Work‐related traumatic dental injuries: Prevalence,characteristics and risk factors

Background/Aims

The prevalence of work‐related oral trauma is underestimated because minor dental injuries are often not reported in patients with several injuries in different parts of the body. In addition, little data are available regarding their characteristics. The aim of this epidemiological study was to determine the prevalence, types, and characteristics of occupational traumatic dental injuries (TDIs) in a large working community.

Materials and Methods

Work‐related TDIs that occurred during the period between 2011 and 2013 in the District of Genoa (Northwest of Italy, 0.86 million inhabitants) were analyzed. Patients’ data were obtained from the National Institute for Insurance against Accidents at Work database.

Results

During the 2 year period, 112 TDIs (345 traumatized teeth) were recorded. The prevalence was 5.6‰ of the total amount of occupational trauma. The highest prevalence was found in the fourth and fifth decades of life (OR=3.6, P < .001), and males were injured more often than females (70.5% vs 29.5%, OR=2.8, P < .001). Service and office workers represented 52% of the sample, and construction/farm/factory workers and craftsmen were 48%. TDIs involved only teeth and surrounding tissue in 66% of cases, or in combination with another maxillofacial injury in 34%. They were statistically associated with construction/farm/factory workers group (Chi squared P < .01). Crown fracture was recorded in 34.5% of cases, subluxation/luxation in 10.7%, avulsion in 9%, root fracture in 3.8%, and concussion in 3.5%. Thirty‐two subjects (28.6%, 133 teeth, OR=4.3, P < .001) presented at least 1 traumatized tooth with previous dental treatment. Among 212 (61.4%) traumatized teeth, 67.5% were upper incisors, 17.5% were lower incisors, 3.3% were upper canines, 1.9% were lower canines, and 9.9% were bicuspids and molars.

Conclusions

Work‐related TDIs had a low overall prevalence, and fractures were the most frequent dental injury. Age, gender, and preexisting dental treatments represented risk factors for work‐related TDIs.     

The risk of moderate‐to‐severe post‐operative pain following the placement of dental implants

In recent years, the implant‐supported dentures have risen rapidly, and thus, more attention was paid to post‐operative pain, following dental implantation. To explore risk factors and establish as well as validate a risk prediction model for moderate‐to‐severe post‐operative pain following dental implantation. A observational study of 352 patients with 563 implants was carried out. The following candidate predictors were collected: age, gender, pain sensitivity, anxiety, pain expectation, operator experience, position, length and number of placed implants, duration of surgery and surgery procedures. The outcome was the presence of moderate‐to‐severe post‐operative pain within the 24 hours post‐surgery. Multivariate logistic regression in combination with bootstrapping techniques was used to explore independent risk factors and establish a prediction model. The mean pain intensity score was 4.21 within 24 hours post‐operatively, while the incidence of moderate‐to‐severe pain was 61.9%. Independent risk factors of moderate‐to‐severe post‐operative pain were flap surgery, surgical template, the interaction between anxiety state and pain sensitivity, the interaction between pain sensitivity and pain expectation and the interaction between implant length and immediate implant. The area under the receiver operator characteristic curve was 0.72. The model's sensitivity was 75.7%, and the specificity was 64.2%. The model reliability was good (Nagelkerke's R² 0.226). The risk factors and the prediction model (needs further improvement) can help dentists to identify patients at increased risk of moderate‐to‐severe post‐operative pain following dental implantation.     

Stress and damage at the bur‐prosthesis interface in dental adjustments of a leucite‐reinforced glass ceramic

Summary This article reports on the effects of dental adjustment parameters on stress and damage induced in a leucite‐reinforced glass ceramic using a high‐speed dental handpiece and coarse diamond burs. As one of machinable dental ceramics for prosthetic restorations, a leucite‐reinforced glass ceramic has higher fracture toughness than feldspar porcelains. However, the extent of subsurface damage and stress induced in clinical dental adjustments is unknown. Tensile, shear, compressive and von Mises stresses at the bur–ceramic interface were investigated as functions of dental adjustment parameters using finite element analysis (FEA). The depths of subsurface damage were predicted using FEA according to the maximum principal stress criterion and experimentally measured using scanning electron microscopy (SEM). The resulting predicted subsurface damage depths agree well with the experimentally measured data. Both adjustment parameters, depth of cut and feed rate, were found to have significant influences on adjustment‐induced stresses (P < 0·01) and subsurface damage (P < 0·01). It is also found that the predicted and measured subsurface damage depths increased linearly with the diamond grit depth of cut.