibular canine region is described. The probable cause was bleeding from the sublingual artery or a branch of that artery following implant perforation of the lingual cortex.

RESULTS

Healing was uneventful and the patient was released from the hospital after 11 days. Three years later, CT showed a well-osseointegrated implant with a severe buccolingual inclination.

CONCLUSIONS

It is stressed that short implants (14 mm or less) should be used in the mandibular canine region and that effective treatment of this complication is essential.

Relationship of blood glucose level to community periodontal index of treatment needs and body mass index in a permanent Israeli military population

BACKGROUND

The goal of this study was to find a possible link between blood glucose levels and periodontal disease.

METHODS

In a prospective study the dental health of 10,590 military service men and women was examined. The relationships of periodontal condition, expressed as CPITN index, and blood glucose levels were tested. The effect of gender, body mass index (BMI), and smoking was also evaluated.

RESULTS

Blood glucose levels were significantly and positively associated with severe periodontal disease, men, and higher BMI. Smoking did not affect blood glucose levels.

CONCLUSIONS

Blood glucose levels might be associated with severe periodontal disease.

Association in the seroprevalence of hepatitis A and herpes simplex-1 viruses in young adults in Israel

BACKGROUND

The rise in the standard of living of the Israeli population during recent decades has been accompanied by a significant decline in the prevalence of various viral diseases including hepatitis A (HAV). This trend is not reflected in the seroprevalence of herpes simplex (HSV) infection, which has remained stable during these years.

MATERIALS AND METHODS

The Public Health Branch of the Israel Defense Force (IDF) Medical Corps continuously draws a systematic, representative sample of male and female recruits on their 1st day of service, based on digit combinations of the military identification number. These recruits are asked to give a blood sample and to undergo a short interview. A quantitative determination of anti-HSV-1 and anti-HAV antibodies was performed.

RESULTS

In the present study that included 124 male and 98 female 18-year-old army recruits, 51.1% of the anti-HSV-positive subjects was also positive for anti-HAV, compared to 27% among anti-HSV-negative persons. Rate ratio (RR) for anti-HAV seropositivity between anti-HSV-1-positive and negative recruits was 1.86 (95% CI 1.3-2.7).

CONCLUSION

The present study suggests a strong association between the seroprevalence of both viruses.

The use of hydroxyapatite bone cement for sinus floor augmentation with simultaneous implant placement in the atrophic maxilla. A report of 10 cases

BACKGROUND

Dental implant placement associated with sinus floor augmentation in a severely atrophic maxilla can be performed in a 1- or 2-stage surgical procedure, depending on the height of the residual alveolar bone. A minimum of 4 to 5 mm is recommended for a 1-stage procedure.

METHODS

This clinical study describes the use of hydroxyapatite (HA) bone cement to stabilize HA-coated cylindrical implants placed simultaneously during sinus augmentation in 100 patients where insufficient bone volume did not allow primary implant stability. A total of 26 HA-coated dental implants were inserted in 100 grafted sinuses of 10 patients.

RESULTS

None of the cases presented any difficulty in achieving initial stabilization and parallelism. No clinical complications of the sinuses were evident. Prior to exposure, radiographic evaluation revealed the implants embedded in a densely homogeneous radiopaque mass. At second-stage surgery, there was no clinical evidence of crestal bone loss around the implants. All implants were clinically osseointegrated. All patients received fixed implant-supported prostheses. Mean follow-up was 18 months (range 12 to 24 months).

CONCLUSIONS

According to this preliminary study, the hydroxyapatite bone cement appears to hold great promise as a grafting alloplastic material for sinus floor augmentations. Its main advantage is its ability to provide initial stability required for osseointegration and proper implant location and parallelism. Further clinical and histological studies are required before it can be recommended for routine use in sinus lift procedures.

Immediate versus non-immediate implantation for full-arch fixed reconstruction following extraction of all residual teeth: a retrospective comparative study

BACKGROUND

Immediate implants placed into fresh extraction sites are considered a predictable and acceptable procedure. The main biological advantage is the preservation of bone height and width. However, there is no direct proof of the clinical and surgical importance of this. The purpose of this study was to evaluate the correlation between implant dimensions, anatomic factors, and survival rates of immediate versus non-immediate implants.

METHODS

From 1989 to 1996, 380 implants (117 immediate and 263 non-immediate) were placed in 43 patients (50 jaws) following extraction of all residual teeth. A total of 253 implants were placed in the maxilla and 127 in the mandible, with a mean of 7.65 and 7.9 per jaw, respectively. Of the implants, 31% were placed immediately into fresh extraction sites.

RESULTS

Total 5-year cumulative survival rate (CSR) was 92%, mandibular 96% and maxillary 90%. Immediate implants had a better 5-year CSR (96%) versus non-immediate implants (89.4%). The maxilla mainly contributed to this difference (95% versus 88%). The mean potential contact surface area (PCSA) was 230 mm2. Implants with significantly higher values yielded a higher 5-year CSR in the maxilla (96.6% versus 82.9%). Immediate implants in the posterior maxilla had a 100% 5-year CSR versus 72% with the non-immediate implants.

CONCLUSIONS

1) Implant-supported fixed ceramo-metal prosthesis is a predictable treatment modality for edentulous patients; 2) factors favorably affecting the survival of implants placed to support full-arch ceramo-metal prosthesis include immediate implantation, higher PCSA values, and implant location; 3) immediate implantation exerts its effect through higher PCSA values and by a compensatory effect to bone quality; 4) immediate implantation does not carry additional morbidity; and 5) potential contact surface area (PCSA) is a reliable mean that accurately represents implant dimensions and may replace length and diameter in future studies.

The clinical effectiveness of implants placed immediately into fresh extraction sites of molar teeth

BACKGROUND

Studies concerning immediate implantation describe its use in the anterior and premolar regions. However, its clinical effectiveness in immediately replacing molar teeth has rarely been challenged. The purpose of this study was to evaluate the survival rate of implants placed immediately after extraction of molar teeth to support a fixed ceramo-metal prosthesis.

METHODS

From 1989 to 1996, 56 immediate implants were placed in 43 patients following extraction of 51 molars; 46 molars were replaced by 1 implant and 5 molars replaced by 2 implants. All implants were restored with fixed prostheses (4 single crowns and 52 splinted). Mean follow-up period was 15 months (range, 4 to 60 months). The influence of the following parameters on implant failure was evaluated: gender, arch, smoking, pre-extraction vertical bone loss, implant length, and severity of complications between the two stages of surgery.

RESULTS

The 5-year cumulative survival rate (5-year CSR) was 89%. The 5-year CSR among men was 84% compared to 93.5% among women. The maxillary 5-year CSR was 82% and the mandibular 92%. Among non-smokers (50 implants), the 5-year CSR was 90% compared to 83% among smokers (6 implants). Complications were evident in 8 (6 minor, 2 major) out of 50 non-failing implants compared to 2 (minor) of the 6 failing implants. No differences were evident in the other study variables.

CONCLUSIONS

Immediate implantation in the molar region is an alternative, predictable surgical treatment. Immediate implantation in the posterior mandible has a better prognosis than in the posterior maxilla.

Salivary flow and its relation with oral symptoms in terminally ill patients

BACKGROUND

Patients with terminal malignant disease commonly report hyposalivation or xerostomia. This leads to "dry mouth," fungal infection, and mucosal abnormalities. To the authors' knowledge oral symptomatology and findings have not been correlated previously with accurate salivary flow measurements.

METHODS

Measurement of stimulated parotid salivary flow rate and clinical recording of oral symptoms within 24 hours from the time of hospital admission were obtained in 48 terminally ill cancer patients. Subjective reporting of symptoms by patients, parotid salivary flow rate, clinical recording of dental status, presence of candidiasis, angular cheilitis, and dryness of the floor of the mouth were obtained.

RESULTS

A clinical diagnosis of oral candidiasis was made tentatively in 94% of patients, and 50% of the patients were found to have angular cheilitis. Thirty-one of 45 evaluable patients (68%) reported a sensation of oral dryness. Sixteen of the 48 patients (33%) had no saliva at the floor of the mouth. Analysis of individual salivary flow rates was stratified into 3 levels of secretion: 0, < 0.2, and > or= 0.2 mL/minute. Symptoms were found to correlate with salivary flow rates.

CONCLUSIONS

In the current study, symptoms were found to be most severe in the patients with xerostomia followed by those patients with hyposalivation. Treatment should be directed individually to each group of patients using either salivary substitutes or stimulants. The rate of incidence of oral pathologic findings may be higher than formerly recognized.

Risk factors contributing to symptomatic plate removal in maxillofacial trauma patients

This study analyzed the fate of plates used to correct maxillofacial injuries and defined risk factors that eventually resulted in plate removal. The outpatient clinic files of 108 patients treated with rigid internal fixation after maxillofacial trauma were reviewed. Study variables included age, sex, trauma circumstances, diagnosis, type of fracture, approach to the facial skeleton, presence of teeth in the line of fracture, plate material, site of plates, and reasons for plate removal. Of 204 plates used for fixation, 44 plates (22 percent) were removed. When all factors were considered together, only fracture diagnosis (mandibular body and angle) and plate location (mandibular body and angle) were statistically significant. Only when each factor was considered separately, the approach to the facial skeleton (intraoral) and the type of fracture (comminuted and compound fractures) were statistically associated with plate removal. Selection of favorable plate location, the extraoral approach, and vigilant infection control may reduce plate removal in patients with maxillofacial injuries. Special attention should be given to compound and comminuted fractures of the mandibular body and angle.

Radiological findings of the post-sinus lift maxillary sinus: a computerized tomography follow-up

The purpose of this paper is to present radiological findings of a short-term (8 to 10 months) computerized tomography (CT) follow-up study on 1-stage maxillary sinus lift cases. Pre- and postoperative dental CT scans of 21 patients (24 sinuses) after sinus lift procedures were compared. CT scans were used to assess newly formed bone and its interface with the implants, condition of the sinus membrane, evidence of buccal window cortication, and presence of any sinus pathology. Of the 57 implants placed, 28 had bone fully covering the implant on all sides which did not extend above the apical portion; 20 had bone fully covering the implant which did extend above the apex; and 9 exhibited incomplete bone coverage. All implants supported a fixed ceramo-metal prosthesis, and no implant failures were recorded after 3 years of follow-up. There was evidence of cortication of the buccal window in 10 sinuses; in the 14 remaining sinuses, bone consolidation on the buccal aspect was evident, but no evidence of cortication was seen. All sinuses healed without complications or clinical signs of sinusitis. In 11 sinuses, no changes in membrane thickness were noted. Membrane thickness decreased postoperatively in 12 sinuses, and in one, there was evidence of membrane thickening. Bone cortication in the anterior wall window may serve as an indicator for the remodeling status of the entire graft. Postoperative findings showed a significant improvement in overall membrane thickness. No clinical symptoms of sinusitis were evident, indicating that sinus lift procedures can be considered safe and do not predispose the sinus to acute or chronic sinusitis.

Reliability of a method for the localization of displaced maxillary canines using a single panoramic radiograph

The present study was initiated to determine the validity and reproducibility of a method previously reported for localization of displaced maxillary canines by panoramic radiographs. Eleven dental specialists (five orthodontists, five surgeons, and one radiologist) and five (final year) dental students were asked to interpret initial panoramic radiographs of 20 patients with 26 unerupted canines. The method contends that, provided that the radiographic image of the unerupted canines superimposes on the root of the lateral incisor at a height coronal to the apical third, a ratio between the widest mesiodistal dimension of the affected canine and the homolateral central incisor [Canine-Incisor Index (CII)] of more than 1.15 indicates palatal displacement. Among the observers, the measurement error was small, insufficient to cause overlap between the ranges of values for the CII of buccal and palatal canines. Inter-observer reproducibility was high. Without exception, all observers correctly diagnosed the location of each of the impacted canines. The CII cut-off point of 1.15, which was arbitrarily chosen in the previous work, was shown to be valid to differentiate buccal from palatal displacement. The present method is rapid, simple, accurate, and easily taught to dental students or dental specialists, with the simplest of initial instruction. While confirmations with other radiographic techniques is strongly advised before a definitive treatment is undertaken, this method has merit in providing more information than has been available from the panoramic radiograph hitherto, to satisfy the needs of an initial orthodontic consultation.

The use of panoramic radiographs to localize displaced maxillary canines

OBJECTIVE

The purpose of this investigation was to develop a reliable method of diagnosing the position of a displaced maxillary canine on the basis of a single panoramic radiograph.

STUDY DESIGN

A total of 115 panoramic radiographs depicting 164 displaced maxillary canines were evaluated. The ratio of the width of the displaced canine to the width of the homolateral central incisor (the canine-incisor index) and the ratio of the width of the displaced canine to the width of the contralateral canine (the canine-canine index) were calculated. The height of the crown of each displaced canine was classified in the vertical plane, relative to the adjacent incisor, as apical, middle, or coronal.

RESULTS

There was an overlap in the canine-incisor index ranges of the buccal (0.94-1. 45) and palatal (1.15-1.29) canines in the apical zone. In the middle and coronal zones, a clear difference could be seen between the canine-incisor indices of labially (0.78-1.11) and palatally (1.15-1.7) located canines. A cut-off point of 1.15 was determined.

CONCLUSIONS

Provided that vertical restriction and the canine-incisor index are used, the panoramic radiograph can serve as a useful indicator for determining the position of an unerupted maxillary canine.

Comparative study of splenic wound healing in young and adult rats

BACKGROUND

Nonoperative management (NOM) of splenic injuries is a common practice in stable trauma patients. Nevertheless, age-related differences in the success rate of NOM have prompted inclusion of age among the criteria of patient selection. Elucidation of the cellular mechanism of splenic wound healing in the young versus that of adults may explain why age can be related to the success of NOM in splenic injuries.

METHODS

A laceration was made in the splenic antihilar surface of 40 young and 40 adult male rats. Postoperatively, at specified intervals extending until day 21, spleens were removed, fixed, and examined by routine histopathology. In addition, sections were stained histochemically for collagen fibers and immunohistochemically for myofibroblast histomorphometry.

RESULTS

The intense local hemorrhage was resorbed within 48 hours in the young rats, and within 7 days in the adults. Disappearance of germinal centers and other splenic alterations started on the first day in both groups, but regeneration of splenic parenchyma was accomplished after 14 days in the young, whereas in the adults, on day 21 it was still incomplete. Maximal myofibroblast accumulation at the laceration site was seen after two days in the young, whereas in adults only on day 4 (p < 0.0001). Collagen scars were not present in either group. Thickening of the damaged capsule, composed of collagen fibers with yellowish-green polarization colors, was observed only in adult rats.

CONCLUSION

Splenic wounds heal by regeneration and not by collagen scarring. In the young, myofibroblasts accumulate in the site of injury faster than in adults. These cells may enhance contraction and increase the rate of wound healing until parenchymatic regeneration is completed. Our results may indirectly explain the higher success rate of NOM of splenic injury in young patients.

Use of lyodura for bone augmentation of osseous defects around dental implants

BACKGROUND

Lyodura has been used in periodontology and maxillofacial surgery to overcome different clinical conditions. The use of lyodura to induce new bone formation in humans has not been widely reported. The purpose of this article is to describe the use of lyodura as a resorbable barrier to promote bone formation in osseous defects around dental implants.

METHODS

The study group consisted of 22 healthy patients (12 women and 10 men), with a mean age of 32 (range 20 to 45). A total of 44 implants (9 titanium screw-type and 35 hydroxyapatite-coated cylinder implants) were placed. Of these, 27 implants were placed in the maxilla and 17 in the mandible. At 27 extraction sites bony vertical defects were measured on the buccal, lingual, mesial and distal sides of the implant. In the remaining 17 cases, where either immediate or staged implantation was performed, and a dehiscence was present, its vertical length was measured from the alveolar crest. All bony defects were grafted with autogenous bone harvested from the tuberosity. Each site was covered with lyodura.

RESULTS

Healing was uneventful; no inflammation, infection, or soft tissue dehiscence was observed. At all extraction sites and in 76% of the dehiscence defects, hard tissue appearing clinically similar to bone completely filled the defect. Of those defects not completely filled, a mean vertical bone increase of 2.5 mm was recorded. A mean vertical bone increase of 2.6 mm was achieved at extraction sites and a mean increase of 2.79 mm was achieved at dehiscence sites.

CONCLUSIONS

Lyodura can safely and effectively be used for guided bone regeneration at both extraction sites and for dehiscence defects.

Risk factors contributing to symptomatic plate removal in orthognathic surgery patients

PURPOSE

This study analyzed the fate of miniplates in orthognathic surgery and defined risk factors that eventually result in plate removal.

PATIENTS AND METHODS

The outpatient clinic files of 70 patients who had undergone orthognathic surgery were reviewed. All osteotomies were rigidly fixed with stainless steel or titanium miniplates. Study variables included age, gender, plate material, site of plates, and reasons for plate removal.

RESULTS

Of 260 plates used for fixation, 31 were removed (12%). When all factors were considered together, only age was statistically significant. Patients older than 30 years of age were more likely to have plate removal (22% vs. 9%). Only when each factor was considered separately were gender and plate material statistically significant. Females (15.4% vs. 6.7%) and stainless steel plates (15.5% vs. 6.7%) were more prone to plate removal. Although more plates were removed from the buttress (15.5%) and chin (14.5%) compared with the piriform area (6.4%), this was not statistically significant.

CONCLUSIONS

Age can be defined as a primary risk factor for plate removal, whereas gender and plate material are secondary. Although age and gender are not controllable, the use of titanium plates and infection control may lower the number of symptomatic plates and the need for their removal.

Surgical management of macroglossia due to primary amyloidosis

A case of macroglossia due to primary amyloidosis is described, followed by a discussion of the various aspects of surgical intervention based on a literature review.

Multiple oncocytic cysts with tyrosine-crystalloids in the parotid gland

A case of multiple oncocytic cysts with intraluminal tyrosine-rich crystalloids involving the parotid gland is described. The microscopic and ultrastructural findings are presented.

Full-arch restoration of the jaw with fixed ceramo-metal prosthesis: late implant placement

BACKGROUND

The completely edentulous patient has few treatment options in conventional dentistry. When implants are considered, treatment plans range from a 2-implant overdenture to a completely implant-supported prosthesis. Fixed prosthesis is often the preferred selection of the edentulous patient. This study assesses the 5-year cumulative survival rate of implants placed to support full-arch fixed restoration.

METHODS

During 1990 to 1995, 171 implants were placed in 22 completely edentulous jaws of 20 patients. All patients were discharged wearing immediate dentures. The implants were analyzed as to the number of implants per jaw, implant location, length, and diameter.

RESULTS

The 5-year cumulative survival rate was 89.9%. The mean number of implants per jaw was 7.7 for the maxilla and 8 for the mandible. In the maxilla, the preferred implant locations were the canines, centrals, laterals, and first premolars; in the mandible, they were the canines, laterals, and first molars. The mean implant length was 14.2 mm for the mandible and 13.2 mm for the maxilla. The mean implant diameter was 3.6 mm for the maxilla and 3.8 for the mandible.

CONCLUSIONS

The results of the present study indicate that fixed full-arch ceramo-metal restorations can be a predictable implant treatment modality for the edentulous patient.